Added delete option to database storage.

venv/Lib/site-packages/urllib3/__init__.py

@@ -0,0 +1,87 @@
+"""
+urllib3 - Thread-safe connection pooling and re-using.
+"""
+from __future__ import absolute_import
+import warnings
+
+from .connectionpool import HTTPConnectionPool, HTTPSConnectionPool, connection_from_url
+
+from . import exceptions
+from .filepost import encode_multipart_formdata
+from .poolmanager import PoolManager, ProxyManager, proxy_from_url
+from .response import HTTPResponse
+from .util.request import make_headers
+from .util.url import get_host
+from .util.timeout import Timeout
+from .util.retry import Retry
+from ._version import __version__
+
+
+# Set default logging handler to avoid "No handler found" warnings.
+import logging
+from logging import NullHandler
+
+__author__ = "Andrey Petrov (andrey.petrov@shazow.net)"
+__license__ = "MIT"
+__version__ = __version__
+
+__all__ = (
+    "HTTPConnectionPool",
+    "HTTPSConnectionPool",
+    "PoolManager",
+    "ProxyManager",
+    "HTTPResponse",
+    "Retry",
+    "Timeout",
+    "add_stderr_logger",
+    "connection_from_url",
+    "disable_warnings",
+    "encode_multipart_formdata",
+    "get_host",
+    "make_headers",
+    "proxy_from_url",
+)
+
+logging.getLogger(__name__).addHandler(NullHandler())
+
+
+def add_stderr_logger(level=logging.DEBUG):
+    """
+    Helper for quickly adding a StreamHandler to the logger. Useful for
+    debugging.
+
+    Returns the handler after adding it.
+    """
+    # This method needs to be in this __init__.py to get the __name__ correct
+    # even if urllib3 is vendored within another package.
+    logger = logging.getLogger(__name__)
+    handler = logging.StreamHandler()
+    handler.setFormatter(logging.Formatter("%(asctime)s %(levelname)s %(message)s"))
+    logger.addHandler(handler)
+    logger.setLevel(level)
+    logger.debug("Added a stderr logging handler to logger: %s", __name__)
+    return handler
+
+
+# ... Clean up.
+del NullHandler
+
+
+# All warning filters *must* be appended unless you're really certain that they
+# shouldn't be: otherwise, it's very hard for users to use most Python
+# mechanisms to silence them.
+# SecurityWarning's always go off by default.
+warnings.simplefilter("always", exceptions.SecurityWarning, append=True)
+# SubjectAltNameWarning's should go off once per host
+warnings.simplefilter("default", exceptions.SubjectAltNameWarning, append=True)
+# InsecurePlatformWarning's don't vary between requests, so we keep it default.
+warnings.simplefilter("default", exceptions.InsecurePlatformWarning, append=True)
+# SNIMissingWarnings should go off only once.
+warnings.simplefilter("default", exceptions.SNIMissingWarning, append=True)
+
+
+def disable_warnings(category=exceptions.HTTPWarning):
+    """
+    Helper for quickly disabling all urllib3 warnings.
+    """
+    warnings.simplefilter("ignore", category)

venv/Lib/site-packages/urllib3/_collections.py

@@ -0,0 +1,336 @@
+from __future__ import absolute_import
+
+try:
+    from collections.abc import Mapping, MutableMapping
+except ImportError:
+    from collections import Mapping, MutableMapping
+try:
+    from threading import RLock
+except ImportError:  # Platform-specific: No threads available
+
+    class RLock:
+        def __enter__(self):
+            pass
+
+        def __exit__(self, exc_type, exc_value, traceback):
+            pass
+
+
+from collections import OrderedDict
+from .exceptions import InvalidHeader
+from .packages.six import iterkeys, itervalues, PY3
+
+
+__all__ = ["RecentlyUsedContainer", "HTTPHeaderDict"]
+
+
+_Null = object()
+
+
+class RecentlyUsedContainer(MutableMapping):
+    """
+    Provides a thread-safe dict-like container which maintains up to
+    ``maxsize`` keys while throwing away the least-recently-used keys beyond
+    ``maxsize``.
+
+    :param maxsize:
+        Maximum number of recent elements to retain.
+
+    :param dispose_func:
+        Every time an item is evicted from the container,
+        ``dispose_func(value)`` is called.  Callback which will get called
+    """
+
+    ContainerCls = OrderedDict
+
+    def __init__(self, maxsize=10, dispose_func=None):
+        self._maxsize = maxsize
+        self.dispose_func = dispose_func
+
+        self._container = self.ContainerCls()
+        self.lock = RLock()
+
+    def __getitem__(self, key):
+        # Re-insert the item, moving it to the end of the eviction line.
+        with self.lock:
+            item = self._container.pop(key)
+            self._container[key] = item
+            return item
+
+    def __setitem__(self, key, value):
+        evicted_value = _Null
+        with self.lock:
+            # Possibly evict the existing value of 'key'
+            evicted_value = self._container.get(key, _Null)
+            self._container[key] = value
+
+            # If we didn't evict an existing value, we might have to evict the
+            # least recently used item from the beginning of the container.
+            if len(self._container) > self._maxsize:
+                _key, evicted_value = self._container.popitem(last=False)
+
+        if self.dispose_func and evicted_value is not _Null:
+            self.dispose_func(evicted_value)
+
+    def __delitem__(self, key):
+        with self.lock:
+            value = self._container.pop(key)
+
+        if self.dispose_func:
+            self.dispose_func(value)
+
+    def __len__(self):
+        with self.lock:
+            return len(self._container)
+
+    def __iter__(self):
+        raise NotImplementedError(
+            "Iteration over this class is unlikely to be threadsafe."
+        )
+
+    def clear(self):
+        with self.lock:
+            # Copy pointers to all values, then wipe the mapping
+            values = list(itervalues(self._container))
+            self._container.clear()
+
+        if self.dispose_func:
+            for value in values:
+                self.dispose_func(value)
+
+    def keys(self):
+        with self.lock:
+            return list(iterkeys(self._container))
+
+
+class HTTPHeaderDict(MutableMapping):
+    """
+    :param headers:
+        An iterable of field-value pairs. Must not contain multiple field names
+        when compared case-insensitively.
+
+    :param kwargs:
+        Additional field-value pairs to pass in to ``dict.update``.
+
+    A ``dict`` like container for storing HTTP Headers.
+
+    Field names are stored and compared case-insensitively in compliance with
+    RFC 7230. Iteration provides the first case-sensitive key seen for each
+    case-insensitive pair.
+
+    Using ``__setitem__`` syntax overwrites fields that compare equal
+    case-insensitively in order to maintain ``dict``'s api. For fields that
+    compare equal, instead create a new ``HTTPHeaderDict`` and use ``.add``
+    in a loop.
+
+    If multiple fields that are equal case-insensitively are passed to the
+    constructor or ``.update``, the behavior is undefined and some will be
+    lost.
+
+    >>> headers = HTTPHeaderDict()
+    >>> headers.add('Set-Cookie', 'foo=bar')
+    >>> headers.add('set-cookie', 'baz=quxx')
+    >>> headers['content-length'] = '7'
+    >>> headers['SET-cookie']
+    'foo=bar, baz=quxx'
+    >>> headers['Content-Length']
+    '7'
+    """
+
+    def __init__(self, headers=None, **kwargs):
+        super(HTTPHeaderDict, self).__init__()
+        self._container = OrderedDict()
+        if headers is not None:
+            if isinstance(headers, HTTPHeaderDict):
+                self._copy_from(headers)
+            else:
+                self.extend(headers)
+        if kwargs:
+            self.extend(kwargs)
+
+    def __setitem__(self, key, val):
+        self._container[key.lower()] = [key, val]
+        return self._container[key.lower()]
+
+    def __getitem__(self, key):
+        val = self._container[key.lower()]
+        return ", ".join(val[1:])
+
+    def __delitem__(self, key):
+        del self._container[key.lower()]
+
+    def __contains__(self, key):
+        return key.lower() in self._container
+
+    def __eq__(self, other):
+        if not isinstance(other, Mapping) and not hasattr(other, "keys"):
+            return False
+        if not isinstance(other, type(self)):
+            other = type(self)(other)
+        return dict((k.lower(), v) for k, v in self.itermerged()) == dict(
+            (k.lower(), v) for k, v in other.itermerged()
+        )
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    if not PY3:  # Python 2
+        iterkeys = MutableMapping.iterkeys
+        itervalues = MutableMapping.itervalues
+
+    __marker = object()
+
+    def __len__(self):
+        return len(self._container)
+
+    def __iter__(self):
+        # Only provide the originally cased names
+        for vals in self._container.values():
+            yield vals[0]
+
+    def pop(self, key, default=__marker):
+        """D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
+          If key is not found, d is returned if given, otherwise KeyError is raised.
+        """
+        # Using the MutableMapping function directly fails due to the private marker.
+        # Using ordinary dict.pop would expose the internal structures.
+        # So let's reinvent the wheel.
+        try:
+            value = self[key]
+        except KeyError:
+            if default is self.__marker:
+                raise
+            return default
+        else:
+            del self[key]
+            return value
+
+    def discard(self, key):
+        try:
+            del self[key]
+        except KeyError:
+            pass
+
+    def add(self, key, val):
+        """Adds a (name, value) pair, doesn't overwrite the value if it already
+        exists.
+
+        >>> headers = HTTPHeaderDict(foo='bar')
+        >>> headers.add('Foo', 'baz')
+        >>> headers['foo']
+        'bar, baz'
+        """
+        key_lower = key.lower()
+        new_vals = [key, val]
+        # Keep the common case aka no item present as fast as possible
+        vals = self._container.setdefault(key_lower, new_vals)
+        if new_vals is not vals:
+            vals.append(val)
+
+    def extend(self, *args, **kwargs):
+        """Generic import function for any type of header-like object.
+        Adapted version of MutableMapping.update in order to insert items
+        with self.add instead of self.__setitem__
+        """
+        if len(args) > 1:
+            raise TypeError(
+                "extend() takes at most 1 positional "
+                "arguments ({0} given)".format(len(args))
+            )
+        other = args[0] if len(args) >= 1 else ()
+
+        if isinstance(other, HTTPHeaderDict):
+            for key, val in other.iteritems():
+                self.add(key, val)
+        elif isinstance(other, Mapping):
+            for key in other:
+                self.add(key, other[key])
+        elif hasattr(other, "keys"):
+            for key in other.keys():
+                self.add(key, other[key])
+        else:
+            for key, value in other:
+                self.add(key, value)
+
+        for key, value in kwargs.items():
+            self.add(key, value)
+
+    def getlist(self, key, default=__marker):
+        """Returns a list of all the values for the named field. Returns an
+        empty list if the key doesn't exist."""
+        try:
+            vals = self._container[key.lower()]
+        except KeyError:
+            if default is self.__marker:
+                return []
+            return default
+        else:
+            return vals[1:]
+
+    # Backwards compatibility for httplib
+    getheaders = getlist
+    getallmatchingheaders = getlist
+    iget = getlist
+
+    # Backwards compatibility for http.cookiejar
+    get_all = getlist
+
+    def __repr__(self):
+        return "%s(%s)" % (type(self).__name__, dict(self.itermerged()))
+
+    def _copy_from(self, other):
+        for key in other:
+            val = other.getlist(key)
+            if isinstance(val, list):
+                # Don't need to convert tuples
+                val = list(val)
+            self._container[key.lower()] = [key] + val
+
+    def copy(self):
+        clone = type(self)()
+        clone._copy_from(self)
+        return clone
+
+    def iteritems(self):
+        """Iterate over all header lines, including duplicate ones."""
+        for key in self:
+            vals = self._container[key.lower()]
+            for val in vals[1:]:
+                yield vals[0], val
+
+    def itermerged(self):
+        """Iterate over all headers, merging duplicate ones together."""
+        for key in self:
+            val = self._container[key.lower()]
+            yield val[0], ", ".join(val[1:])
+
+    def items(self):
+        return list(self.iteritems())
+
+    @classmethod
+    def from_httplib(cls, message):  # Python 2
+        """Read headers from a Python 2 httplib message object."""
+        # python2.7 does not expose a proper API for exporting multiheaders
+        # efficiently. This function re-reads raw lines from the message
+        # object and extracts the multiheaders properly.
+        obs_fold_continued_leaders = (" ", "\t")
+        headers = []
+
+        for line in message.headers:
+            if line.startswith(obs_fold_continued_leaders):
+                if not headers:
+                    # We received a header line that starts with OWS as described
+                    # in RFC-7230 S3.2.4. This indicates a multiline header, but
+                    # there exists no previous header to which we can attach it.
+                    raise InvalidHeader(
+                        "Header continuation with no previous header: %s" % line
+                    )
+                else:
+                    key, value = headers[-1]
+                    headers[-1] = (key, value + " " + line.strip())
+                    continue
+
+            key, value = line.split(":", 1)
+            headers.append((key, value.strip()))
+
+        return cls(headers)

venv/Lib/site-packages/urllib3/_version.py

@@ -0,0 +1,2 @@
+# This file is protected via CODEOWNERS
+__version__ = "1.25.10"

venv/Lib/site-packages/urllib3/connection.py

@@ -0,0 +1,424 @@
+from __future__ import absolute_import
+import re
+import datetime
+import logging
+import os
+import socket
+from socket import error as SocketError, timeout as SocketTimeout
+import warnings
+from .packages import six
+from .packages.six.moves.http_client import HTTPConnection as _HTTPConnection
+from .packages.six.moves.http_client import HTTPException  # noqa: F401
+
+try:  # Compiled with SSL?
+    import ssl
+
+    BaseSSLError = ssl.SSLError
+except (ImportError, AttributeError):  # Platform-specific: No SSL.
+    ssl = None
+
+    class BaseSSLError(BaseException):
+        pass
+
+
+try:
+    # Python 3: not a no-op, we're adding this to the namespace so it can be imported.
+    ConnectionError = ConnectionError
+except NameError:
+    # Python 2
+    class ConnectionError(Exception):
+        pass
+
+
+from .exceptions import (
+    NewConnectionError,
+    ConnectTimeoutError,
+    SubjectAltNameWarning,
+    SystemTimeWarning,
+)
+from .packages.ssl_match_hostname import match_hostname, CertificateError
+
+from .util.ssl_ import (
+    resolve_cert_reqs,
+    resolve_ssl_version,
+    assert_fingerprint,
+    create_urllib3_context,
+    ssl_wrap_socket,
+)
+
+
+from .util import connection
+
+from ._collections import HTTPHeaderDict
+
+log = logging.getLogger(__name__)
+
+port_by_scheme = {"http": 80, "https": 443}
+
+# When it comes time to update this value as a part of regular maintenance
+# (ie test_recent_date is failing) update it to ~6 months before the current date.
+RECENT_DATE = datetime.date(2019, 1, 1)
+
+_CONTAINS_CONTROL_CHAR_RE = re.compile(r"[^-!#$%&'*+.^_`|~0-9a-zA-Z]")
+
+
+class DummyConnection(object):
+    """Used to detect a failed ConnectionCls import."""
+
+    pass
+
+
+class HTTPConnection(_HTTPConnection, object):
+    """
+    Based on httplib.HTTPConnection but provides an extra constructor
+    backwards-compatibility layer between older and newer Pythons.
+
+    Additional keyword parameters are used to configure attributes of the connection.
+    Accepted parameters include:
+
+      - ``strict``: See the documentation on :class:`urllib3.connectionpool.HTTPConnectionPool`
+      - ``source_address``: Set the source address for the current connection.
+      - ``socket_options``: Set specific options on the underlying socket. If not specified, then
+        defaults are loaded from ``HTTPConnection.default_socket_options`` which includes disabling
+        Nagle's algorithm (sets TCP_NODELAY to 1) unless the connection is behind a proxy.
+
+        For example, if you wish to enable TCP Keep Alive in addition to the defaults,
+        you might pass::
+
+            HTTPConnection.default_socket_options + [
+                (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1),
+            ]
+
+        Or you may want to disable the defaults by passing an empty list (e.g., ``[]``).
+    """
+
+    default_port = port_by_scheme["http"]
+
+    #: Disable Nagle's algorithm by default.
+    #: ``[(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]``
+    default_socket_options = [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]
+
+    #: Whether this connection verifies the host's certificate.
+    is_verified = False
+
+    def __init__(self, *args, **kw):
+        if not six.PY2:
+            kw.pop("strict", None)
+
+        # Pre-set source_address.
+        self.source_address = kw.get("source_address")
+
+        #: The socket options provided by the user. If no options are
+        #: provided, we use the default options.
+        self.socket_options = kw.pop("socket_options", self.default_socket_options)
+
+        _HTTPConnection.__init__(self, *args, **kw)
+
+    @property
+    def host(self):
+        """
+        Getter method to remove any trailing dots that indicate the hostname is an FQDN.
+
+        In general, SSL certificates don't include the trailing dot indicating a
+        fully-qualified domain name, and thus, they don't validate properly when
+        checked against a domain name that includes the dot. In addition, some
+        servers may not expect to receive the trailing dot when provided.
+
+        However, the hostname with trailing dot is critical to DNS resolution; doing a
+        lookup with the trailing dot will properly only resolve the appropriate FQDN,
+        whereas a lookup without a trailing dot will search the system's search domain
+        list. Thus, it's important to keep the original host around for use only in
+        those cases where it's appropriate (i.e., when doing DNS lookup to establish the
+        actual TCP connection across which we're going to send HTTP requests).
+        """
+        return self._dns_host.rstrip(".")
+
+    @host.setter
+    def host(self, value):
+        """
+        Setter for the `host` property.
+
+        We assume that only urllib3 uses the _dns_host attribute; httplib itself
+        only uses `host`, and it seems reasonable that other libraries follow suit.
+        """
+        self._dns_host = value
+
+    def _new_conn(self):
+        """ Establish a socket connection and set nodelay settings on it.
+
+        :return: New socket connection.
+        """
+        extra_kw = {}
+        if self.source_address:
+            extra_kw["source_address"] = self.source_address
+
+        if self.socket_options:
+            extra_kw["socket_options"] = self.socket_options
+
+        try:
+            conn = connection.create_connection(
+                (self._dns_host, self.port), self.timeout, **extra_kw
+            )
+
+        except SocketTimeout:
+            raise ConnectTimeoutError(
+                self,
+                "Connection to %s timed out. (connect timeout=%s)"
+                % (self.host, self.timeout),
+            )
+
+        except SocketError as e:
+            raise NewConnectionError(
+                self, "Failed to establish a new connection: %s" % e
+            )
+
+        return conn
+
+    def _prepare_conn(self, conn):
+        self.sock = conn
+        # Google App Engine's httplib does not define _tunnel_host
+        if getattr(self, "_tunnel_host", None):
+            # TODO: Fix tunnel so it doesn't depend on self.sock state.
+            self._tunnel()
+            # Mark this connection as not reusable
+            self.auto_open = 0
+
+    def connect(self):
+        conn = self._new_conn()
+        self._prepare_conn(conn)
+
+    def putrequest(self, method, url, *args, **kwargs):
+        """Send a request to the server"""
+        match = _CONTAINS_CONTROL_CHAR_RE.search(method)
+        if match:
+            raise ValueError(
+                "Method cannot contain non-token characters %r (found at least %r)"
+                % (method, match.group())
+            )
+
+        return _HTTPConnection.putrequest(self, method, url, *args, **kwargs)
+
+    def request_chunked(self, method, url, body=None, headers=None):
+        """
+        Alternative to the common request method, which sends the
+        body with chunked encoding and not as one block
+        """
+        headers = HTTPHeaderDict(headers if headers is not None else {})
+        skip_accept_encoding = "accept-encoding" in headers
+        skip_host = "host" in headers
+        self.putrequest(
+            method, url, skip_accept_encoding=skip_accept_encoding, skip_host=skip_host
+        )
+        for header, value in headers.items():
+            self.putheader(header, value)
+        if "transfer-encoding" not in headers:
+            self.putheader("Transfer-Encoding", "chunked")
+        self.endheaders()
+
+        if body is not None:
+            stringish_types = six.string_types + (bytes,)
+            if isinstance(body, stringish_types):
+                body = (body,)
+            for chunk in body:
+                if not chunk:
+                    continue
+                if not isinstance(chunk, bytes):
+                    chunk = chunk.encode("utf8")
+                len_str = hex(len(chunk))[2:]
+                to_send = bytearray(len_str.encode())
+                to_send += b"\r\n"
+                to_send += chunk
+                to_send += b"\r\n"
+                self.send(to_send)
+
+        # After the if clause, to always have a closed body
+        self.send(b"0\r\n\r\n")
+
+
+class HTTPSConnection(HTTPConnection):
+    default_port = port_by_scheme["https"]
+
+    cert_reqs = None
+    ca_certs = None
+    ca_cert_dir = None
+    ca_cert_data = None
+    ssl_version = None
+    assert_fingerprint = None
+
+    def __init__(
+        self,
+        host,
+        port=None,
+        key_file=None,
+        cert_file=None,
+        key_password=None,
+        strict=None,
+        timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+        ssl_context=None,
+        server_hostname=None,
+        **kw
+    ):
+
+        HTTPConnection.__init__(self, host, port, strict=strict, timeout=timeout, **kw)
+
+        self.key_file = key_file
+        self.cert_file = cert_file
+        self.key_password = key_password
+        self.ssl_context = ssl_context
+        self.server_hostname = server_hostname
+
+        # Required property for Google AppEngine 1.9.0 which otherwise causes
+        # HTTPS requests to go out as HTTP. (See Issue #356)
+        self._protocol = "https"
+
+    def set_cert(
+        self,
+        key_file=None,
+        cert_file=None,
+        cert_reqs=None,
+        key_password=None,
+        ca_certs=None,
+        assert_hostname=None,
+        assert_fingerprint=None,
+        ca_cert_dir=None,
+        ca_cert_data=None,
+    ):
+        """
+        This method should only be called once, before the connection is used.
+        """
+        # If cert_reqs is not provided we'll assume CERT_REQUIRED unless we also
+        # have an SSLContext object in which case we'll use its verify_mode.
+        if cert_reqs is None:
+            if self.ssl_context is not None:
+                cert_reqs = self.ssl_context.verify_mode
+            else:
+                cert_reqs = resolve_cert_reqs(None)
+
+        self.key_file = key_file
+        self.cert_file = cert_file
+        self.cert_reqs = cert_reqs
+        self.key_password = key_password
+        self.assert_hostname = assert_hostname
+        self.assert_fingerprint = assert_fingerprint
+        self.ca_certs = ca_certs and os.path.expanduser(ca_certs)
+        self.ca_cert_dir = ca_cert_dir and os.path.expanduser(ca_cert_dir)
+        self.ca_cert_data = ca_cert_data
+
+    def connect(self):
+        # Add certificate verification
+        conn = self._new_conn()
+        hostname = self.host
+
+        # Google App Engine's httplib does not define _tunnel_host
+        if getattr(self, "_tunnel_host", None):
+            self.sock = conn
+            # Calls self._set_hostport(), so self.host is
+            # self._tunnel_host below.
+            self._tunnel()
+            # Mark this connection as not reusable
+            self.auto_open = 0
+
+            # Override the host with the one we're requesting data from.
+            hostname = self._tunnel_host
+
+        server_hostname = hostname
+        if self.server_hostname is not None:
+            server_hostname = self.server_hostname
+
+        is_time_off = datetime.date.today() < RECENT_DATE
+        if is_time_off:
+            warnings.warn(
+                (
+                    "System time is way off (before {0}). This will probably "
+                    "lead to SSL verification errors"
+                ).format(RECENT_DATE),
+                SystemTimeWarning,
+            )
+
+        # Wrap socket using verification with the root certs in
+        # trusted_root_certs
+        default_ssl_context = False
+        if self.ssl_context is None:
+            default_ssl_context = True
+            self.ssl_context = create_urllib3_context(
+                ssl_version=resolve_ssl_version(self.ssl_version),
+                cert_reqs=resolve_cert_reqs(self.cert_reqs),
+            )
+
+        context = self.ssl_context
+        context.verify_mode = resolve_cert_reqs(self.cert_reqs)
+
+        # Try to load OS default certs if none are given.
+        # Works well on Windows (requires Python3.4+)
+        if (
+            not self.ca_certs
+            and not self.ca_cert_dir
+            and not self.ca_cert_data
+            and default_ssl_context
+            and hasattr(context, "load_default_certs")
+        ):
+            context.load_default_certs()
+
+        self.sock = ssl_wrap_socket(
+            sock=conn,
+            keyfile=self.key_file,
+            certfile=self.cert_file,
+            key_password=self.key_password,
+            ca_certs=self.ca_certs,
+            ca_cert_dir=self.ca_cert_dir,
+            ca_cert_data=self.ca_cert_data,
+            server_hostname=server_hostname,
+            ssl_context=context,
+        )
+
+        if self.assert_fingerprint:
+            assert_fingerprint(
+                self.sock.getpeercert(binary_form=True), self.assert_fingerprint
+            )
+        elif (
+            context.verify_mode != ssl.CERT_NONE
+            and not getattr(context, "check_hostname", False)
+            and self.assert_hostname is not False
+        ):
+            # While urllib3 attempts to always turn off hostname matching from
+            # the TLS library, this cannot always be done. So we check whether
+            # the TLS Library still thinks it's matching hostnames.
+            cert = self.sock.getpeercert()
+            if not cert.get("subjectAltName", ()):
+                warnings.warn(
+                    (
+                        "Certificate for {0} has no `subjectAltName`, falling back to check for a "
+                        "`commonName` for now. This feature is being removed by major browsers and "
+                        "deprecated by RFC 2818. (See https://github.com/urllib3/urllib3/issues/497 "
+                        "for details.)".format(hostname)
+                    ),
+                    SubjectAltNameWarning,
+                )
+            _match_hostname(cert, self.assert_hostname or server_hostname)
+
+        self.is_verified = (
+            context.verify_mode == ssl.CERT_REQUIRED
+            or self.assert_fingerprint is not None
+        )
+
+
+def _match_hostname(cert, asserted_hostname):
+    try:
+        match_hostname(cert, asserted_hostname)
+    except CertificateError as e:
+        log.warning(
+            "Certificate did not match expected hostname: %s. Certificate: %s",
+            asserted_hostname,
+            cert,
+        )
+        # Add cert to exception and reraise so client code can inspect
+        # the cert when catching the exception, if they want to
+        e._peer_cert = cert
+        raise
+
+
+if not ssl:
+    HTTPSConnection = DummyConnection  # noqa: F811
+
+
+VerifiedHTTPSConnection = HTTPSConnection

venv/Lib/site-packages/urllib3/contrib/_appengine_environ.py

@@ -0,0 +1,36 @@
+"""
+This module provides means to detect the App Engine environment.
+"""
+
+import os
+
+
+def is_appengine():
+    return is_local_appengine() or is_prod_appengine()
+
+
+def is_appengine_sandbox():
+    """Reports if the app is running in the first generation sandbox.
+
+    The second generation runtimes are technically still in a sandbox, but it
+    is much less restrictive, so generally you shouldn't need to check for it.
+    see https://cloud.google.com/appengine/docs/standard/runtimes
+    """
+    return is_appengine() and os.environ["APPENGINE_RUNTIME"] == "python27"
+
+
+def is_local_appengine():
+    return "APPENGINE_RUNTIME" in os.environ and os.environ.get(
+        "SERVER_SOFTWARE", ""
+    ).startswith("Development/")
+
+
+def is_prod_appengine():
+    return "APPENGINE_RUNTIME" in os.environ and os.environ.get(
+        "SERVER_SOFTWARE", ""
+    ).startswith("Google App Engine/")
+
+
+def is_prod_appengine_mvms():
+    """Deprecated."""
+    return False

