lib/bitcoin.py

   1 #!/usr/bin/env python
   2 #
   3 # Electrum - lightweight Bitcoin client
   4 # Copyright (C) 2011 thomasv@gitorious
   5 #
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program. If not, see <http://www.gnu.org/licenses/>.
  18
  19
  20 import hashlib, base64, ecdsa, re
  21
  22
  23 def rev_hex(s):
  24     return s.decode('hex')[::-1].encode('hex')
  25
  26 def int_to_hex(i, length=1):
  27     s = hex(i)[2:].rstrip('L')
  28     s = "0"*(2*length - len(s)) + s
  29     return rev_hex(s)
  30
  31 def var_int(i):
  32     # https://en.bitcoin.it/wiki/Protocol_specification#Variable_length_integer
  33     if i<0xfd:
  34         return int_to_hex(i)
  35     elif i<=0xffff:
  36         return "fd"+int_to_hex(i,2)
  37     elif i<=0xffffffff:
  38         return "fe"+int_to_hex(i,4)
  39     else:
  40         return "ff"+int_to_hex(i,8)
  41
  42
  43 Hash = lambda x: hashlib.sha256(hashlib.sha256(x).digest()).digest()
  44 hash_encode = lambda x: x[::-1].encode('hex')
  45 hash_decode = lambda x: x.decode('hex')[::-1]
  46
  47
  48 # pywallet openssl private key implementation
  49
  50 def i2d_ECPrivateKey(pkey, compressed=False):
  51     if compressed:
  52         key = '3081d30201010420' + \
  53               '%064x' % pkey.secret + \
  54               'a081a53081a2020101302c06072a8648ce3d0101022100' + \
  55               '%064x' % _p + \
  56               '3006040100040107042102' + \
  57               '%064x' % _Gx + \
  58               '022100' + \
  59               '%064x' % _r + \
  60               '020101a124032200'
  61     else:
  62         key = '308201130201010420' + \
  63               '%064x' % pkey.secret + \
  64               'a081a53081a2020101302c06072a8648ce3d0101022100' + \
  65               '%064x' % _p + \
  66               '3006040100040107044104' + \
  67               '%064x' % _Gx + \
  68               '%064x' % _Gy + \
  69               '022100' + \
  70               '%064x' % _r + \
  71               '020101a144034200'
  72
  73     return key.decode('hex') + i2o_ECPublicKey(pkey.pubkey, compressed)
  74
  75 def i2o_ECPublicKey(pubkey, compressed=False):
  76     # public keys are 65 bytes long (520 bits)
  77     # 0x04 + 32-byte X-coordinate + 32-byte Y-coordinate
  78     # 0x00 = point at infinity, 0x02 and 0x03 = compressed, 0x04 = uncompressed
  79     # compressed keys: <sign> <x> where <sign> is 0x02 if y is even and 0x03 if y is odd
  80     if compressed:
  81         if pubkey.point.y() & 1:
  82             key = '03' + '%064x' % pubkey.point.x()
  83         else:
  84             key = '02' + '%064x' % pubkey.point.x()
  85     else:
  86         key = '04' + \
  87               '%064x' % pubkey.point.x() + \
  88               '%064x' % pubkey.point.y()
  89
  90     return key.decode('hex')
  91
  92 # end pywallet openssl private key implementation
  93
  94
  95
  96 ############ functions from pywallet #####################
  97
  98 def hash_160(public_key):
  99     try:
 100         md = hashlib.new('ripemd160')
 101         md.update(hashlib.sha256(public_key).digest())
 102         return md.digest()
 103     except:
 104         import ripemd
 105         md = ripemd.new(hashlib.sha256(public_key).digest())
 106         return md.digest()
 107
 108
 109 def public_key_to_bc_address(public_key):
 110     h160 = hash_160(public_key)
 111     return hash_160_to_bc_address(h160)
 112
 113 def hash_160_to_bc_address(h160, addrtype = 0):
 114     vh160 = chr(addrtype) + h160
 115     h = Hash(vh160)
 116     addr = vh160 + h[0:4]
 117     return b58encode(addr)
 118
 119 def bc_address_to_hash_160(addr):
 120     bytes = b58decode(addr, 25)
 121     return ord(bytes[0]), bytes[1:21]
 122
 123 def encode_point(pubkey, compressed=False):
 124     order = generator_secp256k1.order()
 125     p = pubkey.pubkey.point
 126     x_str = ecdsa.util.number_to_string(p.x(), order)
 127     y_str = ecdsa.util.number_to_string(p.y(), order)
 128     if compressed:
 129         return chr(2 + (p.y() & 1)) + x_str
 130     else:
 131         return chr(4) + pubkey.to_string() #x_str + y_str
 132
 133 __b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 134 __b58base = len(__b58chars)
 135
 136 def b58encode(v):
 137     """ encode v, which is a string of bytes, to base58."""
