Vehicle-Anti-Theft-Face-Rec.../venv/Lib/site-packages/Crypto/Hash/SHA384.py

173 lines
6 KiB
Python

# -*- coding: utf-8 -*-
#
# ===================================================================
# The contents of this file are dedicated to the public domain. To
# the extent that dedication to the public domain is not available,
# everyone is granted a worldwide, perpetual, royalty-free,
# non-exclusive license to exercise all rights associated with the
# contents of this file for any purpose whatsoever.
# No rights are reserved.
#
# 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.
# ===================================================================
"""SHA-384 cryptographic hash algorithm.
SHA-384 belongs to the SHA-2_ family of cryptographic hashes.
It produces the 384 bit digest of a message.
>>> from Crypto.Hash import SHA384
>>>
>>> h = SHA384.new()
>>> h.update(b'Hello')
>>> print h.hexdigest()
*SHA* stands for Secure Hash Algorithm.
.. _SHA-2: http://csrc.nist.gov/publications/fips/fips180-2/fips180-4.pdf
"""
from Crypto.Util.py3compat import *
from Crypto.Util._raw_api import (load_pycryptodome_raw_lib,
VoidPointer, SmartPointer,
create_string_buffer,
get_raw_buffer, c_size_t,
expect_byte_string)
_raw_sha384_lib = load_pycryptodome_raw_lib("Crypto.Hash._SHA384",
"""
int SHA384_init(void **shaState);
int SHA384_destroy(void *shaState);
int SHA384_update(void *hs,
const uint8_t *buf,
size_t len);
int SHA384_digest(const void *shaState,
uint8_t digest[48]);
int SHA384_copy(const void *src, void *dst);
""")
class SHA384Hash(object):
"""Class that implements a SHA-384 hash
"""
#: The size of the resulting hash in bytes.
digest_size = 48
#: The internal block size of the hash algorithm in bytes.
block_size = 128
#: ASN.1 Object ID
oid = '2.16.840.1.101.3.4.2.2'
def __init__(self, data=None):
state = VoidPointer()
result = _raw_sha384_lib.SHA384_init(state.address_of())
if result:
raise ValueError("Error %d while instantiating SHA384"
% result)
self._state = SmartPointer(state.get(),
_raw_sha384_lib.SHA384_destroy)
if data:
self.update(data)
def update(self, data):
"""Continue hashing of a message by consuming the next chunk of data.
Repeated calls are equivalent to a single call with the concatenation
of all the arguments. In other words:
>>> m.update(a); m.update(b)
is equivalent to:
>>> m.update(a+b)
:Parameters:
data : byte string
The next chunk of the message being hashed.
"""
expect_byte_string(data)
result = _raw_sha384_lib.SHA384_update(self._state.get(),
data,
c_size_t(len(data)))
if result:
raise ValueError("Error %d while instantiating SHA384"
% result)
def digest(self):
"""Return the **binary** (non-printable) digest of the message that has been hashed so far.
This method does not change the state of the hash object.
You can continue updating the object after calling this function.
:Return: A byte string of `digest_size` bytes. It may contain non-ASCII
characters, including null bytes.
"""
bfr = create_string_buffer(self.digest_size)
result = _raw_sha384_lib.SHA384_digest(self._state.get(),
bfr)
if result:
raise ValueError("Error %d while instantiating SHA384"
% result)
return get_raw_buffer(bfr)
def hexdigest(self):
"""Return the **printable** digest of the message that has been hashed so far.
This method does not change the state of the hash object.
:Return: A string of 2* `digest_size` characters. It contains only
hexadecimal ASCII digits.
"""
return "".join(["%02x" % bord(x) for x in self.digest()])
def copy(self):
"""Return a copy ("clone") of the hash object.
The copy will have the same internal state as the original hash
object.
This can be used to efficiently compute the digests of strings that
share a common initial substring.
:Return: A hash object of the same type
"""
clone = SHA384Hash()
result = _raw_sha384_lib.SHA384_copy(self._state.get(),
clone._state.get())
if result:
raise ValueError("Error %d while copying SHA384" % result)
return clone
def new(self, data=None):
return SHA384Hash(data)
def new(data=None):
"""Return a fresh instance of the hash object.
:Parameters:
data : byte string
The very first chunk of the message to hash.
It is equivalent to an early call to `SHA384Hash.update()`.
Optional.
:Return: A `SHA384Hash` object
"""
return SHA384Hash().new(data)
#: The size of the resulting hash in bytes.
digest_size = SHA384Hash.digest_size
#: The internal block size of the hash algorithm in bytes.
block_size = SHA384Hash.block_size