mirror of
https://github.com/TelegramMessenger/Telegram-iOS.git
synced 2026-07-06 03:33:41 +02:00
0fd2765908
Replace the Ruby decrypt.rb shell-out with a direct Python call to decrypt_match_data(). The iOS build no longer depends on a Ruby interpreter. Includes the spec, plan, AES-256 port, tightened error surfaces for key length and V1 fallback, and the BuildConfiguration wire-up that drops decrypt.rb. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
293 lines
9.7 KiB
Python
293 lines
9.7 KiB
Python
import base64
|
|
import hashlib
|
|
|
|
|
|
# FIPS-197 AES S-box and inverse S-box.
|
|
_SBOX = bytes.fromhex(
|
|
"637c777bf26b6fc53001672bfed7ab76"
|
|
"ca82c97dfa5947f0add4a2af9ca472c0"
|
|
"b7fd9326363ff7cc34a5e5f171d83115"
|
|
"04c723c31896059a071280e2eb27b275"
|
|
"09832c1a1b6e5aa0523bd6b329e32f84"
|
|
"53d100ed20fcb15b6acbbe394a4c58cf"
|
|
"d0efaafb434d338545f9027f503c9fa8"
|
|
"51a3408f929d38f5bcb6da2110fff3d2"
|
|
"cd0c13ec5f974417c4a77e3d645d1973"
|
|
"60814fdc222a908846eeb814de5e0bdb"
|
|
"e0323a0a4906245cc2d3ac629195e479"
|
|
"e7c8376d8dd54ea96c56f4ea657aae08"
|
|
"ba78252e1ca6b4c6e8dd741f4bbd8b8a"
|
|
"703eb5664803f60e613557b986c11d9e"
|
|
"e1f8981169d98e949b1e87e9ce5528df"
|
|
"8ca1890dbfe6426841992d0fb054bb16"
|
|
)
|
|
|
|
_INV_SBOX = bytes.fromhex(
|
|
"52096ad53036a538bf40a39e81f3d7fb"
|
|
"7ce339829b2fff87348e4344c4dee9cb"
|
|
"547b9432a6c2233dee4c950b42fac34e"
|
|
"082ea16628d924b2765ba2496d8bd125"
|
|
"72f8f66486689816d4a45ccc5d65b692"
|
|
"6c704850fdedb9da5e154657a78d9d84"
|
|
"90d8ab008cbcd30af7e45805b8b34506"
|
|
"d02c1e8fca3f0f02c1afbd0301138a6b"
|
|
"3a9111414f67dcea97f2cfcef0b4e673"
|
|
"96ac7422e7ad3585e2f937e81c75df6e"
|
|
"47f11a711d29c5896fb7620eaa18be1b"
|
|
"fc563e4bc6d279209adbc0fe78cd5af4"
|
|
"1fdda8338807c731b11210592780ec5f"
|
|
"60517fa919b54a0d2de57a9f93c99cef"
|
|
"a0e03b4dae2af5b0c8ebbb3c83539961"
|
|
"172b047eba77d626e169146355210c7d"
|
|
)
|
|
|
|
_RCON = bytes.fromhex("01020408102040801b36")
|
|
|
|
|
|
def _xtime(a):
|
|
return (((a << 1) ^ 0x1b) & 0xff) if (a & 0x80) else (a << 1)
|
|
|
|
|
|
def _gf_mul(a, b):
|
|
r = 0
|
|
for _ in range(8):
|
|
if b & 1:
|
|
r ^= a
|
|
b >>= 1
|
|
a = _xtime(a)
|
|
return r
|
|
|
|
|
|
def _key_expansion_256(key):