 138
 139     long_value = 0L
 140     for (i, c) in enumerate(v[::-1]):
 141         long_value += (256**i) * ord(c)
 142
 143     result = ''
 144     while long_value >= __b58base:
 145         div, mod = divmod(long_value, __b58base)
 146         result = __b58chars[mod] + result
 147         long_value = div
 148     result = __b58chars[long_value] + result
 149
 150     # Bitcoin does a little leading-zero-compression:
 151     # leading 0-bytes in the input become leading-1s
 152     nPad = 0
 153     for c in v:
 154         if c == '\0': nPad += 1
 155         else: break
 156
 157     return (__b58chars[0]*nPad) + result
 158
 159 def b58decode(v, length):
 160     """ decode v into a string of len bytes."""
 161     long_value = 0L
 162     for (i, c) in enumerate(v[::-1]):
 163         long_value += __b58chars.find(c) * (__b58base**i)
 164
 165     result = ''
 166     while long_value >= 256:
 167         div, mod = divmod(long_value, 256)
 168         result = chr(mod) + result
 169         long_value = div
 170     result = chr(long_value) + result
 171
 172     nPad = 0
 173     for c in v:
 174         if c == __b58chars[0]: nPad += 1
 175         else: break
 176
 177     result = chr(0)*nPad + result
 178     if length is not None and len(result) != length:
 179         return None
 180
 181     return result
 182
 183
 184 def EncodeBase58Check(vchIn):
 185     hash = Hash(vchIn)
 186     return b58encode(vchIn + hash[0:4])
 187
 188 def DecodeBase58Check(psz):
 189     vchRet = b58decode(psz, None)
 190     key = vchRet[0:-4]
 191     csum = vchRet[-4:]
 192     hash = Hash(key)
 193     cs32 = hash[0:4]
 194     if cs32 != csum:
 195         return None
 196     else:
 197         return key
 198
 199 def PrivKeyToSecret(privkey):
 200     return privkey[9:9+32]
 201
 202 def SecretToASecret(secret, compressed=False, addrtype=0):
 203     vchIn = chr((addrtype+128)&255) + secret
 204     if compressed: vchIn += '\01'
 205     return EncodeBase58Check(vchIn)
 206
 207 def ASecretToSecret(key, addrtype=0):
 208     vch = DecodeBase58Check(key)
 209     if vch and vch[0] == chr((addrtype+128)&255):
 210         return vch[1:]
 211     else:
 212         return False
 213
 214 def regenerate_key(sec):
 215     b = ASecretToSecret(sec)
 216     if not b:
 217         return False
 218     b = b[0:32]
 219     secret = int('0x' + b.encode('hex'), 16)
 220     return EC_KEY(secret)
 221
 222 def GetPubKey(pubkey, compressed=False):
 223     return i2o_ECPublicKey(pubkey, compressed)
 224
 225 def GetPrivKey(pkey, compressed=False):
 226     return i2d_ECPrivateKey(pkey, compressed)
 227
 228 def GetSecret(pkey):
 229     return ('%064x' % pkey.secret).decode('hex')
 230
 231 def is_compressed(sec):
 232     b = ASecretToSecret(sec)
 233     return len(b) == 33
 234
 235
 236 def address_from_private_key(sec):
 237     # rebuild public key from private key, compressed or uncompressed
 238     pkey = regenerate_key(sec)
 239     assert pkey
 240
 241     # figure out if private key is compressed
 242     compressed = is_compressed(sec)
 243
 244     # rebuild private and public key from regenerated secret
 245     private_key = GetPrivKey(pkey, compressed)
 246     public_key = GetPubKey(pkey.pubkey, compressed)
 247     address = public_key_to_bc_address(public_key)
 248     return address
 249
 250
 251 ########### end pywallet functions #######################
 252
