| |
| |
| |
|
|
| from __future__ import annotations |
|
|
| import abc |
|
|
| from cryptography import utils |
| from cryptography.hazmat.bindings._rust import ( |
| ANSIX923PaddingContext, |
| ANSIX923UnpaddingContext, |
| PKCS7PaddingContext, |
| PKCS7UnpaddingContext, |
| ) |
|
|
|
|
| class PaddingContext(metaclass=abc.ABCMeta): |
| @abc.abstractmethod |
| def update(self, data: utils.Buffer) -> bytes: |
| """ |
| Pads the provided bytes and returns any available data as bytes. |
| """ |
|
|
| @abc.abstractmethod |
| def finalize(self) -> bytes: |
| """ |
| Finalize the padding, returns bytes. |
| """ |
|
|
|
|
| def _byte_padding_check(block_size: int) -> None: |
| if not (0 <= block_size <= 2040): |
| raise ValueError("block_size must be in range(0, 2041).") |
|
|
| if block_size % 8 != 0: |
| raise ValueError("block_size must be a multiple of 8.") |
|
|
|
|
| class PKCS7: |
| def __init__(self, block_size: int): |
| _byte_padding_check(block_size) |
| self.block_size = block_size |
|
|
| def padder(self) -> PaddingContext: |
| return PKCS7PaddingContext(self.block_size) |
|
|
| def unpadder(self) -> PaddingContext: |
| return PKCS7UnpaddingContext(self.block_size) |
|
|
|
|
| PaddingContext.register(PKCS7PaddingContext) |
| PaddingContext.register(PKCS7UnpaddingContext) |
|
|
|
|
| class ANSIX923: |
| def __init__(self, block_size: int): |
| _byte_padding_check(block_size) |
| self.block_size = block_size |
|
|
| def padder(self) -> PaddingContext: |
| return ANSIX923PaddingContext(self.block_size) |
|
|
| def unpadder(self) -> PaddingContext: |
| return ANSIX923UnpaddingContext(self.block_size) |
|
|
|
|
| PaddingContext.register(ANSIX923PaddingContext) |
| PaddingContext.register(ANSIX923UnpaddingContext) |
|
|
