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https://github.com/LonamiWebs/Telethon.git
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62 lines
1.6 KiB
Python
Executable File
62 lines
1.6 KiB
Python
Executable File
import os
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import hashlib
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# region Multiple utilities
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def generate_random_long(signed=True):
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"""Generates a random long integer (8 bytes), which is optionally signed"""
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return int.from_bytes(os.urandom(8), signed=signed, byteorder='little')
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def ensure_parent_dir_exists(file_path):
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"""Ensures that the parent directory exists"""
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parent = os.path.dirname(file_path)
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if parent:
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os.makedirs(parent, exist_ok=True)
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# endregion
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# region Cryptographic related utils
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def calc_key(shared_key, msg_key, client):
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"""Calculate the key based on Telegram guidelines, specifying whether it's the client or not"""
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x = 0 if client else 8
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sha1a = sha1(msg_key + shared_key[x:x + 32])
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sha1b = sha1(shared_key[x + 32:x + 48] + msg_key + shared_key[x + 48:x + 64])
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sha1c = sha1(shared_key[x + 64:x + 96] + msg_key)
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sha1d = sha1(msg_key + shared_key[x + 96:x + 128])
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key = sha1a[0:8] + sha1b[8:20] + sha1c[4:16]
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iv = sha1a[8:20] + sha1b[0:8] + sha1c[16:20] + sha1d[0:8]
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return key, iv
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def calc_msg_key(data):
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"""Calculates the message key from the given data"""
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return sha1(data)[4:20]
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def generate_key_data_from_nonces(server_nonce, new_nonce):
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"""Generates the key data corresponding to the given nonces"""
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hash1 = sha1(bytes(new_nonce + server_nonce))
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hash2 = sha1(bytes(server_nonce + new_nonce))
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hash3 = sha1(bytes(new_nonce + new_nonce))
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key = hash1 + hash2[:12]
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iv = hash2[12:20] + hash3 + new_nonce[:4]
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return key, iv
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def sha1(data):
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"""Calculates the SHA1 digest for the given data"""
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sha = hashlib.sha1()
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sha.update(data)
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return sha.digest()
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# endregion
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