venv/Lib/site-packages/urllib3/contrib/_securetransport/bindings.py

@@ -0,0 +1,510 @@
+"""
+This module uses ctypes to bind a whole bunch of functions and constants from
+SecureTransport. The goal here is to provide the low-level API to
+SecureTransport. These are essentially the C-level functions and constants, and
+they're pretty gross to work with.
+
+This code is a bastardised version of the code found in Will Bond's oscrypto
+library. An enormous debt is owed to him for blazing this trail for us. For
+that reason, this code should be considered to be covered both by urllib3's
+license and by oscrypto's:
+
+    Copyright (c) 2015-2016 Will Bond <will@wbond.net>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+"""
+from __future__ import absolute_import
+
+import platform
+from ctypes.util import find_library
+from ctypes import (
+    c_void_p,
+    c_int32,
+    c_char_p,
+    c_size_t,
+    c_byte,
+    c_uint32,
+    c_ulong,
+    c_long,
+    c_bool,
+)
+from ctypes import CDLL, POINTER, CFUNCTYPE
+from urllib3.packages.six import raise_from
+
+
+if platform.system() != "Darwin":
+    raise ImportError("Only macOS is supported")
+
+version = platform.mac_ver()[0]
+version_info = tuple(map(int, version.split(".")))
+if version_info < (10, 8):
+    raise OSError(
+        "Only OS X 10.8 and newer are supported, not %s.%s"
+        % (version_info[0], version_info[1])
+    )
+
+
+def load_cdll(name, macos10_16_path):
+    """Loads a CDLL by name, falling back to known path on 10.16+"""
+    try:
+        # Big Sur is technically 11 but we use 10.16 due to the Big Sur
+        # beta being labeled as 10.16.
+        if version_info >= (10, 16):
+            path = macos10_16_path
+        else:
+            path = find_library(name)
+        if not path:
+            raise OSError  # Caught and reraised as 'ImportError'
+        return CDLL(path, use_errno=True)
+    except OSError:
+        raise_from(ImportError("The library %s failed to load" % name), None)
+
+
+Security = load_cdll(
+    "Security", "/System/Library/Frameworks/Security.framework/Security"
+)
+CoreFoundation = load_cdll(
+    "CoreFoundation",
+    "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation",
+)
+
+
+Boolean = c_bool
+CFIndex = c_long
+CFStringEncoding = c_uint32
+CFData = c_void_p
+CFString = c_void_p
+CFArray = c_void_p
+CFMutableArray = c_void_p
+CFDictionary = c_void_p
+CFError = c_void_p
+CFType = c_void_p
+CFTypeID = c_ulong
+
+CFTypeRef = POINTER(CFType)
+CFAllocatorRef = c_void_p
+
+OSStatus = c_int32
+
+CFDataRef = POINTER(CFData)
+CFStringRef = POINTER(CFString)
+CFArrayRef = POINTER(CFArray)
+CFMutableArrayRef = POINTER(CFMutableArray)
+CFDictionaryRef = POINTER(CFDictionary)
+CFArrayCallBacks = c_void_p
+CFDictionaryKeyCallBacks = c_void_p
+CFDictionaryValueCallBacks = c_void_p
+
+SecCertificateRef = POINTER(c_void_p)
+SecExternalFormat = c_uint32
+SecExternalItemType = c_uint32
+SecIdentityRef = POINTER(c_void_p)
+SecItemImportExportFlags = c_uint32
+SecItemImportExportKeyParameters = c_void_p
+SecKeychainRef = POINTER(c_void_p)
+SSLProtocol = c_uint32
+SSLCipherSuite = c_uint32
+SSLContextRef = POINTER(c_void_p)
+SecTrustRef = POINTER(c_void_p)
+SSLConnectionRef = c_uint32
+SecTrustResultType = c_uint32
+SecTrustOptionFlags = c_uint32
+SSLProtocolSide = c_uint32
+SSLConnectionType = c_uint32
+SSLSessionOption = c_uint32
+
+
+try:
+    Security.SecItemImport.argtypes = [
+        CFDataRef,
+        CFStringRef,
+        POINTER(SecExternalFormat),
+        POINTER(SecExternalItemType),
+        SecItemImportExportFlags,
+        POINTER(SecItemImportExportKeyParameters),
+        SecKeychainRef,
+        POINTER(CFArrayRef),
+    ]
+    Security.SecItemImport.restype = OSStatus
+
+    Security.SecCertificateGetTypeID.argtypes = []
+    Security.SecCertificateGetTypeID.restype = CFTypeID
+
+    Security.SecIdentityGetTypeID.argtypes = []
+    Security.SecIdentityGetTypeID.restype = CFTypeID
+
+    Security.SecKeyGetTypeID.argtypes = []
+    Security.SecKeyGetTypeID.restype = CFTypeID
+
+    Security.SecCertificateCreateWithData.argtypes = [CFAllocatorRef, CFDataRef]
+    Security.SecCertificateCreateWithData.restype = SecCertificateRef
+
+    Security.SecCertificateCopyData.argtypes = [SecCertificateRef]
+    Security.SecCertificateCopyData.restype = CFDataRef
+
+    Security.SecCopyErrorMessageString.argtypes = [OSStatus, c_void_p]
+    Security.SecCopyErrorMessageString.restype = CFStringRef
+
+    Security.SecIdentityCreateWithCertificate.argtypes = [
+        CFTypeRef,
+        SecCertificateRef,
+        POINTER(SecIdentityRef),
+    ]
+    Security.SecIdentityCreateWithCertificate.restype = OSStatus
+
+    Security.SecKeychainCreate.argtypes = [
+        c_char_p,
+        c_uint32,
+        c_void_p,
+        Boolean,
+        c_void_p,
+        POINTER(SecKeychainRef),
+    ]
+    Security.SecKeychainCreate.restype = OSStatus
+
+    Security.SecKeychainDelete.argtypes = [SecKeychainRef]
+    Security.SecKeychainDelete.restype = OSStatus
+
+    Security.SecPKCS12Import.argtypes = [
+        CFDataRef,
+        CFDictionaryRef,
+        POINTER(CFArrayRef),
+    ]
+    Security.SecPKCS12Import.restype = OSStatus
+
+    SSLReadFunc = CFUNCTYPE(OSStatus, SSLConnectionRef, c_void_p, POINTER(c_size_t))
+    SSLWriteFunc = CFUNCTYPE(
+        OSStatus, SSLConnectionRef, POINTER(c_byte), POINTER(c_size_t)
+    )
+
+    Security.SSLSetIOFuncs.argtypes = [SSLContextRef, SSLReadFunc, SSLWriteFunc]
+    Security.SSLSetIOFuncs.restype = OSStatus
+
+    Security.SSLSetPeerID.argtypes = [SSLContextRef, c_char_p, c_size_t]
+    Security.SSLSetPeerID.restype = OSStatus
+
+    Security.SSLSetCertificate.argtypes = [SSLContextRef, CFArrayRef]
+    Security.SSLSetCertificate.restype = OSStatus
+
+    Security.SSLSetCertificateAuthorities.argtypes = [SSLContextRef, CFTypeRef, Boolean]
+    Security.SSLSetCertificateAuthorities.restype = OSStatus
+
+    Security.SSLSetConnection.argtypes = [SSLContextRef, SSLConnectionRef]
+    Security.SSLSetConnection.restype = OSStatus
+
+    Security.SSLSetPeerDomainName.argtypes = [SSLContextRef, c_char_p, c_size_t]
+    Security.SSLSetPeerDomainName.restype = OSStatus
+
+    Security.SSLHandshake.argtypes = [SSLContextRef]
+    Security.SSLHandshake.restype = OSStatus
+
+    Security.SSLRead.argtypes = [SSLContextRef, c_char_p, c_size_t, POINTER(c_size_t)]
+    Security.SSLRead.restype = OSStatus
+
+    Security.SSLWrite.argtypes = [SSLContextRef, c_char_p, c_size_t, POINTER(c_size_t)]
+    Security.SSLWrite.restype = OSStatus
+
+    Security.SSLClose.argtypes = [SSLContextRef]
+    Security.SSLClose.restype = OSStatus
+
+    Security.SSLGetNumberSupportedCiphers.argtypes = [SSLContextRef, POINTER(c_size_t)]
+    Security.SSLGetNumberSupportedCiphers.restype = OSStatus
+
+    Security.SSLGetSupportedCiphers.argtypes = [
+        SSLContextRef,
+        POINTER(SSLCipherSuite),
+        POINTER(c_size_t),
+    ]
+    Security.SSLGetSupportedCiphers.restype = OSStatus
+
+    Security.SSLSetEnabledCiphers.argtypes = [
+        SSLContextRef,
+        POINTER(SSLCipherSuite),
+        c_size_t,
+    ]
+    Security.SSLSetEnabledCiphers.restype = OSStatus
+
+    Security.SSLGetNumberEnabledCiphers.argtype = [SSLContextRef, POINTER(c_size_t)]
+    Security.SSLGetNumberEnabledCiphers.restype = OSStatus
+
+    Security.SSLGetEnabledCiphers.argtypes = [
+        SSLContextRef,
+        POINTER(SSLCipherSuite),
+        POINTER(c_size_t),
+    ]
+    Security.SSLGetEnabledCiphers.restype = OSStatus
+
+    Security.SSLGetNegotiatedCipher.argtypes = [SSLContextRef, POINTER(SSLCipherSuite)]
+    Security.SSLGetNegotiatedCipher.restype = OSStatus
+
+    Security.SSLGetNegotiatedProtocolVersion.argtypes = [
+        SSLContextRef,
+        POINTER(SSLProtocol),
+    ]
+    Security.SSLGetNegotiatedProtocolVersion.restype = OSStatus
+
+    Security.SSLCopyPeerTrust.argtypes = [SSLContextRef, POINTER(SecTrustRef)]
+    Security.SSLCopyPeerTrust.restype = OSStatus
+
+    Security.SecTrustSetAnchorCertificates.argtypes = [SecTrustRef, CFArrayRef]
+    Security.SecTrustSetAnchorCertificates.restype = OSStatus
+
+    Security.SecTrustSetAnchorCertificatesOnly.argstypes = [SecTrustRef, Boolean]
+    Security.SecTrustSetAnchorCertificatesOnly.restype = OSStatus
+
+    Security.SecTrustEvaluate.argtypes = [SecTrustRef, POINTER(SecTrustResultType)]
+    Security.SecTrustEvaluate.restype = OSStatus
+
+    Security.SecTrustGetCertificateCount.argtypes = [SecTrustRef]
+    Security.SecTrustGetCertificateCount.restype = CFIndex
+
+    Security.SecTrustGetCertificateAtIndex.argtypes = [SecTrustRef, CFIndex]
+    Security.SecTrustGetCertificateAtIndex.restype = SecCertificateRef
+
+    Security.SSLCreateContext.argtypes = [
+        CFAllocatorRef,
+        SSLProtocolSide,
+        SSLConnectionType,
+    ]
+    Security.SSLCreateContext.restype = SSLContextRef
+
+    Security.SSLSetSessionOption.argtypes = [SSLContextRef, SSLSessionOption, Boolean]
+    Security.SSLSetSessionOption.restype = OSStatus
+
+    Security.SSLSetProtocolVersionMin.argtypes = [SSLContextRef, SSLProtocol]
+    Security.SSLSetProtocolVersionMin.restype = OSStatus
+
+    Security.SSLSetProtocolVersionMax.argtypes = [SSLContextRef, SSLProtocol]
+    Security.SSLSetProtocolVersionMax.restype = OSStatus
+
+    Security.SecCopyErrorMessageString.argtypes = [OSStatus, c_void_p]
+    Security.SecCopyErrorMessageString.restype = CFStringRef
+
+    Security.SSLReadFunc = SSLReadFunc
+    Security.SSLWriteFunc = SSLWriteFunc
+    Security.SSLContextRef = SSLContextRef
+    Security.SSLProtocol = SSLProtocol
+    Security.SSLCipherSuite = SSLCipherSuite
+    Security.SecIdentityRef = SecIdentityRef
+    Security.SecKeychainRef = SecKeychainRef
+    Security.SecTrustRef = SecTrustRef
+    Security.SecTrustResultType = SecTrustResultType
+    Security.SecExternalFormat = SecExternalFormat
+    Security.OSStatus = OSStatus
+
+    Security.kSecImportExportPassphrase = CFStringRef.in_dll(
+        Security, "kSecImportExportPassphrase"
+    )
+    Security.kSecImportItemIdentity = CFStringRef.in_dll(
+        Security, "kSecImportItemIdentity"
+    )
+
+    # CoreFoundation time!
+    CoreFoundation.CFRetain.argtypes = [CFTypeRef]
+    CoreFoundation.CFRetain.restype = CFTypeRef
+
+    CoreFoundation.CFRelease.argtypes = [CFTypeRef]
+    CoreFoundation.CFRelease.restype = None
+
+    CoreFoundation.CFGetTypeID.argtypes = [CFTypeRef]
+    CoreFoundation.CFGetTypeID.restype = CFTypeID
+
+    CoreFoundation.CFStringCreateWithCString.argtypes = [
+        CFAllocatorRef,
+        c_char_p,
+        CFStringEncoding,
+    ]
+    CoreFoundation.CFStringCreateWithCString.restype = CFStringRef
+
+    CoreFoundation.CFStringGetCStringPtr.argtypes = [CFStringRef, CFStringEncoding]
+    CoreFoundation.CFStringGetCStringPtr.restype = c_char_p
+
+    CoreFoundation.CFStringGetCString.argtypes = [
+        CFStringRef,
+        c_char_p,
+        CFIndex,
+        CFStringEncoding,
+    ]
+    CoreFoundation.CFStringGetCString.restype = c_bool
+
+    CoreFoundation.CFDataCreate.argtypes = [CFAllocatorRef, c_char_p, CFIndex]
+    CoreFoundation.CFDataCreate.restype = CFDataRef
+
+    CoreFoundation.CFDataGetLength.argtypes = [CFDataRef]
+    CoreFoundation.CFDataGetLength.restype = CFIndex
+
+    CoreFoundation.CFDataGetBytePtr.argtypes = [CFDataRef]
+    CoreFoundation.CFDataGetBytePtr.restype = c_void_p
+
+    CoreFoundation.CFDictionaryCreate.argtypes = [
+        CFAllocatorRef,
+        POINTER(CFTypeRef),
+        POINTER(CFTypeRef),
+        CFIndex,
+        CFDictionaryKeyCallBacks,
+        CFDictionaryValueCallBacks,
+    ]
+    CoreFoundation.CFDictionaryCreate.restype = CFDictionaryRef
+
+    CoreFoundation.CFDictionaryGetValue.argtypes = [CFDictionaryRef, CFTypeRef]
+    CoreFoundation.CFDictionaryGetValue.restype = CFTypeRef
+
+    CoreFoundation.CFArrayCreate.argtypes = [
+        CFAllocatorRef,
+        POINTER(CFTypeRef),
+        CFIndex,
+        CFArrayCallBacks,
+    ]
+    CoreFoundation.CFArrayCreate.restype = CFArrayRef
+
+    CoreFoundation.CFArrayCreateMutable.argtypes = [
+        CFAllocatorRef,
+        CFIndex,
+        CFArrayCallBacks,
+    ]
+    CoreFoundation.CFArrayCreateMutable.restype = CFMutableArrayRef
+
+    CoreFoundation.CFArrayAppendValue.argtypes = [CFMutableArrayRef, c_void_p]
+    CoreFoundation.CFArrayAppendValue.restype = None
+
+    CoreFoundation.CFArrayGetCount.argtypes = [CFArrayRef]
+    CoreFoundation.CFArrayGetCount.restype = CFIndex
+
+    CoreFoundation.CFArrayGetValueAtIndex.argtypes = [CFArrayRef, CFIndex]
+    CoreFoundation.CFArrayGetValueAtIndex.restype = c_void_p
+
+    CoreFoundation.kCFAllocatorDefault = CFAllocatorRef.in_dll(
+        CoreFoundation, "kCFAllocatorDefault"
+    )
+    CoreFoundation.kCFTypeArrayCallBacks = c_void_p.in_dll(
+        CoreFoundation, "kCFTypeArrayCallBacks"
+    )
+    CoreFoundation.kCFTypeDictionaryKeyCallBacks = c_void_p.in_dll(
+        CoreFoundation, "kCFTypeDictionaryKeyCallBacks"
+    )
+    CoreFoundation.kCFTypeDictionaryValueCallBacks = c_void_p.in_dll(
+        CoreFoundation, "kCFTypeDictionaryValueCallBacks"
+    )
+
+    CoreFoundation.CFTypeRef = CFTypeRef
+    CoreFoundation.CFArrayRef = CFArrayRef
+    CoreFoundation.CFStringRef = CFStringRef
+    CoreFoundation.CFDictionaryRef = CFDictionaryRef
+
+except (AttributeError):
+    raise ImportError("Error initializing ctypes")
+
+
+class CFConst(object):
+    """
+    A class object that acts as essentially a namespace for CoreFoundation
+    constants.
+    """
+
+    kCFStringEncodingUTF8 = CFStringEncoding(0x08000100)
+
+
+class SecurityConst(object):
+    """
+    A class object that acts as essentially a namespace for Security constants.
+    """
+
+    kSSLSessionOptionBreakOnServerAuth = 0
+
+    kSSLProtocol2 = 1
+    kSSLProtocol3 = 2
+    kTLSProtocol1 = 4
+    kTLSProtocol11 = 7
+    kTLSProtocol12 = 8
+    # SecureTransport does not support TLS 1.3 even if there's a constant for it
+    kTLSProtocol13 = 10
+    kTLSProtocolMaxSupported = 999
+
+    kSSLClientSide = 1
+    kSSLStreamType = 0
+
+    kSecFormatPEMSequence = 10
+
+    kSecTrustResultInvalid = 0
+    kSecTrustResultProceed = 1
+    # This gap is present on purpose: this was kSecTrustResultConfirm, which
+    # is deprecated.
+    kSecTrustResultDeny = 3
+    kSecTrustResultUnspecified = 4
+    kSecTrustResultRecoverableTrustFailure = 5
+    kSecTrustResultFatalTrustFailure = 6
+    kSecTrustResultOtherError = 7
+
+    errSSLProtocol = -9800
+    errSSLWouldBlock = -9803
+    errSSLClosedGraceful = -9805
+    errSSLClosedNoNotify = -9816
+    errSSLClosedAbort = -9806
+
+    errSSLXCertChainInvalid = -9807
+    errSSLCrypto = -9809
+    errSSLInternal = -9810
+    errSSLCertExpired = -9814
+    errSSLCertNotYetValid = -9815
+    errSSLUnknownRootCert = -9812
+    errSSLNoRootCert = -9813
+    errSSLHostNameMismatch = -9843
+    errSSLPeerHandshakeFail = -9824
+    errSSLPeerUserCancelled = -9839
+    errSSLWeakPeerEphemeralDHKey = -9850
+    errSSLServerAuthCompleted = -9841
+    errSSLRecordOverflow = -9847
+
+    errSecVerifyFailed = -67808
+    errSecNoTrustSettings = -25263
+    errSecItemNotFound = -25300
+    errSecInvalidTrustSettings = -25262
+
+    # Cipher suites. We only pick the ones our default cipher string allows.
+    # Source: https://developer.apple.com/documentation/security/1550981-ssl_cipher_suite_values
+    TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 = 0xC02C
+    TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 = 0xC030
+    TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 = 0xC02B
+    TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 = 0xC02F
+    TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 = 0xCCA9
+    TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 = 0xCCA8
+    TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 = 0x009F
+    TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 = 0x009E
+    TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 = 0xC024
+    TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 = 0xC028
+    TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA = 0xC00A
+    TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA = 0xC014
+    TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 = 0x006B
+    TLS_DHE_RSA_WITH_AES_256_CBC_SHA = 0x0039
+    TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 = 0xC023
+    TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 = 0xC027
+    TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA = 0xC009
+    TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA = 0xC013
+    TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 = 0x0067
+    TLS_DHE_RSA_WITH_AES_128_CBC_SHA = 0x0033
+    TLS_RSA_WITH_AES_256_GCM_SHA384 = 0x009D
+    TLS_RSA_WITH_AES_128_GCM_SHA256 = 0x009C
+    TLS_RSA_WITH_AES_256_CBC_SHA256 = 0x003D
+    TLS_RSA_WITH_AES_128_CBC_SHA256 = 0x003C
+    TLS_RSA_WITH_AES_256_CBC_SHA = 0x0035
+    TLS_RSA_WITH_AES_128_CBC_SHA = 0x002F
+    TLS_AES_128_GCM_SHA256 = 0x1301
+    TLS_AES_256_GCM_SHA384 = 0x1302
+    TLS_AES_128_CCM_8_SHA256 = 0x1305
+    TLS_AES_128_CCM_SHA256 = 0x1304

venv/Lib/site-packages/urllib3/contrib/_securetransport/low_level.py

@@ -0,0 +1,328 @@
+"""
+Low-level helpers for the SecureTransport bindings.
+
+These are Python functions that are not directly related to the high-level APIs
+but are necessary to get them to work. They include a whole bunch of low-level
+CoreFoundation messing about and memory management. The concerns in this module
+are almost entirely about trying to avoid memory leaks and providing
+appropriate and useful assistance to the higher-level code.
+"""
+import base64
+import ctypes
+import itertools
+import re
+import os
+import ssl
+import tempfile
+
+from .bindings import Security, CoreFoundation, CFConst
+
+
+# This regular expression is used to grab PEM data out of a PEM bundle.
+_PEM_CERTS_RE = re.compile(
+    b"-----BEGIN CERTIFICATE-----\n(.*?)\n-----END CERTIFICATE-----", re.DOTALL
+)
+
+
+def _cf_data_from_bytes(bytestring):
+    """
+    Given a bytestring, create a CFData object from it. This CFData object must
+    be CFReleased by the caller.
+    """
+    return CoreFoundation.CFDataCreate(
+        CoreFoundation.kCFAllocatorDefault, bytestring, len(bytestring)
+    )
+
+
+def _cf_dictionary_from_tuples(tuples):
+    """
+    Given a list of Python tuples, create an associated CFDictionary.
+    """
+    dictionary_size = len(tuples)
+
+    # We need to get the dictionary keys and values out in the same order.
+    keys = (t[0] for t in tuples)
+    values = (t[1] for t in tuples)
+    cf_keys = (CoreFoundation.CFTypeRef * dictionary_size)(*keys)
+    cf_values = (CoreFoundation.CFTypeRef * dictionary_size)(*values)
+
+    return CoreFoundation.CFDictionaryCreate(
+        CoreFoundation.kCFAllocatorDefault,
+        cf_keys,
+        cf_values,
+        dictionary_size,
+        CoreFoundation.kCFTypeDictionaryKeyCallBacks,
+        CoreFoundation.kCFTypeDictionaryValueCallBacks,
+    )
+
+
+def _cf_string_to_unicode(value):
+    """
+    Creates a Unicode string from a CFString object. Used entirely for error
+    reporting.
+
+    Yes, it annoys me quite a lot that this function is this complex.
+    """
+    value_as_void_p = ctypes.cast(value, ctypes.POINTER(ctypes.c_void_p))
+
+    string = CoreFoundation.CFStringGetCStringPtr(
+        value_as_void_p, CFConst.kCFStringEncodingUTF8
+    )
+    if string is None:
+        buffer = ctypes.create_string_buffer(1024)
+        result = CoreFoundation.CFStringGetCString(
+            value_as_void_p, buffer, 1024, CFConst.kCFStringEncodingUTF8
+        )
+        if not result:
+            raise OSError("Error copying C string from CFStringRef")
+        string = buffer.value
+    if string is not None:
+        string = string.decode("utf-8")
+    return string
+
+
+def _assert_no_error(error, exception_class=None):
+    """
+    Checks the return code and throws an exception if there is an error to
+    report
+    """
+    if error == 0:
+        return
+
+    cf_error_string = Security.SecCopyErrorMessageString(error, None)
+    output = _cf_string_to_unicode(cf_error_string)
+    CoreFoundation.CFRelease(cf_error_string)
+
+    if output is None or output == u"":
+        output = u"OSStatus %s" % error
+
+    if exception_class is None:
+        exception_class = ssl.SSLError
+
+    raise exception_class(output)
+
+
+def _cert_array_from_pem(pem_bundle):
+    """
+    Given a bundle of certs in PEM format, turns them into a CFArray of certs
+    that can be used to validate a cert chain.
+    """
+    # Normalize the PEM bundle's line endings.
+    pem_bundle = pem_bundle.replace(b"\r\n", b"\n")
+
+    der_certs = [
+        base64.b64decode(match.group(1)) for match in _PEM_CERTS_RE.finditer(pem_bundle)
+    ]
+    if not der_certs:
+        raise ssl.SSLError("No root certificates specified")
+
+    cert_array = CoreFoundation.CFArrayCreateMutable(
+        CoreFoundation.kCFAllocatorDefault,
+        0,
+        ctypes.byref(CoreFoundation.kCFTypeArrayCallBacks),
+    )
+    if not cert_array:
+        raise ssl.SSLError("Unable to allocate memory!")
+
+    try:
+        for der_bytes in der_certs:
+            certdata = _cf_data_from_bytes(der_bytes)
+            if not certdata:
+                raise ssl.SSLError("Unable to allocate memory!")
+            cert = Security.SecCertificateCreateWithData(
+                CoreFoundation.kCFAllocatorDefault, certdata
+            )
+            CoreFoundation.CFRelease(certdata)
+            if not cert:
+                raise ssl.SSLError("Unable to build cert object!")
+
+            CoreFoundation.CFArrayAppendValue(cert_array, cert)
+            CoreFoundation.CFRelease(cert)
+    except Exception:
+        # We need to free the array before the exception bubbles further.
+        # We only want to do that if an error occurs: otherwise, the caller
+        # should free.
+        CoreFoundation.CFRelease(cert_array)
+
+    return cert_array
+
+
+def _is_cert(item):
+    """
+    Returns True if a given CFTypeRef is a certificate.
+    """
+    expected = Security.SecCertificateGetTypeID()
+    return CoreFoundation.CFGetTypeID(item) == expected
+
+
+def _is_identity(item):
+    """
+    Returns True if a given CFTypeRef is an identity.
+    """
+    expected = Security.SecIdentityGetTypeID()
+    return CoreFoundation.CFGetTypeID(item) == expected
+
+
+def _temporary_keychain():
+    """
+    This function creates a temporary Mac keychain that we can use to work with
+    credentials. This keychain uses a one-time password and a temporary file to
+    store the data. We expect to have one keychain per socket. The returned
+    SecKeychainRef must be freed by the caller, including calling
+    SecKeychainDelete.
+
+    Returns a tuple of the SecKeychainRef and the path to the temporary
+    directory that contains it.
+    """
+    # Unfortunately, SecKeychainCreate requires a path to a keychain. This
+    # means we cannot use mkstemp to use a generic temporary file. Instead,
+    # we're going to create a temporary directory and a filename to use there.
+    # This filename will be 8 random bytes expanded into base64. We also need
+    # some random bytes to password-protect the keychain we're creating, so we
+    # ask for 40 random bytes.
+    random_bytes = os.urandom(40)
+    filename = base64.b16encode(random_bytes[:8]).decode("utf-8")
+    password = base64.b16encode(random_bytes[8:])  # Must be valid UTF-8
+    tempdirectory = tempfile.mkdtemp()
+
+    keychain_path = os.path.join(tempdirectory, filename).encode("utf-8")
+
+    # We now want to create the keychain itself.
+    keychain = Security.SecKeychainRef()
+    status = Security.SecKeychainCreate(
+        keychain_path, len(password), password, False, None, ctypes.byref(keychain)
+    )
+    _assert_no_error(status)
+
+    # Having created the keychain, we want to pass it off to the caller.
+    return keychain, tempdirectory
+
+
+def _load_items_from_file(keychain, path):
+    """
+    Given a single file, loads all the trust objects from it into arrays and
+    the keychain.
+    Returns a tuple of lists: the first list is a list of identities, the
+    second a list of certs.
+    """
+    certificates = []
+    identities = []
+    result_array = None
+
+    with open(path, "rb") as f:
+        raw_filedata = f.read()
+
+    try:
+        filedata = CoreFoundation.CFDataCreate(
+            CoreFoundation.kCFAllocatorDefault, raw_filedata, len(raw_filedata)
+        )
+        result_array = CoreFoundation.CFArrayRef()
+        result = Security.SecItemImport(
+            filedata,  # cert data
+            None,  # Filename, leaving it out for now
+            None,  # What the type of the file is, we don't care
+            None,  # what's in the file, we don't care
+            0,  # import flags
+            None,  # key params, can include passphrase in the future
+            keychain,  # The keychain to insert into
+            ctypes.byref(result_array),  # Results
+        )
+        _assert_no_error(result)
+
+        # A CFArray is not very useful to us as an intermediary
+        # representation, so we are going to extract the objects we want
+        # and then free the array. We don't need to keep hold of keys: the
+        # keychain already has them!
+        result_count = CoreFoundation.CFArrayGetCount(result_array)
+        for index in range(result_count):
+            item = CoreFoundation.CFArrayGetValueAtIndex(result_array, index)
+            item = ctypes.cast(item, CoreFoundation.CFTypeRef)
+
+            if _is_cert(item):
+                CoreFoundation.CFRetain(item)
+                certificates.append(item)
+            elif _is_identity(item):
+                CoreFoundation.CFRetain(item)
+                identities.append(item)
+    finally:
+        if result_array:
+            CoreFoundation.CFRelease(result_array)
+
+        CoreFoundation.CFRelease(filedata)
+
+    return (identities, certificates)
+
+
+def _load_client_cert_chain(keychain, *paths):
+    """
+    Load certificates and maybe keys from a number of files. Has the end goal
+    of returning a CFArray containing one SecIdentityRef, and then zero or more
+    SecCertificateRef objects, suitable for use as a client certificate trust
+    chain.
+    """
+    # Ok, the strategy.
+    #
+    # This relies on knowing that macOS will not give you a SecIdentityRef
+    # unless you have imported a key into a keychain. This is a somewhat
+    # artificial limitation of macOS (for example, it doesn't necessarily
+    # affect iOS), but there is nothing inside Security.framework that lets you
+    # get a SecIdentityRef without having a key in a keychain.
+    #
+    # So the policy here is we take all the files and iterate them in order.
+    # Each one will use SecItemImport to have one or more objects loaded from
+    # it. We will also point at a keychain that macOS can use to work with the
+    # private key.
+    #
+    # Once we have all the objects, we'll check what we actually have. If we
+    # already have a SecIdentityRef in hand, fab: we'll use that. Otherwise,
+    # we'll take the first certificate (which we assume to be our leaf) and
+    # ask the keychain to give us a SecIdentityRef with that cert's associated
+    # key.
+    #
+    # We'll then return a CFArray containing the trust chain: one
+    # SecIdentityRef and then zero-or-more SecCertificateRef objects. The
+    # responsibility for freeing this CFArray will be with the caller. This
+    # CFArray must remain alive for the entire connection, so in practice it
+    # will be stored with a single SSLSocket, along with the reference to the
+    # keychain.
+    certificates = []
+    identities = []
+
+    # Filter out bad paths.
+    paths = (path for path in paths if path)
+
+    try:
+        for file_path in paths:
+            new_identities, new_certs = _load_items_from_file(keychain, file_path)
+            identities.extend(new_identities)
+            certificates.extend(new_certs)
+
+        # Ok, we have everything. The question is: do we have an identity? If
+        # not, we want to grab one from the first cert we have.
+        if not identities:
+            new_identity = Security.SecIdentityRef()
+            status = Security.SecIdentityCreateWithCertificate(
+                keychain, certificates[0], ctypes.byref(new_identity)
+            )
+            _assert_no_error(status)
+            identities.append(new_identity)
+
+            # We now want to release the original certificate, as we no longer
+            # need it.
+            CoreFoundation.CFRelease(certificates.pop(0))
+
+        # We now need to build a new CFArray that holds the trust chain.
+        trust_chain = CoreFoundation.CFArrayCreateMutable(
+            CoreFoundation.kCFAllocatorDefault,
+            0,
+            ctypes.byref(CoreFoundation.kCFTypeArrayCallBacks),
+        )
+        for item in itertools.chain(identities, certificates):
+            # ArrayAppendValue does a CFRetain on the item. That's fine,
+            # because the finally block will release our other refs to them.
+            CoreFoundation.CFArrayAppendValue(trust_chain, item)
+
+        return trust_chain
+    finally:
+        for obj in itertools.chain(identities, certificates):
+            CoreFoundation.CFRelease(obj)

venv/Lib/site-packages/urllib3/contrib/appengine.py

@@ -0,0 +1,314 @@
+"""
+This module provides a pool manager that uses Google App Engine's
+`URLFetch Service <https://cloud.google.com/appengine/docs/python/urlfetch>`_.
+
+Example usage::
+
+    from urllib3 import PoolManager
+    from urllib3.contrib.appengine import AppEngineManager, is_appengine_sandbox
+
+    if is_appengine_sandbox():
+        # AppEngineManager uses AppEngine's URLFetch API behind the scenes
+        http = AppEngineManager()
+    else:
+        # PoolManager uses a socket-level API behind the scenes
+        http = PoolManager()
+
+    r = http.request('GET', 'https://google.com/')
+
+There are `limitations <https://cloud.google.com/appengine/docs/python/\
+urlfetch/#Python_Quotas_and_limits>`_ to the URLFetch service and it may not be
+the best choice for your application. There are three options for using
+urllib3 on Google App Engine:
+
+1. You can use :class:`AppEngineManager` with URLFetch. URLFetch is
+   cost-effective in many circumstances as long as your usage is within the
+   limitations.
+2. You can use a normal :class:`~urllib3.PoolManager` by enabling sockets.
+   Sockets also have `limitations and restrictions
+   <https://cloud.google.com/appengine/docs/python/sockets/\
+   #limitations-and-restrictions>`_ and have a lower free quota than URLFetch.
+   To use sockets, be sure to specify the following in your ``app.yaml``::
+
+        env_variables:
+            GAE_USE_SOCKETS_HTTPLIB : 'true'
+
+3. If you are using `App Engine Flexible
+<https://cloud.google.com/appengine/docs/flexible/>`_, you can use the standard
+:class:`PoolManager` without any configuration or special environment variables.
+"""
+
+from __future__ import absolute_import
+import io
+import logging
+import warnings
+from ..packages.six.moves.urllib.parse import urljoin
+
+from ..exceptions import (
+    HTTPError,
+    HTTPWarning,
+    MaxRetryError,
+    ProtocolError,
+    TimeoutError,
+    SSLError,
+)
+
+from ..request import RequestMethods
+from ..response import HTTPResponse
+from ..util.timeout import Timeout
+from ..util.retry import Retry
+from . import _appengine_environ
+
+try:
+    from google.appengine.api import urlfetch
+except ImportError:
+    urlfetch = None
+
+
+log = logging.getLogger(__name__)
+
+
+class AppEnginePlatformWarning(HTTPWarning):
+    pass
+
+
+class AppEnginePlatformError(HTTPError):
+    pass
+
+
+class AppEngineManager(RequestMethods):
+    """
+    Connection manager for Google App Engine sandbox applications.
+
+    This manager uses the URLFetch service directly instead of using the
+    emulated httplib, and is subject to URLFetch limitations as described in
+    the App Engine documentation `here
+    <https://cloud.google.com/appengine/docs/python/urlfetch>`_.
+
+    Notably it will raise an :class:`AppEnginePlatformError` if:
+        * URLFetch is not available.
+        * If you attempt to use this on App Engine Flexible, as full socket
+          support is available.
+        * If a request size is more than 10 megabytes.
+        * If a response size is more than 32 megabtyes.
+        * If you use an unsupported request method such as OPTIONS.
+
+    Beyond those cases, it will raise normal urllib3 errors.
+    """
+
+    def __init__(
+        self,
+        headers=None,
+        retries=None,
+        validate_certificate=True,
+        urlfetch_retries=True,
+    ):
+        if not urlfetch:
+            raise AppEnginePlatformError(
+                "URLFetch is not available in this environment."
+            )
+
+        warnings.warn(
+            "urllib3 is using URLFetch on Google App Engine sandbox instead "
+            "of sockets. To use sockets directly instead of URLFetch see "
+            "https://urllib3.readthedocs.io/en/latest/reference/urllib3.contrib.html.",
+            AppEnginePlatformWarning,
+        )
+
+        RequestMethods.__init__(self, headers)
+        self.validate_certificate = validate_certificate
+        self.urlfetch_retries = urlfetch_retries
+
+        self.retries = retries or Retry.DEFAULT
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        # Return False to re-raise any potential exceptions
+        return False
+
+    def urlopen(
+        self,
+        method,
+        url,
+        body=None,
+        headers=None,
+        retries=None,
+        redirect=True,
+        timeout=Timeout.DEFAULT_TIMEOUT,
+        **response_kw
+    ):
+
+        retries = self._get_retries(retries, redirect)
+
+        try:
+            follow_redirects = redirect and retries.redirect != 0 and retries.total
+            response = urlfetch.fetch(
+                url,
+                payload=body,
+                method=method,
+                headers=headers or {},
+                allow_truncated=False,
+                follow_redirects=self.urlfetch_retries and follow_redirects,
+                deadline=self._get_absolute_timeout(timeout),
+                validate_certificate=self.validate_certificate,
+            )
+        except urlfetch.DeadlineExceededError as e:
+            raise TimeoutError(self, e)
+
+        except urlfetch.InvalidURLError as e:
+            if "too large" in str(e):
+                raise AppEnginePlatformError(
+                    "URLFetch request too large, URLFetch only "
+                    "supports requests up to 10mb in size.",
+                    e,
+                )
+            raise ProtocolError(e)
+
+        except urlfetch.DownloadError as e:
+            if "Too many redirects" in str(e):
+                raise MaxRetryError(self, url, reason=e)
+            raise ProtocolError(e)
+
+        except urlfetch.ResponseTooLargeError as e:
+            raise AppEnginePlatformError(
+                "URLFetch response too large, URLFetch only supports"
+                "responses up to 32mb in size.",
+                e,
+            )
+
+        except urlfetch.SSLCertificateError as e:
+            raise SSLError(e)
+
+        except urlfetch.InvalidMethodError as e:
+            raise AppEnginePlatformError(
+                "URLFetch does not support method: %s" % method, e
+            )
+
+        http_response = self._urlfetch_response_to_http_response(
+            response, retries=retries, **response_kw
+        )
+
+        # Handle redirect?
+        redirect_location = redirect and http_response.get_redirect_location()
+        if redirect_location:
+            # Check for redirect response
+            if self.urlfetch_retries and retries.raise_on_redirect:
+                raise MaxRetryError(self, url, "too many redirects")
+            else:
+                if http_response.status == 303:
+                    method = "GET"
+
+                try:
+                    retries = retries.increment(
+                        method, url, response=http_response, _pool=self
+                    )
+                except MaxRetryError:
+                    if retries.raise_on_redirect:
+                        raise MaxRetryError(self, url, "too many redirects")
+                    return http_response
+
+                retries.sleep_for_retry(http_response)
+                log.debug("Redirecting %s -> %s", url, redirect_location)
+                redirect_url = urljoin(url, redirect_location)
+                return self.urlopen(
+                    method,
+                    redirect_url,
+                    body,
+                    headers,
+                    retries=retries,
+                    redirect=redirect,
+                    timeout=timeout,
+                    **response_kw
+                )
+
+        # Check if we should retry the HTTP response.
+        has_retry_after = bool(http_response.getheader("Retry-After"))
+        if retries.is_retry(method, http_response.status, has_retry_after):
+            retries = retries.increment(method, url, response=http_response, _pool=self)
+            log.debug("Retry: %s", url)
+            retries.sleep(http_response)
+            return self.urlopen(
+                method,
+                url,
+                body=body,
+                headers=headers,
+                retries=retries,
+                redirect=redirect,
+                timeout=timeout,
+                **response_kw
+            )
+
+        return http_response
+
+    def _urlfetch_response_to_http_response(self, urlfetch_resp, **response_kw):
+
+        if is_prod_appengine():
+            # Production GAE handles deflate encoding automatically, but does
+            # not remove the encoding header.
+            content_encoding = urlfetch_resp.headers.get("content-encoding")
+
+            if content_encoding == "deflate":
+                del urlfetch_resp.headers["content-encoding"]
+
+        transfer_encoding = urlfetch_resp.headers.get("transfer-encoding")
+        # We have a full response's content,
+        # so let's make sure we don't report ourselves as chunked data.
+        if transfer_encoding == "chunked":
+            encodings = transfer_encoding.split(",")
+            encodings.remove("chunked")
+            urlfetch_resp.headers["transfer-encoding"] = ",".join(encodings)
+
+        original_response = HTTPResponse(
+            # In order for decoding to work, we must present the content as
+            # a file-like object.
+            body=io.BytesIO(urlfetch_resp.content),
+            msg=urlfetch_resp.header_msg,
+            headers=urlfetch_resp.headers,
+            status=urlfetch_resp.status_code,
+            **response_kw
+        )
+
+        return HTTPResponse(
+            body=io.BytesIO(urlfetch_resp.content),
+            headers=urlfetch_resp.headers,
+            status=urlfetch_resp.status_code,
+            original_response=original_response,
+            **response_kw
+        )
+
+    def _get_absolute_timeout(self, timeout):
+        if timeout is Timeout.DEFAULT_TIMEOUT:
+            return None  # Defer to URLFetch's default.
+        if isinstance(timeout, Timeout):
+            if timeout._read is not None or timeout._connect is not None:
+                warnings.warn(
+                    "URLFetch does not support granular timeout settings, "
+                    "reverting to total or default URLFetch timeout.",
+                    AppEnginePlatformWarning,
+                )
+            return timeout.total
+        return timeout
+
+    def _get_retries(self, retries, redirect):
+        if not isinstance(retries, Retry):
+            retries = Retry.from_int(retries, redirect=redirect, default=self.retries)
+
+        if retries.connect or retries.read or retries.redirect:
+            warnings.warn(
+                "URLFetch only supports total retries and does not "
+                "recognize connect, read, or redirect retry parameters.",
+                AppEnginePlatformWarning,
+            )
+
+        return retries
+
+
+# Alias methods from _appengine_environ to maintain public API interface.
+
+is_appengine = _appengine_environ.is_appengine
+is_appengine_sandbox = _appengine_environ.is_appengine_sandbox
+is_local_appengine = _appengine_environ.is_local_appengine
+is_prod_appengine = _appengine_environ.is_prod_appengine
+is_prod_appengine_mvms = _appengine_environ.is_prod_appengine_mvms

