70 lines
1.8 KiB
Python
70 lines
1.8 KiB
Python
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# This file is dual licensed under the terms of the Apache License, Version
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# 2.0, and the BSD License. See the LICENSE file in the root of this repository
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# for complete details.
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from __future__ import annotations
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import abc
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from cryptography import utils
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from cryptography.hazmat.bindings._rust import (
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ANSIX923PaddingContext,
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ANSIX923UnpaddingContext,
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PKCS7PaddingContext,
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PKCS7UnpaddingContext,
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)
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class PaddingContext(metaclass=abc.ABCMeta):
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@abc.abstractmethod
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def update(self, data: utils.Buffer) -> bytes:
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"""
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Pads the provided bytes and returns any available data as bytes.
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"""
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@abc.abstractmethod
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def finalize(self) -> bytes:
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"""
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Finalize the padding, returns bytes.
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"""
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def _byte_padding_check(block_size: int) -> None:
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if not (0 <= block_size <= 2040):
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raise ValueError("block_size must be in range(0, 2041).")
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if block_size % 8 != 0:
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raise ValueError("block_size must be a multiple of 8.")
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class PKCS7:
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def __init__(self, block_size: int):
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_byte_padding_check(block_size)
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self.block_size = block_size
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def padder(self) -> PaddingContext:
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return PKCS7PaddingContext(self.block_size)
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def unpadder(self) -> PaddingContext:
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return PKCS7UnpaddingContext(self.block_size)
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PaddingContext.register(PKCS7PaddingContext)
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PaddingContext.register(PKCS7UnpaddingContext)
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class ANSIX923:
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def __init__(self, block_size: int):
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_byte_padding_check(block_size)
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self.block_size = block_size
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def padder(self) -> PaddingContext:
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return ANSIX923PaddingContext(self.block_size)
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def unpadder(self) -> PaddingContext:
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return ANSIX923UnpaddingContext(self.block_size)
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PaddingContext.register(ANSIX923PaddingContext)
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PaddingContext.register(ANSIX923UnpaddingContext)
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