Telethon/telethon/helpers.py
2018-06-29 11:04:42 +02:00

68 lines
2.0 KiB
Python

"""Various helpers not related to the Telegram API itself"""
import os
import struct
from hashlib import sha1, sha256
# 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)
def add_surrogate(text):
return ''.join(
# SMP -> Surrogate Pairs (Telegram offsets are calculated with these).
# See https://en.wikipedia.org/wiki/Plane_(Unicode)#Overview for more.
''.join(chr(y) for y in struct.unpack('<HH', x.encode('utf-16le')))
if (0x10000 <= ord(x) <= 0x10FFFF) else x for x in text
)
def del_surrogate(text):
return text.encode('utf-16', 'surrogatepass').decode('utf-16')
# endregion
# region Cryptographic related utils
def generate_key_data_from_nonce(server_nonce, new_nonce):
"""Generates the key data corresponding to the given nonce"""
server_nonce = server_nonce.to_bytes(16, 'little', signed=True)
new_nonce = new_nonce.to_bytes(32, 'little', signed=True)
hash1 = sha1(new_nonce + server_nonce).digest()
hash2 = sha1(server_nonce + new_nonce).digest()
hash3 = sha1(new_nonce + new_nonce).digest()
key = hash1 + hash2[:12]
iv = hash2[12:20] + hash3 + new_nonce[:4]
return key, iv
def get_password_hash(pw, current_salt):
"""Gets the password hash for the two-step verification.
current_salt should be the byte array provided by
invoking GetPasswordRequest()
"""
# Passwords are encoded as UTF-8
# At https://github.com/DrKLO/Telegram/blob/e31388
# src/main/java/org/telegram/ui/LoginActivity.java#L2003
data = pw.encode('utf-8')
pw_hash = current_salt + data + current_salt
return sha256(pw_hash).digest()
# endregion