wallet.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 sys, base64, os, re, hashlib, copy, operator, ast, threading, random
  21
  22 try:
  23     import ecdsa
  24     from ecdsa.util import string_to_number, number_to_string
  25 except:
  26     print "python-ecdsa does not seem to be installed. Try 'sudo easy_install ecdsa'"
  27     sys.exit(1)
  28
  29 try:
  30     import aes
  31 except:
  32     print "AES does not seem to be installed. Try 'sudo easy_install slowaes'"
  33     sys.exit(1)
  34
  35
  36 ############ functions from pywallet #####################
  37
  38 addrtype = 0
  39
  40 def hash_160(public_key):
  41     try:
  42         md = hashlib.new('ripemd160')
  43         md.update(hashlib.sha256(public_key).digest())
  44         return md.digest()
  45     except:
  46         import ripemd
  47         md = ripemd.new(hashlib.sha256(public_key).digest())
  48         return md.digest()
  49
  50
  51 def public_key_to_bc_address(public_key):
  52     h160 = hash_160(public_key)
  53     return hash_160_to_bc_address(h160)
  54
  55 def hash_160_to_bc_address(h160):
  56     vh160 = chr(addrtype) + h160
  57     h = Hash(vh160)
  58     addr = vh160 + h[0:4]
  59     return b58encode(addr)
  60
  61 def bc_address_to_hash_160(addr):
  62     bytes = b58decode(addr, 25)
  63     return bytes[1:21]
  64
  65 __b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
  66 __b58base = len(__b58chars)
  67
  68 def b58encode(v):
  69     """ encode v, which is a string of bytes, to base58.
  70     """
  71
  72     long_value = 0L
  73     for (i, c) in enumerate(v[::-1]):
  74         long_value += (256**i) * ord(c)
  75
  76     result = ''
  77     while long_value >= __b58base:
  78         div, mod = divmod(long_value, __b58base)
  79         result = __b58chars[mod] + result
  80         long_value = div
  81     result = __b58chars[long_value] + result
  82
  83     # Bitcoin does a little leading-zero-compression:
  84     # leading 0-bytes in the input become leading-1s
  85     nPad = 0
  86     for c in v:
  87         if c == '\0': nPad += 1
  88         else: break
  89
  90     return (__b58chars[0]*nPad) + result
  91
  92 def b58decode(v, length):
  93     """ decode v into a string of len bytes
  94     """
  95     long_value = 0L
  96     for (i, c) in enumerate(v[::-1]):
  97         long_value += __b58chars.find(c) * (__b58base**i)
  98
  99     result = ''
 100     while long_value >= 256:
 101         div, mod = divmod(long_value, 256)
 102         result = chr(mod) + result
 103         long_value = div
 104     result = chr(long_value) + result
 105
 106     nPad = 0
 107     for c in v:
 108         if c == __b58chars[0]: nPad += 1
 109         else: break
 110
 111     result = chr(0)*nPad + result
 112     if length is not None and len(result) != length:
 113         return None
 114
 115     return result
 116
 117
 118 def Hash(data):
 119     return hashlib.sha256(hashlib.sha256(data).digest()).digest()
 120
 121 def EncodeBase58Check(vchIn):
 122     hash = Hash(vchIn)
 123     return b58encode(vchIn + hash[0:4])
 124
 125 def DecodeBase58Check(psz):
 126     vchRet = b58decode(psz, None)
 127     key = vchRet[0:-4]
 128     csum = vchRet[-4:]
 129     hash = Hash(key)
 130     cs32 = hash[0:4]
 131     if cs32 != csum:
 132         return None
 133     else:
 134         return key
 135
 136 def PrivKeyToSecret(privkey):
 137     return privkey[9:9+32]
 138
 139 def SecretToASecret(secret):
 140     vchIn = chr(addrtype+128) + secret
 141     return EncodeBase58Check(vchIn)
 142
 143 def ASecretToSecret(key):
 144     vch = DecodeBase58Check(key)
 145     if vch and vch[0] == chr(addrtype+128):
 146         return vch[1:]
 147     else:
 148         return False
 149
 150 ########### end pywallet functions #######################
 151
 152 # URL decode
 153 _ud = re.compile('%([0-9a-hA-H]{2})', re.MULTILINE)
