1 # -*- coding: utf-8 -*-
4 # Electrum - lightweight Bitcoin client
5 # Copyright (C) 2011 thomasv@gitorious
7 # This program is free software: you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation, either version 3 of the License, or
10 # (at your option) any later version.
12 # This program is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with this program. If not, see <http://www.gnu.org/licenses/>.
21 import hashlib, base64, ecdsa, re
24 from util import print_error
27 EncodeAES = lambda secret, s: base64.b64encode(aes.encryptData(secret,s))
28 DecodeAES = lambda secret, e: aes.decryptData(secret, base64.b64decode(e))
30 def pw_encode(s, password):
32 secret = Hash(password)
33 return EncodeAES(secret, s.encode("utf8"))
37 def pw_decode(s, password):
38 if password is not None:
39 secret = Hash(password)
41 d = DecodeAES(secret, s).decode("utf8")
43 raise Exception('Invalid password')
53 return s.decode('hex')[::-1].encode('hex')
55 def int_to_hex(i, length=1):
56 s = hex(i)[2:].rstrip('L')
57 s = "0"*(2*length - len(s)) + s
61 # https://en.bitcoin.it/wiki/Protocol_specification#Variable_length_integer
65 return "fd"+int_to_hex(i,2)
67 return "fe"+int_to_hex(i,4)
69 return "ff"+int_to_hex(i,8)
75 return '4c' + int_to_hex(i)
77 return '4d' + int_to_hex(i,2)
79 return '4e' + int_to_hex(i,4)
84 return hashlib.sha256(x).digest()
87 if type(x) is unicode: x=x.encode('utf-8')
88 return sha256(sha256(x))
90 hash_encode = lambda x: x[::-1].encode('hex')
91 hash_decode = lambda x: x.decode('hex')[::-1]
92 hmac_sha_512 = lambda x,y: hmac.new(x, y, hashlib.sha512).digest()
94 def mnemonic_to_seed(mnemonic, passphrase):
95 from pbkdf2 import PBKDF2
98 return PBKDF2(mnemonic, 'mnemonic' + passphrase, iterations = PBKDF2_ROUNDS, macmodule = hmac, digestmodule = hashlib.sha512).read(64)
100 from version import SEED_PREFIX
101 is_new_seed = lambda x: hmac_sha_512("Seed version", x.encode('utf8')).encode('hex')[0:2].startswith(SEED_PREFIX)
103 def is_old_seed(seed):
105 words = seed.strip().split()
107 mnemonic.mn_decode(words)
108 uses_electrum_words = True
110 uses_electrum_words = False
114 is_hex = (len(seed) == 32)
118 return is_hex or (uses_electrum_words and len(words) == 12)
121 # pywallet openssl private key implementation
123 def i2d_ECPrivateKey(pkey, compressed=False):
125 key = '3081d30201010420' + \
126 '%064x' % pkey.secret + \
127 'a081a53081a2020101302c06072a8648ce3d0101022100' + \
129 '3006040100040107042102' + \
135 key = '308201130201010420' + \
136 '%064x' % pkey.secret + \
137 'a081a53081a2020101302c06072a8648ce3d0101022100' + \
139 '3006040100040107044104' + \
146 return key.decode('hex') + i2o_ECPublicKey(pkey.pubkey, compressed)
148 def i2o_ECPublicKey(pubkey, compressed=False):
149 # public keys are 65 bytes long (520 bits)
150 # 0x04 + 32-byte X-coordinate + 32-byte Y-coordinate
151 # 0x00 = point at infinity, 0x02 and 0x03 = compressed, 0x04 = uncompressed
152 # compressed keys: <sign> <x> where <sign> is 0x02 if y is even and 0x03 if y is odd
154 if pubkey.point.y() & 1:
155 key = '03' + '%064x' % pubkey.point.x()
157 key = '02' + '%064x' % pubkey.point.x()
160 '%064x' % pubkey.point.x() + \
161 '%064x' % pubkey.point.y()
163 return key.decode('hex')
165 # end pywallet openssl private key implementation
169 ############ functions from pywallet #####################
171 def hash_160(public_key):
173 md = hashlib.new('ripemd160')
174 md.update(sha256(public_key))
178 md = ripemd.new(sha256(public_key))
182 def public_key_to_bc_address(public_key):
183 h160 = hash_160(public_key)
184 return hash_160_to_bc_address(h160)
186 def hash_160_to_bc_address(h160, addrtype = 0):
187 vh160 = chr(addrtype) + h160
189 addr = vh160 + h[0:4]
190 return b58encode(addr)
192 def bc_address_to_hash_160(addr):
193 bytes = b58decode(addr, 25)
194 return ord(bytes[0]), bytes[1:21]
197 __b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
198 __b58base = len(__b58chars)
201 """ encode v, which is a string of bytes, to base58."""
