commit 75eaf90205f30469344c1a1e46e7582579e77e87
parent e973664490150b64bba1fb41d58857b92cb12b0c
Author: nolash <dev@holbrook.no>
Date: Wed, 17 Mar 2021 21:51:43 +0100
Add keyfile parser, creater
Diffstat:
3 files changed, 248 insertions(+), 2 deletions(-)
diff --git a/crypto_dev_signer/encoding.py b/crypto_dev_signer/encoding.py
@@ -0,0 +1,70 @@
+# standard imports
+import logging
+
+# external imports
+import coincurve
+import sha3
+from hexathon import (
+ strip_0x,
+ uniform,
+ )
+
+logg = logging.getLogger(__name__)
+
+
+def private_key_to_address(pk, result_format='hex'):
+ pubk = coincurve.PublicKey.from_secret(pk.secret)
+ logg.debug('secret {} '.format(pk.secret.hex()))
+ pubk_bytes = pubk.format(compressed=False)
+ h = sha3.keccak_256()
+ logg.debug('public key bytes {}'.format(pubk_bytes.hex()))
+ h.update(pubk_bytes[1:])
+ z = h.digest()[12:]
+ if result_format == 'hex':
+ return to_checksum_address(z[:20].hex())
+ elif result_format == 'bytes':
+ return z[:20]
+ raise ValueError('invalid result format "{}"'.format(result_format))
+
+
+def is_address(address_hex):
+ try:
+ address_hex = strip_0x(address_hex)
+ except ValueError:
+ return False
+ return len(address_hex) == 40
+
+
+def is_checksum_address(address_hex):
+ hx = None
+ try:
+ hx = to_checksum(address_hex)
+ except ValueError:
+ return False
+ print('{} {}'.format(hx, address_hex))
+ return hx == address_hex
+
+
+def to_checksum_address(address_hex):
+ address_hex = strip_0x(address_hex)
+ address_hex = uniform(address_hex)
+ if len(address_hex) != 40:
+ raise ValueError('Invalid address length')
+ h = sha3.keccak_256()
+ h.update(address_hex.encode('utf-8'))
+ z = h.digest()
+
+ checksum_address_hex = '0x'
+
+ for (i, c) in enumerate(address_hex):
+ if c in '1234567890':
+ checksum_address_hex += c
+ elif c in 'abcdef':
+ if z[int(i / 2)] & (0x80 >> ((i % 2) * 4)) > 1:
+ checksum_address_hex += c.upper()
+ else:
+ checksum_address_hex += c
+
+ return checksum_address_hex
+
+to_checksum = to_checksum_address
diff --git a/crypto_dev_signer/keystore/keyfile.py b/crypto_dev_signer/keystore/keyfile.py
@@ -0,0 +1,141 @@
+# standard imports
+import os
+import hashlib
+import logging
+import json
+import uuid
+
+# external imports
+from Crypto.Cipher import AES
+from Crypto.Util import Counter
+import sha3
+
+# local imports
+from crypto_dev_signer.encoding import private_key_to_address
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+algo_keywords = [
+ 'aes-128-ctr',
+ ]
+hash_keywords = [
+ 'scrypt'
+ ]
+
+default_kdfparams = {
+ 'dklen': 32,
+ 'n': 1 << 18,
+ 'p': 1,
+ 'r': 8,
+ 'salt': os.urandom(32).hex(),
+ }
+
+
+def to_mac(mac_key, ciphertext_bytes):
+ h = sha3.keccak_256()
+ h.update(mac_key)
+ h.update(ciphertext_bytes)
+ return h.digest()
+
+
+class Hashes:
+
+ @staticmethod
+ def from_scrypt(kdfparams=default_kdfparams, passphrase=''):
+ dklen = int(kdfparams['dklen'])
+ n = int(kdfparams['n'])
+ p = int(kdfparams['p'])
+ r = int(kdfparams['r'])
+ salt = bytes.fromhex(kdfparams['salt'])
+
+ return hashlib.scrypt(passphrase.encode('utf-8'), salt=salt,n=n, p=p, r=r, maxmem=1024*1024*1024, dklen=dklen)
+
+
+class Ciphers:
+
+ aes_128_block_size = 1 << 7
+ aes_iv_len = 16
+
+ @staticmethod
+ def decrypt_aes_128_ctr(ciphertext, decryption_key, iv):
