Telethon/utils/helpers.py

83 lines
2.3 KiB
Python
Executable File

import os
from utils import BinaryWriter
import hashlib
# region Multiple utilities
def generate_random_long(signed=True):
"""Generates a random long integer (8 bytes), which is optionally signed"""
return int.from_bytes(os.urandom(8), signed=signed, byteorder='little')
def generate_random_bytes(count):
"""Generates a random bytes array"""
return os.urandom(count)
def load_settings(path='api/settings'):
"""Loads the user settings located under `api/`"""
settings = {}
with open(path, 'r', encoding='utf-8') as file:
for line in file:
value_pair = line.split('=')
left = value_pair[0].strip()
right = value_pair[1].strip()
if right.isnumeric():
settings[left] = int(right)
else:
settings[left] = right
return settings
# endregion
# region Cryptographic related utils
def calc_key(shared_key, msg_key, client):
"""Calculate the key based on Telegram guidelines, specifying whether it's the client or not"""
x = 0 if client else 8
sha1a = sha1(msg_key + shared_key[x:x + 32])
sha1b = sha1(shared_key[x + 32:x + 48] + msg_key + shared_key[x + 48:x + 64])
sha1c = sha1(shared_key[x + 64:x + 96] + msg_key)
sha1d = sha1(msg_key + shared_key[x + 96:x + 128])
key = sha1a[0:8] + sha1b[8:20] + sha1c[4:16]
iv = sha1a[8:20] + sha1b[0:8] + sha1c[16:20] + sha1d[0:8]
return key, iv
def calc_msg_key(data):
"""Calculates the message key from the given data"""
return sha1(data)[4:20]
def generate_key_data_from_nonces(server_nonce, new_nonce):
"""Generates the key data corresponding to the given nonces"""
hash1 = sha1(bytes(new_nonce + server_nonce))
hash2 = sha1(bytes(server_nonce + new_nonce))
hash3 = sha1(bytes(new_nonce + new_nonce))
with BinaryWriter() as key_buffer:
with BinaryWriter() as iv_buffer:
key_buffer.write(hash1)
key_buffer.write(hash2[:12])
iv_buffer.write(hash2[12:20])
iv_buffer.write(hash3)
iv_buffer.write(new_nonce[:4])
return key_buffer.get_bytes(), iv_buffer.get_bytes()
def sha1(data):
"""Calculates the SHA1 digest for the given data"""
sha = hashlib.sha1()
sha.update(data)
return sha.digest()
# endregion