venv/Lib/site-packages/urllib3/contrib/ntlmpool.py

@@ -0,0 +1,121 @@
+"""
+NTLM authenticating pool, contributed by erikcederstran
+
+Issue #10, see: http://code.google.com/p/urllib3/issues/detail?id=10
+"""
+from __future__ import absolute_import
+
+from logging import getLogger
+from ntlm import ntlm
+
+from .. import HTTPSConnectionPool
+from ..packages.six.moves.http_client import HTTPSConnection
+
+
+log = getLogger(__name__)
+
+
+class NTLMConnectionPool(HTTPSConnectionPool):
+    """
+    Implements an NTLM authentication version of an urllib3 connection pool
+    """
+
+    scheme = "https"
+
+    def __init__(self, user, pw, authurl, *args, **kwargs):
+        """
+        authurl is a random URL on the server that is protected by NTLM.
+        user is the Windows user, probably in the DOMAIN\\username format.
+        pw is the password for the user.
+        """
+        super(NTLMConnectionPool, self).__init__(*args, **kwargs)
+        self.authurl = authurl
+        self.rawuser = user
+        user_parts = user.split("\\", 1)
+        self.domain = user_parts[0].upper()
+        self.user = user_parts[1]
+        self.pw = pw
+
+    def _new_conn(self):
+        # Performs the NTLM handshake that secures the connection. The socket
+        # must be kept open while requests are performed.
+        self.num_connections += 1
+        log.debug(
+            "Starting NTLM HTTPS connection no. %d: https://%s%s",
+            self.num_connections,
+            self.host,
+            self.authurl,
+        )
+
+        headers = {"Connection": "Keep-Alive"}
+        req_header = "Authorization"
+        resp_header = "www-authenticate"
+
+        conn = HTTPSConnection(host=self.host, port=self.port)
+
+        # Send negotiation message
+        headers[req_header] = "NTLM %s" % ntlm.create_NTLM_NEGOTIATE_MESSAGE(
+            self.rawuser
+        )
+        log.debug("Request headers: %s", headers)
+        conn.request("GET", self.authurl, None, headers)
+        res = conn.getresponse()
+        reshdr = dict(res.getheaders())
+        log.debug("Response status: %s %s", res.status, res.reason)
+        log.debug("Response headers: %s", reshdr)
+        log.debug("Response data: %s [...]", res.read(100))
+
+        # Remove the reference to the socket, so that it can not be closed by
+        # the response object (we want to keep the socket open)
+        res.fp = None
+
+        # Server should respond with a challenge message
+        auth_header_values = reshdr[resp_header].split(", ")
+        auth_header_value = None
+        for s in auth_header_values:
+            if s[:5] == "NTLM ":
+                auth_header_value = s[5:]
+        if auth_header_value is None:
+            raise Exception(
+                "Unexpected %s response header: %s" % (resp_header, reshdr[resp_header])
+            )
+
+        # Send authentication message
+        ServerChallenge, NegotiateFlags = ntlm.parse_NTLM_CHALLENGE_MESSAGE(
+            auth_header_value
+        )
+        auth_msg = ntlm.create_NTLM_AUTHENTICATE_MESSAGE(
+            ServerChallenge, self.user, self.domain, self.pw, NegotiateFlags
+        )
+        headers[req_header] = "NTLM %s" % auth_msg
+        log.debug("Request headers: %s", headers)
+        conn.request("GET", self.authurl, None, headers)
+        res = conn.getresponse()
+        log.debug("Response status: %s %s", res.status, res.reason)
+        log.debug("Response headers: %s", dict(res.getheaders()))
+        log.debug("Response data: %s [...]", res.read()[:100])
+        if res.status != 200:
+            if res.status == 401:
+                raise Exception("Server rejected request: wrong username or password")
+            raise Exception("Wrong server response: %s %s" % (res.status, res.reason))
+
+        res.fp = None
+        log.debug("Connection established")
+        return conn
+
+    def urlopen(
+        self,
+        method,
+        url,
+        body=None,
+        headers=None,
+        retries=3,
+        redirect=True,
+        assert_same_host=True,
+    ):
+        if headers is None:
+            headers = {}
+        headers["Connection"] = "Keep-Alive"
+        return super(NTLMConnectionPool, self).urlopen(
+            method, url, body, headers, retries, redirect, assert_same_host
+        )

venv/Lib/site-packages/urllib3/contrib/pyopenssl.py

@@ -0,0 +1,501 @@
+"""
+SSL with SNI_-support for Python 2. Follow these instructions if you would
+like to verify SSL certificates in Python 2. Note, the default libraries do
+*not* do certificate checking; you need to do additional work to validate
+certificates yourself.
+
+This needs the following packages installed:
+
+* pyOpenSSL (tested with 16.0.0)
+* cryptography (minimum 1.3.4, from pyopenssl)
+* idna (minimum 2.0, from cryptography)
+
+However, pyopenssl depends on cryptography, which depends on idna, so while we
+use all three directly here we end up having relatively few packages required.
+
+You can install them with the following command:
+
+    pip install pyopenssl cryptography idna
+
+To activate certificate checking, call
+:func:`~urllib3.contrib.pyopenssl.inject_into_urllib3` from your Python code
+before you begin making HTTP requests. This can be done in a ``sitecustomize``
+module, or at any other time before your application begins using ``urllib3``,
+like this::
+
+    try:
+        import urllib3.contrib.pyopenssl
+        urllib3.contrib.pyopenssl.inject_into_urllib3()
+    except ImportError:
+        pass
+
+Now you can use :mod:`urllib3` as you normally would, and it will support SNI
+when the required modules are installed.
+
+Activating this module also has the positive side effect of disabling SSL/TLS
+compression in Python 2 (see `CRIME attack`_).
+
+If you want to configure the default list of supported cipher suites, you can
+set the ``urllib3.contrib.pyopenssl.DEFAULT_SSL_CIPHER_LIST`` variable.
+
+.. _sni: https://en.wikipedia.org/wiki/Server_Name_Indication
+.. _crime attack: https://en.wikipedia.org/wiki/CRIME_(security_exploit)
+"""
+from __future__ import absolute_import
+
+import OpenSSL.SSL
+from cryptography import x509
+from cryptography.hazmat.backends.openssl import backend as openssl_backend
+from cryptography.hazmat.backends.openssl.x509 import _Certificate
+
+try:
+    from cryptography.x509 import UnsupportedExtension
+except ImportError:
+    # UnsupportedExtension is gone in cryptography >= 2.1.0
+    class UnsupportedExtension(Exception):
+        pass
+
+
+from socket import timeout, error as SocketError
+from io import BytesIO
+
+try:  # Platform-specific: Python 2
+    from socket import _fileobject
+except ImportError:  # Platform-specific: Python 3
+    _fileobject = None
+    from ..packages.backports.makefile import backport_makefile
+
+import logging
+import ssl
+from ..packages import six
+import sys
+
+from .. import util
+
+
+__all__ = ["inject_into_urllib3", "extract_from_urllib3"]
+
+# SNI always works.
+HAS_SNI = True
+
+# Map from urllib3 to PyOpenSSL compatible parameter-values.
+_openssl_versions = {
+    util.PROTOCOL_TLS: OpenSSL.SSL.SSLv23_METHOD,
+    ssl.PROTOCOL_TLSv1: OpenSSL.SSL.TLSv1_METHOD,
+}
+
+if hasattr(ssl, "PROTOCOL_SSLv3") and hasattr(OpenSSL.SSL, "SSLv3_METHOD"):
+    _openssl_versions[ssl.PROTOCOL_SSLv3] = OpenSSL.SSL.SSLv3_METHOD
+
+if hasattr(ssl, "PROTOCOL_TLSv1_1") and hasattr(OpenSSL.SSL, "TLSv1_1_METHOD"):
+    _openssl_versions[ssl.PROTOCOL_TLSv1_1] = OpenSSL.SSL.TLSv1_1_METHOD
+
+if hasattr(ssl, "PROTOCOL_TLSv1_2") and hasattr(OpenSSL.SSL, "TLSv1_2_METHOD"):
+    _openssl_versions[ssl.PROTOCOL_TLSv1_2] = OpenSSL.SSL.TLSv1_2_METHOD
+
+
+_stdlib_to_openssl_verify = {
+    ssl.CERT_NONE: OpenSSL.SSL.VERIFY_NONE,
+    ssl.CERT_OPTIONAL: OpenSSL.SSL.VERIFY_PEER,
+    ssl.CERT_REQUIRED: OpenSSL.SSL.VERIFY_PEER
+    + OpenSSL.SSL.VERIFY_FAIL_IF_NO_PEER_CERT,
+}
+_openssl_to_stdlib_verify = dict((v, k) for k, v in _stdlib_to_openssl_verify.items())
+
+# OpenSSL will only write 16K at a time
+SSL_WRITE_BLOCKSIZE = 16384
+
+orig_util_HAS_SNI = util.HAS_SNI
+orig_util_SSLContext = util.ssl_.SSLContext
+
+
+log = logging.getLogger(__name__)
+
+
+def inject_into_urllib3():
+    "Monkey-patch urllib3 with PyOpenSSL-backed SSL-support."
+
+    _validate_dependencies_met()
+
+    util.SSLContext = PyOpenSSLContext
+    util.ssl_.SSLContext = PyOpenSSLContext
+    util.HAS_SNI = HAS_SNI
+    util.ssl_.HAS_SNI = HAS_SNI
+    util.IS_PYOPENSSL = True
+    util.ssl_.IS_PYOPENSSL = True
+
+
+def extract_from_urllib3():
+    "Undo monkey-patching by :func:`inject_into_urllib3`."
+
+    util.SSLContext = orig_util_SSLContext
+    util.ssl_.SSLContext = orig_util_SSLContext
+    util.HAS_SNI = orig_util_HAS_SNI
+    util.ssl_.HAS_SNI = orig_util_HAS_SNI
+    util.IS_PYOPENSSL = False
+    util.ssl_.IS_PYOPENSSL = False
+
+
+def _validate_dependencies_met():
+    """
+    Verifies that PyOpenSSL's package-level dependencies have been met.
+    Throws `ImportError` if they are not met.
+    """
+    # Method added in `cryptography==1.1`; not available in older versions
+    from cryptography.x509.extensions import Extensions
+
+    if getattr(Extensions, "get_extension_for_class", None) is None:
+        raise ImportError(
+            "'cryptography' module missing required functionality.  "
+            "Try upgrading to v1.3.4 or newer."
+        )
+
+    # pyOpenSSL 0.14 and above use cryptography for OpenSSL bindings. The _x509
+    # attribute is only present on those versions.
+    from OpenSSL.crypto import X509
+
+    x509 = X509()
+    if getattr(x509, "_x509", None) is None:
+        raise ImportError(
+            "'pyOpenSSL' module missing required functionality. "
+            "Try upgrading to v0.14 or newer."
+        )
+
+
+def _dnsname_to_stdlib(name):
+    """
+    Converts a dNSName SubjectAlternativeName field to the form used by the
+    standard library on the given Python version.
+
+    Cryptography produces a dNSName as a unicode string that was idna-decoded
+    from ASCII bytes. We need to idna-encode that string to get it back, and
+    then on Python 3 we also need to convert to unicode via UTF-8 (the stdlib
+    uses PyUnicode_FromStringAndSize on it, which decodes via UTF-8).
+
+    If the name cannot be idna-encoded then we return None signalling that
+    the name given should be skipped.
+    """
+
+    def idna_encode(name):
+        """
+        Borrowed wholesale from the Python Cryptography Project. It turns out
+        that we can't just safely call `idna.encode`: it can explode for
+        wildcard names. This avoids that problem.
+        """
+        import idna
+
+        try:
+            for prefix in [u"*.", u"."]:
+                if name.startswith(prefix):
+                    name = name[len(prefix) :]
+                    return prefix.encode("ascii") + idna.encode(name)
+            return idna.encode(name)
+        except idna.core.IDNAError:
+            return None
+
+    # Don't send IPv6 addresses through the IDNA encoder.
+    if ":" in name:
+        return name
+
+    name = idna_encode(name)
+    if name is None:
+        return None
+    elif sys.version_info >= (3, 0):
+        name = name.decode("utf-8")
+    return name
+
+
+def get_subj_alt_name(peer_cert):
+    """
+    Given an PyOpenSSL certificate, provides all the subject alternative names.
+    """
+    # Pass the cert to cryptography, which has much better APIs for this.
+    if hasattr(peer_cert, "to_cryptography"):
+        cert = peer_cert.to_cryptography()
+    else:
+        # This is technically using private APIs, but should work across all
+        # relevant versions before PyOpenSSL got a proper API for this.
+        cert = _Certificate(openssl_backend, peer_cert._x509)
+
+    # We want to find the SAN extension. Ask Cryptography to locate it (it's
+    # faster than looping in Python)
+    try:
+        ext = cert.extensions.get_extension_for_class(x509.SubjectAlternativeName).value
+    except x509.ExtensionNotFound:
+        # No such extension, return the empty list.
+        return []
+    except (
+        x509.DuplicateExtension,
+        UnsupportedExtension,
+        x509.UnsupportedGeneralNameType,
+        UnicodeError,
+    ) as e:
+        # A problem has been found with the quality of the certificate. Assume
+        # no SAN field is present.
+        log.warning(
+            "A problem was encountered with the certificate that prevented "
+            "urllib3 from finding the SubjectAlternativeName field. This can "
+            "affect certificate validation. The error was %s",
+            e,
+        )
+        return []
+
+    # We want to return dNSName and iPAddress fields. We need to cast the IPs
+    # back to strings because the match_hostname function wants them as
+    # strings.
+    # Sadly the DNS names need to be idna encoded and then, on Python 3, UTF-8
+    # decoded. This is pretty frustrating, but that's what the standard library
+    # does with certificates, and so we need to attempt to do the same.
+    # We also want to skip over names which cannot be idna encoded.
+    names = [
+        ("DNS", name)
+        for name in map(_dnsname_to_stdlib, ext.get_values_for_type(x509.DNSName))
+        if name is not None
+    ]
+    names.extend(
+        ("IP Address", str(name)) for name in ext.get_values_for_type(x509.IPAddress)
+    )
+
+    return names
+
+
+class WrappedSocket(object):
+    """API-compatibility wrapper for Python OpenSSL's Connection-class.
+
+    Note: _makefile_refs, _drop() and _reuse() are needed for the garbage
+    collector of pypy.
+    """
+
+    def __init__(self, connection, socket, suppress_ragged_eofs=True):
+        self.connection = connection
+        self.socket = socket
+        self.suppress_ragged_eofs = suppress_ragged_eofs
+        self._makefile_refs = 0
+        self._closed = False
+
+    def fileno(self):
+        return self.socket.fileno()
+
+    # Copy-pasted from Python 3.5 source code
+    def _decref_socketios(self):
+        if self._makefile_refs > 0:
+            self._makefile_refs -= 1
+        if self._closed:
+            self.close()
+
+    def recv(self, *args, **kwargs):
+        try:
+            data = self.connection.recv(*args, **kwargs)
+        except OpenSSL.SSL.SysCallError as e:
+            if self.suppress_ragged_eofs and e.args == (-1, "Unexpected EOF"):
+                return b""
+            else:
+                raise SocketError(str(e))
+        except OpenSSL.SSL.ZeroReturnError:
+            if self.connection.get_shutdown() == OpenSSL.SSL.RECEIVED_SHUTDOWN:
+                return b""
+            else:
+                raise
+        except OpenSSL.SSL.WantReadError:
+            if not util.wait_for_read(self.socket, self.socket.gettimeout()):
+                raise timeout("The read operation timed out")
+            else:
+                return self.recv(*args, **kwargs)
+
+        # TLS 1.3 post-handshake authentication
+        except OpenSSL.SSL.Error as e:
+            raise ssl.SSLError("read error: %r" % e)
+        else:
+            return data
+
+    def recv_into(self, *args, **kwargs):
+        try:
+            return self.connection.recv_into(*args, **kwargs)
+        except OpenSSL.SSL.SysCallError as e:
+            if self.suppress_ragged_eofs and e.args == (-1, "Unexpected EOF"):
+                return 0
+            else:
+                raise SocketError(str(e))
+        except OpenSSL.SSL.ZeroReturnError:
+            if self.connection.get_shutdown() == OpenSSL.SSL.RECEIVED_SHUTDOWN:
+                return 0
+            else:
+                raise
+        except OpenSSL.SSL.WantReadError:
+            if not util.wait_for_read(self.socket, self.socket.gettimeout()):
+                raise timeout("The read operation timed out")
+            else:
+                return self.recv_into(*args, **kwargs)
+
+        # TLS 1.3 post-handshake authentication
+        except OpenSSL.SSL.Error as e:
+            raise ssl.SSLError("read error: %r" % e)
+
+    def settimeout(self, timeout):
+        return self.socket.settimeout(timeout)
+
+    def _send_until_done(self, data):
+        while True:
+            try:
+                return self.connection.send(data)
+            except OpenSSL.SSL.WantWriteError:
+                if not util.wait_for_write(self.socket, self.socket.gettimeout()):
+                    raise timeout()
+                continue
+            except OpenSSL.SSL.SysCallError as e:
+                raise SocketError(str(e))
+
+    def sendall(self, data):
+        total_sent = 0
+        while total_sent < len(data):
+            sent = self._send_until_done(
+                data[total_sent : total_sent + SSL_WRITE_BLOCKSIZE]
+            )
+            total_sent += sent
+
+    def shutdown(self):
+        # FIXME rethrow compatible exceptions should we ever use this
+        self.connection.shutdown()
+
+    def close(self):
+        if self._makefile_refs < 1:
+            try:
+                self._closed = True
+                return self.connection.close()
+            except OpenSSL.SSL.Error:
+                return
+        else:
+            self._makefile_refs -= 1
+
+    def getpeercert(self, binary_form=False):
+        x509 = self.connection.get_peer_certificate()
+
+        if not x509:
+            return x509
+
+        if binary_form:
+            return OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_ASN1, x509)
+
+        return {
+            "subject": ((("commonName", x509.get_subject().CN),),),
+            "subjectAltName": get_subj_alt_name(x509),
+        }
+
+    def version(self):
+        return self.connection.get_protocol_version_name()
+
+    def _reuse(self):
+        self._makefile_refs += 1
+
+    def _drop(self):
+        if self._makefile_refs < 1:
+            self.close()
+        else:
+            self._makefile_refs -= 1
+
+
+if _fileobject:  # Platform-specific: Python 2
+
+    def makefile(self, mode, bufsize=-1):
+        self._makefile_refs += 1
+        return _fileobject(self, mode, bufsize, close=True)
+
+
+else:  # Platform-specific: Python 3
+    makefile = backport_makefile
+
+WrappedSocket.makefile = makefile
+
+
+class PyOpenSSLContext(object):
+    """
+    I am a wrapper class for the PyOpenSSL ``Context`` object. I am responsible
+    for translating the interface of the standard library ``SSLContext`` object
+    to calls into PyOpenSSL.
+    """
+
+    def __init__(self, protocol):
+        self.protocol = _openssl_versions[protocol]
+        self._ctx = OpenSSL.SSL.Context(self.protocol)
+        self._options = 0
+        self.check_hostname = False
+
+    @property
+    def options(self):
+        return self._options
+
+    @options.setter
+    def options(self, value):
+        self._options = value
+        self._ctx.set_options(value)
+
+    @property
+    def verify_mode(self):
+        return _openssl_to_stdlib_verify[self._ctx.get_verify_mode()]
+
+    @verify_mode.setter
+    def verify_mode(self, value):
+        self._ctx.set_verify(_stdlib_to_openssl_verify[value], _verify_callback)
+
+    def set_default_verify_paths(self):
+        self._ctx.set_default_verify_paths()
+
+    def set_ciphers(self, ciphers):
+        if isinstance(ciphers, six.text_type):
+            ciphers = ciphers.encode("utf-8")
+        self._ctx.set_cipher_list(ciphers)
+
+    def load_verify_locations(self, cafile=None, capath=None, cadata=None):
+        if cafile is not None:
+            cafile = cafile.encode("utf-8")
+        if capath is not None:
+            capath = capath.encode("utf-8")
+        try:
+            self._ctx.load_verify_locations(cafile, capath)
+            if cadata is not None:
+                self._ctx.load_verify_locations(BytesIO(cadata))
+        except OpenSSL.SSL.Error as e:
+            raise ssl.SSLError("unable to load trusted certificates: %r" % e)
+
+    def load_cert_chain(self, certfile, keyfile=None, password=None):
+        self._ctx.use_certificate_chain_file(certfile)
+        if password is not None:
+            if not isinstance(password, six.binary_type):
+                password = password.encode("utf-8")
+            self._ctx.set_passwd_cb(lambda *_: password)
+        self._ctx.use_privatekey_file(keyfile or certfile)
+
+    def wrap_socket(
+        self,
+        sock,
+        server_side=False,
+        do_handshake_on_connect=True,
+        suppress_ragged_eofs=True,
+        server_hostname=None,
+    ):
+        cnx = OpenSSL.SSL.Connection(self._ctx, sock)
+
+        if isinstance(server_hostname, six.text_type):  # Platform-specific: Python 3
+            server_hostname = server_hostname.encode("utf-8")
+
+        if server_hostname is not None:
+            cnx.set_tlsext_host_name(server_hostname)
+
+        cnx.set_connect_state()
+
+        while True:
+            try:
+                cnx.do_handshake()
+            except OpenSSL.SSL.WantReadError:
+                if not util.wait_for_read(sock, sock.gettimeout()):
+                    raise timeout("select timed out")
+                continue
+            except OpenSSL.SSL.Error as e:
+                raise ssl.SSLError("bad handshake: %r" % e)
+            break
+
+        return WrappedSocket(cnx, sock)
+
+
+def _verify_callback(cnx, x509, err_no, err_depth, return_code):
+    return err_no == 0