|
|
# AES-256: Nk=8, Nr=14, total 4 * (Nr + 1) = 60 words = 240 bytes.
|
|
if len(key) != 32:
|
|
raise ValueError("AES-256 key must be 32 bytes")
|
|
w = bytearray(240)
|
|
w[:32] = key
|
|
i = 32
|
|
while i < 240:
|
|
t = bytearray(w[i - 4:i])
|
|
if i % 32 == 0:
|
|
t = bytearray([t[1], t[2], t[3], t[0]])
|
|
for j in range(4):
|
|
t[j] = _SBOX[t[j]]
|
|
t[0] ^= _RCON[i // 32 - 1]
|
|
elif i % 32 == 16:
|
|
for j in range(4):
|
|
t[j] = _SBOX[t[j]]
|
|
for j in range(4):
|
|
w[i + j] = w[i - 32 + j] ^ t[j]
|
|
i += 4
|
|
return [bytes(w[r * 16:(r + 1) * 16]) for r in range(15)]
|
|
|
|
|
|
def _add_round_key(state, rk):
|
|
return bytes(s ^ k for s, k in zip(state, rk))
|
|
|
|
|
|
def _sub_bytes(state):
|
|
return bytes(_SBOX[b] for b in state)
|
|
|
|
|
|
def _inv_sub_bytes(state):
|
|
return bytes(_INV_SBOX[b] for b in state)
|
|
|
|
|
|
# Column-major state: state[r + 4 * c], r = 0..3 (row), c = 0..3 (column).
|
|
def _shift_rows(state):
|
|
s = bytearray(state)
|
|
s[1], s[5], s[9], s[13] = s[5], s[9], s[13], s[1]
|
|
s[2], s[6], s[10], s[14] = s[10], s[14], s[2], s[6]
|
|
s[3], s[7], s[11], s[15] = s[15], s[3], s[7], s[11]
|
|
return bytes(s)
|
|
|
|
|
|
def _inv_shift_rows(state):
|
|
s = bytearray(state)
|
|
s[1], s[5], s[9], s[13] = s[13], s[1], s[5], s[9]
|
|
s[2], s[6], s[10], s[14] = s[10], s[14], s[2], s[6]
|
|
s[3], s[7], s[11], s[15] = s[7], s[11], s[15], s[3]
|
|
return bytes(s)
|
|
|
|
|
|
def _mix_columns(state):
|
|
s = bytearray(16)
|
|
for c in range(4):
|
|
a0, a1, a2, a3 = state[4 * c], state[4 * c + 1], state[4 * c + 2], state[4 * c + 3]
|
|
s[4 * c] = _xtime(a0) ^ (_xtime(a1) ^ a1) ^ a2 ^ a3
|
|
s[4 * c + 1] = a0 ^ _xtime(a1) ^ (_xtime(a2) ^ a2) ^ a3
|
|
s[4 * c + 2] = a0 ^ a1 ^ _xtime(a2) ^ (_xtime(a3) ^ a3)
|
|
s[4 * c + 3] = (_xtime(a0) ^ a0) ^ a1 ^ a2 ^ _xtime(a3)
|
|
return bytes(s)
|
|
|
|
|
|
def _inv_mix_columns(state):
|
|
s = bytearray(16)
|
|
for c in range(4):
|
|
a0, a1, a2, a3 = state[4 * c], state[4 * c + 1], state[4 * c + 2], state[4 * c + 3]
|
|
s[4 * c] = _gf_mul(a0, 0x0e) ^ _gf_mul(a1, 0x0b) ^ _gf_mul(a2, 0x0d) ^ _gf_mul(a3, 0x09)
|
|
s[4 * c + 1] = _gf_mul(a0, 0x09) ^ _gf_mul(a1, 0x0e) ^ _gf_mul(a2, 0x0b) ^ _gf_mul(a3, 0x0d)
|
|
