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/>.
26 from util import print_error
31 sys.exit("Error: python-ecdsa does not seem to be installed. Try 'sudo pip install ecdsa'")
36 sys.exit("Error: AES does not seem to be installed. Try 'sudo pip install slowaes'")
38 ################################## transactions
40 MIN_RELAY_TX_FEE = 1000
44 EncodeAES = lambda secret, s: base64.b64encode(aes.encryptData(secret,s))
45 DecodeAES = lambda secret, e: aes.decryptData(secret, base64.b64decode(e))
47 def pw_encode(s, password):
49 secret = Hash(password)
50 return EncodeAES(secret, s.encode("utf8"))
54 def pw_decode(s, password):
55 if password is not None:
56 secret = Hash(password)
58 d = DecodeAES(secret, s).decode("utf8")
60 raise Exception('Invalid password')
70 return s.decode('hex')[::-1].encode('hex')
72 def int_to_hex(i, length=1):
73 s = hex(i)[2:].rstrip('L')
74 s = "0"*(2*length - len(s)) + s
78 # https://en.bitcoin.it/wiki/Protocol_specification#Variable_length_integer
82 return "fd"+int_to_hex(i,2)
84 return "fe"+int_to_hex(i,4)
86 return "ff"+int_to_hex(i,8)
92 return '4c' + int_to_hex(i)
94 return '4d' + int_to_hex(i,2)
96 return '4e' + int_to_hex(i,4)
101 return hashlib.sha256(x).digest()
104 if type(x) is unicode: x=x.encode('utf-8')
105 return sha256(sha256(x))
107 hash_encode = lambda x: x[::-1].encode('hex')
108 hash_decode = lambda x: x.decode('hex')[::-1]
109 hmac_sha_512 = lambda x,y: hmac.new(x, y, hashlib.sha512).digest()
111 def mnemonic_to_seed(mnemonic, passphrase):
112 from pbkdf2 import PBKDF2
115 return PBKDF2(mnemonic, 'mnemonic' + passphrase, iterations = PBKDF2_ROUNDS, macmodule = hmac, digestmodule = hashlib.sha512).read(64)
117 from version import SEED_PREFIX
118 is_new_seed = lambda x: hmac_sha_512("Seed version", x.encode('utf8')).encode('hex')[0:2].startswith(SEED_PREFIX)
120 def is_old_seed(seed):
122 words = seed.strip().split()
124 mnemonic.mn_decode(words)
125 uses_electrum_words = True
127 uses_electrum_words = False
131 is_hex = (len(seed) == 32)
135 return is_hex or (uses_electrum_words and len(words) == 12)
138 # pywallet openssl private key implementation
140 def i2d_ECPrivateKey(pkey, compressed=False):
142 key = '3081d30201010420' + \
143 '%064x' % pkey.secret + \
144 'a081a53081a2020101302c06072a8648ce3d0101022100' + \
146 '3006040100040107042102' + \
152 key = '308201130201010420' + \
153 '%064x' % pkey.secret + \
154 'a081a53081a2020101302c06072a8648ce3d0101022100' + \
156 '3006040100040107044104' + \
163 return key.decode('hex') + i2o_ECPublicKey(pkey.pubkey, compressed)
165 def i2o_ECPublicKey(pubkey, compressed=False):
166 # public keys are 65 bytes long (520 bits)
167 # 0x04 + 32-byte X-coordinate + 32-byte Y-coordinate
168 # 0x00 = point at infinity, 0x02 and 0x03 = compressed, 0x04 = uncompressed
169 # compressed keys: <sign> <x> where <sign> is 0x02 if y is even and 0x03 if y is odd
171 if pubkey.point.y() & 1:
172 key = '03' + '%064x' % pubkey.point.x()
174 key = '02' + '%064x' % pubkey.point.x()
177 '%064x' % pubkey.point.x() + \
178 '%064x' % pubkey.point.y()
180 return key.decode('hex')
182 # end pywallet openssl private key implementation
186 ############ functions from pywallet #####################
188 def hash_160(public_key):
190 md = hashlib.new('ripemd160')
191 md.update(sha256(public_key))
195 md = ripemd.new(sha256(public_key))
199 def public_key_to_bc_address(public_key):
200 h160 = hash_160(public_key)
201 return hash_160_to_bc_address(h160)
203 def hash_160_to_bc_address(h160, addrtype = 0):
204 vh160 = chr(addrtype) + h160
206 addr = vh160 + h[0:4]
207 return b58encode(addr)
209 def bc_address_to_hash_160(addr):
210 bytes = b58decode(addr, 25)
211 return ord(bytes[0]), bytes[1:21]
214 __b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
215 __b58base = len(__b58chars)
218 """ encode v, which is a string of bytes, to base58."""