venv/Lib/site-packages/urllib3/contrib/securetransport.py

@@ -0,0 +1,864 @@
+"""
+SecureTranport support for urllib3 via ctypes.
+
+This makes platform-native TLS available to urllib3 users on macOS without the
+use of a compiler. This is an important feature because the Python Package
+Index is moving to become a TLSv1.2-or-higher server, and the default OpenSSL
+that ships with macOS is not capable of doing TLSv1.2. The only way to resolve
+this is to give macOS users an alternative solution to the problem, and that
+solution is to use SecureTransport.
+
+We use ctypes here because this solution must not require a compiler. That's
+because pip is not allowed to require a compiler either.
+
+This is not intended to be a seriously long-term solution to this problem.
+The hope is that PEP 543 will eventually solve this issue for us, at which
+point we can retire this contrib module. But in the short term, we need to
+solve the impending tire fire that is Python on Mac without this kind of
+contrib module. So...here we are.
+
+To use this module, simply import and inject it::
+
+    import urllib3.contrib.securetransport
+    urllib3.contrib.securetransport.inject_into_urllib3()
+
+Happy TLSing!
+
+This code is a bastardised version of the code found in Will Bond's oscrypto
+library. An enormous debt is owed to him for blazing this trail for us. For
+that reason, this code should be considered to be covered both by urllib3's
+license and by oscrypto's:
+
+    Copyright (c) 2015-2016 Will Bond <will@wbond.net>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+"""
+from __future__ import absolute_import
+
+import contextlib
+import ctypes
+import errno
+import os.path
+import shutil
+import socket
+import ssl
+import threading
+import weakref
+
+from .. import util
+from ._securetransport.bindings import Security, SecurityConst, CoreFoundation
+from ._securetransport.low_level import (
+    _assert_no_error,
+    _cert_array_from_pem,
+    _temporary_keychain,
+    _load_client_cert_chain,
+)
+
+try:  # Platform-specific: Python 2
+    from socket import _fileobject
+except ImportError:  # Platform-specific: Python 3
+    _fileobject = None
+    from ..packages.backports.makefile import backport_makefile
+
+__all__ = ["inject_into_urllib3", "extract_from_urllib3"]
+
+# SNI always works
+HAS_SNI = True
+
+orig_util_HAS_SNI = util.HAS_SNI
+orig_util_SSLContext = util.ssl_.SSLContext
+
+# This dictionary is used by the read callback to obtain a handle to the
+# calling wrapped socket. This is a pretty silly approach, but for now it'll
+# do. I feel like I should be able to smuggle a handle to the wrapped socket
+# directly in the SSLConnectionRef, but for now this approach will work I
+# guess.
+#
+# We need to lock around this structure for inserts, but we don't do it for
+# reads/writes in the callbacks. The reasoning here goes as follows:
+#
+#    1. It is not possible to call into the callbacks before the dictionary is
+#       populated, so once in the callback the id must be in the dictionary.
+#    2. The callbacks don't mutate the dictionary, they only read from it, and
+#       so cannot conflict with any of the insertions.
+#
+# This is good: if we had to lock in the callbacks we'd drastically slow down
+# the performance of this code.
+_connection_refs = weakref.WeakValueDictionary()
+_connection_ref_lock = threading.Lock()
+
+# Limit writes to 16kB. This is OpenSSL's limit, but we'll cargo-cult it over
+# for no better reason than we need *a* limit, and this one is right there.
+SSL_WRITE_BLOCKSIZE = 16384
+
+# This is our equivalent of util.ssl_.DEFAULT_CIPHERS, but expanded out to
+# individual cipher suites. We need to do this because this is how
+# SecureTransport wants them.
+CIPHER_SUITES = [
+    SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+    SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+    SecurityConst.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+    SecurityConst.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+    SecurityConst.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
+    SecurityConst.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+    SecurityConst.TLS_DHE_RSA_WITH_AES_256_GCM_SHA384,
+    SecurityConst.TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,
+    SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,
+    SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+    SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
+    SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+    SecurityConst.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,
+    SecurityConst.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+    SecurityConst.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
+    SecurityConst.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+    SecurityConst.TLS_DHE_RSA_WITH_AES_256_CBC_SHA256,
+    SecurityConst.TLS_DHE_RSA_WITH_AES_256_CBC_SHA,
+    SecurityConst.TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,
+    SecurityConst.TLS_DHE_RSA_WITH_AES_128_CBC_SHA,
+    SecurityConst.TLS_AES_256_GCM_SHA384,
+    SecurityConst.TLS_AES_128_GCM_SHA256,
+    SecurityConst.TLS_RSA_WITH_AES_256_GCM_SHA384,
+    SecurityConst.TLS_RSA_WITH_AES_128_GCM_SHA256,
+    SecurityConst.TLS_AES_128_CCM_8_SHA256,
+    SecurityConst.TLS_AES_128_CCM_SHA256,
+    SecurityConst.TLS_RSA_WITH_AES_256_CBC_SHA256,
+    SecurityConst.TLS_RSA_WITH_AES_128_CBC_SHA256,
+    SecurityConst.TLS_RSA_WITH_AES_256_CBC_SHA,
+    SecurityConst.TLS_RSA_WITH_AES_128_CBC_SHA,
+]
+
+# Basically this is simple: for PROTOCOL_SSLv23 we turn it into a low of
+# TLSv1 and a high of TLSv1.2. For everything else, we pin to that version.
+# TLSv1 to 1.2 are supported on macOS 10.8+
+_protocol_to_min_max = {
+    util.PROTOCOL_TLS: (SecurityConst.kTLSProtocol1, SecurityConst.kTLSProtocol12)
+}
+
+if hasattr(ssl, "PROTOCOL_SSLv2"):
+    _protocol_to_min_max[ssl.PROTOCOL_SSLv2] = (
+        SecurityConst.kSSLProtocol2,
+        SecurityConst.kSSLProtocol2,
+    )
+if hasattr(ssl, "PROTOCOL_SSLv3"):
+    _protocol_to_min_max[ssl.PROTOCOL_SSLv3] = (
+        SecurityConst.kSSLProtocol3,
+        SecurityConst.kSSLProtocol3,
+    )
+if hasattr(ssl, "PROTOCOL_TLSv1"):
+    _protocol_to_min_max[ssl.PROTOCOL_TLSv1] = (
+        SecurityConst.kTLSProtocol1,
+        SecurityConst.kTLSProtocol1,
+    )
+if hasattr(ssl, "PROTOCOL_TLSv1_1"):
+    _protocol_to_min_max[ssl.PROTOCOL_TLSv1_1] = (
+        SecurityConst.kTLSProtocol11,
+        SecurityConst.kTLSProtocol11,
+    )
+if hasattr(ssl, "PROTOCOL_TLSv1_2"):
+    _protocol_to_min_max[ssl.PROTOCOL_TLSv1_2] = (
+        SecurityConst.kTLSProtocol12,
+        SecurityConst.kTLSProtocol12,
+    )
+
+
+def inject_into_urllib3():
+    """
+    Monkey-patch urllib3 with SecureTransport-backed SSL-support.
+    """
+    util.SSLContext = SecureTransportContext
+    util.ssl_.SSLContext = SecureTransportContext
+    util.HAS_SNI = HAS_SNI
+    util.ssl_.HAS_SNI = HAS_SNI
+    util.IS_SECURETRANSPORT = True
+    util.ssl_.IS_SECURETRANSPORT = True
+
+
+def extract_from_urllib3():
+    """
+    Undo monkey-patching by :func:`inject_into_urllib3`.
+    """
+    util.SSLContext = orig_util_SSLContext
+    util.ssl_.SSLContext = orig_util_SSLContext
+    util.HAS_SNI = orig_util_HAS_SNI
+    util.ssl_.HAS_SNI = orig_util_HAS_SNI
+    util.IS_SECURETRANSPORT = False
+    util.ssl_.IS_SECURETRANSPORT = False
+
+
+def _read_callback(connection_id, data_buffer, data_length_pointer):
+    """
+    SecureTransport read callback. This is called by ST to request that data
+    be returned from the socket.
+    """
+    wrapped_socket = None
+    try:
+        wrapped_socket = _connection_refs.get(connection_id)
+        if wrapped_socket is None:
+            return SecurityConst.errSSLInternal
+        base_socket = wrapped_socket.socket
+
+        requested_length = data_length_pointer[0]
+
+        timeout = wrapped_socket.gettimeout()
+        error = None
+        read_count = 0
+
+        try:
+            while read_count < requested_length:
+                if timeout is None or timeout >= 0:
+                    if not util.wait_for_read(base_socket, timeout):
+                        raise socket.error(errno.EAGAIN, "timed out")
+
+                remaining = requested_length - read_count
+                buffer = (ctypes.c_char * remaining).from_address(
+                    data_buffer + read_count
+                )
+                chunk_size = base_socket.recv_into(buffer, remaining)
+                read_count += chunk_size
+                if not chunk_size:
+                    if not read_count:
+                        return SecurityConst.errSSLClosedGraceful
+                    break
+        except (socket.error) as e:
+            error = e.errno
+
+            if error is not None and error != errno.EAGAIN:
+                data_length_pointer[0] = read_count
+                if error == errno.ECONNRESET or error == errno.EPIPE:
+                    return SecurityConst.errSSLClosedAbort
+                raise
+
+        data_length_pointer[0] = read_count
+
+        if read_count != requested_length:
+            return SecurityConst.errSSLWouldBlock
+
+        return 0
+    except Exception as e:
+        if wrapped_socket is not None:
+            wrapped_socket._exception = e
+        return SecurityConst.errSSLInternal
+
+
+def _write_callback(connection_id, data_buffer, data_length_pointer):
+    """
+    SecureTransport write callback. This is called by ST to request that data
+    actually be sent on the network.
+    """
+    wrapped_socket = None
+    try:
+        wrapped_socket = _connection_refs.get(connection_id)
+        if wrapped_socket is None:
+            return SecurityConst.errSSLInternal
+        base_socket = wrapped_socket.socket
+
+        bytes_to_write = data_length_pointer[0]
+        data = ctypes.string_at(data_buffer, bytes_to_write)
+
+        timeout = wrapped_socket.gettimeout()
+        error = None
+        sent = 0
+
+        try:
+            while sent < bytes_to_write:
+                if timeout is None or timeout >= 0:
+                    if not util.wait_for_write(base_socket, timeout):
+                        raise socket.error(errno.EAGAIN, "timed out")
+                chunk_sent = base_socket.send(data)
+                sent += chunk_sent
+
+                # This has some needless copying here, but I'm not sure there's
+                # much value in optimising this data path.
+                data = data[chunk_sent:]
+        except (socket.error) as e:
+            error = e.errno
+
+            if error is not None and error != errno.EAGAIN:
+                data_length_pointer[0] = sent
+                if error == errno.ECONNRESET or error == errno.EPIPE:
+                    return SecurityConst.errSSLClosedAbort
+                raise
+
+        data_length_pointer[0] = sent
+
+        if sent != bytes_to_write:
+            return SecurityConst.errSSLWouldBlock
+
+        return 0
+    except Exception as e:
+        if wrapped_socket is not None:
+            wrapped_socket._exception = e
+        return SecurityConst.errSSLInternal
+
+
+# We need to keep these two objects references alive: if they get GC'd while
+# in use then SecureTransport could attempt to call a function that is in freed
+# memory. That would be...uh...bad. Yeah, that's the word. Bad.
+_read_callback_pointer = Security.SSLReadFunc(_read_callback)
+_write_callback_pointer = Security.SSLWriteFunc(_write_callback)
+
+
+class WrappedSocket(object):
+    """
+    API-compatibility wrapper for Python's OpenSSL wrapped socket object.
+
+    Note: _makefile_refs, _drop(), and _reuse() are needed for the garbage
+    collector of PyPy.
+    """
+
+    def __init__(self, socket):
+        self.socket = socket
+        self.context = None
+        self._makefile_refs = 0
+        self._closed = False
+        self._exception = None
+        self._keychain = None
+        self._keychain_dir = None
+        self._client_cert_chain = None
+
+        # We save off the previously-configured timeout and then set it to
+        # zero. This is done because we use select and friends to handle the
+        # timeouts, but if we leave the timeout set on the lower socket then
+        # Python will "kindly" call select on that socket again for us. Avoid
+        # that by forcing the timeout to zero.
+        self._timeout = self.socket.gettimeout()
+        self.socket.settimeout(0)
+
+    @contextlib.contextmanager
+    def _raise_on_error(self):
+        """
+        A context manager that can be used to wrap calls that do I/O from
+        SecureTransport. If any of the I/O callbacks hit an exception, this
+        context manager will correctly propagate the exception after the fact.
+        This avoids silently swallowing those exceptions.
+
+        It also correctly forces the socket closed.
+        """
+        self._exception = None
+
+        # We explicitly don't catch around this yield because in the unlikely
+        # event that an exception was hit in the block we don't want to swallow
+        # it.
+        yield
+        if self._exception is not None:
+            exception, self._exception = self._exception, None
+            self.close()
+            raise exception
+
+    def _set_ciphers(self):
+        """
+        Sets up the allowed ciphers. By default this matches the set in
+        util.ssl_.DEFAULT_CIPHERS, at least as supported by macOS. This is done
+        custom and doesn't allow changing at this time, mostly because parsing
+        OpenSSL cipher strings is going to be a freaking nightmare.
+        """
+        ciphers = (Security.SSLCipherSuite * len(CIPHER_SUITES))(*CIPHER_SUITES)
+        result = Security.SSLSetEnabledCiphers(
+            self.context, ciphers, len(CIPHER_SUITES)
+        )
+        _assert_no_error(result)
+
+    def _custom_validate(self, verify, trust_bundle):
+        """
+        Called when we have set custom validation. We do this in two cases:
+        first, when cert validation is entirely disabled; and second, when
+        using a custom trust DB.
+        """
+        # If we disabled cert validation, just say: cool.
+        if not verify:
+            return
+
+        # We want data in memory, so load it up.
+        if os.path.isfile(trust_bundle):
+            with open(trust_bundle, "rb") as f:
+                trust_bundle = f.read()
+
+        cert_array = None
+        trust = Security.SecTrustRef()
+
+        try:
+            # Get a CFArray that contains the certs we want.
+            cert_array = _cert_array_from_pem(trust_bundle)
+
+            # Ok, now the hard part. We want to get the SecTrustRef that ST has
+            # created for this connection, shove our CAs into it, tell ST to
+            # ignore everything else it knows, and then ask if it can build a
+            # chain. This is a buuuunch of code.
+            result = Security.SSLCopyPeerTrust(self.context, ctypes.byref(trust))
+            _assert_no_error(result)
+            if not trust:
+                raise ssl.SSLError("Failed to copy trust reference")
+
+            result = Security.SecTrustSetAnchorCertificates(trust, cert_array)
+            _assert_no_error(result)
+
+            result = Security.SecTrustSetAnchorCertificatesOnly(trust, True)
+            _assert_no_error(result)
+
+            trust_result = Security.SecTrustResultType()
+            result = Security.SecTrustEvaluate(trust, ctypes.byref(trust_result))
+            _assert_no_error(result)
+        finally:
+            if trust:
+                CoreFoundation.CFRelease(trust)
+
+            if cert_array is not None:
+                CoreFoundation.CFRelease(cert_array)
+
+        # Ok, now we can look at what the result was.
+        successes = (
+            SecurityConst.kSecTrustResultUnspecified,
+            SecurityConst.kSecTrustResultProceed,
+        )
+        if trust_result.value not in successes:
+            raise ssl.SSLError(
+                "certificate verify failed, error code: %d" % trust_result.value
+            )
+
+    def handshake(
+        self,
+        server_hostname,
+        verify,
+        trust_bundle,
+        min_version,
+        max_version,
+        client_cert,
+        client_key,
+        client_key_passphrase,
+    ):
+        """
+        Actually performs the TLS handshake. This is run automatically by
+        wrapped socket, and shouldn't be needed in user code.
+        """
+        # First, we do the initial bits of connection setup. We need to create
+        # a context, set its I/O funcs, and set the connection reference.
+        self.context = Security.SSLCreateContext(
+            None, SecurityConst.kSSLClientSide, SecurityConst.kSSLStreamType
+        )
+        result = Security.SSLSetIOFuncs(
+            self.context, _read_callback_pointer, _write_callback_pointer
+        )
+        _assert_no_error(result)
+
+        # Here we need to compute the handle to use. We do this by taking the
+        # id of self modulo 2**31 - 1. If this is already in the dictionary, we
+        # just keep incrementing by one until we find a free space.
+        with _connection_ref_lock:
+            handle = id(self) % 2147483647
+            while handle in _connection_refs:
+                handle = (handle + 1) % 2147483647
+            _connection_refs[handle] = self
+
+        result = Security.SSLSetConnection(self.context, handle)
+        _assert_no_error(result)
+
+        # If we have a server hostname, we should set that too.
+        if server_hostname:
+            if not isinstance(server_hostname, bytes):
+                server_hostname = server_hostname.encode("utf-8")
+
+            result = Security.SSLSetPeerDomainName(
+                self.context, server_hostname, len(server_hostname)
+            )
+            _assert_no_error(result)
+
+        # Setup the ciphers.
+        self._set_ciphers()
+
+        # Set the minimum and maximum TLS versions.
+        result = Security.SSLSetProtocolVersionMin(self.context, min_version)
+        _assert_no_error(result)
+
+        result = Security.SSLSetProtocolVersionMax(self.context, max_version)
+        _assert_no_error(result)
+
+        # If there's a trust DB, we need to use it. We do that by telling
+        # SecureTransport to break on server auth. We also do that if we don't
+        # want to validate the certs at all: we just won't actually do any
+        # authing in that case.
+        if not verify or trust_bundle is not None:
+            result = Security.SSLSetSessionOption(
+                self.context, SecurityConst.kSSLSessionOptionBreakOnServerAuth, True
+            )
+            _assert_no_error(result)
+
+        # If there's a client cert, we need to use it.
+        if client_cert:
+            self._keychain, self._keychain_dir = _temporary_keychain()
+            self._client_cert_chain = _load_client_cert_chain(
+                self._keychain, client_cert, client_key
+            )
+            result = Security.SSLSetCertificate(self.context, self._client_cert_chain)
+            _assert_no_error(result)
+
+        while True:
+            with self._raise_on_error():
+                result = Security.SSLHandshake(self.context)
+
+                if result == SecurityConst.errSSLWouldBlock:
+                    raise socket.timeout("handshake timed out")
+                elif result == SecurityConst.errSSLServerAuthCompleted:
+                    self._custom_validate(verify, trust_bundle)
+                    continue
+                else:
+                    _assert_no_error(result)
+                    break
+
+    def fileno(self):
+        return self.socket.fileno()
+
+    # Copy-pasted from Python 3.5 source code
+    def _decref_socketios(self):
+        if self._makefile_refs > 0:
+            self._makefile_refs -= 1
+        if self._closed:
+            self.close()
+
+    def recv(self, bufsiz):
+        buffer = ctypes.create_string_buffer(bufsiz)
+        bytes_read = self.recv_into(buffer, bufsiz)
+        data = buffer[:bytes_read]
+        return data
+
+    def recv_into(self, buffer, nbytes=None):
+        # Read short on EOF.
+        if self._closed:
+            return 0
+
+        if nbytes is None:
+            nbytes = len(buffer)
+
+        buffer = (ctypes.c_char * nbytes).from_buffer(buffer)
+        processed_bytes = ctypes.c_size_t(0)
+
+        with self._raise_on_error():
+            result = Security.SSLRead(
+                self.context, buffer, nbytes, ctypes.byref(processed_bytes)
+            )
+
+        # There are some result codes that we want to treat as "not always
+        # errors". Specifically, those are errSSLWouldBlock,
+        # errSSLClosedGraceful, and errSSLClosedNoNotify.
+        if result == SecurityConst.errSSLWouldBlock:
+            # If we didn't process any bytes, then this was just a time out.
+            # However, we can get errSSLWouldBlock in situations when we *did*
+            # read some data, and in those cases we should just read "short"
+            # and return.
+            if processed_bytes.value == 0:
+                # Timed out, no data read.
+                raise socket.timeout("recv timed out")
+        elif result in (
+            SecurityConst.errSSLClosedGraceful,
+            SecurityConst.errSSLClosedNoNotify,
+        ):
+            # The remote peer has closed this connection. We should do so as
+            # well. Note that we don't actually return here because in
+            # principle this could actually be fired along with return data.
+            # It's unlikely though.
+            self.close()
+        else:
+            _assert_no_error(result)
+
+        # Ok, we read and probably succeeded. We should return whatever data
+        # was actually read.
+        return processed_bytes.value
+
+    def settimeout(self, timeout):
+        self._timeout = timeout
+
+    def gettimeout(self):
+        return self._timeout
+
+    def send(self, data):
+        processed_bytes = ctypes.c_size_t(0)
+
+        with self._raise_on_error():
+            result = Security.SSLWrite(
+                self.context, data, len(data), ctypes.byref(processed_bytes)
+            )
+
+        if result == SecurityConst.errSSLWouldBlock and processed_bytes.value == 0:
+            # Timed out
+            raise socket.timeout("send timed out")
+        else:
+            _assert_no_error(result)
+
+        # We sent, and probably succeeded. Tell them how much we sent.
+        return processed_bytes.value
+
+    def sendall(self, data):
+        total_sent = 0
+        while total_sent < len(data):
+            sent = self.send(data[total_sent : total_sent + SSL_WRITE_BLOCKSIZE])
+            total_sent += sent
+
+    def shutdown(self):
+        with self._raise_on_error():
+            Security.SSLClose(self.context)
+
+    def close(self):
+        # TODO: should I do clean shutdown here? Do I have to?
+        if self._makefile_refs < 1:
+            self._closed = True
+            if self.context:
+                CoreFoundation.CFRelease(self.context)
+                self.context = None
+            if self._client_cert_chain:
+                CoreFoundation.CFRelease(self._client_cert_chain)
+                self._client_cert_chain = None
+            if self._keychain:
+                Security.SecKeychainDelete(self._keychain)
+                CoreFoundation.CFRelease(self._keychain)
+                shutil.rmtree(self._keychain_dir)
+                self._keychain = self._keychain_dir = None
+            return self.socket.close()
+        else:
+            self._makefile_refs -= 1
+
+    def getpeercert(self, binary_form=False):
+        # Urgh, annoying.
+        #
+        # Here's how we do this:
+        #
+        # 1. Call SSLCopyPeerTrust to get hold of the trust object for this
+        #    connection.
+        # 2. Call SecTrustGetCertificateAtIndex for index 0 to get the leaf.
+        # 3. To get the CN, call SecCertificateCopyCommonName and process that
+        #    string so that it's of the appropriate type.
+        # 4. To get the SAN, we need to do something a bit more complex:
+        #    a. Call SecCertificateCopyValues to get the data, requesting
+        #       kSecOIDSubjectAltName.
+        #    b. Mess about with this dictionary to try to get the SANs out.
+        #
+        # This is gross. Really gross. It's going to be a few hundred LoC extra
+        # just to repeat something that SecureTransport can *already do*. So my
+        # operating assumption at this time is that what we want to do is
+        # instead to just flag to urllib3 that it shouldn't do its own hostname
+        # validation when using SecureTransport.
+        if not binary_form:
+            raise ValueError("SecureTransport only supports dumping binary certs")
+        trust = Security.SecTrustRef()
+        certdata = None
+        der_bytes = None
+
+        try:
+            # Grab the trust store.
+            result = Security.SSLCopyPeerTrust(self.context, ctypes.byref(trust))
+            _assert_no_error(result)
+            if not trust:
+                # Probably we haven't done the handshake yet. No biggie.
+                return None
+
+            cert_count = Security.SecTrustGetCertificateCount(trust)
+            if not cert_count:
+                # Also a case that might happen if we haven't handshaked.
+                # Handshook? Handshaken?
+                return None
+
+            leaf = Security.SecTrustGetCertificateAtIndex(trust, 0)
+            assert leaf
+
+            # Ok, now we want the DER bytes.
+            certdata = Security.SecCertificateCopyData(leaf)
+            assert certdata
+
+            data_length = CoreFoundation.CFDataGetLength(certdata)
+            data_buffer = CoreFoundation.CFDataGetBytePtr(certdata)
+            der_bytes = ctypes.string_at(data_buffer, data_length)
+        finally:
+            if certdata:
+                CoreFoundation.CFRelease(certdata)
+            if trust:
+                CoreFoundation.CFRelease(trust)
+
+        return der_bytes
+
+    def version(self):
+        protocol = Security.SSLProtocol()
+        result = Security.SSLGetNegotiatedProtocolVersion(
+            self.context, ctypes.byref(protocol)
+        )
+        _assert_no_error(result)
+        if protocol.value == SecurityConst.kTLSProtocol13:
+            raise ssl.SSLError("SecureTransport does not support TLS 1.3")
+        elif protocol.value == SecurityConst.kTLSProtocol12:
+            return "TLSv1.2"
+        elif protocol.value == SecurityConst.kTLSProtocol11:
+            return "TLSv1.1"
+        elif protocol.value == SecurityConst.kTLSProtocol1:
+            return "TLSv1"
+        elif protocol.value == SecurityConst.kSSLProtocol3:
+            return "SSLv3"
+        elif protocol.value == SecurityConst.kSSLProtocol2:
+            return "SSLv2"
+        else:
+            raise ssl.SSLError("Unknown TLS version: %r" % protocol)
+
+    def _reuse(self):
+        self._makefile_refs += 1
+
+    def _drop(self):
+        if self._makefile_refs < 1:
+            self.close()
+        else:
+            self._makefile_refs -= 1
+
+
+if _fileobject:  # Platform-specific: Python 2
+
+    def makefile(self, mode, bufsize=-1):
+        self._makefile_refs += 1
+        return _fileobject(self, mode, bufsize, close=True)
+
+
+else:  # Platform-specific: Python 3
+
+    def makefile(self, mode="r", buffering=None, *args, **kwargs):
+        # We disable buffering with SecureTransport because it conflicts with
+        # the buffering that ST does internally (see issue #1153 for more).
+        buffering = 0
+        return backport_makefile(self, mode, buffering, *args, **kwargs)
+
+
+WrappedSocket.makefile = makefile
+
+
+class SecureTransportContext(object):
+    """
+    I am a wrapper class for the SecureTransport library, to translate the
+    interface of the standard library ``SSLContext`` object to calls into
+    SecureTransport.
+    """
+
+    def __init__(self, protocol):
+        self._min_version, self._max_version = _protocol_to_min_max[protocol]
+        self._options = 0
+        self._verify = False
+        self._trust_bundle = None
+        self._client_cert = None
+        self._client_key = None
+        self._client_key_passphrase = None
+
+    @property
+    def check_hostname(self):
+        """
+        SecureTransport cannot have its hostname checking disabled. For more,
+        see the comment on getpeercert() in this file.
+        """
+        return True
+
+    @check_hostname.setter
+    def check_hostname(self, value):
+        """
+        SecureTransport cannot have its hostname checking disabled. For more,
+        see the comment on getpeercert() in this file.
+        """
+        pass
+
+    @property
+    def options(self):
+        # TODO: Well, crap.
+        #
+        # So this is the bit of the code that is the most likely to cause us
+        # trouble. Essentially we need to enumerate all of the SSL options that
+        # users might want to use and try to see if we can sensibly translate
+        # them, or whether we should just ignore them.
+        return self._options
+
+    @options.setter
+    def options(self, value):
+        # TODO: Update in line with above.
+        self._options = value
+
+    @property
+    def verify_mode(self):
+        return ssl.CERT_REQUIRED if self._verify else ssl.CERT_NONE
+
+    @verify_mode.setter
+    def verify_mode(self, value):
+        self._verify = True if value == ssl.CERT_REQUIRED else False
+
+    def set_default_verify_paths(self):
+        # So, this has to do something a bit weird. Specifically, what it does
+        # is nothing.
+        #
+        # This means that, if we had previously had load_verify_locations
+        # called, this does not undo that. We need to do that because it turns
+        # out that the rest of the urllib3 code will attempt to load the
+        # default verify paths if it hasn't been told about any paths, even if
+        # the context itself was sometime earlier. We resolve that by just
+        # ignoring it.
+        pass
+
+    def load_default_certs(self):
+        return self.set_default_verify_paths()
+
+    def set_ciphers(self, ciphers):
+        # For now, we just require the default cipher string.
+        if ciphers != util.ssl_.DEFAULT_CIPHERS:
+            raise ValueError("SecureTransport doesn't support custom cipher strings")
+
+    def load_verify_locations(self, cafile=None, capath=None, cadata=None):
+        # OK, we only really support cadata and cafile.
+        if capath is not None:
+            raise ValueError("SecureTransport does not support cert directories")
+
+        # Raise if cafile does not exist.
+        if cafile is not None:
+            with open(cafile):
+                pass
+
+        self._trust_bundle = cafile or cadata
+
+    def load_cert_chain(self, certfile, keyfile=None, password=None):
+        self._client_cert = certfile
+        self._client_key = keyfile
+        self._client_cert_passphrase = password
+
+    def wrap_socket(
+        self,
+        sock,
+        server_side=False,
+        do_handshake_on_connect=True,
+        suppress_ragged_eofs=True,
+        server_hostname=None,
+    ):
+        # So, what do we do here? Firstly, we assert some properties. This is a
+        # stripped down shim, so there is some functionality we don't support.
+        # See PEP 543 for the real deal.
+        assert not server_side
+        assert do_handshake_on_connect
+        assert suppress_ragged_eofs
+
+        # Ok, we're good to go. Now we want to create the wrapped socket object
+        # and store it in the appropriate place.
+        wrapped_socket = WrappedSocket(sock)
+
+        # Now we can handshake
+        wrapped_socket.handshake(
+            server_hostname,
+            self._verify,
+            self._trust_bundle,
+            self._min_version,
+            self._max_version,
+            self._client_cert,
+            self._client_key,
+            self._client_key_passphrase,
+        )
+        return wrapped_socket

venv/Lib/site-packages/urllib3/contrib/socks.py

@@ -0,0 +1,210 @@
+# -*- coding: utf-8 -*-
+"""
+This module contains provisional support for SOCKS proxies from within
+urllib3. This module supports SOCKS4, SOCKS4A (an extension of SOCKS4), and
+SOCKS5. To enable its functionality, either install PySocks or install this
+module with the ``socks`` extra.
+
+The SOCKS implementation supports the full range of urllib3 features. It also
+supports the following SOCKS features:
+
+- SOCKS4A (``proxy_url='socks4a://...``)
+- SOCKS4 (``proxy_url='socks4://...``)
+- SOCKS5 with remote DNS (``proxy_url='socks5h://...``)
+- SOCKS5 with local DNS (``proxy_url='socks5://...``)
+- Usernames and passwords for the SOCKS proxy
+
+ .. note::
+    It is recommended to use ``socks5h://`` or ``socks4a://`` schemes in
+    your ``proxy_url`` to ensure that DNS resolution is done from the remote
+    server instead of client-side when connecting to a domain name.
+
+SOCKS4 supports IPv4 and domain names with the SOCKS4A extension. SOCKS5
+supports IPv4, IPv6, and domain names.
+
+When connecting to a SOCKS4 proxy the ``username`` portion of the ``proxy_url``
+will be sent as the ``userid`` section of the SOCKS request::
+
+    proxy_url="socks4a://<userid>@proxy-host"
+
+When connecting to a SOCKS5 proxy the ``username`` and ``password`` portion
+of the ``proxy_url`` will be sent as the username/password to authenticate
+with the proxy::
+
+    proxy_url="socks5h://<username>:<password>@proxy-host"
+
+"""
+from __future__ import absolute_import
+
+try:
+    import socks
+except ImportError:
+    import warnings
+    from ..exceptions import DependencyWarning
+
+    warnings.warn(
+        (
+            "SOCKS support in urllib3 requires the installation of optional "
+            "dependencies: specifically, PySocks.  For more information, see "
+            "https://urllib3.readthedocs.io/en/latest/contrib.html#socks-proxies"
+        ),
+        DependencyWarning,
+    )
+    raise
+
+from socket import error as SocketError, timeout as SocketTimeout
+
+from ..connection import HTTPConnection, HTTPSConnection
+from ..connectionpool import HTTPConnectionPool, HTTPSConnectionPool
+from ..exceptions import ConnectTimeoutError, NewConnectionError
+from ..poolmanager import PoolManager
+from ..util.url import parse_url
+
+try:
+    import ssl
+except ImportError:
+    ssl = None
+
+
+class SOCKSConnection(HTTPConnection):
+    """
+    A plain-text HTTP connection that connects via a SOCKS proxy.
+    """
+
+    def __init__(self, *args, **kwargs):
+        self._socks_options = kwargs.pop("_socks_options")
+        super(SOCKSConnection, self).__init__(*args, **kwargs)
+
+    def _new_conn(self):
+        """
+        Establish a new connection via the SOCKS proxy.
+        """
+        extra_kw = {}
+        if self.source_address:
+            extra_kw["source_address"] = self.source_address
+
+        if self.socket_options:
+            extra_kw["socket_options"] = self.socket_options
+
+        try:
+            conn = socks.create_connection(
+                (self.host, self.port),
+                proxy_type=self._socks_options["socks_version"],
+                proxy_addr=self._socks_options["proxy_host"],
+                proxy_port=self._socks_options["proxy_port"],
+                proxy_username=self._socks_options["username"],
+                proxy_password=self._socks_options["password"],
+                proxy_rdns=self._socks_options["rdns"],
+                timeout=self.timeout,
+                **extra_kw
+            )
+
+        except SocketTimeout:
+            raise ConnectTimeoutError(
+                self,
+                "Connection to %s timed out. (connect timeout=%s)"
+                % (self.host, self.timeout),
+            )
+
+        except socks.ProxyError as e:
+            # This is fragile as hell, but it seems to be the only way to raise
+            # useful errors here.
+            if e.socket_err:
+                error = e.socket_err
+                if isinstance(error, SocketTimeout):
+                    raise ConnectTimeoutError(
+                        self,
+                        "Connection to %s timed out. (connect timeout=%s)"
+                        % (self.host, self.timeout),
+                    )
+                else:
+                    raise NewConnectionError(
+                        self, "Failed to establish a new connection: %s" % error
+                    )
+            else:
+                raise NewConnectionError(
+                    self, "Failed to establish a new connection: %s" % e
+                )
+
+        except SocketError as e:  # Defensive: PySocks should catch all these.
+            raise NewConnectionError(
+                self, "Failed to establish a new connection: %s" % e
+            )
+
+        return conn
+
+
+# We don't need to duplicate the Verified/Unverified distinction from
+# urllib3/connection.py here because the HTTPSConnection will already have been
+# correctly set to either the Verified or Unverified form by that module. This
+# means the SOCKSHTTPSConnection will automatically be the correct type.
+class SOCKSHTTPSConnection(SOCKSConnection, HTTPSConnection):
+    pass
+
+
+class SOCKSHTTPConnectionPool(HTTPConnectionPool):
+    ConnectionCls = SOCKSConnection
+
+
+class SOCKSHTTPSConnectionPool(HTTPSConnectionPool):
+    ConnectionCls = SOCKSHTTPSConnection
+
+
+class SOCKSProxyManager(PoolManager):
+    """
+    A version of the urllib3 ProxyManager that routes connections via the
+    defined SOCKS proxy.
+    """
+
+    pool_classes_by_scheme = {
+        "http": SOCKSHTTPConnectionPool,
+        "https": SOCKSHTTPSConnectionPool,
+    }
+
+    def __init__(
+        self,
+        proxy_url,
+        username=None,
+        password=None,
+        num_pools=10,
+        headers=None,
+        **connection_pool_kw
+    ):
+        parsed = parse_url(proxy_url)
+
+        if username is None and password is None and parsed.auth is not None:
+            split = parsed.auth.split(":")
+            if len(split) == 2:
+                username, password = split
+        if parsed.scheme == "socks5":
+            socks_version = socks.PROXY_TYPE_SOCKS5
+            rdns = False
+        elif parsed.scheme == "socks5h":
+            socks_version = socks.PROXY_TYPE_SOCKS5
+            rdns = True
+        elif parsed.scheme == "socks4":
+            socks_version = socks.PROXY_TYPE_SOCKS4
+            rdns = False
+        elif parsed.scheme == "socks4a":
+            socks_version = socks.PROXY_TYPE_SOCKS4
+            rdns = True
+        else:
+            raise ValueError("Unable to determine SOCKS version from %s" % proxy_url)
+
+        self.proxy_url = proxy_url
+
+        socks_options = {
+            "socks_version": socks_version,
+            "proxy_host": parsed.host,
+            "proxy_port": parsed.port,
+            "username": username,
+            "password": password,
+            "rdns": rdns,
+        }
+        connection_pool_kw["_socks_options"] = socks_options
+
+        super(SOCKSProxyManager, self).__init__(
+            num_pools, headers, **connection_pool_kw
+        )
+
+        self.pool_classes_by_scheme = SOCKSProxyManager.pool_classes_by_scheme

venv/Lib/site-packages/urllib3/exceptions.py

@@ -0,0 +1,272 @@
+from __future__ import absolute_import
+from .packages.six.moves.http_client import IncompleteRead as httplib_IncompleteRead
+
+# Base Exceptions
+
+
+class HTTPError(Exception):
+    "Base exception used by this module."
+    pass
+
+
+class HTTPWarning(Warning):
+    "Base warning used by this module."
+    pass
+
+
+class PoolError(HTTPError):
+    "Base exception for errors caused within a pool."
+
+    def __init__(self, pool, message):
+        self.pool = pool
+        HTTPError.__init__(self, "%s: %s" % (pool, message))
+
+    def __reduce__(self):
+        # For pickling purposes.
+        return self.__class__, (None, None)
+
+
+class RequestError(PoolError):
+    "Base exception for PoolErrors that have associated URLs."
+
+    def __init__(self, pool, url, message):
+        self.url = url
+        PoolError.__init__(self, pool, message)
+
+    def __reduce__(self):
+        # For pickling purposes.
+        return self.__class__, (None, self.url, None)
+
+
+class SSLError(HTTPError):
+    "Raised when SSL certificate fails in an HTTPS connection."
+    pass
+
+
+class ProxyError(HTTPError):
+    "Raised when the connection to a proxy fails."
+
+    def __init__(self, message, error, *args):
+        super(ProxyError, self).__init__(message, error, *args)
+        self.original_error = error
+
+
+class DecodeError(HTTPError):
+    "Raised when automatic decoding based on Content-Type fails."
+    pass
+
+
+class ProtocolError(HTTPError):
+    "Raised when something unexpected happens mid-request/response."
+    pass
+
+
+#: Renamed to ProtocolError but aliased for backwards compatibility.
+ConnectionError = ProtocolError
+
+
+# Leaf Exceptions
+
+
+class MaxRetryError(RequestError):
+    """Raised when the maximum number of retries is exceeded.
+
+    :param pool: The connection pool
+    :type pool: :class:`~urllib3.connectionpool.HTTPConnectionPool`
+    :param string url: The requested Url
+    :param exceptions.Exception reason: The underlying error
+
+    """
+
+    def __init__(self, pool, url, reason=None):
+        self.reason = reason
+
+        message = "Max retries exceeded with url: %s (Caused by %r)" % (url, reason)
+
+        RequestError.__init__(self, pool, url, message)
+
+
+class HostChangedError(RequestError):
+    "Raised when an existing pool gets a request for a foreign host."
+
+    def __init__(self, pool, url, retries=3):
+        message = "Tried to open a foreign host with url: %s" % url
+        RequestError.__init__(self, pool, url, message)
+        self.retries = retries
+
+
+class TimeoutStateError(HTTPError):
+    """ Raised when passing an invalid state to a timeout """
+
+    pass
+
+
+class TimeoutError(HTTPError):
+    """ Raised when a socket timeout error occurs.
+
+    Catching this error will catch both :exc:`ReadTimeoutErrors
+    <ReadTimeoutError>` and :exc:`ConnectTimeoutErrors <ConnectTimeoutError>`.
+    """
+
+    pass
+
+
+class ReadTimeoutError(TimeoutError, RequestError):
+    "Raised when a socket timeout occurs while receiving data from a server"
+    pass
+
+
+# This timeout error does not have a URL attached and needs to inherit from the
+# base HTTPError
+class ConnectTimeoutError(TimeoutError):
+    "Raised when a socket timeout occurs while connecting to a server"
+    pass
+
+
+class NewConnectionError(ConnectTimeoutError, PoolError):
+    "Raised when we fail to establish a new connection. Usually ECONNREFUSED."
+    pass
+
+
+class EmptyPoolError(PoolError):
+    "Raised when a pool runs out of connections and no more are allowed."
+    pass
+
+
+class ClosedPoolError(PoolError):
+    "Raised when a request enters a pool after the pool has been closed."
+    pass
+
+
+class LocationValueError(ValueError, HTTPError):
+    "Raised when there is something wrong with a given URL input."
+    pass
+
+
+class LocationParseError(LocationValueError):
+    "Raised when get_host or similar fails to parse the URL input."
+
+    def __init__(self, location):
+        message = "Failed to parse: %s" % location
+        HTTPError.__init__(self, message)
+
+        self.location = location
+
+
+class ResponseError(HTTPError):
+    "Used as a container for an error reason supplied in a MaxRetryError."
+    GENERIC_ERROR = "too many error responses"
+    SPECIFIC_ERROR = "too many {status_code} error responses"
+
+
+class SecurityWarning(HTTPWarning):
+    "Warned when performing security reducing actions"
+    pass
+
+
+class SubjectAltNameWarning(SecurityWarning):
+    "Warned when connecting to a host with a certificate missing a SAN."
+    pass
+
+
+class InsecureRequestWarning(SecurityWarning):
+    "Warned when making an unverified HTTPS request."
+    pass
+
+
+class SystemTimeWarning(SecurityWarning):
+    "Warned when system time is suspected to be wrong"
+    pass
+
+
+class InsecurePlatformWarning(SecurityWarning):
+    "Warned when certain SSL configuration is not available on a platform."
+    pass
+
+
+class SNIMissingWarning(HTTPWarning):
+    "Warned when making a HTTPS request without SNI available."
+    pass
+
+
+class DependencyWarning(HTTPWarning):
+    """
+    Warned when an attempt is made to import a module with missing optional
+    dependencies.
+    """
+
+    pass
+
+
+class InvalidProxyConfigurationWarning(HTTPWarning):
+    """
+    Warned when using an HTTPS proxy and an HTTPS URL. Currently
+    urllib3 doesn't support HTTPS proxies and the proxy will be
+    contacted via HTTP instead. This warning can be fixed by
+    changing your HTTPS proxy URL into an HTTP proxy URL.
+
+    If you encounter this warning read this:
+    https://github.com/urllib3/urllib3/issues/1850
+    """
+
+    pass
+
+
+class ResponseNotChunked(ProtocolError, ValueError):
+    "Response needs to be chunked in order to read it as chunks."
+    pass
+
+
+class BodyNotHttplibCompatible(HTTPError):
+    """
+    Body should be httplib.HTTPResponse like (have an fp attribute which
+    returns raw chunks) for read_chunked().
+    """
+
+    pass
+
+
+class IncompleteRead(HTTPError, httplib_IncompleteRead):
+    """
+    Response length doesn't match expected Content-Length
+
+    Subclass of http_client.IncompleteRead to allow int value
+    for `partial` to avoid creating large objects on streamed
+    reads.
+    """
+
+    def __init__(self, partial, expected):
+        super(IncompleteRead, self).__init__(partial, expected)
+
+    def __repr__(self):
+        return "IncompleteRead(%i bytes read, %i more expected)" % (
+            self.partial,
+            self.expected,
+        )
+
+
+class InvalidHeader(HTTPError):
+    "The header provided was somehow invalid."
+    pass
+
+
+class ProxySchemeUnknown(AssertionError, ValueError):
+    "ProxyManager does not support the supplied scheme"
+    # TODO(t-8ch): Stop inheriting from AssertionError in v2.0.
+
+    def __init__(self, scheme):
+        message = "Not supported proxy scheme %s" % scheme
+        super(ProxySchemeUnknown, self).__init__(message)
+
+
+class HeaderParsingError(HTTPError):
+    "Raised by assert_header_parsing, but we convert it to a log.warning statement."
+
+    def __init__(self, defects, unparsed_data):
+        message = "%s, unparsed data: %r" % (defects or "Unknown", unparsed_data)
+        super(HeaderParsingError, self).__init__(message)
+
+
+class UnrewindableBodyError(HTTPError):
+    "urllib3 encountered an error when trying to rewind a body"
+    pass

