49 lines
1.5 KiB
Python
49 lines
1.5 KiB
Python
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# Copyright 2011 Sybren A. Stüvel <sybren@stuvel.eu>
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# https://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Python compatibility wrappers."""
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from struct import pack
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def byte(num: int) -> bytes:
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"""
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Converts a number between 0 and 255 (both inclusive) to a base-256 (byte)
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representation.
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:param num:
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An unsigned integer between 0 and 255 (both inclusive).
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:returns:
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A single byte.
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"""
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return pack("B", num)
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def xor_bytes(b1: bytes, b2: bytes) -> bytes:
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"""
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Returns the bitwise XOR result between two bytes objects, b1 ^ b2.
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Bitwise XOR operation is commutative, so order of parameters doesn't
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generate different results. If parameters have different length, extra
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length of the largest one is ignored.
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:param b1:
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First bytes object.
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:param b2:
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Second bytes object.
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:returns:
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Bytes object, result of XOR operation.
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"""
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return bytes(x ^ y for x, y in zip(b1, b2))
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