221 for (i, c) in enumerate(v[::-1]):
222 long_value += (256**i) * ord(c)
225 while long_value >= __b58base:
226 div, mod = divmod(long_value, __b58base)
227 result = __b58chars[mod] + result
229 result = __b58chars[long_value] + result
231 # Bitcoin does a little leading-zero-compression:
232 # leading 0-bytes in the input become leading-1s
235 if c == '\0': nPad += 1
238 return (__b58chars[0]*nPad) + result
240 def b58decode(v, length):
241 """ decode v into a string of len bytes."""
243 for (i, c) in enumerate(v[::-1]):
244 long_value += __b58chars.find(c) * (__b58base**i)
247 while long_value >= 256:
248 div, mod = divmod(long_value, 256)
249 result = chr(mod) + result
251 result = chr(long_value) + result
255 if c == __b58chars[0]: nPad += 1
258 result = chr(0)*nPad + result
259 if length is not None and len(result) != length:
265 def EncodeBase58Check(vchIn):
267 return b58encode(vchIn + hash[0:4])
269 def DecodeBase58Check(psz):
270 vchRet = b58decode(psz, None)
280 def PrivKeyToSecret(privkey):
281 return privkey[9:9+32]
283 def SecretToASecret(secret, compressed=False, addrtype=0):
284 vchIn = chr((addrtype+128)&255) + secret
285 if compressed: vchIn += '\01'
286 return EncodeBase58Check(vchIn)
288 def ASecretToSecret(key, addrtype=0):
289 vch = DecodeBase58Check(key)
290 if vch and vch[0] == chr((addrtype+128)&255):
295 def regenerate_key(sec):
296 b = ASecretToSecret(sec)
302 def GetPubKey(pubkey, compressed=False):
303 return i2o_ECPublicKey(pubkey, compressed)
305 def GetPrivKey(pkey, compressed=False):
306 return i2d_ECPrivateKey(pkey, compressed)
309 return ('%064x' % pkey.secret).decode('hex')
311 def is_compressed(sec):
312 b = ASecretToSecret(sec)
316 def public_key_from_private_key(sec):
317 # rebuild public key from private key, compressed or uncompressed
318 pkey = regenerate_key(sec)
320 compressed = is_compressed(sec)
321 public_key = GetPubKey(pkey.pubkey, compressed)
322 return public_key.encode('hex')
325 def address_from_private_key(sec):
326 public_key = public_key_from_private_key(sec)
327 address = public_key_to_bc_address(public_key.decode('hex'))
332 return is_address(addr)
335 def is_address(addr):
336 ADDRESS_RE = re.compile('[1-9A-HJ-NP-Za-km-z]{26,}\\Z')
337 if not ADDRESS_RE.match(addr): return False
339 addrtype, h = bc_address_to_hash_160(addr)
342 return addr == hash_160_to_bc_address(h, addrtype)
345 def is_private_key(key):
347 k = ASecretToSecret(key)
348 return k is not False
353 ########### end pywallet functions #######################
356 from ecdsa.ecdsa import curve_secp256k1, generator_secp256k1
358 print "cannot import ecdsa.curve_secp256k1. You probably need to upgrade ecdsa.\nTry: sudo pip install --upgrade ecdsa"
361 from ecdsa.curves import SECP256k1
362 from ecdsa.ellipticcurve import Point
363 from ecdsa.util import string_to_number, number_to_string
365 def msg_magic(message):
366 varint = var_int(len(message))
367 encoded_varint = "".join([chr(int(varint[i:i+2], 16)) for i in xrange(0, len(varint), 2)])
368 return "\x18Bitcoin Signed Message:\n" + encoded_varint + message
371 def verify_message(address, signature, message):
373 EC_KEY.verify_message(address, signature, message)
375 except Exception as e:
376 print_error("Verification error: {0}".format(e))