204 for (i, c) in enumerate(v[::-1]):
205 long_value += (256**i) * ord(c)
208 while long_value >= __b58base:
209 div, mod = divmod(long_value, __b58base)
210 result = __b58chars[mod] + result
212 result = __b58chars[long_value] + result
214 # Bitcoin does a little leading-zero-compression:
215 # leading 0-bytes in the input become leading-1s
218 if c == '\0': nPad += 1
221 return (__b58chars[0]*nPad) + result
223 def b58decode(v, length):
224 """ decode v into a string of len bytes."""
226 for (i, c) in enumerate(v[::-1]):
227 long_value += __b58chars.find(c) * (__b58base**i)
230 while long_value >= 256:
231 div, mod = divmod(long_value, 256)
232 result = chr(mod) + result
234 result = chr(long_value) + result
238 if c == __b58chars[0]: nPad += 1
241 result = chr(0)*nPad + result
242 if length is not None and len(result) != length:
248 def EncodeBase58Check(vchIn):
250 return b58encode(vchIn + hash[0:4])
252 def DecodeBase58Check(psz):
253 vchRet = b58decode(psz, None)
263 def PrivKeyToSecret(privkey):
264 return privkey[9:9+32]
266 def SecretToASecret(secret, compressed=False, addrtype=0):
267 vchIn = chr((addrtype+128)&255) + secret
268 if compressed: vchIn += '\01'
269 return EncodeBase58Check(vchIn)
271 def ASecretToSecret(key, addrtype=0):
272 vch = DecodeBase58Check(key)
273 if vch and vch[0] == chr((addrtype+128)&255):
278 def regenerate_key(sec):
279 b = ASecretToSecret(sec)
285 def GetPubKey(pubkey, compressed=False):
286 return i2o_ECPublicKey(pubkey, compressed)
288 def GetPrivKey(pkey, compressed=False):
289 return i2d_ECPrivateKey(pkey, compressed)
292 return ('%064x' % pkey.secret).decode('hex')
294 def is_compressed(sec):
295 b = ASecretToSecret(sec)
299 def public_key_from_private_key(sec):
300 # rebuild public key from private key, compressed or uncompressed
301 pkey = regenerate_key(sec)
303 compressed = is_compressed(sec)
304 public_key = GetPubKey(pkey.pubkey, compressed)
305 return public_key.encode('hex')
308 def address_from_private_key(sec):
309 public_key = public_key_from_private_key(sec)
310 address = public_key_to_bc_address(public_key.decode('hex'))
315 return is_address(addr)
318 def is_address(addr):
319 ADDRESS_RE = re.compile('[1-9A-HJ-NP-Za-km-z]{26,}\\Z')
320 if not ADDRESS_RE.match(addr): return False
322 addrtype, h = bc_address_to_hash_160(addr)
325 return addr == hash_160_to_bc_address(h, addrtype)
328 def is_private_key(key):
330 k = ASecretToSecret(key)
331 return k is not False
336 ########### end pywallet functions #######################
339 from ecdsa.ecdsa import curve_secp256k1, generator_secp256k1
341 print "cannot import ecdsa.curve_secp256k1. You probably need to upgrade ecdsa.\nTry: sudo pip install --upgrade ecdsa"
344 from ecdsa.curves import SECP256k1
345 from ecdsa.ellipticcurve import Point
346 from ecdsa.util import string_to_number, number_to_string
348 def msg_magic(message):
349 varint = var_int(len(message))
350 encoded_varint = "".join([chr(int(varint[i:i+2], 16)) for i in xrange(0, len(varint), 2)])
351 return "\x18Bitcoin Signed Message:\n" + encoded_varint + message
354 def verify_message(address, signature, message):
356 EC_KEY.verify_message(address, signature, message)
358 except Exception as e:
359 print_error("Verification error: {0}".format(e))
363 def encrypt_message(message, pubkey):
364 return EC_KEY.encrypt_message(message, pubkey.decode('hex'))
368 return [l[i:i+n] for i in xrange(0, len(l), n)]
371 def ECC_YfromX(x,curved=curve_secp256k1, odd=True):
375 for offset in range(128):
377 My2 = pow(Mx, 3, _p) + _a * pow(Mx, 2, _p) + _b % _p
378 My = pow(My2, (_p+1)/4, _p )