 253 # secp256k1, http://www.oid-info.com/get/1.3.132.0.10
 254 _p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2FL
 255 _r = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141L
 256 _b = 0x0000000000000000000000000000000000000000000000000000000000000007L
 257 _a = 0x0000000000000000000000000000000000000000000000000000000000000000L
 258 _Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798L
 259 _Gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8L
 260 curve_secp256k1 = ecdsa.ellipticcurve.CurveFp( _p, _a, _b )
 261 generator_secp256k1 = ecdsa.ellipticcurve.Point( curve_secp256k1, _Gx, _Gy, _r )
 262 oid_secp256k1 = (1,3,132,0,10)
 263 SECP256k1 = ecdsa.curves.Curve("SECP256k1", curve_secp256k1, generator_secp256k1, oid_secp256k1 )
 264
 265 class EC_KEY(object):
 266     def __init__( self, secret ):
 267         self.pubkey = ecdsa.ecdsa.Public_key( generator_secp256k1, generator_secp256k1 * secret )
 268         self.privkey = ecdsa.ecdsa.Private_key( self.pubkey, secret )
 269         self.secret = secret
 270
 271
 272 ###################################### BIP32 ##############################
 273
 274 def bip32_init(seed):
 275     import hmac
 276
 277     I = hmac.new("Bitcoin seed", seed, hashlib.sha512).digest()
 278
 279     print "seed", seed.encode('hex')
 280     master_secret = I[0:32]
 281     master_chain = I[32:]
 282
 283     # public key
 284     curve = SECP256k1
 285     master_private_key = ecdsa.SigningKey.from_string( master_secret, curve = SECP256k1 )
 286     master_public_key = master_private_key.get_verifying_key()
 287     K = master_public_key.to_string()
 288     K_compressed = GetPubKey(master_public_key.pubkey,True)
 289     return master_secret, master_chain, K, K_compressed
 290
 291
 292 def CKD(k, c, n):
 293     import hmac
 294     from ecdsa.util import string_to_number, number_to_string
 295     order = generator_secp256k1.order()
 296     keypair = EC_KEY(string_to_number(k))
 297     K = GetPubKey(keypair.pubkey,True)
 298     I = hmac.new(c, K + rev_hex(int_to_hex(n,4)).decode('hex'), hashlib.sha512).digest()
 299     k_n = number_to_string( (string_to_number(I[0:32]) * string_to_number(k)) % order , order )
 300     c_n = I[32:]
 301     return k_n, c_n
 302
 303
 304 def CKD_prime(K, c, n):
 305     import hmac
 306     from ecdsa.util import string_to_number, number_to_string
 307     order = generator_secp256k1.order()
 308
 309     K_public_key = ecdsa.VerifyingKey.from_string( K, curve = SECP256k1 )
 310     K_compressed = GetPubKey(K_public_key.pubkey,True)
 311
 312     I = hmac.new(c, K_compressed + rev_hex(int_to_hex(n,4)).decode('hex'), hashlib.sha512).digest()
 313
 314     #pubkey = ecdsa.ecdsa.Public_key( generator_secp256k1, string_to_number(I[0:32]) * K_public_key.pubkey.point )
 315     public_key = ecdsa.VerifyingKey.from_public_point( string_to_number(I[0:32]) * K_public_key.pubkey.point, curve = SECP256k1 )
 316     K_n = public_key.to_string()
 317     K_n_compressed = GetPubKey(public_key.pubkey,True)
 318     c_n = I[32:]
 319
 320     return K_n, K_n_compressed, c_n
 321
 322
 323
 324
 325
 326 ################################## transactions
 327
 328
 329 def tx_filter(s):
 330     out = re.sub('( [^\n]*|)\n','',s)
 331     out = out.replace(' ','')
 332     out = out.replace('\n','')
 333     return out
 334
 335 def raw_tx( inputs, outputs, for_sig = None ):
 336
 337     s  = int_to_hex(1,4)                                         # version