 154 urldecode = lambda x: _ud.sub(lambda m: chr(int(m.group(1), 16)), x)
 155
 156
 157 def int_to_hex(i, length=1):
 158     s = hex(i)[2:].rstrip('L')
 159     s = "0"*(2*length - len(s)) + s
 160     return s.decode('hex')[::-1].encode('hex')
 161
 162
 163 # AES
 164 EncodeAES = lambda secret, s: base64.b64encode(aes.encryptData(secret,s))
 165 DecodeAES = lambda secret, e: aes.decryptData(secret, base64.b64decode(e))
 166
 167
 168
 169 # secp256k1, http://www.oid-info.com/get/1.3.132.0.10
 170 _p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2FL
 171 _r = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141L
 172 _b = 0x0000000000000000000000000000000000000000000000000000000000000007L
 173 _a = 0x0000000000000000000000000000000000000000000000000000000000000000L
 174 _Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798L
 175 _Gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8L
 176 curve_secp256k1 = ecdsa.ellipticcurve.CurveFp( _p, _a, _b )
 177 generator_secp256k1 = ecdsa.ellipticcurve.Point( curve_secp256k1, _Gx, _Gy, _r )
 178 oid_secp256k1 = (1,3,132,0,10)
 179 SECP256k1 = ecdsa.curves.Curve("SECP256k1", curve_secp256k1, generator_secp256k1, oid_secp256k1 )
 180
 181
 182 def filter(s):
 183     out = re.sub('( [^\n]*|)\n','',s)
 184     out = out.replace(' ','')
 185     out = out.replace('\n','')
 186     return out
 187
 188 def raw_tx( inputs, outputs, for_sig = None ):
 189     s  = int_to_hex(1,4)                                     +   '     version\n'
 190     s += int_to_hex( len(inputs) )                           +   '     number of inputs\n'
 191     for i in range(len(inputs)):
 192         _, _, p_hash, p_index, p_script, pubkey, sig = inputs[i]
 193         s += p_hash.decode('hex')[::-1].encode('hex')        +  '     prev hash\n'
 194         s += int_to_hex(p_index,4)                           +  '     prev index\n'
 195         if for_sig is None:
 196             sig = sig + chr(1)                               # hashtype
 197             script  = int_to_hex( len(sig))                  +  '     push %d bytes\n'%len(sig)
 198             script += sig.encode('hex')                      +  '     sig\n'
 199             pubkey = chr(4) + pubkey
 200             script += int_to_hex( len(pubkey))               +  '     push %d bytes\n'%len(pubkey)
 201             script += pubkey.encode('hex')                   +  '     pubkey\n'
 202         elif for_sig==i:
 203             script = p_script                                +  '     scriptsig \n'
 204         else:
 205             script=''
 206         s += int_to_hex( len(filter(script))/2 )             +  '     script length \n'
 207         s += script
 208         s += "ffffffff"                                      +  '     sequence\n'
 209     s += int_to_hex( len(outputs) )                          +  '     number of outputs\n'
 210     for output in outputs:
 211         addr, amount = output
 212         s += int_to_hex( amount, 8)                          +  '     amount: %d\n'%amount
 213         script = '76a9'                                      # op_dup, op_hash_160
 214         script += '14'                                       # push 0x14 bytes
 215         script += bc_address_to_hash_160(addr).encode('hex')
 216         script += '88ac'                                     # op_equalverify, op_checksig
 217         s += int_to_hex( len(filter(script))/2 )             +  '     script length \n'
 218         s += script                                          +  '     script \n'
 219     s += int_to_hex(0,4)                                     # lock time
 220     if for_sig is not None: s += int_to_hex(1, 4)            # hash type
 221     return s
 222
 223
 224
 225
 226 def format_satoshis(x, is_diff=False):
 227     from decimal import Decimal
 228     s = str( Decimal(x) /100000000 )
 229     if is_diff and x>0:
 230         s = "+" + s
 231     if not '.' in s: s += '.'
 232     p = s.find('.')
