64 lines
1.8 KiB
Python
64 lines
1.8 KiB
Python
"""
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This module holds the AuthKey class.
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"""
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import struct
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from hashlib import sha1
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from ..extensions import BinaryReader
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class AuthKey:
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"""
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Represents an authorization key, used to encrypt and decrypt
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messages sent to Telegram's data centers.
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"""
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def __init__(self, data):
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"""
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Initializes a new authorization key.
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:param data: the data in bytes that represent this auth key.
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"""
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self.key = data
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@property
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def key(self):
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return self._key
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@key.setter
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def key(self, value):
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if not value:
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self._key = self.aux_hash = self.key_id = None
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return
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if isinstance(value, type(self)):
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self._key, self.aux_hash, self.key_id = \
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value._key, value.aux_hash, value.key_id
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return
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self._key = value
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with BinaryReader(sha1(self._key).digest()) as reader:
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self.aux_hash = reader.read_long(signed=False)
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reader.read(4)
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self.key_id = reader.read_long(signed=False)
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# TODO This doesn't really fit here, it's only used in authentication
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def calc_new_nonce_hash(self, new_nonce, number):
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"""
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Calculates the new nonce hash based on the current attributes.
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:param new_nonce: the new nonce to be hashed.
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:param number: number to prepend before the hash.
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:return: the hash for the given new nonce.
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"""
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new_nonce = new_nonce.to_bytes(32, 'little', signed=True)
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data = new_nonce + struct.pack('<BQ', number, self.aux_hash)
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# Calculates the message key from the given data
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return int.from_bytes(sha1(data).digest()[4:20], 'little', signed=True)
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def __bool__(self):
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return bool(self._key)
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def __eq__(self, other):
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return isinstance(other, type(self)) and other.key == self._key
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