+ ctr = Counter.new(Ciphers.aes_128_block_size, initial_value=iv)
+ cipher = AES.new(decryption_key, AES.MODE_CTR, counter=ctr)
+ plaintext = cipher.decrypt(ciphertext)
+ return plaintext
+
+
+ @staticmethod
+ def encrypt_aes_128_ctr(plaintext, encryption_key, iv):
+ ctr = Counter.new(Ciphers.aes_128_block_size, initial_value=iv)
+ cipher = AES.new(encryption_key, AES.MODE_CTR, counter=ctr)
+ ciphertext = cipher.encrypt(plaintext)
+ return ciphertext
+
+
+def to_dict(private_key, passphrase=''):
+
+ encryption_key = Hashes.from_scrypt(passphrase=passphrase)
+
+ address_hex = private_key_to_address(private_key)
+ iv_bytes = os.urandom(Ciphers.aes_iv_len)
+ iv = int.from_bytes(iv_bytes, 'big')
+ ciphertext_bytes = Ciphers.encrypt_aes_128_ctr(private_key.secret, encryption_key[:16], iv)
+
+ mac = to_mac(encryption_key[16:], ciphertext_bytes)
+
+ crypto_dict = {
+ 'cipher': 'aes-128-ctr',
+ 'ciphertext': ciphertext_bytes.hex(),
+ 'cipherparams': {
+ 'iv': iv_bytes.hex(),
+ },
+ 'kdf': 'scrypt',
+ 'kdfparams': default_kdfparams,
+ 'mac': mac.hex(),
+ }
+
+ uu = uuid.uuid1()
+ o = {
+ 'address': address_hex,
+ 'version': 3,
+ 'crypto': crypto_dict,
+ 'id': str(uu),
+ }
+ return o
+
+
+def from_dict(o, passphrase=''):
+
+ cipher = o['crypto']['cipher']
+ if cipher not in algo_keywords:
+ raise NotImplementedError('cipher "{}" not implemented'.format(cipher))
+
+ kdf = o['crypto']['kdf']
+ if kdf not in hash_keywords:
+ raise NotImplementedError('kdf "{}" not implemented'.format(kdf))
+
+ m = getattr(Hashes, 'from_{}'.format(kdf.replace('-', '_')))
+ decryption_key = m(o['crypto']['kdfparams'], passphrase)
+
+ control_mac = bytes.fromhex(o['crypto']['mac'])
+ iv_bytes = bytes.fromhex(o['crypto']['cipherparams']['iv'])
+ iv = int.from_bytes(iv_bytes, "big")
+ ciphertext_bytes = bytes.fromhex(o['crypto']['ciphertext'])
+
+ # check mac
+ calculated_mac = to_mac(decryption_key[16:], ciphertext_bytes)
+ assert control_mac == calculated_mac
+
+ m = getattr(Ciphers, 'decrypt_{}'.format(cipher.replace('-', '_')))
+ pk = m(ciphertext_bytes, decryption_key[:16], iv)
+ return pk
+
+
+def from_file(filepath, passphrase=''):
+
+ f = open(filepath, 'r')
+ o = json.load(f)
+ f.close()
+
+ return from_dict(o, passphrase)
diff --git a/crypto_dev_signer/runnable/keyfile.py b/crypto_dev_signer/runnable/keyfile.py
@@ -1,8 +1,43 @@
# standard imports
+import os
import logging
import sys
+import json
+import argparse
+
+# external impors
+import coincurve
# local imports
-from crypto_dev_signer.keystore.keyfile import parse_file
+from crypto_dev_signer.keystore.keyfile import (
+ from_file,
+ to_dict,
+ )
+
+
+logging.basicConfig(level=logging.WARNING)
+logg = logging.getLogger()
+
+argparser = argparse.ArgumentParser()
+argparser.add_argument('-d', type=str, help='decrypt file')
+argparser.add_argument('-v', action='store_true', help='be verbose')
+argparser.add_argument('arg', type=str, help='decrypt file')
+args = argparser.parse_args()
+
+if args.v:
+ logg.setLevel(logging.DEBUG)
+
+r = None
+if args.d:
+ try:
+ r = from_file(args.d, args.arg).hex()
+ except AssertionError:
+ sys.stderr.write('Invalid passphrase\n')
+ sys.exit(1)
+else:
+ pk_bytes = os.urandom(32)
+ pk = coincurve.PrivateKey(secret=pk_bytes)
+ o = to_dict(pk, args.arg)
+ r = json.dumps(o)
-print(from_file(sys.argv[1]).hex())
+print(r)