 233     s += " "*( 9 - ( len(s) - p ))
 234     s = " "*( 5 - ( p )) + s
 235     return s
 236
 237
 238 from version import ELECTRUM_VERSION, SEED_VERSION
 239 from interface import DEFAULT_SERVERS
 240
 241
 242
 243
 244 class Wallet:
 245     def __init__(self, gui_callback = lambda: None):
 246
 247         self.electrum_version = ELECTRUM_VERSION
 248         self.seed_version = SEED_VERSION
 249         self.gui_callback = gui_callback
 250
 251         self.gap_limit = 5           # configuration
 252         self.fee = 100000
 253         self.master_public_key = ''
 254
 255         # saved fields
 256         self.use_encryption = False
 257         self.addresses = []          # receiving addresses visible for user
 258         self.change_addresses = []   # addresses used as change
 259         self.seed = ''               # encrypted
 260         self.history = {}
 261         self.labels = {}             # labels for addresses and transactions
 262         self.aliases = {}            # aliases for addresses
 263         self.authorities = {}        # trusted addresses
 264
 265         self.receipts = {}           # signed URIs
 266         self.receipt = None          # next receipt
 267         self.addressbook = []        # outgoing addresses, for payments
 268
 269         # not saved
 270         self.tx_history = {}
 271
 272         self.imported_keys = {}
 273         self.remote_url = None
 274
 275         self.was_updated = True
 276         self.blocks = -1
 277         self.banner = ''
 278         self.up_to_date_event = threading.Event()
 279         self.up_to_date_event.clear()
 280         self.up_to_date = False
 281         self.lock = threading.Lock()
 282         self.tx_event = threading.Event()
 283
 284         #
 285         self.addresses_waiting_for_status = []
 286         self.addresses_waiting_for_history = []
 287         self.pick_random_server()
 288
 289
 290
 291     def pick_random_server(self):
 292         self.server = random.choice( DEFAULT_SERVERS )         # random choice when the wallet is created
 293
 294     def is_up_to_date(self):
 295         return self.interface.responses.empty() and not ( self.addresses_waiting_for_status or self.addresses_waiting_for_history )
 296
 297
 298     def set_server(self, server):
 299         # raise an error if the format isnt correct
 300         a,b,c = server.split(':')
 301         b = int(b)
 302         assert c in ['t','h','n']
 303         # set the server
 304         if server != self.server:
 305             self.server = server
 306             self.save()
 307             self.interface.is_connected = False  # this exits the polling loop
 308
 309     def set_path(self, wallet_path):
 310
 311         if wallet_path is not None:
 312             self.path = wallet_path
 313         else:
 314             # backward compatibility: look for wallet file in the default data directory
 315             if "HOME" in os.environ:
 316                 wallet_dir = os.path.join( os.environ["HOME"], '.electrum')
 317             elif "LOCALAPPDATA" in os.environ:
 318                 wallet_dir = os.path.join( os.environ["LOCALAPPDATA"], 'Electrum' )
 319             elif "APPDATA" in os.environ:
 320                 wallet_dir = os.path.join( os.environ["APPDATA"], 'Electrum' )
 321             else:
 322                 raise BaseException("No home directory found in environment variables.")
 323
 324             if not os.path.exists( wallet_dir ): os.mkdir( wallet_dir )
 325             self.path = os.path.join( wallet_dir, 'electrum.dat' )
 326
 327     def import_key(self, keypair, password):
 328         address, key = keypair.split(':')
 329         if not self.is_valid(address): return False
 330         if address in self.all_addresses(): return False
 331         b = ASecretToSecret( key )
 332         if not b: return False
 333         secexp = int( b.encode('hex'), 16)
 334         private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve=SECP256k1 )
 335         # sanity check
 336         public_key = private_key.get_verifying_key()
 337         if not address == public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() ): return False
 338         self.imported_keys[address] = self.pw_encode( key, password )
 339         return True
 340
 341     def new_seed(self, password):
 342         seed = "%032x"%ecdsa.util.randrange( pow(2,128) )
 343         #self.init_mpk(seed)
 344         # encrypt
 345         self.seed = self.pw_encode( seed, password )
 346
 347
 348     def init_mpk(self,seed):
 349         # public key
 350         curve = SECP256k1