380 def encrypt_message(message, pubkey):
381 return EC_KEY.encrypt_message(message, pubkey.decode('hex'))
385 return [l[i:i+n] for i in xrange(0, len(l), n)]
388 def ECC_YfromX(x,curved=curve_secp256k1, odd=True):
392 for offset in range(128):
394 My2 = pow(Mx, 3, _p) + _a * pow(Mx, 2, _p) + _b % _p
395 My = pow(My2, (_p+1)/4, _p )
397 if curved.contains_point(Mx,My):
398 if odd == bool(My&1):
400 return [_p-My,offset]
401 raise Exception('ECC_YfromX: No Y found')
404 def negative_point(P):
405 return Point( P.curve(), P.x(), -P.y(), P.order() )
408 def point_to_ser(P, comp=True ):
410 return ( ('%02x'%(2+(P.y()&1)))+('%064x'%P.x()) ).decode('hex')
411 return ( '04'+('%064x'%P.x())+('%064x'%P.y()) ).decode('hex')
414 def ser_to_point(Aser):
415 curve = curve_secp256k1
416 generator = generator_secp256k1
417 _r = generator.order()
418 assert Aser[0] in ['\x02','\x03','\x04']
419 if Aser[0] == '\x04':
420 return Point( curve, string_to_number(Aser[1:33]), string_to_number(Aser[33:]), _r )
421 Mx = string_to_number(Aser[1:])
422 return Point( curve, Mx, ECC_YfromX(Mx, curve, Aser[0]=='\x03')[0], _r )
426 class MyVerifyingKey(ecdsa.VerifyingKey):
428 def from_signature(klass, sig, recid, h, curve):
429 """ See http://www.secg.org/download/aid-780/sec1-v2.pdf, chapter 4.1.6 """
430 from ecdsa import util, numbertheory
432 curveFp = curve.curve
435 # extract r,s from signature
436 r, s = util.sigdecode_string(sig, order)
438 x = r + (recid/2) * order
440 alpha = ( x * x * x + curveFp.a() * x + curveFp.b() ) % curveFp.p()
441 beta = msqr.modular_sqrt(alpha, curveFp.p())
442 y = beta if (beta - recid) % 2 == 0 else curveFp.p() - beta
443 # 1.4 the constructor checks that nR is at infinity
444 R = Point(curveFp, x, y, order)
445 # 1.5 compute e from message:
446 e = string_to_number(h)
448 # 1.6 compute Q = r^-1 (sR - eG)
449 inv_r = numbertheory.inverse_mod(r,order)
450 Q = inv_r * ( s * R + minus_e * G )
451 return klass.from_public_point( Q, curve )
454 class EC_KEY(object):
455 def __init__( self, k ):
456 secret = string_to_number(k)
457 self.pubkey = ecdsa.ecdsa.Public_key( generator_secp256k1, generator_secp256k1 * secret )
458 self.privkey = ecdsa.ecdsa.Private_key( self.pubkey, secret )
461 def get_public_key(self, compressed=True):
462 return point_to_ser(self.pubkey.point, compressed).encode('hex')
464 def sign_message(self, message, compressed, address):
465 private_key = ecdsa.SigningKey.from_secret_exponent( self.secret, curve = SECP256k1 )
466 public_key = private_key.get_verifying_key()
467 signature = private_key.sign_digest_deterministic( Hash( msg_magic(message) ), hashfunc=hashlib.sha256, sigencode = ecdsa.util.sigencode_string )
468 assert public_key.verify_digest( signature, Hash( msg_magic(message) ), sigdecode = ecdsa.util.sigdecode_string)
470 sig = base64.b64encode( chr(27 + i + (4 if compressed else 0)) + signature )
472 self.verify_message( address, sig, message)
477 raise Exception("error: cannot sign message")
481 def verify_message(self, address, signature, message):
482 sig = base64.b64decode(signature)
483 if len(sig) != 65: raise Exception("Wrong encoding")
486 if nV < 27 or nV >= 35:
487 raise Exception("Bad encoding")
495 h = Hash( msg_magic(message) )
496 public_key = MyVerifyingKey.from_signature( sig[1:], recid, h, curve = SECP256k1 )
