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