 351         secexp = self.stretch_key(seed)
 352         master_private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve = SECP256k1 )
 353         self.master_public_key = master_private_key.get_verifying_key().to_string()
 354
 355     def all_addresses(self):
 356         return self.addresses + self.change_addresses + self.imported_keys.keys()
 357
 358     def is_mine(self, address):
 359         return address in self.all_addresses()
 360
 361     def is_change(self, address):
 362         return address in self.change_addresses
 363
 364     def is_valid(self,addr):
 365         ADDRESS_RE = re.compile('[1-9A-HJ-NP-Za-km-z]{26,}\\Z')
 366         if not ADDRESS_RE.match(addr): return False
 367         try:
 368             h = bc_address_to_hash_160(addr)
 369         except:
 370             return False
 371         return addr == hash_160_to_bc_address(h)
 372
 373     def stretch_key(self,seed):
 374         oldseed = seed
 375         for i in range(100000):
 376             seed = hashlib.sha256(seed + oldseed).digest()
 377         return string_to_number( seed )
 378
 379     def get_sequence(self,n,for_change):
 380         return string_to_number( Hash( "%d:%d:"%(n,for_change) + self.master_public_key ) )
 381
 382     def get_private_key(self, address, password):
 383         """  Privatekey(type,n) = Master_private_key + H(n|S|type)  """
 384         order = generator_secp256k1.order()
 385
 386         if address in self.imported_keys.keys():
 387             b = self.pw_decode( self.imported_keys[address], password )
 388             b = ASecretToSecret( b )
 389             secexp = int( b.encode('hex'), 16)
 390         else:
 391             if address in self.addresses:
 392                 n = self.addresses.index(address)
 393                 for_change = False
 394             elif address in self.change_addresses:
 395                 n = self.change_addresses.index(address)
 396                 for_change = True
 397             else:
 398                 raise BaseException("unknown address")
 399             try:
 400                 seed = self.pw_decode( self.seed, password)
 401             except:
 402                 raise BaseException("Invalid password")
 403             secexp = self.stretch_key(seed)
 404             secexp = ( secexp + self.get_sequence(n,for_change) ) % order
 405
 406         pk = number_to_string(secexp,order)
 407         return pk
 408
 409     def msg_magic(self, message):
 410         return "\x18Bitcoin Signed Message:\n" + chr( len(message) ) + message
 411
 412     def sign_message(self, address, message, password):
 413         private_key = ecdsa.SigningKey.from_string( self.get_private_key(address, password), curve = SECP256k1 )
 414         public_key = private_key.get_verifying_key()
 415         signature = private_key.sign_digest( Hash( self.msg_magic( message ) ), sigencode = ecdsa.util.sigencode_string )
 416         assert public_key.verify_digest( signature, Hash( self.msg_magic( message ) ), sigdecode = ecdsa.util.sigdecode_string)
 417         for i in range(4):
 418             sig = base64.b64encode( chr(27+i) + signature )
 419             try:
 420                 self.verify_message( address, sig, message)
 421                 return sig
 422             except:
 423                 continue
 424         else:
 425             raise BaseException("error: cannot sign message")
 426
 427
 428     def verify_message(self, address, signature, message):
 429         """ See http://www.secg.org/download/aid-780/sec1-v2.pdf for the math """
 430         from ecdsa import numbertheory, ellipticcurve, util
 431         import msqr
 432         curve = curve_secp256k1
 433         G = generator_secp256k1
 434         order = G.order()
 435         # extract r,s from signature
 436         sig = base64.b64decode(signature)
 437         if len(sig) != 65: raise BaseException("Wrong encoding")
 438         r,s = util.sigdecode_string(sig[1:], order)
 439         recid = ord(sig[0]) - 27
 440         # 1.1
 441         x = r + (recid/2) * order
 442         # 1.3
 443         alpha = ( x * x * x  + curve.a() * x + curve.b() ) % curve.p()
 444         beta = msqr.modular_sqrt(alpha, curve.p())
 445         y = beta if (beta - recid) % 2 == 0 else curve.p() - beta
 446         # 1.4 the constructor checks that nR is at infinity
 447         R = ellipticcurve.Point(curve, x, y, order)
 448         # 1.5 compute e from message:
 449         h = Hash( self.msg_magic( message ) )
 450         e = string_to_number(h)
 451         minus_e = -e % order
 452         # 1.6 compute Q = r^-1 (sR - eG)
 453         inv_r = numbertheory.inverse_mod(r,order)