499 public_key.verify_digest( sig[1:], h, sigdecode = ecdsa.util.sigdecode_string)
501 # check that we get the original signing address
502 addr = public_key_to_bc_address( point_to_ser(public_key.pubkey.point, compressed) )
504 raise Exception("Bad signature")
507 # ecies encryption/decryption methods; aes-256-cbc is used as the cipher; hmac-sha256 is used as the mac
510 def encrypt_message(self, message, pubkey):
512 pk = ser_to_point(pubkey)
513 if not ecdsa.ecdsa.point_is_valid(generator_secp256k1, pk.x(), pk.y()):
514 raise Exception('invalid pubkey')
516 ephemeral_exponent = number_to_string(ecdsa.util.randrange(pow(2,256)), generator_secp256k1.order())
517 ephemeral = EC_KEY(ephemeral_exponent)
519 ecdh_key = (pk * ephemeral.privkey.secret_multiplier).x()
520 ecdh_key = ('%064x' % ecdh_key).decode('hex')
521 key = hashlib.sha512(ecdh_key).digest()
522 key_e, key_m = key[:32], key[32:]
524 iv_ciphertext = aes.encryptData(key_e, message)
526 ephemeral_pubkey = ephemeral.get_public_key(compressed=True).decode('hex')
527 encrypted = 'BIE1' + ephemeral_pubkey + iv_ciphertext
528 mac = hmac.new(key_m, encrypted, hashlib.sha256).digest()
530 return base64.b64encode(encrypted + mac)
533 def decrypt_message(self, encrypted):
535 encrypted = base64.b64decode(encrypted)
537 if len(encrypted) < 85:
538 raise Exception('invalid ciphertext: length')
540 magic = encrypted[:4]
541 ephemeral_pubkey = encrypted[4:37]
542 iv_ciphertext = encrypted[37:-32]
543 mac = encrypted[-32:]
546 raise Exception('invalid ciphertext: invalid magic bytes')
549 ephemeral_pubkey = ser_to_point(ephemeral_pubkey)
550 except AssertionError, e:
551 raise Exception('invalid ciphertext: invalid ephemeral pubkey')
553 if not ecdsa.ecdsa.point_is_valid(generator_secp256k1, ephemeral_pubkey.x(), ephemeral_pubkey.y()):
554 raise Exception('invalid ciphertext: invalid ephemeral pubkey')
556 ecdh_key = (ephemeral_pubkey * self.privkey.secret_multiplier).x()
557 ecdh_key = ('%064x' % ecdh_key).decode('hex')
558 key = hashlib.sha512(ecdh_key).digest()
559 key_e, key_m = key[:32], key[32:]
560 if mac != hmac.new(key_m, encrypted[:-32], hashlib.sha256).digest():
561 raise Exception('invalid ciphertext: invalid mac')
563 return aes.decryptData(key_e, iv_ciphertext)
566 ###################################### BIP32 ##############################
568 random_seed = lambda n: "%032x"%ecdsa.util.randrange( pow(2,n) )
569 BIP32_PRIME = 0x80000000
572 def get_pubkeys_from_secret(secret):
574 private_key = ecdsa.SigningKey.from_string( secret, curve = SECP256k1 )
575 public_key = private_key.get_verifying_key()
576 K = public_key.to_string()
577 K_compressed = GetPubKey(public_key.pubkey,True)
578 return K, K_compressed
581 # Child private key derivation function (from master private key)
582 # k = master private key (32 bytes)
583 # c = master chain code (extra entropy for key derivation) (32 bytes)
584 # n = the index of the key we want to derive. (only 32 bits will be used)
585 # If n is negative (i.e. the 32nd bit is set), the resulting private key's
586 # corresponding public key can NOT be determined without the master private key.
587 # However, if n is positive, the resulting private key's corresponding
588 # public key can be determined without the master private key.