380 if curved.contains_point(Mx,My):
381 if odd == bool(My&1):
383 return [_p-My,offset]
384 raise Exception('ECC_YfromX: No Y found')
387 def negative_point(P):
388 return Point( P.curve(), P.x(), -P.y(), P.order() )
391 def point_to_ser(P, comp=True ):
393 return ( ('%02x'%(2+(P.y()&1)))+('%064x'%P.x()) ).decode('hex')
394 return ( '04'+('%064x'%P.x())+('%064x'%P.y()) ).decode('hex')
397 def ser_to_point(Aser):
398 curve = curve_secp256k1
399 generator = generator_secp256k1
400 _r = generator.order()
401 assert Aser[0] in ['\x02','\x03','\x04']
402 if Aser[0] == '\x04':
403 return Point( curve, str_to_long(Aser[1:33]), str_to_long(Aser[33:]), _r )
404 Mx = string_to_number(Aser[1:])
405 return Point( curve, Mx, ECC_YfromX(Mx, curve, Aser[0]=='\x03')[0], _r )
409 class EC_KEY(object):
410 def __init__( self, k ):
411 secret = string_to_number(k)
412 self.pubkey = ecdsa.ecdsa.Public_key( generator_secp256k1, generator_secp256k1 * secret )
413 self.privkey = ecdsa.ecdsa.Private_key( self.pubkey, secret )
416 def get_public_key(self, compressed=True):
417 return point_to_ser(self.pubkey.point, compressed).encode('hex')
419 def sign_message(self, message, compressed, address):
420 private_key = ecdsa.SigningKey.from_secret_exponent( self.secret, curve = SECP256k1 )
421 public_key = private_key.get_verifying_key()
422 signature = private_key.sign_digest_deterministic( Hash( msg_magic(message) ), hashfunc=hashlib.sha256, sigencode = ecdsa.util.sigencode_string )
423 assert public_key.verify_digest( signature, Hash( msg_magic(message) ), sigdecode = ecdsa.util.sigdecode_string)
425 sig = base64.b64encode( chr(27 + i + (4 if compressed else 0)) + signature )
427 self.verify_message( address, sig, message)
432 raise Exception("error: cannot sign message")
436 def verify_message(self, address, signature, message):
437 """ See http://www.secg.org/download/aid-780/sec1-v2.pdf for the math """
438 from ecdsa import numbertheory, util
440 curve = curve_secp256k1
441 G = generator_secp256k1
443 # extract r,s from signature
444 sig = base64.b64decode(signature)
445 if len(sig) != 65: raise Exception("Wrong encoding")
446 r,s = util.sigdecode_string(sig[1:], order)
448 if nV < 27 or nV >= 35:
449 raise Exception("Bad encoding")
458 x = r + (recid/2) * order
460 alpha = ( x * x * x + curve.a() * x + curve.b() ) % curve.p()
461 beta = msqr.modular_sqrt(alpha, curve.p())
462 y = beta if (beta - recid) % 2 == 0 else curve.p() - beta
463 # 1.4 the constructor checks that nR is at infinity
464 R = Point(curve, x, y, order)
465 # 1.5 compute e from message:
466 h = Hash( msg_magic(message) )
467 e = string_to_number(h)
469 # 1.6 compute Q = r^-1 (sR - eG)
470 inv_r = numbertheory.inverse_mod(r,order)
471 Q = inv_r * ( s * R + minus_e * G )
472 public_key = ecdsa.VerifyingKey.from_public_point( Q, curve = SECP256k1 )
473 # check that Q is the public key
474 public_key.verify_digest( sig[1:], h, sigdecode = ecdsa.util.sigdecode_string)
475 # check that we get the original signing address
476 addr = public_key_to_bc_address( point_to_ser(public_key.pubkey.point, compressed) )
478 raise Exception("Bad signature")
481 # ecies encryption/decryption methods; aes-256-cbc is used as the cipher; hmac-sha256 is used as the mac
484 def encrypt_message(self, message, pubkey):
486 pk = ser_to_point(pubkey)
487 if not ecdsa.ecdsa.point_is_valid(generator_secp256k1, pk.x(), pk.y()):
488 raise Exception('invalid pubkey')
490 ephemeral_exponent = number_to_string(ecdsa.util.randrange(pow(2,256)), generator_secp256k1.order())
491 ephemeral = EC_KEY(ephemeral_exponent)