venv/Lib/site-packages/urllib3/fields.py

@@ -0,0 +1,273 @@
+from __future__ import absolute_import
+import email.utils
+import mimetypes
+import re
+
+from .packages import six
+
+
+def guess_content_type(filename, default="application/octet-stream"):
+    """
+    Guess the "Content-Type" of a file.
+
+    :param filename:
+        The filename to guess the "Content-Type" of using :mod:`mimetypes`.
+    :param default:
+        If no "Content-Type" can be guessed, default to `default`.
+    """
+    if filename:
+        return mimetypes.guess_type(filename)[0] or default
+    return default
+
+
+def format_header_param_rfc2231(name, value):
+    """
+    Helper function to format and quote a single header parameter using the
+    strategy defined in RFC 2231.
+
+    Particularly useful for header parameters which might contain
+    non-ASCII values, like file names. This follows RFC 2388 Section 4.4.
+
+    :param name:
+        The name of the parameter, a string expected to be ASCII only.
+    :param value:
+        The value of the parameter, provided as ``bytes`` or `str``.
+    :ret:
+        An RFC-2231-formatted unicode string.
+    """
+    if isinstance(value, six.binary_type):
+        value = value.decode("utf-8")
+
+    if not any(ch in value for ch in '"\\\r\n'):
+        result = u'%s="%s"' % (name, value)
+        try:
+            result.encode("ascii")
+        except (UnicodeEncodeError, UnicodeDecodeError):
+            pass
+        else:
+            return result
+
+    if six.PY2:  # Python 2:
+        value = value.encode("utf-8")
+
+    # encode_rfc2231 accepts an encoded string and returns an ascii-encoded
+    # string in Python 2 but accepts and returns unicode strings in Python 3
+    value = email.utils.encode_rfc2231(value, "utf-8")
+    value = "%s*=%s" % (name, value)
+
+    if six.PY2:  # Python 2:
+        value = value.decode("utf-8")
+
+    return value
+
+
+_HTML5_REPLACEMENTS = {
+    u"\u0022": u"%22",
+    # Replace "\" with "\\".
+    u"\u005C": u"\u005C\u005C",
+    u"\u005C": u"\u005C\u005C",
+}
+
+# All control characters from 0x00 to 0x1F *except* 0x1B.
+_HTML5_REPLACEMENTS.update(
+    {
+        six.unichr(cc): u"%{:02X}".format(cc)
+        for cc in range(0x00, 0x1F + 1)
+        if cc not in (0x1B,)
+    }
+)
+
+
+def _replace_multiple(value, needles_and_replacements):
+    def replacer(match):
+        return needles_and_replacements[match.group(0)]
+
+    pattern = re.compile(
+        r"|".join([re.escape(needle) for needle in needles_and_replacements.keys()])
+    )
+
+    result = pattern.sub(replacer, value)
+
+    return result
+
+
+def format_header_param_html5(name, value):
+    """
+    Helper function to format and quote a single header parameter using the
+    HTML5 strategy.
+
+    Particularly useful for header parameters which might contain
+    non-ASCII values, like file names. This follows the `HTML5 Working Draft
+    Section 4.10.22.7`_ and matches the behavior of curl and modern browsers.
+
+    .. _HTML5 Working Draft Section 4.10.22.7:
+        https://w3c.github.io/html/sec-forms.html#multipart-form-data
+
+    :param name:
+        The name of the parameter, a string expected to be ASCII only.
+    :param value:
+        The value of the parameter, provided as ``bytes`` or `str``.
+    :ret:
+        A unicode string, stripped of troublesome characters.
+    """
+    if isinstance(value, six.binary_type):
+        value = value.decode("utf-8")
+
+    value = _replace_multiple(value, _HTML5_REPLACEMENTS)
+
+    return u'%s="%s"' % (name, value)
+
+
+# For backwards-compatibility.
+format_header_param = format_header_param_html5
+
+
+class RequestField(object):
+    """
+    A data container for request body parameters.
+
+    :param name:
+        The name of this request field. Must be unicode.
+    :param data:
+        The data/value body.
+    :param filename:
+        An optional filename of the request field. Must be unicode.
+    :param headers:
+        An optional dict-like object of headers to initially use for the field.
+    :param header_formatter:
+        An optional callable that is used to encode and format the headers. By
+        default, this is :func:`format_header_param_html5`.
+    """
+
+    def __init__(
+        self,
+        name,
+        data,
+        filename=None,
+        headers=None,
+        header_formatter=format_header_param_html5,
+    ):
+        self._name = name
+        self._filename = filename
+        self.data = data
+        self.headers = {}
+        if headers:
+            self.headers = dict(headers)
+        self.header_formatter = header_formatter
+
+    @classmethod
+    def from_tuples(cls, fieldname, value, header_formatter=format_header_param_html5):
+        """
+        A :class:`~urllib3.fields.RequestField` factory from old-style tuple parameters.
+
+        Supports constructing :class:`~urllib3.fields.RequestField` from
+        parameter of key/value strings AND key/filetuple. A filetuple is a
+        (filename, data, MIME type) tuple where the MIME type is optional.
+        For example::
+
+            'foo': 'bar',
+            'fakefile': ('foofile.txt', 'contents of foofile'),
+            'realfile': ('barfile.txt', open('realfile').read()),
+            'typedfile': ('bazfile.bin', open('bazfile').read(), 'image/jpeg'),
+            'nonamefile': 'contents of nonamefile field',
+
+        Field names and filenames must be unicode.
+        """
+        if isinstance(value, tuple):
+            if len(value) == 3:
+                filename, data, content_type = value
+            else:
+                filename, data = value
+                content_type = guess_content_type(filename)
+        else:
+            filename = None
+            content_type = None
+            data = value
+
+        request_param = cls(
+            fieldname, data, filename=filename, header_formatter=header_formatter
+        )
+        request_param.make_multipart(content_type=content_type)
+
+        return request_param
+
+    def _render_part(self, name, value):
+        """
+        Overridable helper function to format a single header parameter. By
+        default, this calls ``self.header_formatter``.
+
+        :param name:
+            The name of the parameter, a string expected to be ASCII only.
+        :param value:
+            The value of the parameter, provided as a unicode string.
+        """
+
+        return self.header_formatter(name, value)
+
+    def _render_parts(self, header_parts):
+        """
+        Helper function to format and quote a single header.
+
+        Useful for single headers that are composed of multiple items. E.g.,
+        'Content-Disposition' fields.
+
+        :param header_parts:
+            A sequence of (k, v) tuples or a :class:`dict` of (k, v) to format
+            as `k1="v1"; k2="v2"; ...`.
+        """
+        parts = []
+        iterable = header_parts
+        if isinstance(header_parts, dict):
+            iterable = header_parts.items()
+
+        for name, value in iterable:
+            if value is not None:
+                parts.append(self._render_part(name, value))
+
+        return u"; ".join(parts)
+
+    def render_headers(self):
+        """
+        Renders the headers for this request field.
+        """
+        lines = []
+
+        sort_keys = ["Content-Disposition", "Content-Type", "Content-Location"]
+        for sort_key in sort_keys:
+            if self.headers.get(sort_key, False):
+                lines.append(u"%s: %s" % (sort_key, self.headers[sort_key]))
+
+        for header_name, header_value in self.headers.items():
+            if header_name not in sort_keys:
+                if header_value:
+                    lines.append(u"%s: %s" % (header_name, header_value))
+
+        lines.append(u"\r\n")
+        return u"\r\n".join(lines)
+
+    def make_multipart(
+        self, content_disposition=None, content_type=None, content_location=None
+    ):
+        """
+        Makes this request field into a multipart request field.
+
+        This method overrides "Content-Disposition", "Content-Type" and
+        "Content-Location" headers to the request parameter.
+
+        :param content_type:
+            The 'Content-Type' of the request body.
+        :param content_location:
+            The 'Content-Location' of the request body.
+
+        """
+        self.headers["Content-Disposition"] = content_disposition or u"form-data"
+        self.headers["Content-Disposition"] += u"; ".join(
+            [
+                u"",
+                self._render_parts(
+                    ((u"name", self._name), (u"filename", self._filename))
+                ),
+            ]
+        )
+        self.headers["Content-Type"] = content_type
+        self.headers["Content-Location"] = content_location

venv/Lib/site-packages/urllib3/filepost.py

@@ -0,0 +1,98 @@
+from __future__ import absolute_import
+import binascii
+import codecs
+import os
+
+from io import BytesIO
+
+from .packages import six
+from .packages.six import b
+from .fields import RequestField
+
+writer = codecs.lookup("utf-8")[3]
+
+
+def choose_boundary():
+    """
+    Our embarrassingly-simple replacement for mimetools.choose_boundary.
+    """
+    boundary = binascii.hexlify(os.urandom(16))
+    if not six.PY2:
+        boundary = boundary.decode("ascii")
+    return boundary
+
+
+def iter_field_objects(fields):
+    """
+    Iterate over fields.
+
+    Supports list of (k, v) tuples and dicts, and lists of
+    :class:`~urllib3.fields.RequestField`.
+
+    """
+    if isinstance(fields, dict):
+        i = six.iteritems(fields)
+    else:
+        i = iter(fields)
+
+    for field in i:
+        if isinstance(field, RequestField):
+            yield field
+        else:
+            yield RequestField.from_tuples(*field)
+
+
+def iter_fields(fields):
+    """
+    .. deprecated:: 1.6
+
+    Iterate over fields.
+
+    The addition of :class:`~urllib3.fields.RequestField` makes this function
+    obsolete. Instead, use :func:`iter_field_objects`, which returns
+    :class:`~urllib3.fields.RequestField` objects.
+
+    Supports list of (k, v) tuples and dicts.
+    """
+    if isinstance(fields, dict):
+        return ((k, v) for k, v in six.iteritems(fields))
+
+    return ((k, v) for k, v in fields)
+
+
+def encode_multipart_formdata(fields, boundary=None):
+    """
+    Encode a dictionary of ``fields`` using the multipart/form-data MIME format.
+
+    :param fields:
+        Dictionary of fields or list of (key, :class:`~urllib3.fields.RequestField`).
+
+    :param boundary:
+        If not specified, then a random boundary will be generated using
+        :func:`urllib3.filepost.choose_boundary`.
+    """
+    body = BytesIO()
+    if boundary is None:
+        boundary = choose_boundary()
+
+    for field in iter_field_objects(fields):
+        body.write(b("--%s\r\n" % (boundary)))
+
+        writer(body).write(field.render_headers())
+        data = field.data
+
+        if isinstance(data, int):
+            data = str(data)  # Backwards compatibility
+
+        if isinstance(data, six.text_type):
+            writer(body).write(data)
+        else:
+            body.write(data)
+
+        body.write(b"\r\n")
+
+    body.write(b("--%s--\r\n" % (boundary)))
+
+    content_type = str("multipart/form-data; boundary=%s" % boundary)
+
+    return body.getvalue(), content_type

venv/Lib/site-packages/urllib3/packages/__init__.py

@@ -0,0 +1,5 @@
+from __future__ import absolute_import
+
+from . import ssl_match_hostname
+
+__all__ = ("ssl_match_hostname",)

venv/Lib/site-packages/urllib3/packages/backports/makefile.py

@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+"""
+backports.makefile
+~~~~~~~~~~~~~~~~~~
+
+Backports the Python 3 ``socket.makefile`` method for use with anything that
+wants to create a "fake" socket object.
+"""
+import io
+
+from socket import SocketIO
+
+
+def backport_makefile(
+    self, mode="r", buffering=None, encoding=None, errors=None, newline=None
+):
+    """
+    Backport of ``socket.makefile`` from Python 3.5.
+    """
+    if not set(mode) <= {"r", "w", "b"}:
+        raise ValueError("invalid mode %r (only r, w, b allowed)" % (mode,))
+    writing = "w" in mode
+    reading = "r" in mode or not writing
+    assert reading or writing
+    binary = "b" in mode
+    rawmode = ""
+    if reading:
+        rawmode += "r"
+    if writing:
+        rawmode += "w"
+    raw = SocketIO(self, rawmode)
+    self._makefile_refs += 1
+    if buffering is None:
+        buffering = -1
+    if buffering < 0:
+        buffering = io.DEFAULT_BUFFER_SIZE
+    if buffering == 0:
+        if not binary:
+            raise ValueError("unbuffered streams must be binary")
+        return raw
+    if reading and writing:
+        buffer = io.BufferedRWPair(raw, raw, buffering)
+    elif reading:
+        buffer = io.BufferedReader(raw, buffering)
+    else:
+        assert writing
+        buffer = io.BufferedWriter(raw, buffering)
+    if binary:
+        return buffer
+    text = io.TextIOWrapper(buffer, encoding, errors, newline)
+    text.mode = mode
+    return text

venv/Lib/site-packages/urllib3/packages/ssl_match_hostname/__init__.py

@@ -0,0 +1,19 @@
+import sys
+
+try:
+    # Our match_hostname function is the same as 3.5's, so we only want to
+    # import the match_hostname function if it's at least that good.
+    if sys.version_info < (3, 5):
+        raise ImportError("Fallback to vendored code")
+
+    from ssl import CertificateError, match_hostname
+except ImportError:
+    try:
+        # Backport of the function from a pypi module
+        from backports.ssl_match_hostname import CertificateError, match_hostname
+    except ImportError:
+        # Our vendored copy
+        from ._implementation import CertificateError, match_hostname
+
+# Not needed, but documenting what we provide.
+__all__ = ("CertificateError", "match_hostname")

venv/Lib/site-packages/urllib3/packages/ssl_match_hostname/_implementation.py

@@ -0,0 +1,160 @@
+"""The match_hostname() function from Python 3.3.3, essential when using SSL."""
+
+# Note: This file is under the PSF license as the code comes from the python
+# stdlib.   http://docs.python.org/3/license.html
+
+import re
+import sys
+
+# ipaddress has been backported to 2.6+ in pypi.  If it is installed on the
+# system, use it to handle IPAddress ServerAltnames (this was added in
+# python-3.5) otherwise only do DNS matching.  This allows
+# backports.ssl_match_hostname to continue to be used in Python 2.7.
+try:
+    import ipaddress
+except ImportError:
+    ipaddress = None
+
+__version__ = "3.5.0.1"
+
+
+class CertificateError(ValueError):
+    pass
+
+
+def _dnsname_match(dn, hostname, max_wildcards=1):
+    """Matching according to RFC 6125, section 6.4.3
+
+    http://tools.ietf.org/html/rfc6125#section-6.4.3
+    """
+    pats = []
+    if not dn:
+        return False
+
+    # Ported from python3-syntax:
+    # leftmost, *remainder = dn.split(r'.')
+    parts = dn.split(r".")
+    leftmost = parts[0]
+    remainder = parts[1:]
+
+    wildcards = leftmost.count("*")
+    if wildcards > max_wildcards:
+        # Issue #17980: avoid denials of service by refusing more
+        # than one wildcard per fragment.  A survey of established
+        # policy among SSL implementations showed it to be a
+        # reasonable choice.
+        raise CertificateError(
+            "too many wildcards in certificate DNS name: " + repr(dn)
+        )
+
+    # speed up common case w/o wildcards
+    if not wildcards:
+        return dn.lower() == hostname.lower()
+
+    # RFC 6125, section 6.4.3, subitem 1.
+    # The client SHOULD NOT attempt to match a presented identifier in which
+    # the wildcard character comprises a label other than the left-most label.
+    if leftmost == "*":
+        # When '*' is a fragment by itself, it matches a non-empty dotless
+        # fragment.
+        pats.append("[^.]+")
+    elif leftmost.startswith("xn--") or hostname.startswith("xn--"):
+        # RFC 6125, section 6.4.3, subitem 3.
+        # The client SHOULD NOT attempt to match a presented identifier
+        # where the wildcard character is embedded within an A-label or
+        # U-label of an internationalized domain name.
+        pats.append(re.escape(leftmost))
+    else:
+        # Otherwise, '*' matches any dotless string, e.g. www*
+        pats.append(re.escape(leftmost).replace(r"\*", "[^.]*"))
+
+    # add the remaining fragments, ignore any wildcards
+    for frag in remainder:
+        pats.append(re.escape(frag))
+
+    pat = re.compile(r"\A" + r"\.".join(pats) + r"\Z", re.IGNORECASE)
+    return pat.match(hostname)
+
+
+def _to_unicode(obj):
+    if isinstance(obj, str) and sys.version_info < (3,):
+        obj = unicode(obj, encoding="ascii", errors="strict")
+    return obj
+
+
+def _ipaddress_match(ipname, host_ip):
+    """Exact matching of IP addresses.
+
+    RFC 6125 explicitly doesn't define an algorithm for this
+    (section 1.7.2 - "Out of Scope").
+    """
+    # OpenSSL may add a trailing newline to a subjectAltName's IP address
+    # Divergence from upstream: ipaddress can't handle byte str
+    ip = ipaddress.ip_address(_to_unicode(ipname).rstrip())
+    return ip == host_ip
+
+
+def match_hostname(cert, hostname):
+    """Verify that *cert* (in decoded format as returned by
+    SSLSocket.getpeercert()) matches the *hostname*.  RFC 2818 and RFC 6125
+    rules are followed, but IP addresses are not accepted for *hostname*.
+
+    CertificateError is raised on failure. On success, the function
+    returns nothing.
+    """
+    if not cert:
+        raise ValueError(
+            "empty or no certificate, match_hostname needs a "
+            "SSL socket or SSL context with either "
+            "CERT_OPTIONAL or CERT_REQUIRED"
+        )
+    try:
+        # Divergence from upstream: ipaddress can't handle byte str
+        host_ip = ipaddress.ip_address(_to_unicode(hostname))
+    except ValueError:
+        # Not an IP address (common case)
+        host_ip = None
+    except UnicodeError:
+        # Divergence from upstream: Have to deal with ipaddress not taking
+        # byte strings.  addresses should be all ascii, so we consider it not
+        # an ipaddress in this case
+        host_ip = None
+    except AttributeError:
+        # Divergence from upstream: Make ipaddress library optional
+        if ipaddress is None:
+            host_ip = None
+        else:
+            raise
+    dnsnames = []
+    san = cert.get("subjectAltName", ())
+    for key, value in san:
+        if key == "DNS":
+            if host_ip is None and _dnsname_match(value, hostname):
+                return
+            dnsnames.append(value)
+        elif key == "IP Address":
+            if host_ip is not None and _ipaddress_match(value, host_ip):
+                return
+            dnsnames.append(value)
+    if not dnsnames:
+        # The subject is only checked when there is no dNSName entry
+        # in subjectAltName
+        for sub in cert.get("subject", ()):
+            for key, value in sub:
+                # XXX according to RFC 2818, the most specific Common Name
+                # must be used.
+                if key == "commonName":
+                    if _dnsname_match(value, hostname):
+                        return
+                    dnsnames.append(value)
+    if len(dnsnames) > 1:
+        raise CertificateError(
+            "hostname %r "
+            "doesn't match either of %s" % (hostname, ", ".join(map(repr, dnsnames)))
+        )
+    elif len(dnsnames) == 1:
+        raise CertificateError("hostname %r doesn't match %r" % (hostname, dnsnames[0]))
+    else:
+        raise CertificateError(
+            "no appropriate commonName or subjectAltName fields were found"
+        )

venv/Lib/site-packages/urllib3/poolmanager.py

@@ -0,0 +1,492 @@
+from __future__ import absolute_import
+import collections
+import functools
+import logging
+import warnings
+
+from ._collections import RecentlyUsedContainer
+from .connectionpool import HTTPConnectionPool, HTTPSConnectionPool
+from .connectionpool import port_by_scheme
+from .exceptions import (
+    LocationValueError,
+    MaxRetryError,
+    ProxySchemeUnknown,
+    InvalidProxyConfigurationWarning,
+)
+from .packages import six
+from .packages.six.moves.urllib.parse import urljoin
+from .request import RequestMethods
+from .util.url import parse_url
+from .util.retry import Retry
+
+
+__all__ = ["PoolManager", "ProxyManager", "proxy_from_url"]
+
+
+log = logging.getLogger(__name__)
+
+SSL_KEYWORDS = (
+    "key_file",
+    "cert_file",
+    "cert_reqs",
+    "ca_certs",
+    "ssl_version",
+    "ca_cert_dir",
+    "ssl_context",
+    "key_password",
+)
+
+# All known keyword arguments that could be provided to the pool manager, its
+# pools, or the underlying connections. This is used to construct a pool key.
+_key_fields = (
+    "key_scheme",  # str
+    "key_host",  # str
+    "key_port",  # int
+    "key_timeout",  # int or float or Timeout
+    "key_retries",  # int or Retry
+    "key_strict",  # bool
+    "key_block",  # bool
+    "key_source_address",  # str
+    "key_key_file",  # str
+    "key_key_password",  # str
+    "key_cert_file",  # str
+    "key_cert_reqs",  # str
+    "key_ca_certs",  # str
+    "key_ssl_version",  # str
+    "key_ca_cert_dir",  # str
+    "key_ssl_context",  # instance of ssl.SSLContext or urllib3.util.ssl_.SSLContext
+    "key_maxsize",  # int
+    "key_headers",  # dict
+    "key__proxy",  # parsed proxy url
+    "key__proxy_headers",  # dict
+    "key_socket_options",  # list of (level (int), optname (int), value (int or str)) tuples
+    "key__socks_options",  # dict
+    "key_assert_hostname",  # bool or string
+    "key_assert_fingerprint",  # str
+    "key_server_hostname",  # str
+)
+
+#: The namedtuple class used to construct keys for the connection pool.
+#: All custom key schemes should include the fields in this key at a minimum.
+PoolKey = collections.namedtuple("PoolKey", _key_fields)
+
+
+def _default_key_normalizer(key_class, request_context):
+    """
+    Create a pool key out of a request context dictionary.
+
+    According to RFC 3986, both the scheme and host are case-insensitive.
+    Therefore, this function normalizes both before constructing the pool
+    key for an HTTPS request. If you wish to change this behaviour, provide
+    alternate callables to ``key_fn_by_scheme``.
+
+    :param key_class:
+        The class to use when constructing the key. This should be a namedtuple
+        with the ``scheme`` and ``host`` keys at a minimum.
+    :type  key_class: namedtuple
+    :param request_context:
+        A dictionary-like object that contain the context for a request.
+    :type  request_context: dict
+
+    :return: A namedtuple that can be used as a connection pool key.
+    :rtype:  PoolKey
+    """
+    # Since we mutate the dictionary, make a copy first
+    context = request_context.copy()
+    context["scheme"] = context["scheme"].lower()
+    context["host"] = context["host"].lower()
+
+    # These are both dictionaries and need to be transformed into frozensets
+    for key in ("headers", "_proxy_headers", "_socks_options"):
+        if key in context and context[key] is not None:
+            context[key] = frozenset(context[key].items())
+
+    # The socket_options key may be a list and needs to be transformed into a
+    # tuple.
+    socket_opts = context.get("socket_options")
+    if socket_opts is not None:
+        context["socket_options"] = tuple(socket_opts)
+
+    # Map the kwargs to the names in the namedtuple - this is necessary since
+    # namedtuples can't have fields starting with '_'.
+    for key in list(context.keys()):
+        context["key_" + key] = context.pop(key)
+
+    # Default to ``None`` for keys missing from the context
+    for field in key_class._fields:
+        if field not in context:
+            context[field] = None
+
+    return key_class(**context)
+
+
+#: A dictionary that maps a scheme to a callable that creates a pool key.
+#: This can be used to alter the way pool keys are constructed, if desired.
+#: Each PoolManager makes a copy of this dictionary so they can be configured
+#: globally here, or individually on the instance.
+key_fn_by_scheme = {
+    "http": functools.partial(_default_key_normalizer, PoolKey),
+    "https": functools.partial(_default_key_normalizer, PoolKey),
+}
+
+pool_classes_by_scheme = {"http": HTTPConnectionPool, "https": HTTPSConnectionPool}
+
+
+class PoolManager(RequestMethods):
+    """
+    Allows for arbitrary requests while transparently keeping track of
+    necessary connection pools for you.
+
+    :param num_pools:
+        Number of connection pools to cache before discarding the least
+        recently used pool.
+
+    :param headers:
+        Headers to include with all requests, unless other headers are given
+        explicitly.
+
+    :param \\**connection_pool_kw:
+        Additional parameters are used to create fresh
+        :class:`urllib3.connectionpool.ConnectionPool` instances.
+
+    Example::
+
+        >>> manager = PoolManager(num_pools=2)
+        >>> r = manager.request('GET', 'http://google.com/')
+        >>> r = manager.request('GET', 'http://google.com/mail')
+        >>> r = manager.request('GET', 'http://yahoo.com/')
+        >>> len(manager.pools)
+        2
+
+    """
+
+    proxy = None
+
+    def __init__(self, num_pools=10, headers=None, **connection_pool_kw):
+        RequestMethods.__init__(self, headers)
+        self.connection_pool_kw = connection_pool_kw
+        self.pools = RecentlyUsedContainer(num_pools, dispose_func=lambda p: p.close())
+
+        # Locally set the pool classes and keys so other PoolManagers can
+        # override them.
+        self.pool_classes_by_scheme = pool_classes_by_scheme
+        self.key_fn_by_scheme = key_fn_by_scheme.copy()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.clear()
+        # Return False to re-raise any potential exceptions
+        return False
+
+    def _new_pool(self, scheme, host, port, request_context=None):
+        """
+        Create a new :class:`ConnectionPool` based on host, port, scheme, and
+        any additional pool keyword arguments.
+
+        If ``request_context`` is provided, it is provided as keyword arguments
+        to the pool class used. This method is used to actually create the
+        connection pools handed out by :meth:`connection_from_url` and
+        companion methods. It is intended to be overridden for customization.
+        """
+        pool_cls = self.pool_classes_by_scheme[scheme]
+        if request_context is None:
+            request_context = self.connection_pool_kw.copy()
+
+        # Although the context has everything necessary to create the pool,
+        # this function has historically only used the scheme, host, and port
+        # in the positional args. When an API change is acceptable these can
+        # be removed.
+        for key in ("scheme", "host", "port"):
+            request_context.pop(key, None)
+
+        if scheme == "http":
+            for kw in SSL_KEYWORDS:
+                request_context.pop(kw, None)
+
+        return pool_cls(host, port, **request_context)
+
+    def clear(self):
+        """
+        Empty our store of pools and direct them all to close.
+
+        This will not affect in-flight connections, but they will not be
+        re-used after completion.
+        """
+        self.pools.clear()
+
+    def connection_from_host(self, host, port=None, scheme="http", pool_kwargs=None):
+        """
+        Get a :class:`ConnectionPool` based on the host, port, and scheme.
+
+        If ``port`` isn't given, it will be derived from the ``scheme`` using
+        ``urllib3.connectionpool.port_by_scheme``. If ``pool_kwargs`` is
+        provided, it is merged with the instance's ``connection_pool_kw``
+        variable and used to create the new connection pool, if one is
+        needed.
+        """
+
+        if not host:
+            raise LocationValueError("No host specified.")
+
+        request_context = self._merge_pool_kwargs(pool_kwargs)
+        request_context["scheme"] = scheme or "http"
+        if not port:
+            port = port_by_scheme.get(request_context["scheme"].lower(), 80)
+        request_context["port"] = port
+        request_context["host"] = host
+
+        return self.connection_from_context(request_context)
+
+    def connection_from_context(self, request_context):
+        """
+        Get a :class:`ConnectionPool` based on the request context.
+
+        ``request_context`` must at least contain the ``scheme`` key and its
+        value must be a key in ``key_fn_by_scheme`` instance variable.
+        """
+        scheme = request_context["scheme"].lower()
+        pool_key_constructor = self.key_fn_by_scheme[scheme]
+        pool_key = pool_key_constructor(request_context)
+
+        return self.connection_from_pool_key(pool_key, request_context=request_context)
+
+    def connection_from_pool_key(self, pool_key, request_context=None):
+        """
+        Get a :class:`ConnectionPool` based on the provided pool key.
+
+        ``pool_key`` should be a namedtuple that only contains immutable
+        objects. At a minimum it must have the ``scheme``, ``host``, and
+        ``port`` fields.
+        """
+        with self.pools.lock:
+            # If the scheme, host, or port doesn't match existing open
+            # connections, open a new ConnectionPool.
+            pool = self.pools.get(pool_key)
+            if pool:
+                return pool
+
+            # Make a fresh ConnectionPool of the desired type
+            scheme = request_context["scheme"]
+            host = request_context["host"]
+            port = request_context["port"]
+            pool = self._new_pool(scheme, host, port, request_context=request_context)
+            self.pools[pool_key] = pool
+
+        return pool
+
+    def connection_from_url(self, url, pool_kwargs=None):
+        """
+        Similar to :func:`urllib3.connectionpool.connection_from_url`.
+
+        If ``pool_kwargs`` is not provided and a new pool needs to be
+        constructed, ``self.connection_pool_kw`` is used to initialize
+        the :class:`urllib3.connectionpool.ConnectionPool`. If ``pool_kwargs``
+        is provided, it is used instead. Note that if a new pool does not
+        need to be created for the request, the provided ``pool_kwargs`` are
+        not used.
+        """
+        u = parse_url(url)
+        return self.connection_from_host(
+            u.host, port=u.port, scheme=u.scheme, pool_kwargs=pool_kwargs
+        )
+
+    def _merge_pool_kwargs(self, override):
+        """
+        Merge a dictionary of override values for self.connection_pool_kw.
+
+        This does not modify self.connection_pool_kw and returns a new dict.
+        Any keys in the override dictionary with a value of ``None`` are
+        removed from the merged dictionary.
+        """
+        base_pool_kwargs = self.connection_pool_kw.copy()
+        if override:
+            for key, value in override.items():
+                if value is None:
+                    try:
+                        del base_pool_kwargs[key]
+                    except KeyError:
+                        pass
+                else:
+                    base_pool_kwargs[key] = value
+        return base_pool_kwargs
+
+    def urlopen(self, method, url, redirect=True, **kw):
+        """
+        Same as :meth:`urllib3.connectionpool.HTTPConnectionPool.urlopen`
+        with custom cross-host redirect logic and only sends the request-uri
+        portion of the ``url``.
+
+        The given ``url`` parameter must be absolute, such that an appropriate
+        :class:`urllib3.connectionpool.ConnectionPool` can be chosen for it.
+        """
+        u = parse_url(url)
+        conn = self.connection_from_host(u.host, port=u.port, scheme=u.scheme)
+
+        kw["assert_same_host"] = False
+        kw["redirect"] = False
+
+        if "headers" not in kw:
+            kw["headers"] = self.headers.copy()
+
+        if self.proxy is not None and u.scheme == "http":
+            response = conn.urlopen(method, url, **kw)
+        else:
+            response = conn.urlopen(method, u.request_uri, **kw)
+
+        redirect_location = redirect and response.get_redirect_location()
+        if not redirect_location:
+            return response
+
+        # Support relative URLs for redirecting.
+        redirect_location = urljoin(url, redirect_location)
+
+        # RFC 7231, Section 6.4.4
+        if response.status == 303:
+            method = "GET"
+
+        retries = kw.get("retries")
+        if not isinstance(retries, Retry):
+            retries = Retry.from_int(retries, redirect=redirect)
+
+        # Strip headers marked as unsafe to forward to the redirected location.
+        # Check remove_headers_on_redirect to avoid a potential network call within
+        # conn.is_same_host() which may use socket.gethostbyname() in the future.
+        if retries.remove_headers_on_redirect and not conn.is_same_host(
+            redirect_location
+        ):
+            headers = list(six.iterkeys(kw["headers"]))
+            for header in headers:
+                if header.lower() in retries.remove_headers_on_redirect:
+                    kw["headers"].pop(header, None)
+
+        try:
+            retries = retries.increment(method, url, response=response, _pool=conn)
+        except MaxRetryError:
+            if retries.raise_on_redirect:
+                response.drain_conn()
+                raise
+            return response
+
+        kw["retries"] = retries
+        kw["redirect"] = redirect
+
+        log.info("Redirecting %s -> %s", url, redirect_location)
+
+        response.drain_conn()
+        return self.urlopen(method, redirect_location, **kw)
+
+
+class ProxyManager(PoolManager):
+    """
+    Behaves just like :class:`PoolManager`, but sends all requests through
+    the defined proxy, using the CONNECT method for HTTPS URLs.
+
+    :param proxy_url:
+        The URL of the proxy to be used.
+
+    :param proxy_headers:
+        A dictionary containing headers that will be sent to the proxy. In case
+        of HTTP they are being sent with each request, while in the
+        HTTPS/CONNECT case they are sent only once. Could be used for proxy
+        authentication.
+
+    Example:
+        >>> proxy = urllib3.ProxyManager('http://localhost:3128/')
+        >>> r1 = proxy.request('GET', 'http://google.com/')
+        >>> r2 = proxy.request('GET', 'http://httpbin.org/')
+        >>> len(proxy.pools)
+        1
+        >>> r3 = proxy.request('GET', 'https://httpbin.org/')
+        >>> r4 = proxy.request('GET', 'https://twitter.com/')
+        >>> len(proxy.pools)
+        3
+
+    """
+
+    def __init__(
+        self,
+        proxy_url,
+        num_pools=10,
+        headers=None,
+        proxy_headers=None,
+        **connection_pool_kw
+    ):
+
+        if isinstance(proxy_url, HTTPConnectionPool):
+            proxy_url = "%s://%s:%i" % (
+                proxy_url.scheme,
+                proxy_url.host,
+                proxy_url.port,
+            )
+        proxy = parse_url(proxy_url)
+        if not proxy.port:
+            port = port_by_scheme.get(proxy.scheme, 80)
+            proxy = proxy._replace(port=port)
+
+        if proxy.scheme not in ("http", "https"):
+            raise ProxySchemeUnknown(proxy.scheme)
+
+        self.proxy = proxy
+        self.proxy_headers = proxy_headers or {}
+
+        connection_pool_kw["_proxy"] = self.proxy
+        connection_pool_kw["_proxy_headers"] = self.proxy_headers
+
+        super(ProxyManager, self).__init__(num_pools, headers, **connection_pool_kw)
+
+    def connection_from_host(self, host, port=None, scheme="http", pool_kwargs=None):
+        if scheme == "https":
+            return super(ProxyManager, self).connection_from_host(
+                host, port, scheme, pool_kwargs=pool_kwargs
+            )
+
+        return super(ProxyManager, self).connection_from_host(
+            self.proxy.host, self.proxy.port, self.proxy.scheme, pool_kwargs=pool_kwargs
+        )
+
+    def _set_proxy_headers(self, url, headers=None):
+        """
+        Sets headers needed by proxies: specifically, the Accept and Host
+        headers. Only sets headers not provided by the user.
+        """
+        headers_ = {"Accept": "*/*"}
+
+        netloc = parse_url(url).netloc
+        if netloc:
+            headers_["Host"] = netloc
+
+        if headers:
+            headers_.update(headers)
+        return headers_
+
+    def _validate_proxy_scheme_url_selection(self, url_scheme):
+        if url_scheme == "https" and self.proxy.scheme == "https":
+            warnings.warn(
+                "Your proxy configuration specified an HTTPS scheme for the proxy. "
+                "Are you sure you want to use HTTPS to contact the proxy? "
+                "This most likely indicates an error in your configuration. "
+                "Read this issue for more info: "
+                "https://github.com/urllib3/urllib3/issues/1850",
+                InvalidProxyConfigurationWarning,
+                stacklevel=3,
+            )
+
+    def urlopen(self, method, url, redirect=True, **kw):
+        "Same as HTTP(S)ConnectionPool.urlopen, ``url`` must be absolute."
+        u = parse_url(url)
+        self._validate_proxy_scheme_url_selection(u.scheme)
+
+        if u.scheme == "http":
+            # For proxied HTTPS requests, httplib sets the necessary headers
+            # on the CONNECT to the proxy. For HTTP, we'll definitely
+            # need to set 'Host' at the very least.
+            headers = kw.get("headers", self.headers)
+            kw["headers"] = self._set_proxy_headers(url, headers)
+
+        return super(ProxyManager, self).urlopen(method, url, redirect=redirect, **kw)
+
+
+def proxy_from_url(url, **kw):
+    return ProxyManager(proxy_url=url, **kw)