 454         Q = inv_r * ( s * R + minus_e * G )
 455         public_key = ecdsa.VerifyingKey.from_public_point( Q, curve = SECP256k1 )
 456         # check that Q is the public key
 457         public_key.verify_digest( sig[1:], h, sigdecode = ecdsa.util.sigdecode_string)
 458         # check that we get the original signing address
 459         addr = public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() )
 460         # print addr
 461         if address != addr:
 462             print "bad signature"
 463             raise BaseException("Bad signature")
 464
 465
 466     def create_new_address(self, for_change):
 467         """   Publickey(type,n) = Master_public_key + H(n|S|type)*point  """
 468         curve = SECP256k1
 469         n = len(self.change_addresses) if for_change else len(self.addresses)
 470         z = self.get_sequence(n,for_change)
 471         master_public_key = ecdsa.VerifyingKey.from_string( self.master_public_key, curve = SECP256k1 )
 472         pubkey_point = master_public_key.pubkey.point + z*curve.generator
 473         public_key2 = ecdsa.VerifyingKey.from_public_point( pubkey_point, curve = SECP256k1 )
 474         address = public_key_to_bc_address( '04'.decode('hex') + public_key2.to_string() )
 475         if for_change:
 476             self.change_addresses.append(address)
 477         else:
 478             self.addresses.append(address)
 479
 480         self.history[address] = []
 481         print address
 482         return address
 483
 484
 485
 486     def synchronize(self):
 487         if not self.master_public_key:
 488             return []
 489
 490         new_addresses = []
 491         while True:
 492             if self.change_addresses == []:
 493                 new_addresses.append( self.create_new_address(True) )
 494                 continue
 495             a = self.change_addresses[-1]
 496             if self.history.get(a):
 497                 new_addresses.append( self.create_new_address(True) )
 498             else:
 499                 break
 500
 501         n = self.gap_limit
 502         while True:
 503             if len(self.addresses) < n:
 504                 new_addresses.append( self.create_new_address(False) )
 505                 continue
 506             if map( lambda a: self.history.get(a), self.addresses[-n:] ) == n*[[]]:
 507                 break
 508             else:
 509                 new_addresses.append( self.create_new_address(False) )
 510
 511         if self.remote_url:
 512             num = self.get_remote_number()
 513             while len(self.addresses)<num:
 514                 new_addresses.append( self.create_new_address(False) )
 515
 516         return new_addresses
 517
 518
 519     def get_remote_number(self):
 520         import jsonrpclib
 521         server = jsonrpclib.Server(self.remote_url)
 522         out = server.getnum()
 523         return out
 524
 525     def get_remote_mpk(self):
 526         import jsonrpclib
 527         server = jsonrpclib.Server(self.remote_url)
 528         out = server.getkey()
 529         return out
 530
 531     def is_found(self):
 532         return (len(self.change_addresses) > 1 ) or ( len(self.addresses) > self.gap_limit )
 533
 534     def fill_addressbook(self):
 535         for tx in self.tx_history.values():
 536             if tx['value']<0:
 537                 for i in tx['outputs']:
 538                     if not self.is_mine(i) and i not in self.addressbook:
 539                         self.addressbook.append(i)
 540         # redo labels
 541         self.update_tx_labels()
 542
 543
 544     def save(self):
 545         s = {
 546             'seed_version':self.seed_version,
 547             'use_encryption':self.use_encryption,
 548             'master_public_key': self.master_public_key.encode('hex'),
 549             'fee':self.fee,
 550             'server':self.server,
 551             'seed':self.seed,
 552             'addresses':self.addresses,
 553             'change_addresses':self.change_addresses,
 554             'history':self.history,
 555             'labels':self.labels,
 556             'contacts':self.addressbook,
 557             'imported_keys':self.imported_keys,
 558             'aliases':self.aliases,
 559             'authorities':self.authorities,
 560             'receipts':self.receipts,
 561             }
 562         f = open(self.path,"w")
 563         f.write( repr(s) )
 564         f.close()
 565
 566     def read(self):
 567         import interface
 568
 569         upgrade_msg = """This wallet seed is deprecated. Please run upgrade.py for a diagnostic."""