s[4 * c + 2] = _gf_mul(a0, 0x0d) ^ _gf_mul(a1, 0x09) ^ _gf_mul(a2, 0x0e) ^ _gf_mul(a3, 0x0b)
|
|
s[4 * c + 3] = _gf_mul(a0, 0x0b) ^ _gf_mul(a1, 0x0d) ^ _gf_mul(a2, 0x09) ^ _gf_mul(a3, 0x0e)
|
|
return bytes(s)
|
|
|
|
|
|
def _aes_encrypt_block(block, round_keys):
|
|
state = _add_round_key(block, round_keys[0])
|
|
for r in range(1, 14):
|
|
state = _sub_bytes(state)
|
|
state = _shift_rows(state)
|
|
state = _mix_columns(state)
|
|
state = _add_round_key(state, round_keys[r])
|
|
state = _sub_bytes(state)
|
|
state = _shift_rows(state)
|
|
state = _add_round_key(state, round_keys[14])
|
|
return state
|
|
|
|
|
|
def _aes_decrypt_block(block, round_keys):
|
|
state = _add_round_key(block, round_keys[14])
|
|
for r in range(13, 0, -1):
|
|
state = _inv_shift_rows(state)
|
|
state = _inv_sub_bytes(state)
|
|
state = _add_round_key(state, round_keys[r])
|
|
state = _inv_mix_columns(state)
|
|
state = _inv_shift_rows(state)
|
|
state = _inv_sub_bytes(state)
|
|
state = _add_round_key(state, round_keys[0])
|
|
return state
|
|
|
|
|
|
def _evp_bytes_to_key(password, salt, hash_name, key_len=32, iv_len=16):
|
|
# OpenSSL EVP_BytesToKey with count=1, matching Ruby's
|
|
# Cipher#pkcs5_keyivgen(password, salt, 1, hash).
|
|
if isinstance(password, str):
|
|
password = password.encode('utf-8')
|
|
required = key_len + iv_len
|
|
material = b""
|
|
prev = b""
|
|
while len(material) < required:
|
|
h = hashlib.new(hash_name)
|
|
h.update(prev + password + salt)
|
|
prev = h.digest()
|
|
material += prev
|
|
return material[:key_len], material[key_len:key_len + iv_len]
|
|
|
|
|
|
def _aes_cbc_decrypt(ciphertext, key, iv):
|
|
if len(ciphertext) == 0 or len(ciphertext) % 16 != 0:
|
|
raise ValueError("V1 ciphertext length must be a non-zero multiple of 16")
|
|
round_keys = _key_expansion_256(key)
|
|
out = bytearray()
|
|
prev = iv
|
|
for i in range(0, len(ciphertext), 16):
|
|
block = ciphertext[i:i + 16]
|
|
decrypted = _aes_decrypt_block(block, round_keys)
|
|
out.extend(bytes(d ^ p for d, p in zip(decrypted, prev)))
|
|
prev = block
|
|
pad = out[-1]
|
|
if pad < 1 or pad > 16 or not all(b == pad for b in out[-pad:]):
|
|
raise ValueError("V1 PKCS#7 padding check failed")
|
|
return bytes(out[:-pad])
|
|
|
|
|
|
def _ghash(h_bytes, data):