venv/Lib/site-packages/urllib3/request.py

@@ -0,0 +1,171 @@
+from __future__ import absolute_import
+
+from .filepost import encode_multipart_formdata
+from .packages.six.moves.urllib.parse import urlencode
+
+
+__all__ = ["RequestMethods"]
+
+
+class RequestMethods(object):
+    """
+    Convenience mixin for classes who implement a :meth:`urlopen` method, such
+    as :class:`~urllib3.connectionpool.HTTPConnectionPool` and
+    :class:`~urllib3.poolmanager.PoolManager`.
+
+    Provides behavior for making common types of HTTP request methods and
+    decides which type of request field encoding to use.
+
+    Specifically,
+
+    :meth:`.request_encode_url` is for sending requests whose fields are
+    encoded in the URL (such as GET, HEAD, DELETE).
+
+    :meth:`.request_encode_body` is for sending requests whose fields are
+    encoded in the *body* of the request using multipart or www-form-urlencoded
+    (such as for POST, PUT, PATCH).
+
+    :meth:`.request` is for making any kind of request, it will look up the
+    appropriate encoding format and use one of the above two methods to make
+    the request.
+
+    Initializer parameters:
+
+    :param headers:
+        Headers to include with all requests, unless other headers are given
+        explicitly.
+    """
+
+    _encode_url_methods = {"DELETE", "GET", "HEAD", "OPTIONS"}
+
+    def __init__(self, headers=None):
+        self.headers = headers or {}
+
+    def urlopen(
+        self,
+        method,
+        url,
+        body=None,
+        headers=None,
+        encode_multipart=True,
+        multipart_boundary=None,
+        **kw
+    ):  # Abstract
+        raise NotImplementedError(
+            "Classes extending RequestMethods must implement "
+            "their own ``urlopen`` method."
+        )
+
+    def request(self, method, url, fields=None, headers=None, **urlopen_kw):
+        """
+        Make a request using :meth:`urlopen` with the appropriate encoding of
+        ``fields`` based on the ``method`` used.
+
+        This is a convenience method that requires the least amount of manual
+        effort. It can be used in most situations, while still having the
+        option to drop down to more specific methods when necessary, such as
+        :meth:`request_encode_url`, :meth:`request_encode_body`,
+        or even the lowest level :meth:`urlopen`.
+        """
+        method = method.upper()
+
+        urlopen_kw["request_url"] = url
+
+        if method in self._encode_url_methods:
+            return self.request_encode_url(
+                method, url, fields=fields, headers=headers, **urlopen_kw
+            )
+        else:
+            return self.request_encode_body(
+                method, url, fields=fields, headers=headers, **urlopen_kw
+            )
+
+    def request_encode_url(self, method, url, fields=None, headers=None, **urlopen_kw):
+        """
+        Make a request using :meth:`urlopen` with the ``fields`` encoded in
+        the url. This is useful for request methods like GET, HEAD, DELETE, etc.
+        """
+        if headers is None:
+            headers = self.headers
+
+        extra_kw = {"headers": headers}
+        extra_kw.update(urlopen_kw)
+
+        if fields:
+            url += "?" + urlencode(fields)
+
+        return self.urlopen(method, url, **extra_kw)
+
+    def request_encode_body(
+        self,
+        method,
+        url,
+        fields=None,
+        headers=None,
+        encode_multipart=True,
+        multipart_boundary=None,
+        **urlopen_kw
+    ):
+        """
+        Make a request using :meth:`urlopen` with the ``fields`` encoded in
+        the body. This is useful for request methods like POST, PUT, PATCH, etc.
+
+        When ``encode_multipart=True`` (default), then
+        :meth:`urllib3.filepost.encode_multipart_formdata` is used to encode
+        the payload with the appropriate content type. Otherwise
+        :meth:`urllib.urlencode` is used with the
+        'application/x-www-form-urlencoded' content type.
+
+        Multipart encoding must be used when posting files, and it's reasonably
+        safe to use it in other times too. However, it may break request
+        signing, such as with OAuth.
+
+        Supports an optional ``fields`` parameter of key/value strings AND
+        key/filetuple. A filetuple is a (filename, data, MIME type) tuple where
+        the MIME type is optional. For example::
+
+            fields = {
+                'foo': 'bar',
+                'fakefile': ('foofile.txt', 'contents of foofile'),
+                'realfile': ('barfile.txt', open('realfile').read()),
+                'typedfile': ('bazfile.bin', open('bazfile').read(),
+                              'image/jpeg'),
+                'nonamefile': 'contents of nonamefile field',
+            }
+
+        When uploading a file, providing a filename (the first parameter of the
+        tuple) is optional but recommended to best mimic behavior of browsers.
+
+        Note that if ``headers`` are supplied, the 'Content-Type' header will
+        be overwritten because it depends on the dynamic random boundary string
+        which is used to compose the body of the request. The random boundary
+        string can be explicitly set with the ``multipart_boundary`` parameter.
+        """
+        if headers is None:
+            headers = self.headers
+
+        extra_kw = {"headers": {}}
+
+        if fields:
+            if "body" in urlopen_kw:
+                raise TypeError(
+                    "request got values for both 'fields' and 'body', can only specify one."
+                )
+
+            if encode_multipart:
+                body, content_type = encode_multipart_formdata(
+                    fields, boundary=multipart_boundary
+                )
+            else:
+                body, content_type = (
+                    urlencode(fields),
+                    "application/x-www-form-urlencoded",
+                )
+
+            extra_kw["body"] = body
+            extra_kw["headers"] = {"Content-Type": content_type}
+
+        extra_kw["headers"].update(headers)
+        extra_kw.update(urlopen_kw)
+
+        return self.urlopen(method, url, **extra_kw)

venv/Lib/site-packages/urllib3/response.py

@@ -0,0 +1,820 @@
+from __future__ import absolute_import
+from contextlib import contextmanager
+import zlib
+import io
+import logging
+from socket import timeout as SocketTimeout
+from socket import error as SocketError
+
+try:
+    import brotli
+except ImportError:
+    brotli = None
+
+from ._collections import HTTPHeaderDict
+from .exceptions import (
+    BodyNotHttplibCompatible,
+    ProtocolError,
+    DecodeError,
+    ReadTimeoutError,
+    ResponseNotChunked,
+    IncompleteRead,
+    InvalidHeader,
+    HTTPError,
+)
+from .packages.six import string_types as basestring, PY3
+from .packages.six.moves import http_client as httplib
+from .connection import HTTPException, BaseSSLError
+from .util.response import is_fp_closed, is_response_to_head
+
+log = logging.getLogger(__name__)
+
+
+class DeflateDecoder(object):
+    def __init__(self):
+        self._first_try = True
+        self._data = b""
+        self._obj = zlib.decompressobj()
+
+    def __getattr__(self, name):
+        return getattr(self._obj, name)
+
+    def decompress(self, data):
+        if not data:
+            return data
+
+        if not self._first_try:
+            return self._obj.decompress(data)
+
+        self._data += data
+        try:
+            decompressed = self._obj.decompress(data)
+            if decompressed:
+                self._first_try = False
+                self._data = None
+            return decompressed
+        except zlib.error:
+            self._first_try = False
+            self._obj = zlib.decompressobj(-zlib.MAX_WBITS)
+            try:
+                return self.decompress(self._data)
+            finally:
+                self._data = None
+
+
+class GzipDecoderState(object):
+
+    FIRST_MEMBER = 0
+    OTHER_MEMBERS = 1
+    SWALLOW_DATA = 2
+
+
+class GzipDecoder(object):
+    def __init__(self):
+        self._obj = zlib.decompressobj(16 + zlib.MAX_WBITS)
+        self._state = GzipDecoderState.FIRST_MEMBER
+
+    def __getattr__(self, name):
+        return getattr(self._obj, name)
+
+    def decompress(self, data):
+        ret = bytearray()
+        if self._state == GzipDecoderState.SWALLOW_DATA or not data:
+            return bytes(ret)
+        while True:
+            try:
+                ret += self._obj.decompress(data)
+            except zlib.error:
+                previous_state = self._state
+                # Ignore data after the first error
+                self._state = GzipDecoderState.SWALLOW_DATA
+                if previous_state == GzipDecoderState.OTHER_MEMBERS:
+                    # Allow trailing garbage acceptable in other gzip clients
+                    return bytes(ret)
+                raise
+            data = self._obj.unused_data
+            if not data:
+                return bytes(ret)
+            self._state = GzipDecoderState.OTHER_MEMBERS
+            self._obj = zlib.decompressobj(16 + zlib.MAX_WBITS)
+
+
+if brotli is not None:
+
+    class BrotliDecoder(object):
+        # Supports both 'brotlipy' and 'Brotli' packages
+        # since they share an import name. The top branches
+        # are for 'brotlipy' and bottom branches for 'Brotli'
+        def __init__(self):
+            self._obj = brotli.Decompressor()
+            if hasattr(self._obj, "decompress"):
+                self.decompress = self._obj.decompress
+            else:
+                self.decompress = self._obj.process
+
+        def flush(self):
+            if hasattr(self._obj, "flush"):
+                return self._obj.flush()
+            return b""
+
+
+class MultiDecoder(object):
+    """
+    From RFC7231:
+        If one or more encodings have been applied to a representation, the
+        sender that applied the encodings MUST generate a Content-Encoding
+        header field that lists the content codings in the order in which
+        they were applied.
+    """
+
+    def __init__(self, modes):
+        self._decoders = [_get_decoder(m.strip()) for m in modes.split(",")]
+
+    def flush(self):
+        return self._decoders[0].flush()
+
+    def decompress(self, data):
+        for d in reversed(self._decoders):
+            data = d.decompress(data)
+        return data
+
+
+def _get_decoder(mode):
+    if "," in mode:
+        return MultiDecoder(mode)
+
+    if mode == "gzip":
+        return GzipDecoder()
+
+    if brotli is not None and mode == "br":
+        return BrotliDecoder()
+
+    return DeflateDecoder()
+
+
+class HTTPResponse(io.IOBase):
+    """
+    HTTP Response container.
+
+    Backwards-compatible to httplib's HTTPResponse but the response ``body`` is
+    loaded and decoded on-demand when the ``data`` property is accessed.  This
+    class is also compatible with the Python standard library's :mod:`io`
+    module, and can hence be treated as a readable object in the context of that
+    framework.
+
+    Extra parameters for behaviour not present in httplib.HTTPResponse:
+
+    :param preload_content:
+        If True, the response's body will be preloaded during construction.
+
+    :param decode_content:
+        If True, will attempt to decode the body based on the
+        'content-encoding' header.
+
+    :param original_response:
+        When this HTTPResponse wrapper is generated from an httplib.HTTPResponse
+        object, it's convenient to include the original for debug purposes. It's
+        otherwise unused.
+
+    :param retries:
+        The retries contains the last :class:`~urllib3.util.retry.Retry` that
+        was used during the request.
+
+    :param enforce_content_length:
+        Enforce content length checking. Body returned by server must match
+        value of Content-Length header, if present. Otherwise, raise error.
+    """
+
+    CONTENT_DECODERS = ["gzip", "deflate"]
+    if brotli is not None:
+        CONTENT_DECODERS += ["br"]
+    REDIRECT_STATUSES = [301, 302, 303, 307, 308]
+
+    def __init__(
+        self,
+        body="",
+        headers=None,
+        status=0,
+        version=0,
+        reason=None,
+        strict=0,
+        preload_content=True,
+        decode_content=True,
+        original_response=None,
+        pool=None,
+        connection=None,
+        msg=None,
+        retries=None,
+        enforce_content_length=False,
+        request_method=None,
+        request_url=None,
+        auto_close=True,
+    ):
+
+        if isinstance(headers, HTTPHeaderDict):
+            self.headers = headers
+        else:
+            self.headers = HTTPHeaderDict(headers)
+        self.status = status
+        self.version = version
+        self.reason = reason
+        self.strict = strict
+        self.decode_content = decode_content
+        self.retries = retries
+        self.enforce_content_length = enforce_content_length
+        self.auto_close = auto_close
+
+        self._decoder = None
+        self._body = None
+        self._fp = None
+        self._original_response = original_response
+        self._fp_bytes_read = 0
+        self.msg = msg
+        self._request_url = request_url
+
+        if body and isinstance(body, (basestring, bytes)):
+            self._body = body
+
+        self._pool = pool
+        self._connection = connection
+
+        if hasattr(body, "read"):
+            self._fp = body
+
+        # Are we using the chunked-style of transfer encoding?
+        self.chunked = False
+        self.chunk_left = None
+        tr_enc = self.headers.get("transfer-encoding", "").lower()
+        # Don't incur the penalty of creating a list and then discarding it
+        encodings = (enc.strip() for enc in tr_enc.split(","))
+        if "chunked" in encodings:
+            self.chunked = True
+
+        # Determine length of response
+        self.length_remaining = self._init_length(request_method)
+
+        # If requested, preload the body.
+        if preload_content and not self._body:
+            self._body = self.read(decode_content=decode_content)
+
+    def get_redirect_location(self):
+        """
+        Should we redirect and where to?
+
+        :returns: Truthy redirect location string if we got a redirect status
+            code and valid location. ``None`` if redirect status and no
+            location. ``False`` if not a redirect status code.
+        """
+        if self.status in self.REDIRECT_STATUSES:
+            return self.headers.get("location")
+
+        return False
+
+    def release_conn(self):
+        if not self._pool or not self._connection:
+            return
+
+        self._pool._put_conn(self._connection)
+        self._connection = None
+
+    def drain_conn(self):
+        """
+        Read and discard any remaining HTTP response data in the response connection.
+
+        Unread data in the HTTPResponse connection blocks the connection from being released back to the pool.
+        """
+        try:
+            self.read()
+        except (HTTPError, SocketError, BaseSSLError, HTTPException):
+            pass
+
+    @property
+    def data(self):
+        # For backwords-compat with earlier urllib3 0.4 and earlier.
+        if self._body:
+            return self._body
+
+        if self._fp:
+            return self.read(cache_content=True)
+
+    @property
+    def connection(self):
+        return self._connection
+
+    def isclosed(self):
+        return is_fp_closed(self._fp)
+
+    def tell(self):
+        """
+        Obtain the number of bytes pulled over the wire so far. May differ from
+        the amount of content returned by :meth:``HTTPResponse.read`` if bytes
+        are encoded on the wire (e.g, compressed).
+        """
+        return self._fp_bytes_read
+
+    def _init_length(self, request_method):
+        """
+        Set initial length value for Response content if available.
+        """
+        length = self.headers.get("content-length")
+
+        if length is not None:
+            if self.chunked:
+                # This Response will fail with an IncompleteRead if it can't be
+                # received as chunked. This method falls back to attempt reading
+                # the response before raising an exception.
+                log.warning(
+                    "Received response with both Content-Length and "
+                    "Transfer-Encoding set. This is expressly forbidden "
+                    "by RFC 7230 sec 3.3.2. Ignoring Content-Length and "
+                    "attempting to process response as Transfer-Encoding: "
+                    "chunked."
+                )
+                return None
+
+            try:
+                # RFC 7230 section 3.3.2 specifies multiple content lengths can
+                # be sent in a single Content-Length header
+                # (e.g. Content-Length: 42, 42). This line ensures the values
+                # are all valid ints and that as long as the `set` length is 1,
+                # all values are the same. Otherwise, the header is invalid.
+                lengths = set([int(val) for val in length.split(",")])
+                if len(lengths) > 1:
+                    raise InvalidHeader(
+                        "Content-Length contained multiple "
+                        "unmatching values (%s)" % length
+                    )
+                length = lengths.pop()
+            except ValueError:
+                length = None
+            else:
+                if length < 0:
+                    length = None
+
+        # Convert status to int for comparison
+        # In some cases, httplib returns a status of "_UNKNOWN"
+        try:
+            status = int(self.status)
+        except ValueError:
+            status = 0
+
+        # Check for responses that shouldn't include a body
+        if status in (204, 304) or 100 <= status < 200 or request_method == "HEAD":
+            length = 0
+
+        return length
+
+    def _init_decoder(self):
+        """
+        Set-up the _decoder attribute if necessary.
+        """
+        # Note: content-encoding value should be case-insensitive, per RFC 7230
+        # Section 3.2
+        content_encoding = self.headers.get("content-encoding", "").lower()
+        if self._decoder is None:
+            if content_encoding in self.CONTENT_DECODERS:
+                self._decoder = _get_decoder(content_encoding)
+            elif "," in content_encoding:
+                encodings = [
+                    e.strip()
+                    for e in content_encoding.split(",")
+                    if e.strip() in self.CONTENT_DECODERS
+                ]
+                if len(encodings):
+                    self._decoder = _get_decoder(content_encoding)
+
+    DECODER_ERROR_CLASSES = (IOError, zlib.error)
+    if brotli is not None:
+        DECODER_ERROR_CLASSES += (brotli.error,)
+
+    def _decode(self, data, decode_content, flush_decoder):
+        """
+        Decode the data passed in and potentially flush the decoder.
+        """
+        if not decode_content:
+            return data
+
+        try:
+            if self._decoder:
+                data = self._decoder.decompress(data)
+        except self.DECODER_ERROR_CLASSES as e:
+            content_encoding = self.headers.get("content-encoding", "").lower()
+            raise DecodeError(
+                "Received response with content-encoding: %s, but "
+                "failed to decode it." % content_encoding,
+                e,
+            )
+        if flush_decoder:
+            data += self._flush_decoder()
+
+        return data
+
+    def _flush_decoder(self):
+        """
+        Flushes the decoder. Should only be called if the decoder is actually
+        being used.
+        """
+        if self._decoder:
+            buf = self._decoder.decompress(b"")
+            return buf + self._decoder.flush()
+
+        return b""
+
+    @contextmanager
+    def _error_catcher(self):
+        """
+        Catch low-level python exceptions, instead re-raising urllib3
+        variants, so that low-level exceptions are not leaked in the
+        high-level api.
+
+        On exit, release the connection back to the pool.
+        """
+        clean_exit = False
+
+        try:
+            try:
+                yield
+
+            except SocketTimeout:
+                # FIXME: Ideally we'd like to include the url in the ReadTimeoutError but
+                # there is yet no clean way to get at it from this context.
+                raise ReadTimeoutError(self._pool, None, "Read timed out.")
+
+            except BaseSSLError as e:
+                # FIXME: Is there a better way to differentiate between SSLErrors?
+                if "read operation timed out" not in str(e):  # Defensive:
+                    # This shouldn't happen but just in case we're missing an edge
+                    # case, let's avoid swallowing SSL errors.
+                    raise
+
+                raise ReadTimeoutError(self._pool, None, "Read timed out.")
+
+            except (HTTPException, SocketError) as e:
+                # This includes IncompleteRead.
+                raise ProtocolError("Connection broken: %r" % e, e)
+
+            # If no exception is thrown, we should avoid cleaning up
+            # unnecessarily.
+            clean_exit = True
+        finally:
+            # If we didn't terminate cleanly, we need to throw away our
+            # connection.
+            if not clean_exit:
+                # The response may not be closed but we're not going to use it
+                # anymore so close it now to ensure that the connection is
+                # released back to the pool.
+                if self._original_response:
+                    self._original_response.close()
+
+                # Closing the response may not actually be sufficient to close
+                # everything, so if we have a hold of the connection close that
+                # too.
+                if self._connection:
+                    self._connection.close()
+
+            # If we hold the original response but it's closed now, we should
+            # return the connection back to the pool.
+            if self._original_response and self._original_response.isclosed():
+                self.release_conn()
+
+    def read(self, amt=None, decode_content=None, cache_content=False):
+        """
+        Similar to :meth:`httplib.HTTPResponse.read`, but with two additional
+        parameters: ``decode_content`` and ``cache_content``.
+
+        :param amt:
+            How much of the content to read. If specified, caching is skipped
+            because it doesn't make sense to cache partial content as the full
+            response.
+
+        :param decode_content:
+            If True, will attempt to decode the body based on the
+            'content-encoding' header.
+
+        :param cache_content:
+            If True, will save the returned data such that the same result is
+            returned despite of the state of the underlying file object. This
+            is useful if you want the ``.data`` property to continue working
+            after having ``.read()`` the file object. (Overridden if ``amt`` is
+            set.)
+        """
+        self._init_decoder()
+        if decode_content is None:
+            decode_content = self.decode_content
+
+        if self._fp is None:
+            return
+
+        flush_decoder = False
+        fp_closed = getattr(self._fp, "closed", False)
+
+        with self._error_catcher():
+            if amt is None:
+                # cStringIO doesn't like amt=None
+                data = self._fp.read() if not fp_closed else b""
+                flush_decoder = True
+            else:
+                cache_content = False
+                data = self._fp.read(amt) if not fp_closed else b""
+                if (
+                    amt != 0 and not data
+                ):  # Platform-specific: Buggy versions of Python.
+                    # Close the connection when no data is returned
+                    #
+                    # This is redundant to what httplib/http.client _should_
+                    # already do.  However, versions of python released before
+                    # December 15, 2012 (http://bugs.python.org/issue16298) do
+                    # not properly close the connection in all cases. There is
+                    # no harm in redundantly calling close.
+                    self._fp.close()
+                    flush_decoder = True
+                    if self.enforce_content_length and self.length_remaining not in (
+                        0,
+                        None,
+                    ):
+                        # This is an edge case that httplib failed to cover due
+                        # to concerns of backward compatibility. We're
+                        # addressing it here to make sure IncompleteRead is
+                        # raised during streaming, so all calls with incorrect
+                        # Content-Length are caught.
+                        raise IncompleteRead(self._fp_bytes_read, self.length_remaining)
+
+        if data:
+            self._fp_bytes_read += len(data)
+            if self.length_remaining is not None:
+                self.length_remaining -= len(data)
+
+            data = self._decode(data, decode_content, flush_decoder)
+
+            if cache_content:
+                self._body = data
+
+        return data
+
+    def stream(self, amt=2 ** 16, decode_content=None):
+        """
+        A generator wrapper for the read() method. A call will block until
+        ``amt`` bytes have been read from the connection or until the
+        connection is closed.
+
+        :param amt:
+            How much of the content to read. The generator will return up to
+            much data per iteration, but may return less. This is particularly
+            likely when using compressed data. However, the empty string will
+            never be returned.
+
+        :param decode_content:
+            If True, will attempt to decode the body based on the
+            'content-encoding' header.
+        """
+        if self.chunked and self.supports_chunked_reads():
+            for line in self.read_chunked(amt, decode_content=decode_content):
+                yield line
+        else:
+            while not is_fp_closed(self._fp):
+                data = self.read(amt=amt, decode_content=decode_content)
+
+                if data:
+                    yield data
+
+    @classmethod
+    def from_httplib(ResponseCls, r, **response_kw):
+        """
+        Given an :class:`httplib.HTTPResponse` instance ``r``, return a
+        corresponding :class:`urllib3.response.HTTPResponse` object.
+
+        Remaining parameters are passed to the HTTPResponse constructor, along
+        with ``original_response=r``.
+        """
+        headers = r.msg
+
+        if not isinstance(headers, HTTPHeaderDict):
+            if PY3:
+                headers = HTTPHeaderDict(headers.items())
+            else:
+                # Python 2.7
+                headers = HTTPHeaderDict.from_httplib(headers)
+
+        # HTTPResponse objects in Python 3 don't have a .strict attribute
+        strict = getattr(r, "strict", 0)
+        resp = ResponseCls(
+            body=r,
+            headers=headers,
+            status=r.status,
+            version=r.version,
+            reason=r.reason,
+            strict=strict,
+            original_response=r,
+            **response_kw
+        )
+        return resp
+
+    # Backwards-compatibility methods for httplib.HTTPResponse
+    def getheaders(self):
+        return self.headers
+
+    def getheader(self, name, default=None):
+        return self.headers.get(name, default)
+
+    # Backwards compatibility for http.cookiejar
+    def info(self):
+        return self.headers
+
+    # Overrides from io.IOBase
+    def close(self):
+        if not self.closed:
+            self._fp.close()
+
+        if self._connection:
+            self._connection.close()
+
+        if not self.auto_close:
+            io.IOBase.close(self)
+
+    @property
+    def closed(self):
+        if not self.auto_close:
+            return io.IOBase.closed.__get__(self)
+        elif self._fp is None:
+            return True
+        elif hasattr(self._fp, "isclosed"):
+            return self._fp.isclosed()
+        elif hasattr(self._fp, "closed"):
+            return self._fp.closed
+        else:
+            return True
+
+    def fileno(self):
+        if self._fp is None:
+            raise IOError("HTTPResponse has no file to get a fileno from")
+        elif hasattr(self._fp, "fileno"):
+            return self._fp.fileno()
+        else:
+            raise IOError(
+                "The file-like object this HTTPResponse is wrapped "
+                "around has no file descriptor"
+            )
+
+    def flush(self):
+        if (
+            self._fp is not None
+            and hasattr(self._fp, "flush")
+            and not getattr(self._fp, "closed", False)
+        ):
+            return self._fp.flush()
+
+    def readable(self):
+        # This method is required for `io` module compatibility.
+        return True
+
+    def readinto(self, b):
+        # This method is required for `io` module compatibility.
+        temp = self.read(len(b))
+        if len(temp) == 0:
+            return 0
+        else:
+            b[: len(temp)] = temp
+            return len(temp)
+
+    def supports_chunked_reads(self):
+        """
+        Checks if the underlying file-like object looks like a
+        httplib.HTTPResponse object. We do this by testing for the fp
+        attribute. If it is present we assume it returns raw chunks as
+        processed by read_chunked().
+        """
+        return hasattr(self._fp, "fp")
+
+    def _update_chunk_length(self):
+        # First, we'll figure out length of a chunk and then
+        # we'll try to read it from socket.
+        if self.chunk_left is not None:
+            return
+        line = self._fp.fp.readline()
+        line = line.split(b";", 1)[0]
+        try:
+            self.chunk_left = int(line, 16)
+        except ValueError:
+            # Invalid chunked protocol response, abort.
+            self.close()
+            raise httplib.IncompleteRead(line)
+
+    def _handle_chunk(self, amt):
+        returned_chunk = None
+        if amt is None:
+            chunk = self._fp._safe_read(self.chunk_left)
+            returned_chunk = chunk
+            self._fp._safe_read(2)  # Toss the CRLF at the end of the chunk.
+            self.chunk_left = None
+        elif amt < self.chunk_left:
+            value = self._fp._safe_read(amt)
+            self.chunk_left = self.chunk_left - amt
+            returned_chunk = value
+        elif amt == self.chunk_left:
+            value = self._fp._safe_read(amt)
+            self._fp._safe_read(2)  # Toss the CRLF at the end of the chunk.
+            self.chunk_left = None
+            returned_chunk = value
+        else:  # amt > self.chunk_left
+            returned_chunk = self._fp._safe_read(self.chunk_left)
+            self._fp._safe_read(2)  # Toss the CRLF at the end of the chunk.
+            self.chunk_left = None
+        return returned_chunk
+
+    def read_chunked(self, amt=None, decode_content=None):
+        """
+        Similar to :meth:`HTTPResponse.read`, but with an additional
+        parameter: ``decode_content``.
+
+        :param amt:
+            How much of the content to read. If specified, caching is skipped
+            because it doesn't make sense to cache partial content as the full
+            response.
+
+        :param decode_content:
+            If True, will attempt to decode the body based on the
+            'content-encoding' header.
+        """
+        self._init_decoder()
+        # FIXME: Rewrite this method and make it a class with a better structured logic.
+        if not self.chunked:
+            raise ResponseNotChunked(
+                "Response is not chunked. "
+                "Header 'transfer-encoding: chunked' is missing."
+            )
+        if not self.supports_chunked_reads():
+            raise BodyNotHttplibCompatible(
+                "Body should be httplib.HTTPResponse like. "
+                "It should have have an fp attribute which returns raw chunks."
+            )
+
+        with self._error_catcher():
+            # Don't bother reading the body of a HEAD request.
+            if self._original_response and is_response_to_head(self._original_response):
+                self._original_response.close()
+                return
+
+            # If a response is already read and closed
+            # then return immediately.
+            if self._fp.fp is None:
+                return
+
+            while True:
+                self._update_chunk_length()
+                if self.chunk_left == 0:
+                    break
+                chunk = self._handle_chunk(amt)
+                decoded = self._decode(
+                    chunk, decode_content=decode_content, flush_decoder=False
+                )
+                if decoded:
+                    yield decoded
+
+            if decode_content:
+                # On CPython and PyPy, we should never need to flush the
+                # decoder. However, on Jython we *might* need to, so
+                # lets defensively do it anyway.
+                decoded = self._flush_decoder()
+                if decoded:  # Platform-specific: Jython.
+                    yield decoded
+
+            # Chunk content ends with \r\n: discard it.
+            while True:
+                line = self._fp.fp.readline()
+                if not line:
+                    # Some sites may not end with '\r\n'.
+                    break
+                if line == b"\r\n":
+                    break
+
+            # We read everything; close the "file".
+            if self._original_response:
+                self._original_response.close()
+
+    def geturl(self):
+        """
+        Returns the URL that was the source of this response.
+        If the request that generated this response redirected, this method
+        will return the final redirect location.
+        """
+        if self.retries is not None and len(self.retries.history):
+            return self.retries.history[-1].redirect_location
+        else:
+            return self._request_url
+
+    def __iter__(self):
+        buffer = []
+        for chunk in self.stream(decode_content=True):
+            if b"\n" in chunk:
+                chunk = chunk.split(b"\n")
+                yield b"".join(buffer) + chunk[0] + b"\n"
+                for x in chunk[1:-1]:
+                    yield x + b"\n"
+                if chunk[-1]:
+                    buffer = [chunk[-1]]
+                else:
+                    buffer = []
+            else:
+                buffer.append(chunk)
+        if buffer:
+            yield b"".join(buffer)

venv/Lib/site-packages/urllib3/util/__init__.py

@@ -0,0 +1,46 @@
+from __future__ import absolute_import
+
+# For backwards compatibility, provide imports that used to be here.
+from .connection import is_connection_dropped
+from .request import make_headers
+from .response import is_fp_closed
+from .ssl_ import (
+    SSLContext,
+    HAS_SNI,
+    IS_PYOPENSSL,
+    IS_SECURETRANSPORT,
+    assert_fingerprint,
+    resolve_cert_reqs,
+    resolve_ssl_version,
+    ssl_wrap_socket,
+    PROTOCOL_TLS,
+)
+from .timeout import current_time, Timeout
+
+from .retry import Retry
+from .url import get_host, parse_url, split_first, Url
+from .wait import wait_for_read, wait_for_write
+
+__all__ = (
+    "HAS_SNI",
+    "IS_PYOPENSSL",
+    "IS_SECURETRANSPORT",
+    "SSLContext",
+    "PROTOCOL_TLS",
+    "Retry",
+    "Timeout",
+    "Url",
+    "assert_fingerprint",
+    "current_time",
+    "is_connection_dropped",
+    "is_fp_closed",
+    "get_host",
+    "parse_url",
+    "make_headers",
+    "resolve_cert_reqs",
+    "resolve_ssl_version",
+    "split_first",
+    "ssl_wrap_socket",
+    "wait_for_read",
+    "wait_for_write",
+)

