106 lines
2.8 KiB
Python
106 lines
2.8 KiB
Python
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# Copyright 2013 Donald Stufft and individual contributors
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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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# http://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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import base64
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import binascii
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from abc import ABCMeta, abstractmethod
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from typing import SupportsBytes, Type
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# TODO: when the minimum supported version of Python is 3.8, we can import
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# Protocol from typing, and replace Encoder with a Protocol instead.
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class _Encoder(metaclass=ABCMeta):
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@staticmethod
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@abstractmethod
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def encode(data: bytes) -> bytes:
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"""Transform raw data to encoded data."""
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@staticmethod
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@abstractmethod
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def decode(data: bytes) -> bytes:
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"""Transform encoded data back to raw data.
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Decoding after encoding should be a no-op, i.e. `decode(encode(x)) == x`.
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"""
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# Functions that use encoders are passed a subclass of _Encoder, not an instance
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# (because the methods are all static). Let's gloss over that detail by defining
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# an alias for Type[_Encoder].
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Encoder = Type[_Encoder]
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class RawEncoder(_Encoder):
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@staticmethod
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def encode(data: bytes) -> bytes:
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return data
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@staticmethod
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def decode(data: bytes) -> bytes:
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return data
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class HexEncoder(_Encoder):
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@staticmethod
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def encode(data: bytes) -> bytes:
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return binascii.hexlify(data)
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@staticmethod
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def decode(data: bytes) -> bytes:
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return binascii.unhexlify(data)
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class Base16Encoder(_Encoder):
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@staticmethod
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def encode(data: bytes) -> bytes:
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return base64.b16encode(data)
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@staticmethod
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def decode(data: bytes) -> bytes:
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return base64.b16decode(data)
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class Base32Encoder(_Encoder):
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@staticmethod
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def encode(data: bytes) -> bytes:
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return base64.b32encode(data)
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@staticmethod
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def decode(data: bytes) -> bytes:
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return base64.b32decode(data)
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class Base64Encoder(_Encoder):
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@staticmethod
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def encode(data: bytes) -> bytes:
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return base64.b64encode(data)
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@staticmethod
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def decode(data: bytes) -> bytes:
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return base64.b64decode(data)
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class URLSafeBase64Encoder(_Encoder):
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@staticmethod
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def encode(data: bytes) -> bytes:
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return base64.urlsafe_b64encode(data)
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@staticmethod
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def decode(data: bytes) -> bytes:
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return base64.urlsafe_b64decode(data)
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class Encodable:
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def encode(self: SupportsBytes, encoder: Encoder = RawEncoder) -> bytes:
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return encoder.encode(bytes(self))
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