|
|
# GHASH over GF(2^128) with reduction polynomial x^128 + x^7 + x^2 + x + 1,
|
|
# using GCM's bit-reversed convention (top-bit-first when encoded as bytes).
|
|
h = int.from_bytes(h_bytes, 'big')
|
|
y = 0
|
|
reduction = 0xe1 << 120
|
|
for i in range(0, len(data), 16):
|
|
block = data[i:i + 16].ljust(16, b"\x00")
|
|
y ^= int.from_bytes(block, 'big')
|
|
z = 0
|
|
v = y
|
|
for bit in range(127, -1, -1):
|
|
if (h >> bit) & 1:
|
|
z ^= v
|
|
if v & 1:
|
|
v = (v >> 1) ^ reduction
|
|
else:
|
|
v >>= 1
|
|
y = z
|
|
return y.to_bytes(16, 'big')
|
|
|
|
|
|
def _aes_gcm_decrypt(ciphertext, key, iv, aad, auth_tag):
|
|
if len(iv) != 12:
|
|
raise ValueError("V2 requires a 96-bit IV")
|
|
round_keys = _key_expansion_256(key)
|
|
H = _aes_encrypt_block(b"\x00" * 16, round_keys)
|
|
j0 = iv + b"\x00\x00\x00\x01"
|
|
|
|
plaintext = bytearray()
|
|
j0_int = int.from_bytes(j0, 'big')
|
|
mask32 = (1 << 32) - 1
|
|
counter_high = j0_int & ~mask32
|
|
counter_low = j0_int & mask32
|
|
n_blocks = (len(ciphertext) + 15) // 16
|
|
for i in range(n_blocks):
|
|
counter_low = (counter_low + 1) & mask32
|
|
ctr_bytes = (counter_high | counter_low).to_bytes(16, 'big')
|
|
keystream = _aes_encrypt_block(ctr_bytes, round_keys)
|
|
block = ciphertext[i * 16:(i + 1) * 16]
|
|
plaintext.extend(bytes(c ^ k for c, k in zip(block, keystream[:len(block)])))
|
|
|
|
aad_pad = b"\x00" * ((16 - len(aad) % 16) % 16)
|
|
ct_pad = b"\x00" * ((16 - len(ciphertext) % 16) % 16)
|
|
length_block = (len(aad) * 8).to_bytes(8, 'big') + (len(ciphertext) * 8).to_bytes(8, 'big')
|
|
s = _ghash(H, aad + aad_pad + ciphertext + ct_pad + length_block)
|
|
e_j0 = _aes_encrypt_block(j0, round_keys)
|
|
computed_tag = bytes(a ^ b for a, b in zip(s, e_j0))
|
|
if computed_tag != auth_tag:
|
|
raise ValueError("V2 GCM auth tag mismatch")
|
|
return bytes(plaintext)
|
|
|
|
|
|
_V1_PREFIX = b"Salted__"
|
|
_V2_PREFIX = b"match_encrypted_v2__"
|
|
|
|
|
|
def _decrypt_stored(stored_data, password):
|
|
if stored_data.startswith(_V2_PREFIX):
|
|
salt = stored_data[20:28]
|
|
auth_tag = stored_data[28:44]
|
|
ciphertext = stored_data[44:]
|
|
material = hashlib.pbkdf2_hmac(
|
|
'sha256',
|
|
password.encode('utf-8'),
|
|
salt,
|
|
10_000,
|
|
dklen=32 + 12 + 24,
|
|
)
|
|
key = material[0:32]
|
|
iv = material[32:44]
|
|
aad = material[44:68]
|
|
return _aes_gcm_decrypt(ciphertext, key, iv, aad, auth_tag)
|
|
if stored_data.startswith(_V1_PREFIX):
|
|
salt = stored_data[8:16]
|
|
ciphertext = stored_data[16:]
|
|
try:
|
|
key, iv = _evp_bytes_to_key(password, salt, 'md5', 32, 16)
|
|
return _aes_cbc_decrypt(ciphertext, key, iv)
|
|
except ValueError:
|
|
key, iv = _evp_bytes_to_key(password, salt, 'sha256', 32, 16)
|
|
return _aes_cbc_decrypt(ciphertext, key, iv)
|
|
raise ValueError("Unrecognized fastlane match payload (missing V1 'Salted__' or V2 'match_encrypted_v2__' prefix)")
|
|
|
|
|
|
def decrypt_match_data(source_path: str, destination_path: str, password: str):
|
|
with open(source_path, 'rb') as f:
|
|
raw = f.read()
|
|
stored_data = base64.b64decode(raw)
|
|
decrypted = _decrypt_stored(stored_data, password)
|
|
with open(destination_path, 'wb') as f:
|
|
f.write(decrypted)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
import sys
|
|
if len(sys.argv) != 4:
|
|
print('Usage: DecryptMatch.py <password> <source_path> <destination_path>')
|
|
sys.exit(1)
|
|
decrypt_match_data(source_path=sys.argv[2], destination_path=sys.argv[3], password=sys.argv[1])
|