 338     s += var_int( len(inputs) )                                  # number of inputs
 339     for i in range(len(inputs)):
 340         txin = inputs[i]
 341         s += txin['tx_hash'].decode('hex')[::-1].encode('hex')            # prev hash
 342         s += int_to_hex(txin['index'],4)                               # prev index
 343
 344         if for_sig is None:
 345             pubkeysig = txin['pubkeysig']
 346             if len(pubkeysig) == 1:
 347                 pubkey, sig = pubkeysig[0]
 348                 sig = sig + chr(1)                               # hashtype
 349                 script  = int_to_hex( len(sig))
 350                 script += sig.encode('hex')
 351                 script += int_to_hex( len(pubkey))
 352                 script += pubkey.encode('hex')
 353             else:
 354                 n = txin['multisig_num']
 355                 pubkeys = map(lambda x:x[0], pubkeysig)
 356                 script = '00'                                    # op_0
 357                 for item in pubkeysig:
 358                     pubkey, sig = item
 359                     sig = sig + chr(1)
 360                     script += int_to_hex(len(sig))
 361                     script += sig.encode('hex')
 362                 inner_script = multisig_script(pubkeys)
 363                 script += var_int(len(inner_script)/2)
 364                 script += inner_script
 365
 366         elif for_sig==i:
 367             pubkeys = txin.get('pubkeys')
 368             if pubkeys:
 369                 num = txin['p2sh_num']
 370                 script = multisig_script(pubkeys, num)           # p2sh uses the inner script
 371             else:
 372                 script = txin['raw_output_script']               # scriptsig
 373         else:
 374             script=''
 375         s += var_int( len(tx_filter(script))/2 )                 # script length
 376         s += script
 377         s += "ffffffff"                                          # sequence
 378
 379     s += var_int( len(outputs) )                                 # number of outputs
 380     for output in outputs:
 381         addr, amount = output
 382         s += int_to_hex( amount, 8)                              # amount
 383         addrtype, hash_160 = bc_address_to_hash_160(addr)
 384         if addrtype == 0:
 385             script = '76a9'                                      # op_dup, op_hash_160
 386             script += '14'                                       # push 0x14 bytes
 387             script += hash_160.encode('hex')
 388             script += '88ac'                                     # op_equalverify, op_checksig
 389         elif addrtype == 5:
 390             script = 'a9'                                        # op_hash_160
 391             script += '14'                                       # push 0x14 bytes
 392             script += hash_160.encode('hex')
 393             script += '87'                                       # op_equal
 394         else:
 395             raise
 396
 397         s += var_int( len(tx_filter(script))/2 )                #  script length
 398         s += script                                             #  script
 399     s += int_to_hex(0,4)                                        #  lock time
 400     if for_sig is not None and for_sig != -1: s += int_to_hex(1, 4)               #  hash type
 401     return tx_filter(s)