493 ecdh_key = (pk * ephemeral.privkey.secret_multiplier).x()
494 ecdh_key = ('%064x' % ecdh_key).decode('hex')
495 key = hashlib.sha512(ecdh_key).digest()
496 key_e, key_m = key[:32], key[32:]
498 iv_ciphertext = aes.encryptData(key_e, message)
500 ephemeral_pubkey = ephemeral.get_public_key(compressed=True).decode('hex')
501 encrypted = 'BIE1' + hash_160(pubkey) + ephemeral_pubkey + iv_ciphertext
502 mac = hmac.new(key_m, encrypted, hashlib.sha256).digest()
504 return base64.b64encode(encrypted + mac)
507 def decrypt_message(self, encrypted):
509 encrypted = base64.b64decode(encrypted)
511 if len(encrypted) < 105:
512 raise Exception('invalid ciphertext: length')
514 magic = encrypted[:4]
515 recipient_pubkeyhash = encrypted[4:24]
516 ephemeral_pubkey = encrypted[24:57]
517 iv_ciphertext = encrypted[57:-32]
518 mac = encrypted[-32:]
521 raise Exception('invalid ciphertext: invalid magic bytes')
523 if hash_160(self.get_public_key().decode('hex')) != recipient_pubkeyhash:
524 raise Exception('invalid ciphertext: invalid key')
527 ephemeral_pubkey = ser_to_point(ephemeral_pubkey)
528 except AssertionError, e:
529 raise Exception('invalid ciphertext: invalid ephemeral pubkey')
531 if not ecdsa.ecdsa.point_is_valid(generator_secp256k1, ephemeral_pubkey.x(), ephemeral_pubkey.y()):
532 raise Exception('invalid ciphertext: invalid ephemeral pubkey')
534 ecdh_key = (ephemeral_pubkey * self.privkey.secret_multiplier).x()
535 ecdh_key = ('%064x' % ecdh_key).decode('hex')
536 key = hashlib.sha512(ecdh_key).digest()
537 key_e, key_m = key[:32], key[32:]
538 if mac != hmac.new(key_m, encrypted[:-32], hashlib.sha256).digest():
539 raise Exception('invalid ciphertext: invalid mac')
541 return aes.decryptData(key_e, iv_ciphertext)
545 ###################################### BIP32 ##############################
547 random_seed = lambda n: "%032x"%ecdsa.util.randrange( pow(2,n) )
548 BIP32_PRIME = 0x80000000
551 def get_pubkeys_from_secret(secret):
553 private_key = ecdsa.SigningKey.from_string( secret, curve = SECP256k1 )
554 public_key = private_key.get_verifying_key()
555 K = public_key.to_string()
556 K_compressed = GetPubKey(public_key.pubkey,True)
557 return K, K_compressed
560 # Child private key derivation function (from master private key)
561 # k = master private key (32 bytes)
562 # c = master chain code (extra entropy for key derivation) (32 bytes)
563 # n = the index of the key we want to derive. (only 32 bits will be used)
564 # If n is negative (i.e. the 32nd bit is set), the resulting private key's
565 # corresponding public key can NOT be determined without the master private key.
566 # However, if n is positive, the resulting private key's corresponding
567 # public key can be determined without the master private key.
568 def CKD_priv(k, c, n):
569 is_prime = n & BIP32_PRIME
570 return _CKD_priv(k, c, rev_hex(int_to_hex(n,4)).decode('hex'), is_prime)
572 def _CKD_priv(k, c, s, is_prime):
574 from ecdsa.util import string_to_number, number_to_string
575 order = generator_secp256k1.order()
577 cK = GetPubKey(keypair.pubkey,True)
578 data = chr(0) + k + s if is_prime else cK + s
579 I = hmac.new(c, data, hashlib.sha512).digest()
580 k_n = number_to_string( (string_to_number(I[0:32]) + string_to_number(k)) % order , order )
584 # Child public key derivation function (from public key only)
585 # K = master public key
586 # c = master chain code
587 # n = index of key we want to derive
588 # This function allows us to find the nth public key, as long as n is
589 # non-negative. If n is negative, we need the master private key to find it.