venv/Lib/site-packages/urllib3/util/connection.py

@@ -0,0 +1,138 @@
+from __future__ import absolute_import
+import socket
+from .wait import NoWayToWaitForSocketError, wait_for_read
+from ..contrib import _appengine_environ
+
+
+def is_connection_dropped(conn):  # Platform-specific
+    """
+    Returns True if the connection is dropped and should be closed.
+
+    :param conn:
+        :class:`httplib.HTTPConnection` object.
+
+    Note: For platforms like AppEngine, this will always return ``False`` to
+    let the platform handle connection recycling transparently for us.
+    """
+    sock = getattr(conn, "sock", False)
+    if sock is False:  # Platform-specific: AppEngine
+        return False
+    if sock is None:  # Connection already closed (such as by httplib).
+        return True
+    try:
+        # Returns True if readable, which here means it's been dropped
+        return wait_for_read(sock, timeout=0.0)
+    except NoWayToWaitForSocketError:  # Platform-specific: AppEngine
+        return False
+
+
+# This function is copied from socket.py in the Python 2.7 standard
+# library test suite. Added to its signature is only `socket_options`.
+# One additional modification is that we avoid binding to IPv6 servers
+# discovered in DNS if the system doesn't have IPv6 functionality.
+def create_connection(
+    address,
+    timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+    source_address=None,
+    socket_options=None,
+):
+    """Connect to *address* and return the socket object.
+
+    Convenience function.  Connect to *address* (a 2-tuple ``(host,
+    port)``) and return the socket object.  Passing the optional
+    *timeout* parameter will set the timeout on the socket instance
+    before attempting to connect.  If no *timeout* is supplied, the
+    global default timeout setting returned by :func:`getdefaulttimeout`
+    is used.  If *source_address* is set it must be a tuple of (host, port)
+    for the socket to bind as a source address before making the connection.
+    An host of '' or port 0 tells the OS to use the default.
+    """
+
+    host, port = address
+    if host.startswith("["):
+        host = host.strip("[]")
+    err = None
+
+    # Using the value from allowed_gai_family() in the context of getaddrinfo lets
+    # us select whether to work with IPv4 DNS records, IPv6 records, or both.
+    # The original create_connection function always returns all records.
+    family = allowed_gai_family()
+
+    for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM):
+        af, socktype, proto, canonname, sa = res
+        sock = None
+        try:
+            sock = socket.socket(af, socktype, proto)
+
+            # If provided, set socket level options before connecting.
+            _set_socket_options(sock, socket_options)
+
+            if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
+                sock.settimeout(timeout)
+            if source_address:
+                sock.bind(source_address)
+            sock.connect(sa)
+            return sock
+
+        except socket.error as e:
+            err = e
+            if sock is not None:
+                sock.close()
+                sock = None
+
+    if err is not None:
+        raise err
+
+    raise socket.error("getaddrinfo returns an empty list")
+
+
+def _set_socket_options(sock, options):
+    if options is None:
+        return
+
+    for opt in options:
+        sock.setsockopt(*opt)
+
+
+def allowed_gai_family():
+    """This function is designed to work in the context of
+    getaddrinfo, where family=socket.AF_UNSPEC is the default and
+    will perform a DNS search for both IPv6 and IPv4 records."""
+
+    family = socket.AF_INET
+    if HAS_IPV6:
+        family = socket.AF_UNSPEC
+    return family
+
+
+def _has_ipv6(host):
+    """ Returns True if the system can bind an IPv6 address. """
+    sock = None
+    has_ipv6 = False
+
+    # App Engine doesn't support IPV6 sockets and actually has a quota on the
+    # number of sockets that can be used, so just early out here instead of
+    # creating a socket needlessly.
+    # See https://github.com/urllib3/urllib3/issues/1446
+    if _appengine_environ.is_appengine_sandbox():
+        return False
+
+    if socket.has_ipv6:
+        # has_ipv6 returns true if cPython was compiled with IPv6 support.
+        # It does not tell us if the system has IPv6 support enabled. To
+        # determine that we must bind to an IPv6 address.
+        # https://github.com/urllib3/urllib3/pull/611
+        # https://bugs.python.org/issue658327
+        try:
+            sock = socket.socket(socket.AF_INET6)
+            sock.bind((host, 0))
+            has_ipv6 = True
+        except Exception:
+            pass
+
+    if sock:
+        sock.close()
+    return has_ipv6
+
+
+HAS_IPV6 = _has_ipv6("::1")

venv/Lib/site-packages/urllib3/util/queue.py

@@ -0,0 +1,21 @@
+import collections
+from ..packages import six
+from ..packages.six.moves import queue
+
+if six.PY2:
+    # Queue is imported for side effects on MS Windows. See issue #229.
+    import Queue as _unused_module_Queue  # noqa: F401
+
+
+class LifoQueue(queue.Queue):
+    def _init(self, _):
+        self.queue = collections.deque()
+
+    def _qsize(self, len=len):
+        return len(self.queue)
+
+    def _put(self, item):
+        self.queue.append(item)
+
+    def _get(self):
+        return self.queue.pop()

venv/Lib/site-packages/urllib3/util/request.py

@@ -0,0 +1,135 @@
+from __future__ import absolute_import
+from base64 import b64encode
+
+from ..packages.six import b, integer_types
+from ..exceptions import UnrewindableBodyError
+
+ACCEPT_ENCODING = "gzip,deflate"
+try:
+    import brotli as _unused_module_brotli  # noqa: F401
+except ImportError:
+    pass
+else:
+    ACCEPT_ENCODING += ",br"
+
+_FAILEDTELL = object()
+
+
+def make_headers(
+    keep_alive=None,
+    accept_encoding=None,
+    user_agent=None,
+    basic_auth=None,
+    proxy_basic_auth=None,
+    disable_cache=None,
+):
+    """
+    Shortcuts for generating request headers.
+
+    :param keep_alive:
+        If ``True``, adds 'connection: keep-alive' header.
+
+    :param accept_encoding:
+        Can be a boolean, list, or string.
+        ``True`` translates to 'gzip,deflate'.
+        List will get joined by comma.
+        String will be used as provided.
+
+    :param user_agent:
+        String representing the user-agent you want, such as
+        "python-urllib3/0.6"
+
+    :param basic_auth:
+        Colon-separated username:password string for 'authorization: basic ...'
+        auth header.
+
+    :param proxy_basic_auth:
+        Colon-separated username:password string for 'proxy-authorization: basic ...'
+        auth header.
+
+    :param disable_cache:
+        If ``True``, adds 'cache-control: no-cache' header.
+
+    Example::
+
+        >>> make_headers(keep_alive=True, user_agent="Batman/1.0")
+        {'connection': 'keep-alive', 'user-agent': 'Batman/1.0'}
+        >>> make_headers(accept_encoding=True)
+        {'accept-encoding': 'gzip,deflate'}
+    """
+    headers = {}
+    if accept_encoding:
+        if isinstance(accept_encoding, str):
+            pass
+        elif isinstance(accept_encoding, list):
+            accept_encoding = ",".join(accept_encoding)
+        else:
+            accept_encoding = ACCEPT_ENCODING
+        headers["accept-encoding"] = accept_encoding
+
+    if user_agent:
+        headers["user-agent"] = user_agent
+
+    if keep_alive:
+        headers["connection"] = "keep-alive"
+
+    if basic_auth:
+        headers["authorization"] = "Basic " + b64encode(b(basic_auth)).decode("utf-8")
+
+    if proxy_basic_auth:
+        headers["proxy-authorization"] = "Basic " + b64encode(
+            b(proxy_basic_auth)
+        ).decode("utf-8")
+
+    if disable_cache:
+        headers["cache-control"] = "no-cache"
+
+    return headers
+
+
+def set_file_position(body, pos):
+    """
+    If a position is provided, move file to that point.
+    Otherwise, we'll attempt to record a position for future use.
+    """
+    if pos is not None:
+        rewind_body(body, pos)
+    elif getattr(body, "tell", None) is not None:
+        try:
+            pos = body.tell()
+        except (IOError, OSError):
+            # This differentiates from None, allowing us to catch
+            # a failed `tell()` later when trying to rewind the body.
+            pos = _FAILEDTELL
+
+    return pos
+
+
+def rewind_body(body, body_pos):
+    """
+    Attempt to rewind body to a certain position.
+    Primarily used for request redirects and retries.
+
+    :param body:
+        File-like object that supports seek.
+
+    :param int pos:
+        Position to seek to in file.
+    """
+    body_seek = getattr(body, "seek", None)
+    if body_seek is not None and isinstance(body_pos, integer_types):
+        try:
+            body_seek(body_pos)
+        except (IOError, OSError):
+            raise UnrewindableBodyError(
+                "An error occurred when rewinding request body for redirect/retry."
+            )
+    elif body_pos is _FAILEDTELL:
+        raise UnrewindableBodyError(
+            "Unable to record file position for rewinding "
+            "request body during a redirect/retry."
+        )
+    else:
+        raise ValueError(
+            "body_pos must be of type integer, instead it was %s." % type(body_pos)
+        )

venv/Lib/site-packages/urllib3/util/response.py

@@ -0,0 +1,86 @@
+from __future__ import absolute_import
+from ..packages.six.moves import http_client as httplib
+
+from ..exceptions import HeaderParsingError
+
+
+def is_fp_closed(obj):
+    """
+    Checks whether a given file-like object is closed.
+
+    :param obj:
+        The file-like object to check.
+    """
+
+    try:
+        # Check `isclosed()` first, in case Python3 doesn't set `closed`.
+        # GH Issue #928
+        return obj.isclosed()
+    except AttributeError:
+        pass
+
+    try:
+        # Check via the official file-like-object way.
+        return obj.closed
+    except AttributeError:
+        pass
+
+    try:
+        # Check if the object is a container for another file-like object that
+        # gets released on exhaustion (e.g. HTTPResponse).
+        return obj.fp is None
+    except AttributeError:
+        pass
+
+    raise ValueError("Unable to determine whether fp is closed.")
+
+
+def assert_header_parsing(headers):
+    """
+    Asserts whether all headers have been successfully parsed.
+    Extracts encountered errors from the result of parsing headers.
+
+    Only works on Python 3.
+
+    :param headers: Headers to verify.
+    :type headers: `httplib.HTTPMessage`.
+
+    :raises urllib3.exceptions.HeaderParsingError:
+        If parsing errors are found.
+    """
+
+    # This will fail silently if we pass in the wrong kind of parameter.
+    # To make debugging easier add an explicit check.
+    if not isinstance(headers, httplib.HTTPMessage):
+        raise TypeError("expected httplib.Message, got {0}.".format(type(headers)))
+
+    defects = getattr(headers, "defects", None)
+    get_payload = getattr(headers, "get_payload", None)
+
+    unparsed_data = None
+    if get_payload:
+        # get_payload is actually email.message.Message.get_payload;
+        # we're only interested in the result if it's not a multipart message
+        if not headers.is_multipart():
+            payload = get_payload()
+
+            if isinstance(payload, (bytes, str)):
+                unparsed_data = payload
+
+    if defects or unparsed_data:
+        raise HeaderParsingError(defects=defects, unparsed_data=unparsed_data)
+
+
+def is_response_to_head(response):
+    """
+    Checks whether the request of a response has been a HEAD-request.
+    Handles the quirks of AppEngine.
+
+    :param conn:
+    :type conn: :class:`httplib.HTTPResponse`
+    """
+    # FIXME: Can we do this somehow without accessing private httplib _method?
+    method = response._method
+    if isinstance(method, int):  # Platform-specific: Appengine
+        return method == 3
+    return method.upper() == "HEAD"

venv/Lib/site-packages/urllib3/util/retry.py

@@ -0,0 +1,453 @@
+from __future__ import absolute_import
+import time
+import logging
+from collections import namedtuple
+from itertools import takewhile
+import email
+import re
+
+from ..exceptions import (
+    ConnectTimeoutError,
+    MaxRetryError,
+    ProtocolError,
+    ReadTimeoutError,
+    ResponseError,
+    InvalidHeader,
+    ProxyError,
+)
+from ..packages import six
+
+
+log = logging.getLogger(__name__)
+
+
+# Data structure for representing the metadata of requests that result in a retry.
+RequestHistory = namedtuple(
+    "RequestHistory", ["method", "url", "error", "status", "redirect_location"]
+)
+
+
+class Retry(object):
+    """ Retry configuration.
+
+    Each retry attempt will create a new Retry object with updated values, so
+    they can be safely reused.
+
+    Retries can be defined as a default for a pool::
+
+        retries = Retry(connect=5, read=2, redirect=5)
+        http = PoolManager(retries=retries)
+        response = http.request('GET', 'http://example.com/')
+
+    Or per-request (which overrides the default for the pool)::
+
+        response = http.request('GET', 'http://example.com/', retries=Retry(10))
+
+    Retries can be disabled by passing ``False``::
+
+        response = http.request('GET', 'http://example.com/', retries=False)
+
+    Errors will be wrapped in :class:`~urllib3.exceptions.MaxRetryError` unless
+    retries are disabled, in which case the causing exception will be raised.
+
+    :param int total:
+        Total number of retries to allow. Takes precedence over other counts.
+
+        Set to ``None`` to remove this constraint and fall back on other
+        counts. It's a good idea to set this to some sensibly-high value to
+        account for unexpected edge cases and avoid infinite retry loops.
+
+        Set to ``0`` to fail on the first retry.
+
+        Set to ``False`` to disable and imply ``raise_on_redirect=False``.
+
+    :param int connect:
+        How many connection-related errors to retry on.
+
+        These are errors raised before the request is sent to the remote server,
+        which we assume has not triggered the server to process the request.
+
+        Set to ``0`` to fail on the first retry of this type.
+
+    :param int read:
+        How many times to retry on read errors.
+
+        These errors are raised after the request was sent to the server, so the
+        request may have side-effects.
+
+        Set to ``0`` to fail on the first retry of this type.
+
+    :param int redirect:
+        How many redirects to perform. Limit this to avoid infinite redirect
+        loops.
+
+        A redirect is a HTTP response with a status code 301, 302, 303, 307 or
+        308.
+
+        Set to ``0`` to fail on the first retry of this type.
+
+        Set to ``False`` to disable and imply ``raise_on_redirect=False``.
+
+    :param int status:
+        How many times to retry on bad status codes.
+
+        These are retries made on responses, where status code matches
+        ``status_forcelist``.
+
+        Set to ``0`` to fail on the first retry of this type.
+
+    :param iterable method_whitelist:
+        Set of uppercased HTTP method verbs that we should retry on.
+
+        By default, we only retry on methods which are considered to be
+        idempotent (multiple requests with the same parameters end with the
+        same state). See :attr:`Retry.DEFAULT_METHOD_WHITELIST`.
+
+        Set to a ``False`` value to retry on any verb.
+
+    :param iterable status_forcelist:
+        A set of integer HTTP status codes that we should force a retry on.
+        A retry is initiated if the request method is in ``method_whitelist``
+        and the response status code is in ``status_forcelist``.
+
+        By default, this is disabled with ``None``.
+
+    :param float backoff_factor:
+        A backoff factor to apply between attempts after the second try
+        (most errors are resolved immediately by a second try without a
+        delay). urllib3 will sleep for::
+
+            {backoff factor} * (2 ** ({number of total retries} - 1))
+
+        seconds. If the backoff_factor is 0.1, then :func:`.sleep` will sleep
+        for [0.0s, 0.2s, 0.4s, ...] between retries. It will never be longer
+        than :attr:`Retry.BACKOFF_MAX`.
+
+        By default, backoff is disabled (set to 0).
+
+    :param bool raise_on_redirect: Whether, if the number of redirects is
+        exhausted, to raise a MaxRetryError, or to return a response with a
+        response code in the 3xx range.
+
+    :param bool raise_on_status: Similar meaning to ``raise_on_redirect``:
+        whether we should raise an exception, or return a response,
+        if status falls in ``status_forcelist`` range and retries have
+        been exhausted.
+
+    :param tuple history: The history of the request encountered during
+        each call to :meth:`~Retry.increment`. The list is in the order
+        the requests occurred. Each list item is of class :class:`RequestHistory`.
+
+    :param bool respect_retry_after_header:
+        Whether to respect Retry-After header on status codes defined as
+        :attr:`Retry.RETRY_AFTER_STATUS_CODES` or not.
+
+    :param iterable remove_headers_on_redirect:
+        Sequence of headers to remove from the request when a response
+        indicating a redirect is returned before firing off the redirected
+        request.
+    """
+
+    DEFAULT_METHOD_WHITELIST = frozenset(
+        ["HEAD", "GET", "PUT", "DELETE", "OPTIONS", "TRACE"]
+    )
+
+    RETRY_AFTER_STATUS_CODES = frozenset([413, 429, 503])
+
+    DEFAULT_REDIRECT_HEADERS_BLACKLIST = frozenset(["Authorization"])
+
+    #: Maximum backoff time.
+    BACKOFF_MAX = 120
+
+    def __init__(
+        self,
+        total=10,
+        connect=None,
+        read=None,
+        redirect=None,
+        status=None,
+        method_whitelist=DEFAULT_METHOD_WHITELIST,
+        status_forcelist=None,
+        backoff_factor=0,
+        raise_on_redirect=True,
+        raise_on_status=True,
+        history=None,
+        respect_retry_after_header=True,
+        remove_headers_on_redirect=DEFAULT_REDIRECT_HEADERS_BLACKLIST,
+    ):
+
+        self.total = total
+        self.connect = connect
+        self.read = read
+        self.status = status
+
+        if redirect is False or total is False:
+            redirect = 0
+            raise_on_redirect = False
+
+        self.redirect = redirect
+        self.status_forcelist = status_forcelist or set()
+        self.method_whitelist = method_whitelist
+        self.backoff_factor = backoff_factor
+        self.raise_on_redirect = raise_on_redirect
+        self.raise_on_status = raise_on_status
+        self.history = history or tuple()
+        self.respect_retry_after_header = respect_retry_after_header
+        self.remove_headers_on_redirect = frozenset(
+            [h.lower() for h in remove_headers_on_redirect]
+        )
+
+    def new(self, **kw):
+        params = dict(
+            total=self.total,
+            connect=self.connect,
+            read=self.read,
+            redirect=self.redirect,
+            status=self.status,
+            method_whitelist=self.method_whitelist,
+            status_forcelist=self.status_forcelist,
+            backoff_factor=self.backoff_factor,
+            raise_on_redirect=self.raise_on_redirect,
+            raise_on_status=self.raise_on_status,
+            history=self.history,
+            remove_headers_on_redirect=self.remove_headers_on_redirect,
+            respect_retry_after_header=self.respect_retry_after_header,
+        )
+        params.update(kw)
+        return type(self)(**params)
+
+    @classmethod
+    def from_int(cls, retries, redirect=True, default=None):
+        """ Backwards-compatibility for the old retries format."""
+        if retries is None:
+            retries = default if default is not None else cls.DEFAULT
+
+        if isinstance(retries, Retry):
+            return retries
+
+        redirect = bool(redirect) and None
+        new_retries = cls(retries, redirect=redirect)
+        log.debug("Converted retries value: %r -> %r", retries, new_retries)
+        return new_retries
+
+    def get_backoff_time(self):
+        """ Formula for computing the current backoff
+
+        :rtype: float
+        """
+        # We want to consider only the last consecutive errors sequence (Ignore redirects).
+        consecutive_errors_len = len(
+            list(
+                takewhile(lambda x: x.redirect_location is None, reversed(self.history))
+            )
+        )
+        if consecutive_errors_len <= 1:
+            return 0
+
+        backoff_value = self.backoff_factor * (2 ** (consecutive_errors_len - 1))
+        return min(self.BACKOFF_MAX, backoff_value)
+
+    def parse_retry_after(self, retry_after):
+        # Whitespace: https://tools.ietf.org/html/rfc7230#section-3.2.4
+        if re.match(r"^\s*[0-9]+\s*$", retry_after):
+            seconds = int(retry_after)
+        else:
+            retry_date_tuple = email.utils.parsedate(retry_after)
+            if retry_date_tuple is None:
+                raise InvalidHeader("Invalid Retry-After header: %s" % retry_after)
+            retry_date = time.mktime(retry_date_tuple)
+            seconds = retry_date - time.time()
+
+        if seconds < 0:
+            seconds = 0
+
+        return seconds
+
+    def get_retry_after(self, response):
+        """ Get the value of Retry-After in seconds. """
+
+        retry_after = response.getheader("Retry-After")
+
+        if retry_after is None:
+            return None
+
+        return self.parse_retry_after(retry_after)
+
+    def sleep_for_retry(self, response=None):
+        retry_after = self.get_retry_after(response)
+        if retry_after:
+            time.sleep(retry_after)
+            return True
+
+        return False
+
+    def _sleep_backoff(self):
+        backoff = self.get_backoff_time()
+        if backoff <= 0:
+            return
+        time.sleep(backoff)
+
+    def sleep(self, response=None):
+        """ Sleep between retry attempts.
+
+        This method will respect a server's ``Retry-After`` response header
+        and sleep the duration of the time requested. If that is not present, it
+        will use an exponential backoff. By default, the backoff factor is 0 and
+        this method will return immediately.
+        """
+
+        if self.respect_retry_after_header and response:
+            slept = self.sleep_for_retry(response)
+            if slept:
+                return
+
+        self._sleep_backoff()
+
+    def _is_connection_error(self, err):
+        """ Errors when we're fairly sure that the server did not receive the
+        request, so it should be safe to retry.
+        """
+        if isinstance(err, ProxyError):
+            err = err.original_error
+        return isinstance(err, ConnectTimeoutError)
+
+    def _is_read_error(self, err):
+        """ Errors that occur after the request has been started, so we should
+        assume that the server began processing it.
+        """
+        return isinstance(err, (ReadTimeoutError, ProtocolError))
+
+    def _is_method_retryable(self, method):
+        """ Checks if a given HTTP method should be retried upon, depending if
+        it is included on the method whitelist.
+        """
+        if self.method_whitelist and method.upper() not in self.method_whitelist:
+            return False
+
+        return True
+
+    def is_retry(self, method, status_code, has_retry_after=False):
+        """ Is this method/status code retryable? (Based on whitelists and control
+        variables such as the number of total retries to allow, whether to
+        respect the Retry-After header, whether this header is present, and
+        whether the returned status code is on the list of status codes to
+        be retried upon on the presence of the aforementioned header)
+        """
+        if not self._is_method_retryable(method):
+            return False
+
+        if self.status_forcelist and status_code in self.status_forcelist:
+            return True
+
+        return (
+            self.total
+            and self.respect_retry_after_header
+            and has_retry_after
+            and (status_code in self.RETRY_AFTER_STATUS_CODES)
+        )
+
+    def is_exhausted(self):
+        """ Are we out of retries? """
+        retry_counts = (self.total, self.connect, self.read, self.redirect, self.status)
+        retry_counts = list(filter(None, retry_counts))
+        if not retry_counts:
+            return False
+
+        return min(retry_counts) < 0
+
+    def increment(
+        self,
+        method=None,
+        url=None,
+        response=None,
+        error=None,
+        _pool=None,
+        _stacktrace=None,
+    ):
+        """ Return a new Retry object with incremented retry counters.
+
+        :param response: A response object, or None, if the server did not
+            return a response.
+        :type response: :class:`~urllib3.response.HTTPResponse`
+        :param Exception error: An error encountered during the request, or
+            None if the response was received successfully.
+
+        :return: A new ``Retry`` object.
+        """
+        if self.total is False and error:
+            # Disabled, indicate to re-raise the error.
+            raise six.reraise(type(error), error, _stacktrace)
+
+        total = self.total
+        if total is not None:
+            total -= 1
+
+        connect = self.connect
+        read = self.read
+        redirect = self.redirect
+        status_count = self.status
+        cause = "unknown"
+        status = None
+        redirect_location = None
+
+        if error and self._is_connection_error(error):
+            # Connect retry?
+            if connect is False:
+                raise six.reraise(type(error), error, _stacktrace)
+            elif connect is not None:
+                connect -= 1
+
+        elif error and self._is_read_error(error):
+            # Read retry?
+            if read is False or not self._is_method_retryable(method):
+                raise six.reraise(type(error), error, _stacktrace)
+            elif read is not None:
+                read -= 1
+
+        elif response and response.get_redirect_location():
+            # Redirect retry?
+            if redirect is not None:
+                redirect -= 1
+            cause = "too many redirects"
+            redirect_location = response.get_redirect_location()
+            status = response.status
+
+        else:
+            # Incrementing because of a server error like a 500 in
+            # status_forcelist and a the given method is in the whitelist
+            cause = ResponseError.GENERIC_ERROR
+            if response and response.status:
+                if status_count is not None:
+                    status_count -= 1
+                cause = ResponseError.SPECIFIC_ERROR.format(status_code=response.status)
+                status = response.status
+
+        history = self.history + (
+            RequestHistory(method, url, error, status, redirect_location),
+        )
+
+        new_retry = self.new(
+            total=total,
+            connect=connect,
+            read=read,
+            redirect=redirect,
+            status=status_count,
+            history=history,
+        )
+
+        if new_retry.is_exhausted():
+            raise MaxRetryError(_pool, url, error or ResponseError(cause))
+
+        log.debug("Incremented Retry for (url='%s'): %r", url, new_retry)
+
+        return new_retry
+
+    def __repr__(self):
+        return (
+            "{cls.__name__}(total={self.total}, connect={self.connect}, "
+            "read={self.read}, redirect={self.redirect}, status={self.status})"
+        ).format(cls=type(self), self=self)
+
+
+# For backwards compatibility (equivalent to pre-v1.9):
+Retry.DEFAULT = Retry(3)

venv/Lib/site-packages/urllib3/util/ssl_.py

@@ -0,0 +1,421 @@
+from __future__ import absolute_import
+import errno
+import warnings
+import hmac
+import os
+import sys
+
+from binascii import hexlify, unhexlify
+from hashlib import md5, sha1, sha256
+
+from .url import IPV4_RE, BRACELESS_IPV6_ADDRZ_RE
+from ..exceptions import SSLError, InsecurePlatformWarning, SNIMissingWarning
+from ..packages import six
+
+
+SSLContext = None
+HAS_SNI = False
+IS_PYOPENSSL = False
+IS_SECURETRANSPORT = False
+
+# Maps the length of a digest to a possible hash function producing this digest
+HASHFUNC_MAP = {32: md5, 40: sha1, 64: sha256}
+
+
+def _const_compare_digest_backport(a, b):
+    """
+    Compare two digests of equal length in constant time.
+
+    The digests must be of type str/bytes.
+    Returns True if the digests match, and False otherwise.
+    """
+    result = abs(len(a) - len(b))
+    for left, right in zip(bytearray(a), bytearray(b)):
+        result |= left ^ right
+    return result == 0
+
+
+_const_compare_digest = getattr(hmac, "compare_digest", _const_compare_digest_backport)
+
+try:  # Test for SSL features
+    import ssl
+    from ssl import wrap_socket, CERT_REQUIRED
+    from ssl import HAS_SNI  # Has SNI?
+except ImportError:
+    pass
+
+try:  # Platform-specific: Python 3.6
+    from ssl import PROTOCOL_TLS
+
+    PROTOCOL_SSLv23 = PROTOCOL_TLS
+except ImportError:
+    try:
+        from ssl import PROTOCOL_SSLv23 as PROTOCOL_TLS
+
+        PROTOCOL_SSLv23 = PROTOCOL_TLS
+    except ImportError:
+        PROTOCOL_SSLv23 = PROTOCOL_TLS = 2
+
+
+try:
+    from ssl import OP_NO_SSLv2, OP_NO_SSLv3, OP_NO_COMPRESSION
+except ImportError:
+    OP_NO_SSLv2, OP_NO_SSLv3 = 0x1000000, 0x2000000
+    OP_NO_COMPRESSION = 0x20000
+
+
+# A secure default.
+# Sources for more information on TLS ciphers:
+#
+# - https://wiki.mozilla.org/Security/Server_Side_TLS
+# - https://www.ssllabs.com/projects/best-practices/index.html
+# - https://hynek.me/articles/hardening-your-web-servers-ssl-ciphers/
+#
+# The general intent is:
+# - prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE),
+# - prefer ECDHE over DHE for better performance,
+# - prefer any AES-GCM and ChaCha20 over any AES-CBC for better performance and
+#   security,
+# - prefer AES-GCM over ChaCha20 because hardware-accelerated AES is common,
+# - disable NULL authentication, MD5 MACs, DSS, and other
+#   insecure ciphers for security reasons.
+# - NOTE: TLS 1.3 cipher suites are managed through a different interface
+#   not exposed by CPython (yet!) and are enabled by default if they're available.
+DEFAULT_CIPHERS = ":".join(
+    [
+        "ECDHE+AESGCM",
+        "ECDHE+CHACHA20",
+        "DHE+AESGCM",
+        "DHE+CHACHA20",
+        "ECDH+AESGCM",
+        "DH+AESGCM",
+        "ECDH+AES",
+        "DH+AES",
+        "RSA+AESGCM",
+        "RSA+AES",
+        "!aNULL",
+        "!eNULL",
+        "!MD5",
+        "!DSS",
+    ]
+)
+
+try:
+    from ssl import SSLContext  # Modern SSL?
+except ImportError:
+
+    class SSLContext(object):  # Platform-specific: Python 2
+        def __init__(self, protocol_version):
+            self.protocol = protocol_version
+            # Use default values from a real SSLContext
+            self.check_hostname = False
+            self.verify_mode = ssl.CERT_NONE
+            self.ca_certs = None
+            self.options = 0
+            self.certfile = None
+            self.keyfile = None
+            self.ciphers = None
+
+        def load_cert_chain(self, certfile, keyfile):
+            self.certfile = certfile
+            self.keyfile = keyfile
+
+        def load_verify_locations(self, cafile=None, capath=None, cadata=None):
+            self.ca_certs = cafile
+
+            if capath is not None:
+                raise SSLError("CA directories not supported in older Pythons")
+
+            if cadata is not None:
+                raise SSLError("CA data not supported in older Pythons")
+
+        def set_ciphers(self, cipher_suite):
+            self.ciphers = cipher_suite
+
+        def wrap_socket(self, socket, server_hostname=None, server_side=False):
+            warnings.warn(
+                "A true SSLContext object is not available. This prevents "
+                "urllib3 from configuring SSL appropriately and may cause "
+                "certain SSL connections to fail. You can upgrade to a newer "
+                "version of Python to solve this. For more information, see "
+                "https://urllib3.readthedocs.io/en/latest/advanced-usage.html"
+                "#ssl-warnings",
+                InsecurePlatformWarning,
+            )
+            kwargs = {
+                "keyfile": self.keyfile,
+                "certfile": self.certfile,
+                "ca_certs": self.ca_certs,
+                "cert_reqs": self.verify_mode,
+                "ssl_version": self.protocol,
+                "server_side": server_side,
+            }
+            return wrap_socket(socket, ciphers=self.ciphers, **kwargs)
+
+
+def assert_fingerprint(cert, fingerprint):
+    """
+    Checks if given fingerprint matches the supplied certificate.
+
+    :param cert:
+        Certificate as bytes object.
+    :param fingerprint:
+        Fingerprint as string of hexdigits, can be interspersed by colons.
+    """
+
+    fingerprint = fingerprint.replace(":", "").lower()
+    digest_length = len(fingerprint)
+    hashfunc = HASHFUNC_MAP.get(digest_length)
+    if not hashfunc:
+        raise SSLError("Fingerprint of invalid length: {0}".format(fingerprint))
+
+    # We need encode() here for py32; works on py2 and p33.
+    fingerprint_bytes = unhexlify(fingerprint.encode())
+
+    cert_digest = hashfunc(cert).digest()
+
+    if not _const_compare_digest(cert_digest, fingerprint_bytes):
+        raise SSLError(
+            'Fingerprints did not match. Expected "{0}", got "{1}".'.format(
+                fingerprint, hexlify(cert_digest)
+            )
+        )
+
+
+def resolve_cert_reqs(candidate):
+    """
+    Resolves the argument to a numeric constant, which can be passed to
+    the wrap_socket function/method from the ssl module.
+    Defaults to :data:`ssl.CERT_REQUIRED`.
+    If given a string it is assumed to be the name of the constant in the
+    :mod:`ssl` module or its abbreviation.
+    (So you can specify `REQUIRED` instead of `CERT_REQUIRED`.
+    If it's neither `None` nor a string we assume it is already the numeric
+    constant which can directly be passed to wrap_socket.
+    """
+    if candidate is None:
+        return CERT_REQUIRED
+
+    if isinstance(candidate, str):
+        res = getattr(ssl, candidate, None)
+        if res is None:
+            res = getattr(ssl, "CERT_" + candidate)
+        return res
+
+    return candidate
+
+
+def resolve_ssl_version(candidate):
+    """
+    like resolve_cert_reqs
+    """
+    if candidate is None:
+        return PROTOCOL_TLS
+
+    if isinstance(candidate, str):
+        res = getattr(ssl, candidate, None)
+        if res is None:
+            res = getattr(ssl, "PROTOCOL_" + candidate)
+        return res
+
+    return candidate
+
+
+def create_urllib3_context(
+    ssl_version=None, cert_reqs=None, options=None, ciphers=None
+):
+    """All arguments have the same meaning as ``ssl_wrap_socket``.
+
+    By default, this function does a lot of the same work that
+    ``ssl.create_default_context`` does on Python 3.4+. It:
+
+    - Disables SSLv2, SSLv3, and compression
+    - Sets a restricted set of server ciphers
+
+    If you wish to enable SSLv3, you can do::
+
+        from urllib3.util import ssl_
+        context = ssl_.create_urllib3_context()
+        context.options &= ~ssl_.OP_NO_SSLv3
+
+    You can do the same to enable compression (substituting ``COMPRESSION``
+    for ``SSLv3`` in the last line above).
+
+    :param ssl_version:
+        The desired protocol version to use. This will default to
+        PROTOCOL_SSLv23 which will negotiate the highest protocol that both
+        the server and your installation of OpenSSL support.
+    :param cert_reqs:
+        Whether to require the certificate verification. This defaults to
+        ``ssl.CERT_REQUIRED``.
+    :param options:
+        Specific OpenSSL options. These default to ``ssl.OP_NO_SSLv2``,
+        ``ssl.OP_NO_SSLv3``, ``ssl.OP_NO_COMPRESSION``.
+    :param ciphers:
+        Which cipher suites to allow the server to select.
+    :returns:
+        Constructed SSLContext object with specified options
+    :rtype: SSLContext
+    """
+    context = SSLContext(ssl_version or PROTOCOL_TLS)
+
+    context.set_ciphers(ciphers or DEFAULT_CIPHERS)
+
+    # Setting the default here, as we may have no ssl module on import
+    cert_reqs = ssl.CERT_REQUIRED if cert_reqs is None else cert_reqs
+
+    if options is None:
+        options = 0
+        # SSLv2 is easily broken and is considered harmful and dangerous
+        options |= OP_NO_SSLv2
+        # SSLv3 has several problems and is now dangerous
+        options |= OP_NO_SSLv3
+        # Disable compression to prevent CRIME attacks for OpenSSL 1.0+
+        # (issue #309)
+        options |= OP_NO_COMPRESSION
+
+    context.options |= options
+
+    # Enable post-handshake authentication for TLS 1.3, see GH #1634. PHA is
+    # necessary for conditional client cert authentication with TLS 1.3.
+    # The attribute is None for OpenSSL <= 1.1.0 or does not exist in older
+    # versions of Python.  We only enable on Python 3.7.4+ or if certificate
+    # verification is enabled to work around Python issue #37428
+    # See: https://bugs.python.org/issue37428
+    if (cert_reqs == ssl.CERT_REQUIRED or sys.version_info >= (3, 7, 4)) and getattr(
+        context, "post_handshake_auth", None
+    ) is not None:
+        context.post_handshake_auth = True
+
+    context.verify_mode = cert_reqs
+    if (
+        getattr(context, "check_hostname", None) is not None
+    ):  # Platform-specific: Python 3.2
+        # We do our own verification, including fingerprints and alternative
+        # hostnames. So disable it here
+        context.check_hostname = False
+
+    # Enable logging of TLS session keys via defacto standard environment variable
+    # 'SSLKEYLOGFILE', if the feature is available (Python 3.8+).
+    if hasattr(context, "keylog_filename"):
+        context.keylog_filename = os.environ.get("SSLKEYLOGFILE")
+
+    return context
+
+
+def ssl_wrap_socket(
+    sock,
+    keyfile=None,
+    certfile=None,
+    cert_reqs=None,
+    ca_certs=None,
+    server_hostname=None,
+    ssl_version=None,
+    ciphers=None,
+    ssl_context=None,
+    ca_cert_dir=None,
+    key_password=None,
+    ca_cert_data=None,
+):
+    """
+    All arguments except for server_hostname, ssl_context, and ca_cert_dir have
+    the same meaning as they do when using :func:`ssl.wrap_socket`.
+
+    :param server_hostname:
+        When SNI is supported, the expected hostname of the certificate
+    :param ssl_context:
+        A pre-made :class:`SSLContext` object. If none is provided, one will
+        be created using :func:`create_urllib3_context`.
+    :param ciphers:
+        A string of ciphers we wish the client to support.
+    :param ca_cert_dir:
+        A directory containing CA certificates in multiple separate files, as
+        supported by OpenSSL's -CApath flag or the capath argument to
+        SSLContext.load_verify_locations().
+    :param key_password:
+        Optional password if the keyfile is encrypted.
+    :param ca_cert_data:
+        Optional string containing CA certificates in PEM format suitable for
+        passing as the cadata parameter to SSLContext.load_verify_locations()
+    """
+    context = ssl_context
+    if context is None:
+        # Note: This branch of code and all the variables in it are no longer
+        # used by urllib3 itself. We should consider deprecating and removing
+        # this code.
+        context = create_urllib3_context(ssl_version, cert_reqs, ciphers=ciphers)
+
+    if ca_certs or ca_cert_dir or ca_cert_data:
+        try:
+            context.load_verify_locations(ca_certs, ca_cert_dir, ca_cert_data)
+        except IOError as e:  # Platform-specific: Python 2.7
+            raise SSLError(e)
+        # Py33 raises FileNotFoundError which subclasses OSError
+        # These are not equivalent unless we check the errno attribute
+        except OSError as e:  # Platform-specific: Python 3.3 and beyond
+            if e.errno == errno.ENOENT:
+                raise SSLError(e)
+            raise
+
+    elif ssl_context is None and hasattr(context, "load_default_certs"):
+        # try to load OS default certs; works well on Windows (require Python3.4+)
+        context.load_default_certs()
+
+    # Attempt to detect if we get the goofy behavior of the
+    # keyfile being encrypted and OpenSSL asking for the
+    # passphrase via the terminal and instead error out.
+    if keyfile and key_password is None and _is_key_file_encrypted(keyfile):
+        raise SSLError("Client private key is encrypted, password is required")
+
+    if certfile:
+        if key_password is None:
+            context.load_cert_chain(certfile, keyfile)
+        else:
+            context.load_cert_chain(certfile, keyfile, key_password)
+
+    # If we detect server_hostname is an IP address then the SNI
+    # extension should not be used according to RFC3546 Section 3.1
+    # We shouldn't warn the user if SNI isn't available but we would
+    # not be using SNI anyways due to IP address for server_hostname.
+    if (
+        server_hostname is not None and not is_ipaddress(server_hostname)
+    ) or IS_SECURETRANSPORT:
+        if HAS_SNI and server_hostname is not None:
+            return context.wrap_socket(sock, server_hostname=server_hostname)
+
+        warnings.warn(
+            "An HTTPS request has been made, but the SNI (Server Name "
+            "Indication) extension to TLS is not available on this platform. "
+            "This may cause the server to present an incorrect TLS "
+            "certificate, which can cause validation failures. You can upgrade to "
+            "a newer version of Python to solve this. For more information, see "
+            "https://urllib3.readthedocs.io/en/latest/advanced-usage.html"
+            "#ssl-warnings",
+            SNIMissingWarning,
+        )
+
+    return context.wrap_socket(sock)
+
+
+def is_ipaddress(hostname):
+    """Detects whether the hostname given is an IPv4 or IPv6 address.
+    Also detects IPv6 addresses with Zone IDs.
+
+    :param str hostname: Hostname to examine.
+    :return: True if the hostname is an IP address, False otherwise.
+    """
+    if not six.PY2 and isinstance(hostname, bytes):
+        # IDN A-label bytes are ASCII compatible.
+        hostname = hostname.decode("ascii")
+    return bool(IPV4_RE.match(hostname) or BRACELESS_IPV6_ADDRZ_RE.match(hostname))
+
+
+def _is_key_file_encrypted(key_file):
+    """Detects if a key file is encrypted or not."""
+    with open(key_file, "r") as f:
+        for line in f:
+            # Look for Proc-Type: 4,ENCRYPTED
+            if "ENCRYPTED" in line:
+                return True
+
+    return False