 402
 403
 404
 405
 406 def multisig_script(public_keys, num=None):
 407     # supports only "2 of 2", and "2 of 3" transactions
 408     n = len(public_keys)
 409
 410     if num is None:
 411         num = n
 412
 413     assert num <= n and n <= 3 and n >= 2
 414
 415     if num==2:
 416         s = '52'
 417     elif num == 3:
 418         s = '53'
 419     else:
 420         raise
 421
 422     for k in public_keys:
 423         s += var_int(len(k)/2)
 424         s += k
 425     if n==2:
 426         s += '52'
 427     elif n==3:
 428         s += '53'
 429     else:
 430         raise
 431     s += 'ae'
 432     return s
 433
 434
 435
 436 class Transaction:
 437
 438     def __init__(self, raw):
 439         self.raw = raw
 440         self.deserialize()
 441         self.inputs = self.d['inputs']
 442         self.outputs = self.d['outputs']
 443         self.outputs = map(lambda x: (x['address'],x['value']), self.outputs)
 444
 445     @classmethod
 446     def from_io(klass, inputs, outputs):
 447         raw = raw_tx(inputs, outputs, for_sig = -1) # for_sig=-1 means do not sign
 448         self = klass(raw)
 449         self.inputs = inputs
 450         self.outputs = outputs
 451         return self
 452
 453     def __str__(self):
 454         return self.raw
 455
 456     def for_sig(self,i):
 457         return raw_tx(self.inputs, self.outputs, for_sig = i)
 458
 459     def hash(self):
 460         return Hash(self.raw.decode('hex') )[::-1].encode('hex')
 461
 462     def sign(self, private_keys):
 463
 464         for i in range(len(self.inputs)):
 465             txin = self.inputs[i]
 466             sec = private_keys[txin['address']]
 467             compressed = is_compressed(sec)
 468             pkey = regenerate_key(sec)
 469             secexp = pkey.secret
 470
 471             private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve = SECP256k1 )
 472             public_key = private_key.get_verifying_key()
 473             pkey = EC_KEY(secexp)
 474             pubkey = GetPubKey(pkey.pubkey, compressed)
 475             tx = raw_tx( self.inputs, self.outputs, for_sig = i )
 476             sig = private_key.sign_digest( Hash( tx.decode('hex') ), sigencode = ecdsa.util.sigencode_der )
 477             assert public_key.verify_digest( sig, Hash( tx.decode('hex') ), sigdecode = ecdsa.util.sigdecode_der)
 478             self.inputs[i]["pubkeysig"] = [(pubkey, sig)]
 479
 480         self.raw = raw_tx( self.inputs, self.outputs )
 481
 482
 483     def deserialize(self):
 484         import deserialize
 485         vds = deserialize.BCDataStream()
 486         vds.write(self.raw.decode('hex'))
 487         self.d = deserialize.parse_Transaction(vds)
 488         return self.d
 489
 490
 491
 492
 493 def test_bip32():
 494     seed = "ff000000000000000000000000000000".decode('hex')
 495     master_secret, master_chain, master_public_key, master_public_key_compressed = bip32_init(seed)
 496
 497     print "secret key", master_secret.encode('hex')
 498     print "chain code", master_chain.encode('hex')
 499
 500     key_id = hash_160(master_public_key_compressed)
 501     print "keyid", key_id.encode('hex')
 502     print "base58"
 503     print "address", hash_160_to_bc_address(key_id)
 504     print "secret key", SecretToASecret(master_secret, True)
 505
 506     print "-- m/0 --"
 507     k0, c0 = CKD(master_secret, master_chain, 0)
 508     print "secret", k0.encode('hex')