590 def CKD_pub(cK, c, n):
591 if n & BIP32_PRIME: raise
592 return _CKD_pub(cK, c, rev_hex(int_to_hex(n,4)).decode('hex'))
594 # helper function, callable with arbitrary string
595 def _CKD_pub(cK, c, s):
597 from ecdsa.util import string_to_number, number_to_string
598 order = generator_secp256k1.order()
599 I = hmac.new(c, cK + s, hashlib.sha512).digest()
601 pubkey_point = string_to_number(I[0:32])*curve.generator + ser_to_point(cK)
602 public_key = ecdsa.VerifyingKey.from_public_point( pubkey_point, curve = SECP256k1 )
604 cK_n = GetPubKey(public_key.pubkey,True)
609 def deserialize_xkey(xkey):
610 xkey = DecodeBase58Check(xkey)
611 assert len(xkey) == 78
612 assert xkey[0:4].encode('hex') in ["0488ade4", "0488b21e"]
614 fingerprint = xkey[5:9]
615 child_number = xkey[9:13]
617 if xkey[0:4].encode('hex') == "0488ade4":
618 K_or_k = xkey[13+33:]
620 K_or_k = xkey[13+32:]
621 return depth, fingerprint, child_number, c, K_or_k
625 def bip32_root(seed):
627 seed = seed.decode('hex')
628 I = hmac.new("Bitcoin seed", seed, hashlib.sha512).digest()
631 K, cK = get_pubkeys_from_secret(master_k)
632 xprv = ("0488ADE4" + "00" + "00000000" + "00000000").decode("hex") + master_c + chr(0) + master_k
633 xpub = ("0488B21E" + "00" + "00000000" + "00000000").decode("hex") + master_c + cK
634 return EncodeBase58Check(xprv), EncodeBase58Check(xpub)
638 def bip32_private_derivation(xprv, branch, sequence):
639 depth, fingerprint, child_number, c, k = deserialize_xkey(xprv)
640 assert sequence.startswith(branch)
641 sequence = sequence[len(branch):]
642 for n in sequence.split('/'):
644 i = int(n[:-1]) + BIP32_PRIME if n[-1] == "'" else int(n)
646 k, c = CKD_priv(k, c, i)
649 _, parent_cK = get_pubkeys_from_secret(parent_k)
650 fingerprint = hash_160(parent_cK)[0:4]
651 child_number = ("%08X"%i).decode('hex')
652 K, cK = get_pubkeys_from_secret(k)
653 xprv = "0488ADE4".decode('hex') + chr(depth) + fingerprint + child_number + c + chr(0) + k
654 xpub = "0488B21E".decode('hex') + chr(depth) + fingerprint + child_number + c + cK
655 return EncodeBase58Check(xprv), EncodeBase58Check(xpub)
659 def bip32_public_derivation(xpub, branch, sequence):
660 depth, fingerprint, child_number, c, cK = deserialize_xkey(xpub)
661 assert sequence.startswith(branch)
662 sequence = sequence[len(branch):]
663 for n in sequence.split('/'):
667 cK, c = CKD_pub(cK, c, i)
670 fingerprint = hash_160(parent_cK)[0:4]
671 child_number = ("%08X"%i).decode('hex')
672 xpub = "0488B21E".decode('hex') + chr(depth) + fingerprint + child_number + c + cK
673 return EncodeBase58Check(xpub)
678 def bip32_private_key(sequence, k, chain):
680 k, chain = CKD_priv(k, chain, i)
681 return SecretToASecret(k, True)
686 ################################## transactions
688 MIN_RELAY_TX_FEE = 1000
692 def test_bip32(seed, sequence):
695 see https://en.bitcoin.it/wiki/BIP_0032_TestVectors
698 xprv, xpub = bip32_root(seed)
702 assert sequence[0:2] == "m/"
704 sequence = sequence[2:]
705 for n in sequence.split('/'):
706 child_path = path + '/' + n
708 xpub2 = bip32_public_derivation(xpub, path, child_path)
709 xprv, xpub = bip32_private_derivation(xprv, path, child_path)
725 G = generator_secp256k1
727 pvk = ecdsa.util.randrange( pow(2,256) ) %_r
730 pubkey_c = point_to_ser(Pub,True)
731 pubkey_u = point_to_ser(Pub,False)
732 addr_c = public_key_to_bc_address(pubkey_c)
733 addr_u = public_key_to_bc_address(pubkey_u)
735 print "Private key ", '%064x'%pvk
736 print "Compressed public key ", pubkey_c.encode('hex')
737 print "Uncompressed public key", pubkey_u.encode('hex')
739 message = "Chancellor on brink of second bailout for banks"
740 enc = EC_KEY.encrypt_message(message,pubkey_c)
741 eck = EC_KEY(number_to_string(pvk,_r))
742 dec = eck.decrypt_message(enc)
743 print "decrypted", dec
745 signature = eck.sign_message(message, True, addr_c)
747 EC_KEY.verify_message(addr_c, signature, message)
750 if __name__ == '__main__':
752 test_bip32("000102030405060708090a0b0c0d0e0f", "m/0'/1/2'/2/1000000000")
753 test_bip32("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542","m/0/2147483647'/1/2147483646'/2")