venv/Lib/site-packages/urllib3/util/timeout.py

@@ -0,0 +1,261 @@
+from __future__ import absolute_import
+
+# The default socket timeout, used by httplib to indicate that no timeout was
+# specified by the user
+from socket import _GLOBAL_DEFAULT_TIMEOUT
+import time
+
+from ..exceptions import TimeoutStateError
+
+# A sentinel value to indicate that no timeout was specified by the user in
+# urllib3
+_Default = object()
+
+
+# Use time.monotonic if available.
+current_time = getattr(time, "monotonic", time.time)
+
+
+class Timeout(object):
+    """ Timeout configuration.
+
+    Timeouts can be defined as a default for a pool::
+
+        timeout = Timeout(connect=2.0, read=7.0)
+        http = PoolManager(timeout=timeout)
+        response = http.request('GET', 'http://example.com/')
+
+    Or per-request (which overrides the default for the pool)::
+
+        response = http.request('GET', 'http://example.com/', timeout=Timeout(10))
+
+    Timeouts can be disabled by setting all the parameters to ``None``::
+
+        no_timeout = Timeout(connect=None, read=None)
+        response = http.request('GET', 'http://example.com/, timeout=no_timeout)
+
+
+    :param total:
+        This combines the connect and read timeouts into one; the read timeout
+        will be set to the time leftover from the connect attempt. In the
+        event that both a connect timeout and a total are specified, or a read
+        timeout and a total are specified, the shorter timeout will be applied.
+
+        Defaults to None.
+
+    :type total: integer, float, or None
+
+    :param connect:
+        The maximum amount of time (in seconds) to wait for a connection
+        attempt to a server to succeed. Omitting the parameter will default the
+        connect timeout to the system default, probably `the global default
+        timeout in socket.py
+        <http://hg.python.org/cpython/file/603b4d593758/Lib/socket.py#l535>`_.
+        None will set an infinite timeout for connection attempts.
+
+    :type connect: integer, float, or None
+
+    :param read:
+        The maximum amount of time (in seconds) to wait between consecutive
+        read operations for a response from the server. Omitting the parameter
+        will default the read timeout to the system default, probably `the
+        global default timeout in socket.py
+        <http://hg.python.org/cpython/file/603b4d593758/Lib/socket.py#l535>`_.
+        None will set an infinite timeout.
+
+    :type read: integer, float, or None
+
+    .. note::
+
+        Many factors can affect the total amount of time for urllib3 to return
+        an HTTP response.
+
+        For example, Python's DNS resolver does not obey the timeout specified
+        on the socket. Other factors that can affect total request time include
+        high CPU load, high swap, the program running at a low priority level,
+        or other behaviors.
+
+        In addition, the read and total timeouts only measure the time between
+        read operations on the socket connecting the client and the server,
+        not the total amount of time for the request to return a complete
+        response. For most requests, the timeout is raised because the server
+        has not sent the first byte in the specified time. This is not always
+        the case; if a server streams one byte every fifteen seconds, a timeout
+        of 20 seconds will not trigger, even though the request will take
+        several minutes to complete.
+
+        If your goal is to cut off any request after a set amount of wall clock
+        time, consider having a second "watcher" thread to cut off a slow
+        request.
+    """
+
+    #: A sentinel object representing the default timeout value
+    DEFAULT_TIMEOUT = _GLOBAL_DEFAULT_TIMEOUT
+
+    def __init__(self, total=None, connect=_Default, read=_Default):
+        self._connect = self._validate_timeout(connect, "connect")
+        self._read = self._validate_timeout(read, "read")
+        self.total = self._validate_timeout(total, "total")
+        self._start_connect = None
+
+    def __repr__(self):
+        return "%s(connect=%r, read=%r, total=%r)" % (
+            type(self).__name__,
+            self._connect,
+            self._read,
+            self.total,
+        )
+
+    # __str__ provided for backwards compatibility
+    __str__ = __repr__
+
+    @classmethod
+    def _validate_timeout(cls, value, name):
+        """ Check that a timeout attribute is valid.
+
+        :param value: The timeout value to validate
+        :param name: The name of the timeout attribute to validate. This is
+            used to specify in error messages.
+        :return: The validated and casted version of the given value.
+        :raises ValueError: If it is a numeric value less than or equal to
+            zero, or the type is not an integer, float, or None.
+        """
+        if value is _Default:
+            return cls.DEFAULT_TIMEOUT
+
+        if value is None or value is cls.DEFAULT_TIMEOUT:
+            return value
+
+        if isinstance(value, bool):
+            raise ValueError(
+                "Timeout cannot be a boolean value. It must "
+                "be an int, float or None."
+            )
+        try:
+            float(value)
+        except (TypeError, ValueError):
+            raise ValueError(
+                "Timeout value %s was %s, but it must be an "
+                "int, float or None." % (name, value)
+            )
+
+        try:
+            if value <= 0:
+                raise ValueError(
+                    "Attempted to set %s timeout to %s, but the "
+                    "timeout cannot be set to a value less "
+                    "than or equal to 0." % (name, value)
+                )
+        except TypeError:
+            # Python 3
+            raise ValueError(
+                "Timeout value %s was %s, but it must be an "
+                "int, float or None." % (name, value)
+            )
+
+        return value
+
+    @classmethod
+    def from_float(cls, timeout):
+        """ Create a new Timeout from a legacy timeout value.
+
+        The timeout value used by httplib.py sets the same timeout on the
+        connect(), and recv() socket requests. This creates a :class:`Timeout`
+        object that sets the individual timeouts to the ``timeout`` value
+        passed to this function.
+
+        :param timeout: The legacy timeout value.
+        :type timeout: integer, float, sentinel default object, or None
+        :return: Timeout object
+        :rtype: :class:`Timeout`
+        """
+        return Timeout(read=timeout, connect=timeout)
+
+    def clone(self):
+        """ Create a copy of the timeout object
+
+        Timeout properties are stored per-pool but each request needs a fresh
+        Timeout object to ensure each one has its own start/stop configured.
+
+        :return: a copy of the timeout object
+        :rtype: :class:`Timeout`
+        """
+        # We can't use copy.deepcopy because that will also create a new object
+        # for _GLOBAL_DEFAULT_TIMEOUT, which socket.py uses as a sentinel to
+        # detect the user default.
+        return Timeout(connect=self._connect, read=self._read, total=self.total)
+
+    def start_connect(self):
+        """ Start the timeout clock, used during a connect() attempt
+
+        :raises urllib3.exceptions.TimeoutStateError: if you attempt
+            to start a timer that has been started already.
+        """
+        if self._start_connect is not None:
+            raise TimeoutStateError("Timeout timer has already been started.")
+        self._start_connect = current_time()
+        return self._start_connect
+
+    def get_connect_duration(self):
+        """ Gets the time elapsed since the call to :meth:`start_connect`.
+
+        :return: Elapsed time in seconds.
+        :rtype: float
+        :raises urllib3.exceptions.TimeoutStateError: if you attempt
+            to get duration for a timer that hasn't been started.
+        """
+        if self._start_connect is None:
+            raise TimeoutStateError(
+                "Can't get connect duration for timer that has not started."
+            )
+        return current_time() - self._start_connect
+
+    @property
+    def connect_timeout(self):
+        """ Get the value to use when setting a connection timeout.
+
+        This will be a positive float or integer, the value None
+        (never timeout), or the default system timeout.
+
+        :return: Connect timeout.
+        :rtype: int, float, :attr:`Timeout.DEFAULT_TIMEOUT` or None
+        """
+        if self.total is None:
+            return self._connect
+
+        if self._connect is None or self._connect is self.DEFAULT_TIMEOUT:
+            return self.total
+
+        return min(self._connect, self.total)
+
+    @property
+    def read_timeout(self):
+        """ Get the value for the read timeout.
+
+        This assumes some time has elapsed in the connection timeout and
+        computes the read timeout appropriately.
+
+        If self.total is set, the read timeout is dependent on the amount of
+        time taken by the connect timeout. If the connection time has not been
+        established, a :exc:`~urllib3.exceptions.TimeoutStateError` will be
+        raised.
+
+        :return: Value to use for the read timeout.
+        :rtype: int, float, :attr:`Timeout.DEFAULT_TIMEOUT` or None
+        :raises urllib3.exceptions.TimeoutStateError: If :meth:`start_connect`
+            has not yet been called on this object.
+        """
+        if (
+            self.total is not None
+            and self.total is not self.DEFAULT_TIMEOUT
+            and self._read is not None
+            and self._read is not self.DEFAULT_TIMEOUT
+        ):
+            # In case the connect timeout has not yet been established.
+            if self._start_connect is None:
+                return self._read
+            return max(0, min(self.total - self.get_connect_duration(), self._read))
+        elif self.total is not None and self.total is not self.DEFAULT_TIMEOUT:
+            return max(0, self.total - self.get_connect_duration())
+        else:
+            return self._read

venv/Lib/site-packages/urllib3/util/url.py

@@ -0,0 +1,430 @@
+from __future__ import absolute_import
+import re
+from collections import namedtuple
+
+from ..exceptions import LocationParseError
+from ..packages import six
+
+
+url_attrs = ["scheme", "auth", "host", "port", "path", "query", "fragment"]
+
+# We only want to normalize urls with an HTTP(S) scheme.
+# urllib3 infers URLs without a scheme (None) to be http.
+NORMALIZABLE_SCHEMES = ("http", "https", None)
+
+# Almost all of these patterns were derived from the
+# 'rfc3986' module: https://github.com/python-hyper/rfc3986
+PERCENT_RE = re.compile(r"%[a-fA-F0-9]{2}")
+SCHEME_RE = re.compile(r"^(?:[a-zA-Z][a-zA-Z0-9+-]*:|/)")
+URI_RE = re.compile(
+    r"^(?:([a-zA-Z][a-zA-Z0-9+.-]*):)?"
+    r"(?://([^\\/?#]*))?"
+    r"([^?#]*)"
+    r"(?:\?([^#]*))?"
+    r"(?:#(.*))?$",
+    re.UNICODE | re.DOTALL,
+)
+
+IPV4_PAT = r"(?:[0-9]{1,3}\.){3}[0-9]{1,3}"
+HEX_PAT = "[0-9A-Fa-f]{1,4}"
+LS32_PAT = "(?:{hex}:{hex}|{ipv4})".format(hex=HEX_PAT, ipv4=IPV4_PAT)
+_subs = {"hex": HEX_PAT, "ls32": LS32_PAT}
+_variations = [
+    #                            6( h16 ":" ) ls32
+    "(?:%(hex)s:){6}%(ls32)s",
+    #                       "::" 5( h16 ":" ) ls32
+    "::(?:%(hex)s:){5}%(ls32)s",
+    # [               h16 ] "::" 4( h16 ":" ) ls32
+    "(?:%(hex)s)?::(?:%(hex)s:){4}%(ls32)s",
+    # [ *1( h16 ":" ) h16 ] "::" 3( h16 ":" ) ls32
+    "(?:(?:%(hex)s:)?%(hex)s)?::(?:%(hex)s:){3}%(ls32)s",
+    # [ *2( h16 ":" ) h16 ] "::" 2( h16 ":" ) ls32
+    "(?:(?:%(hex)s:){0,2}%(hex)s)?::(?:%(hex)s:){2}%(ls32)s",
+    # [ *3( h16 ":" ) h16 ] "::"    h16 ":"   ls32
+    "(?:(?:%(hex)s:){0,3}%(hex)s)?::%(hex)s:%(ls32)s",
+    # [ *4( h16 ":" ) h16 ] "::"              ls32
+    "(?:(?:%(hex)s:){0,4}%(hex)s)?::%(ls32)s",
+    # [ *5( h16 ":" ) h16 ] "::"              h16
+    "(?:(?:%(hex)s:){0,5}%(hex)s)?::%(hex)s",
+    # [ *6( h16 ":" ) h16 ] "::"
+    "(?:(?:%(hex)s:){0,6}%(hex)s)?::",
+]
+
+UNRESERVED_PAT = r"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789._!\-~"
+IPV6_PAT = "(?:" + "|".join([x % _subs for x in _variations]) + ")"
+ZONE_ID_PAT = "(?:%25|%)(?:[" + UNRESERVED_PAT + "]|%[a-fA-F0-9]{2})+"
+IPV6_ADDRZ_PAT = r"\[" + IPV6_PAT + r"(?:" + ZONE_ID_PAT + r")?\]"
+REG_NAME_PAT = r"(?:[^\[\]%:/?#]|%[a-fA-F0-9]{2})*"
+TARGET_RE = re.compile(r"^(/[^?#]*)(?:\?([^#]*))?(?:#.*)?$")
+
+IPV4_RE = re.compile("^" + IPV4_PAT + "$")
+IPV6_RE = re.compile("^" + IPV6_PAT + "$")
+IPV6_ADDRZ_RE = re.compile("^" + IPV6_ADDRZ_PAT + "$")
+BRACELESS_IPV6_ADDRZ_RE = re.compile("^" + IPV6_ADDRZ_PAT[2:-2] + "$")
+ZONE_ID_RE = re.compile("(" + ZONE_ID_PAT + r")\]$")
+
+SUBAUTHORITY_PAT = (u"^(?:(.*)@)?(%s|%s|%s)(?::([0-9]{0,5}))?$") % (
+    REG_NAME_PAT,
+    IPV4_PAT,
+    IPV6_ADDRZ_PAT,
+)
+SUBAUTHORITY_RE = re.compile(SUBAUTHORITY_PAT, re.UNICODE | re.DOTALL)
+
+UNRESERVED_CHARS = set(
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789._-~"
+)
+SUB_DELIM_CHARS = set("!$&'()*+,;=")
+USERINFO_CHARS = UNRESERVED_CHARS | SUB_DELIM_CHARS | {":"}
+PATH_CHARS = USERINFO_CHARS | {"@", "/"}
+QUERY_CHARS = FRAGMENT_CHARS = PATH_CHARS | {"?"}
+
+
+class Url(namedtuple("Url", url_attrs)):
+    """
+    Data structure for representing an HTTP URL. Used as a return value for
+    :func:`parse_url`. Both the scheme and host are normalized as they are
+    both case-insensitive according to RFC 3986.
+    """
+
+    __slots__ = ()
+
+    def __new__(
+        cls,
+        scheme=None,
+        auth=None,
+        host=None,
+        port=None,
+        path=None,
+        query=None,
+        fragment=None,
+    ):
+        if path and not path.startswith("/"):
+            path = "/" + path
+        if scheme is not None:
+            scheme = scheme.lower()
+        return super(Url, cls).__new__(
+            cls, scheme, auth, host, port, path, query, fragment
+        )
+
+    @property
+    def hostname(self):
+        """For backwards-compatibility with urlparse. We're nice like that."""
+        return self.host
+
+    @property
+    def request_uri(self):
+        """Absolute path including the query string."""
+        uri = self.path or "/"
+
+        if self.query is not None:
+            uri += "?" + self.query
+
+        return uri
+
+    @property
+    def netloc(self):
+        """Network location including host and port"""
+        if self.port:
+            return "%s:%d" % (self.host, self.port)
+        return self.host
+
+    @property
+    def url(self):
+        """
+        Convert self into a url
+
+        This function should more or less round-trip with :func:`.parse_url`. The
+        returned url may not be exactly the same as the url inputted to
+        :func:`.parse_url`, but it should be equivalent by the RFC (e.g., urls
+        with a blank port will have : removed).
+
+        Example: ::
+
+            >>> U = parse_url('http://google.com/mail/')
+            >>> U.url
+            'http://google.com/mail/'
+            >>> Url('http', 'username:password', 'host.com', 80,
+            ... '/path', 'query', 'fragment').url
+            'http://username:password@host.com:80/path?query#fragment'
+        """
+        scheme, auth, host, port, path, query, fragment = self
+        url = u""
+
+        # We use "is not None" we want things to happen with empty strings (or 0 port)
+        if scheme is not None:
+            url += scheme + u"://"
+        if auth is not None:
+            url += auth + u"@"
+        if host is not None:
+            url += host
+        if port is not None:
+            url += u":" + str(port)
+        if path is not None:
+            url += path
+        if query is not None:
+            url += u"?" + query
+        if fragment is not None:
+            url += u"#" + fragment
+
+        return url
+
+    def __str__(self):
+        return self.url
+
+
+def split_first(s, delims):
+    """
+    .. deprecated:: 1.25
+
+    Given a string and an iterable of delimiters, split on the first found
+    delimiter. Return two split parts and the matched delimiter.
+
+    If not found, then the first part is the full input string.
+
+    Example::
+
+        >>> split_first('foo/bar?baz', '?/=')
+        ('foo', 'bar?baz', '/')
+        >>> split_first('foo/bar?baz', '123')
+        ('foo/bar?baz', '', None)
+
+    Scales linearly with number of delims. Not ideal for large number of delims.
+    """
+    min_idx = None
+    min_delim = None
+    for d in delims:
+        idx = s.find(d)
+        if idx < 0:
+            continue
+
+        if min_idx is None or idx < min_idx:
+            min_idx = idx
+            min_delim = d
+
+    if min_idx is None or min_idx < 0:
+        return s, "", None
+
+    return s[:min_idx], s[min_idx + 1 :], min_delim
+
+
+def _encode_invalid_chars(component, allowed_chars, encoding="utf-8"):
+    """Percent-encodes a URI component without reapplying
+    onto an already percent-encoded component.
+    """
+    if component is None:
+        return component
+
+    component = six.ensure_text(component)
+
+    # Normalize existing percent-encoded bytes.
+    # Try to see if the component we're encoding is already percent-encoded
+    # so we can skip all '%' characters but still encode all others.
+    component, percent_encodings = PERCENT_RE.subn(
+        lambda match: match.group(0).upper(), component
+    )
+
+    uri_bytes = component.encode("utf-8", "surrogatepass")
+    is_percent_encoded = percent_encodings == uri_bytes.count(b"%")
+    encoded_component = bytearray()
+
+    for i in range(0, len(uri_bytes)):
+        # Will return a single character bytestring on both Python 2 & 3
+        byte = uri_bytes[i : i + 1]
+        byte_ord = ord(byte)
+        if (is_percent_encoded and byte == b"%") or (
+            byte_ord < 128 and byte.decode() in allowed_chars
+        ):
+            encoded_component += byte
+            continue
+        encoded_component.extend(b"%" + (hex(byte_ord)[2:].encode().zfill(2).upper()))
+
+    return encoded_component.decode(encoding)
+
+
+def _remove_path_dot_segments(path):
+    # See http://tools.ietf.org/html/rfc3986#section-5.2.4 for pseudo-code
+    segments = path.split("/")  # Turn the path into a list of segments
+    output = []  # Initialize the variable to use to store output
+
+    for segment in segments:
+        # '.' is the current directory, so ignore it, it is superfluous
+        if segment == ".":
+            continue
+        # Anything other than '..', should be appended to the output
+        elif segment != "..":
+            output.append(segment)
+        # In this case segment == '..', if we can, we should pop the last
+        # element
+        elif output:
+            output.pop()
+
+    # If the path starts with '/' and the output is empty or the first string
+    # is non-empty
+    if path.startswith("/") and (not output or output[0]):
+        output.insert(0, "")
+
+    # If the path starts with '/.' or '/..' ensure we add one more empty
+    # string to add a trailing '/'
+    if path.endswith(("/.", "/..")):
+        output.append("")
+
+    return "/".join(output)
+
+
+def _normalize_host(host, scheme):
+    if host:
+        if isinstance(host, six.binary_type):
+            host = six.ensure_str(host)
+
+        if scheme in NORMALIZABLE_SCHEMES:
+            is_ipv6 = IPV6_ADDRZ_RE.match(host)
+            if is_ipv6:
+                match = ZONE_ID_RE.search(host)
+                if match:
+                    start, end = match.span(1)
+                    zone_id = host[start:end]
+
+                    if zone_id.startswith("%25") and zone_id != "%25":
+                        zone_id = zone_id[3:]
+                    else:
+                        zone_id = zone_id[1:]
+                    zone_id = "%" + _encode_invalid_chars(zone_id, UNRESERVED_CHARS)
+                    return host[:start].lower() + zone_id + host[end:]
+                else:
+                    return host.lower()
+            elif not IPV4_RE.match(host):
+                return six.ensure_str(
+                    b".".join([_idna_encode(label) for label in host.split(".")])
+                )
+    return host
+
+
+def _idna_encode(name):
+    if name and any([ord(x) > 128 for x in name]):
+        try:
+            import idna
+        except ImportError:
+            six.raise_from(
+                LocationParseError("Unable to parse URL without the 'idna' module"),
+                None,
+            )
+        try:
+            return idna.encode(name.lower(), strict=True, std3_rules=True)
+        except idna.IDNAError:
+            six.raise_from(
+                LocationParseError(u"Name '%s' is not a valid IDNA label" % name), None
+            )
+    return name.lower().encode("ascii")
+
+
+def _encode_target(target):
+    """Percent-encodes a request target so that there are no invalid characters"""
+    path, query = TARGET_RE.match(target).groups()
+    target = _encode_invalid_chars(path, PATH_CHARS)
+    query = _encode_invalid_chars(query, QUERY_CHARS)
+    if query is not None:
+        target += "?" + query
+    return target
+
+
+def parse_url(url):
+    """
+    Given a url, return a parsed :class:`.Url` namedtuple. Best-effort is
+    performed to parse incomplete urls. Fields not provided will be None.
+    This parser is RFC 3986 compliant.
+
+    The parser logic and helper functions are based heavily on
+    work done in the ``rfc3986`` module.
+
+    :param str url: URL to parse into a :class:`.Url` namedtuple.
+
+    Partly backwards-compatible with :mod:`urlparse`.
+
+    Example::
+
+        >>> parse_url('http://google.com/mail/')
+        Url(scheme='http', host='google.com', port=None, path='/mail/', ...)
+        >>> parse_url('google.com:80')
+        Url(scheme=None, host='google.com', port=80, path=None, ...)
+        >>> parse_url('/foo?bar')
+        Url(scheme=None, host=None, port=None, path='/foo', query='bar', ...)
+    """
+    if not url:
+        # Empty
+        return Url()
+
+    source_url = url
+    if not SCHEME_RE.search(url):
+        url = "//" + url
+
+    try:
+        scheme, authority, path, query, fragment = URI_RE.match(url).groups()
+        normalize_uri = scheme is None or scheme.lower() in NORMALIZABLE_SCHEMES
+
+        if scheme:
+            scheme = scheme.lower()
+
+        if authority:
+            auth, host, port = SUBAUTHORITY_RE.match(authority).groups()
+            if auth and normalize_uri:
+                auth = _encode_invalid_chars(auth, USERINFO_CHARS)
+            if port == "":
+                port = None
+        else:
+            auth, host, port = None, None, None
+
+        if port is not None:
+            port = int(port)
+            if not (0 <= port <= 65535):
+                raise LocationParseError(url)
+
+        host = _normalize_host(host, scheme)
+
+        if normalize_uri and path:
+            path = _remove_path_dot_segments(path)
+            path = _encode_invalid_chars(path, PATH_CHARS)
+        if normalize_uri and query:
+            query = _encode_invalid_chars(query, QUERY_CHARS)
+        if normalize_uri and fragment:
+            fragment = _encode_invalid_chars(fragment, FRAGMENT_CHARS)
+
+    except (ValueError, AttributeError):
+        return six.raise_from(LocationParseError(source_url), None)
+
+    # For the sake of backwards compatibility we put empty
+    # string values for path if there are any defined values
+    # beyond the path in the URL.
+    # TODO: Remove this when we break backwards compatibility.
+    if not path:
+        if query is not None or fragment is not None:
+            path = ""
+        else:
+            path = None
+
+    # Ensure that each part of the URL is a `str` for
+    # backwards compatibility.
+    if isinstance(url, six.text_type):
+        ensure_func = six.ensure_text
+    else:
+        ensure_func = six.ensure_str
+
+    def ensure_type(x):
+        return x if x is None else ensure_func(x)
+
+    return Url(
+        scheme=ensure_type(scheme),
+        auth=ensure_type(auth),
+        host=ensure_type(host),
+        port=port,
+        path=ensure_type(path),
+        query=ensure_type(query),
+        fragment=ensure_type(fragment),
+    )
+
+
+def get_host(url):
+    """
+    Deprecated. Use :func:`parse_url` instead.
+    """
+    p = parse_url(url)
+    return p.scheme or "http", p.hostname, p.port

venv/Lib/site-packages/urllib3/util/wait.py

@@ -0,0 +1,153 @@
+import errno
+from functools import partial
+import select
+import sys
+
+try:
+    from time import monotonic
+except ImportError:
+    from time import time as monotonic
+
+__all__ = ["NoWayToWaitForSocketError", "wait_for_read", "wait_for_write"]
+
+
+class NoWayToWaitForSocketError(Exception):
+    pass
+
+
+# How should we wait on sockets?
+#
+# There are two types of APIs you can use for waiting on sockets: the fancy
+# modern stateful APIs like epoll/kqueue, and the older stateless APIs like
+# select/poll. The stateful APIs are more efficient when you have a lots of
+# sockets to keep track of, because you can set them up once and then use them
+# lots of times. But we only ever want to wait on a single socket at a time
+# and don't want to keep track of state, so the stateless APIs are actually
+# more efficient. So we want to use select() or poll().
+#
+# Now, how do we choose between select() and poll()? On traditional Unixes,
+# select() has a strange calling convention that makes it slow, or fail
+# altogether, for high-numbered file descriptors. The point of poll() is to fix
+# that, so on Unixes, we prefer poll().
+#
+# On Windows, there is no poll() (or at least Python doesn't provide a wrapper
+# for it), but that's OK, because on Windows, select() doesn't have this
+# strange calling convention; plain select() works fine.
+#
+# So: on Windows we use select(), and everywhere else we use poll(). We also
+# fall back to select() in case poll() is somehow broken or missing.
+
+if sys.version_info >= (3, 5):
+    # Modern Python, that retries syscalls by default
+    def _retry_on_intr(fn, timeout):
+        return fn(timeout)
+
+
+else:
+    # Old and broken Pythons.
+    def _retry_on_intr(fn, timeout):
+        if timeout is None:
+            deadline = float("inf")
+        else:
+            deadline = monotonic() + timeout
+
+        while True:
+            try:
+                return fn(timeout)
+            # OSError for 3 <= pyver < 3.5, select.error for pyver <= 2.7
+            except (OSError, select.error) as e:
+                # 'e.args[0]' incantation works for both OSError and select.error
+                if e.args[0] != errno.EINTR:
+                    raise
+                else:
+                    timeout = deadline - monotonic()
+                    if timeout < 0:
+                        timeout = 0
+                    if timeout == float("inf"):
+                        timeout = None
+                    continue
+
+
+def select_wait_for_socket(sock, read=False, write=False, timeout=None):
+    if not read and not write:
+        raise RuntimeError("must specify at least one of read=True, write=True")
+    rcheck = []
+    wcheck = []
+    if read:
+        rcheck.append(sock)
+    if write:
+        wcheck.append(sock)
+    # When doing a non-blocking connect, most systems signal success by
+    # marking the socket writable. Windows, though, signals success by marked
+    # it as "exceptional". We paper over the difference by checking the write
+    # sockets for both conditions. (The stdlib selectors module does the same
+    # thing.)
+    fn = partial(select.select, rcheck, wcheck, wcheck)
+    rready, wready, xready = _retry_on_intr(fn, timeout)
+    return bool(rready or wready or xready)
+
+
+def poll_wait_for_socket(sock, read=False, write=False, timeout=None):
+    if not read and not write:
+        raise RuntimeError("must specify at least one of read=True, write=True")
+    mask = 0
+    if read:
+        mask |= select.POLLIN
+    if write:
+        mask |= select.POLLOUT
+    poll_obj = select.poll()
+    poll_obj.register(sock, mask)
+
+    # For some reason, poll() takes timeout in milliseconds
+    def do_poll(t):
+        if t is not None:
+            t *= 1000
+        return poll_obj.poll(t)
+
+    return bool(_retry_on_intr(do_poll, timeout))
+
+
+def null_wait_for_socket(*args, **kwargs):
+    raise NoWayToWaitForSocketError("no select-equivalent available")
+
+
+def _have_working_poll():
+    # Apparently some systems have a select.poll that fails as soon as you try
+    # to use it, either due to strange configuration or broken monkeypatching
+    # from libraries like eventlet/greenlet.
+    try:
+        poll_obj = select.poll()
+        _retry_on_intr(poll_obj.poll, 0)
+    except (AttributeError, OSError):
+        return False
+    else:
+        return True
+
+
+def wait_for_socket(*args, **kwargs):
+    # We delay choosing which implementation to use until the first time we're
+    # called. We could do it at import time, but then we might make the wrong
+    # decision if someone goes wild with monkeypatching select.poll after
+    # we're imported.
+    global wait_for_socket
+    if _have_working_poll():
+        wait_for_socket = poll_wait_for_socket
+    elif hasattr(select, "select"):
+        wait_for_socket = select_wait_for_socket
+    else:  # Platform-specific: Appengine.
+        wait_for_socket = null_wait_for_socket
+    return wait_for_socket(*args, **kwargs)
+
+
+def wait_for_read(sock, timeout=None):
+    """ Waits for reading to be available on a given socket.
+    Returns True if the socket is readable, or False if the timeout expired.
+    """
+    return wait_for_socket(sock, read=True, timeout=timeout)
+
+
+def wait_for_write(sock, timeout=None):
+    """ Waits for writing to be available on a given socket.
+    Returns True if the socket is readable, or False if the timeout expired.
+    """
+    return wait_for_socket(sock, write=True, timeout=timeout)