Telethon/telethon/helpers.py
Lonami 51a531225f Totally refactored source files location
Now it *should* be easier to turn Telethon
into a pip package
2016-09-17 20:45:12 +02:00

62 lines
1.6 KiB
Python
Executable File

import os
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 ensure_parent_dir_exists(file_path):
"""Ensures that the parent directory exists"""
parent = os.path.dirname(file_path)
if parent:
os.makedirs(parent, exist_ok=True)
# 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))
key = hash1 + hash2[:12]
iv = hash2[12:20] + hash3 + new_nonce[:4]
return key, iv
def sha1(data):
"""Calculates the SHA1 digest for the given data"""
sha = hashlib.sha1()
sha.update(data)
return sha.digest()
# endregion