|
|
@@ -0,0 +1,82 @@
|
|
|
+#!/usr/bin/env python3
|
|
|
+#
|
|
|
+# mmgen = Multi-Mode GENerator, a command-line cryptocurrency wallet
|
|
|
+# Copyright (C)2013-2023 The MMGen Project <mmgen@tuta.io>
|
|
|
+# Licensed under the GNU General Public License, Version 3:
|
|
|
+# https://www.gnu.org/licenses
|
|
|
+# Public project repositories:
|
|
|
+# https://github.com/mmgen/mmgen-wallet
|
|
|
+# https://gitlab.com/mmgen/mmgen-wallet
|
|
|
+
|
|
|
+"""
|
|
|
+altcoin.util: various altcoin-related utilities
|
|
|
+"""
|
|
|
+
|
|
|
+from mmgen.util import die
|
|
|
+
|
|
|
+def decrypt_keystore(data,passwd,mac_algo=None,mac_params={}):
|
|
|
+ """
|
|
|
+ Decrypt the encrypted data in a cross-chain keystore
|
|
|
+ Returns the decrypted data as a bytestring
|
|
|
+ """
|
|
|
+
|
|
|
+ cdata = data['crypto']
|
|
|
+ parms = cdata['kdfparams']
|
|
|
+
|
|
|
+ valid_kdfs = ['scrypt','pbkdf2']
|
|
|
+ valid_ciphers = ['aes-128-ctr','aes-256-ctr']
|
|
|
+
|
|
|
+ if (kdf := cdata['kdf']) not in valid_kdfs:
|
|
|
+ die(1, f'unsupported key derivation function {kdf!r} (must be one of {valid_kdfs})')
|
|
|
+
|
|
|
+ if (cipher := cdata['cipher']) not in valid_ciphers:
|
|
|
+ die(1,f'unsupported cipher {cipher!r} (must be one of {valid_ciphers})')
|
|
|
+
|
|
|
+ # Derive encryption key from password:
|
|
|
+ if kdf == 'scrypt':
|
|
|
+ if not mac_algo:
|
|
|
+ die(1,f'the ‘mac_algo’ parameter is required for scrypt kdf')
|
|
|
+ from hashlib import scrypt
|
|
|
+ hashed_pw = scrypt(
|
|
|
+ password = passwd,
|
|
|
+ salt = bytes.fromhex(parms['salt']),
|
|
|
+ n = parms['n'],
|
|
|
+ r = parms['r'],
|
|
|
+ p = parms['p'],
|
|
|
+ maxmem = 0,
|
|
|
+ dklen = parms['dklen'])
|
|
|
+ elif kdf == 'pbkdf2':
|
|
|
+ if (prf := parms.get('prf')) != 'hmac-sha256':
|
|
|
+ die(1, f"unsupported hash function {prf!r} (must be 'hmac-sha256')")
|
|
|
+ from pbkdf2 import PBKDF2
|
|
|
+ hashed_pw = PBKDF2(
|
|
|
+ passphrase = passwd,
|
|
|
+ salt = bytes.fromhex(parms['salt']),
|
|
|
+ iterations = parms['c'],
|
|
|
+ digestmodule = 'sha256',
|
|
|
+ ).read(parms['dklen'])
|
|
|
+ # see:
|
|
|
+ # https://github.com/xchainjs/xchainjs-lib.git
|
|
|
+ # https://github.com/xchainjs/foundry-primitives-js.git
|
|
|
+ from hashlib import blake2b
|
|
|
+ mac_algo = mac_algo or blake2b
|
|
|
+ mac_params = mac_params or {'digest_size': 32}
|
|
|
+
|
|
|
+ mac = mac_algo(
|
|
|
+ hashed_pw[16:32] + bytes.fromhex(cdata['ciphertext']),
|
|
|
+ **mac_params
|
|
|
+ ).digest().hex()
|
|
|
+
|
|
|
+ if mac != cdata['mac']:
|
|
|
+ die(1, 'incorrect password')
|
|
|
+
|
|
|
+ # Decrypt data:
|
|
|
+ from cryptography.hazmat.primitives.ciphers import Cipher,algorithms,modes
|
|
|
+ from cryptography.hazmat.backends import default_backend
|
|
|
+ cipher_len = int(cipher.split('-')[1]) // 8
|
|
|
+ c = Cipher(
|
|
|
+ algorithms.AES(hashed_pw[:cipher_len]),
|
|
|
+ modes.CTR(bytes.fromhex(cdata['cipherparams']['iv'])),
|
|
|
+ backend = default_backend())
|
|
|
+ encryptor = c.encryptor()
|
|
|
+ return encryptor.update(bytes.fromhex(cdata['ciphertext'])) + encryptor.finalize()
|