589 def CKD_priv(k, c, n):
590 is_prime = n & BIP32_PRIME
591 return _CKD_priv(k, c, rev_hex(int_to_hex(n,4)).decode('hex'), is_prime)
593 def _CKD_priv(k, c, s, is_prime):
595 from ecdsa.util import string_to_number, number_to_string
596 order = generator_secp256k1.order()
598 cK = GetPubKey(keypair.pubkey,True)
599 data = chr(0) + k + s if is_prime else cK + s
600 I = hmac.new(c, data, hashlib.sha512).digest()
601 k_n = number_to_string( (string_to_number(I[0:32]) + string_to_number(k)) % order , order )
605 # Child public key derivation function (from public key only)
606 # K = master public key
607 # c = master chain code
608 # n = index of key we want to derive
609 # This function allows us to find the nth public key, as long as n is
610 # non-negative. If n is negative, we need the master private key to find it.
611 def CKD_pub(cK, c, n):
612 if n & BIP32_PRIME: raise
613 return _CKD_pub(cK, c, rev_hex(int_to_hex(n,4)).decode('hex'))
615 # helper function, callable with arbitrary string
616 def _CKD_pub(cK, c, s):
618 from ecdsa.util import string_to_number, number_to_string
619 order = generator_secp256k1.order()
620 I = hmac.new(c, cK + s, hashlib.sha512).digest()
622 pubkey_point = string_to_number(I[0:32])*curve.generator + ser_to_point(cK)
623 public_key = ecdsa.VerifyingKey.from_public_point( pubkey_point, curve = SECP256k1 )
625 cK_n = GetPubKey(public_key.pubkey,True)
630 def deserialize_xkey(xkey):
631 xkey = DecodeBase58Check(xkey)
632 assert len(xkey) == 78
633 assert xkey[0:4].encode('hex') in ["0488ade4", "0488b21e"]
635 fingerprint = xkey[5:9]
636 child_number = xkey[9:13]
638 if xkey[0:4].encode('hex') == "0488ade4":
639 K_or_k = xkey[13+33:]
641 K_or_k = xkey[13+32:]
642 return depth, fingerprint, child_number, c, K_or_k
646 def bip32_root(seed):
648 seed = seed.decode('hex')
649 I = hmac.new("Bitcoin seed", seed, hashlib.sha512).digest()
652 K, cK = get_pubkeys_from_secret(master_k)
653 xprv = ("0488ADE4" + "00" + "00000000" + "00000000").decode("hex") + master_c + chr(0) + master_k
654 xpub = ("0488B21E" + "00" + "00000000" + "00000000").decode("hex") + master_c + cK
655 return EncodeBase58Check(xprv), EncodeBase58Check(xpub)
659 def bip32_private_derivation(xprv, branch, sequence):
660 depth, fingerprint, child_number, c, k = deserialize_xkey(xprv)
661 assert sequence.startswith(branch)
662 sequence = sequence[len(branch):]
663 for n in sequence.split('/'):
665 i = int(n[:-1]) + BIP32_PRIME if n[-1] == "'" else int(n)
667 k, c = CKD_priv(k, c, i)
670 _, parent_cK = get_pubkeys_from_secret(parent_k)
671 fingerprint = hash_160(parent_cK)[0:4]
672 child_number = ("%08X"%i).decode('hex')
673 K, cK = get_pubkeys_from_secret(k)
674 xprv = "0488ADE4".decode('hex') + chr(depth) + fingerprint + child_number + c + chr(0) + k
675 xpub = "0488B21E".decode('hex') + chr(depth) + fingerprint + child_number + c + cK
676 return EncodeBase58Check(xprv), EncodeBase58Check(xpub)
680 def bip32_public_derivation(xpub, branch, sequence):
681 depth, fingerprint, child_number, c, cK = deserialize_xkey(xpub)
682 assert sequence.startswith(branch)
683 sequence = sequence[len(branch):]
684 for n in sequence.split('/'):
688 cK, c = CKD_pub(cK, c, i)
691 fingerprint = hash_160(parent_cK)[0:4]
692 child_number = ("%08X"%i).decode('hex')
693 xpub = "0488B21E".decode('hex') + chr(depth) + fingerprint + child_number + c + cK
694 return EncodeBase58Check(xpub)
699 def bip32_private_key(sequence, k, chain):
701 k, chain = CKD_priv(k, chain, i)
702 return SecretToASecret(k, True)