 509     print "chain", c0.encode('hex')
 510     print "secret key", SecretToASecret(k0, True)
 511
 512     K0, K0_compressed, c0 = CKD_prime(master_public_key, master_chain, 0)
 513     print "address", hash_160_to_bc_address(hash_160(K0_compressed))
 514
 515     print "-- m/0/1 --"
 516     K01, K01_compressed, c01 = CKD_prime(K0, c0, 1)
 517     print "address", hash_160_to_bc_address(hash_160(K01_compressed))
 518
 519     print "-- m/0/1/3 --"
 520     K013, K013_compressed, c013 = CKD_prime(K01, c01, 3)
 521     print "address", hash_160_to_bc_address(hash_160(K013_compressed))
 522
 523     print "-- m/0/1/3/7 --"
 524     K0137, K0137_compressed, c0137 = CKD_prime(K013, c013, 7)
 525     print "address", hash_160_to_bc_address(hash_160(K0137_compressed))
 526
 527
 528 def test_p2sh():
 529
 530     print "2 of 2"
 531     pubkeys = ["04e89a79651522201d756f14b1874ae49139cc984e5782afeca30ffe84e5e6b2cfadcfe9875c490c8a1a05a4debd715dd57471af8886ab5dfbb3959d97f087f77a",
 532                "0455cf4a3ab68a011b18cb0a86aae2b8e9cad6c6355476de05247c57a9632d127084ac7630ad89893b43c486c5a9f7ec6158fb0feb708fa9255d5c4d44bc0858f8"]
 533     s = multisig_script(pubkeys)
 534     print "address", hash_160_to_bc_address(hash_160(s.decode('hex')), 5)
 535
 536
 537     print "Gavin's tutorial: redeem p2sh:  http://blockchain.info/tx-index/30888901"
 538     pubkey1 = "0491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f86"
 539     pubkey2 = "04865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a986818a7cb624532f062c1d1f8722084861c5c3291ccffef4ec6874"
 540     pubkey3 = "048d2455d2403e08708fc1f556002f1b6cd83f992d085097f9974ab08a28838f07896fbab08f39495e15fa6fad6edbfb1e754e35fa1c7844c41f322a1863d46213"
 541     pubkeys = [pubkey1, pubkey2, pubkey3]
 542
 543     tx = Transaction.from_io(
 544         [{'tx_hash':'3c9018e8d5615c306d72397f8f5eef44308c98fb576a88e030c25456b4f3a7ac', 'index':0,
 545           'raw_output_script':'a914f815b036d9bbbce5e9f2a00abd1bf3dc91e9551087', 'pubkeys':pubkeys, 'p2sh_num':2}],
 546         [('1GtpSrGhRGY5kkrNz4RykoqRQoJuG2L6DS',1000000)])
 547
 548     tx_for_sig = tx.for_sig(0)
 549     print "tx for sig", tx_for_sig
 550
 551     signature1 = "304502200187af928e9d155c4b1ac9c1c9118153239aba76774f775d7c1f9c3e106ff33c0221008822b0f658edec22274d0b6ae9de10ebf2da06b1bbdaaba4e50eb078f39e3d78"
 552     signature2 = "30440220795f0f4f5941a77ae032ecb9e33753788d7eb5cb0c78d805575d6b00a1d9bfed02203e1f4ad9332d1416ae01e27038e945bc9db59c732728a383a6f1ed2fb99da7a4"
 553
 554     for pubkey in pubkeys:
 555         import traceback, sys
 556
 557         public_key = ecdsa.VerifyingKey.from_string(pubkey[2:].decode('hex'), curve = SECP256k1)
 558
 559         try:
 560             public_key.verify_digest( signature1.decode('hex'), Hash( tx_for_sig.decode('hex') ), sigdecode = ecdsa.util.sigdecode_der)
 561             print True
 562         except ecdsa.keys.BadSignatureError:
 563             #traceback.print_exc(file=sys.stdout)
 564             print False
 565
 566         try:
 567             public_key.verify_digest( signature2.decode('hex'), Hash( tx_for_sig.decode('hex') ), sigdecode = ecdsa.util.sigdecode_der)
 568             print True
 569         except ecdsa.keys.BadSignatureError:
 570             #traceback.print_exc(file=sys.stdout)
 571             print False
 572
 573 if __name__ == '__main__':
 574     #test_bip32()
 575     test_p2sh()
 576