 570         self.file_exists = False
 571         try:
 572             f = open(self.path,"r")
 573             data = f.read()
 574             f.close()
 575         except:
 576             return
 577         data = interface.old_to_new(data)
 578         try:
 579             d = ast.literal_eval( data )
 580             self.seed_version = d.get('seed_version')
 581             self.master_public_key = d.get('master_public_key').decode('hex')
 582             self.use_encryption = d.get('use_encryption')
 583             self.fee = int( d.get('fee') )
 584             self.seed = d.get('seed')
 585             self.server = d.get('server')
 586             #blocks = d.get('blocks')
 587             self.addresses = d.get('addresses')
 588             self.change_addresses = d.get('change_addresses')
 589             self.history = d.get('history')
 590             self.labels = d.get('labels')
 591             self.addressbook = d.get('contacts')
 592             self.imported_keys = d.get('imported_keys',{})
 593             self.aliases = d.get('aliases',{})
 594             self.authorities = d.get('authorities',{})
 595             self.receipts = d.get('receipts',{})
 596         except:
 597             raise BaseException("cannot read wallet file")
 598
 599         self.update_tx_history()
 600
 601         if self.seed_version != SEED_VERSION:
 602             raise BaseException(upgrade_msg)
 603
 604         if self.remote_url: assert self.master_public_key.encode('hex') == self.get_remote_mpk()
 605
 606         self.file_exists = True
 607
 608
 609
 610
 611     def get_addr_balance(self, addr):
 612         if self.is_mine(addr):
 613             h = self.history.get(addr)
 614         else:
 615             h = self.interface.retrieve_history(addr)
 616         if not h: return 0,0
 617         c = u = 0
 618         for item in h:
 619             v = item['value']
 620             if item['height']:
 621                 c += v
 622             else:
 623                 u += v
 624         return c, u
 625
 626     def get_balance(self):
 627         conf = unconf = 0
 628         for addr in self.all_addresses():
 629             c, u = self.get_addr_balance(addr)
 630             conf += c
 631             unconf += u
 632         return conf, unconf
 633
 634
 635     def choose_tx_inputs( self, amount, fixed_fee, from_addr = None ):
 636         """ todo: minimize tx size """
 637         total = 0
 638         fee = self.fee if fixed_fee is None else fixed_fee
 639
 640         coins = []
 641         domain = [from_addr] if from_addr else self.all_addresses()
 642         for addr in domain:
 643             h = self.history.get(addr)
 644             if h is None: continue
 645             for item in h:
 646                 if item.get('raw_output_script'):
 647                     coins.append( (addr,item))
 648
 649         coins = sorted( coins, key = lambda x: x[1]['timestamp'] )
 650         inputs = []
 651         for c in coins:
 652             addr, item = c
 653             v = item.get('value')
 654             total += v
 655             inputs.append((addr, v, item['tx_hash'], item['index'], item['raw_output_script'], None, None) )
 656             fee = self.fee*len(inputs) if fixed_fee is None else fixed_fee
 657             if total >= amount + fee: break
 658         else:
 659             #print "not enough funds: %d %d"%(total, fee)
 660             inputs = []
 661         return inputs, total, fee
 662
 663     def choose_tx_outputs( self, to_addr, amount, fee, total, change_addr=None ):
 664         outputs = [ (to_addr, amount) ]
 665         change_amount = total - ( amount + fee )
 666         if change_amount != 0:
 667             # normally, the update thread should ensure that the last change address is unused
 668             if not change_addr:
 669                 change_addr = self.change_addresses[-1]
 670             outputs.append( ( change_addr,  change_amount) )
 671         return outputs
 672
 673     def sign_inputs( self, inputs, outputs, password ):
 674         s_inputs = []
 675         for i in range(len(inputs)):
 676             addr, v, p_hash, p_pos, p_scriptPubKey, _, _ = inputs[i]
 677             private_key = ecdsa.SigningKey.from_string( self.get_private_key(addr, password), curve = SECP256k1 )
 678             public_key = private_key.get_verifying_key()
 679             pubkey = public_key.to_string()
 680             tx = filter( raw_tx( inputs, outputs, for_sig = i ) )
 681             sig = private_key.sign_digest( Hash( tx.decode('hex') ), sigencode = ecdsa.util.sigencode_der )
 682             assert public_key.verify_digest( sig, Hash( tx.decode('hex') ), sigdecode = ecdsa.util.sigdecode_der)
 683             s_inputs.append( (addr, v, p_hash, p_pos, p_scriptPubKey, pubkey, sig) )
 684         return s_inputs
 685
 686     def pw_encode(self, s, password):
 687         if password:
 688             secret = Hash(password)
 689             return EncodeAES(secret, s)
 690         else:
 691             return s
 692
 693     def pw_decode(self, s, password):
 694         if password is not None:
 695             secret = Hash(password)
 696             d = DecodeAES(secret, s)
 697             if s == self.seed:
 698                 try:
 699                     d.decode('hex')
 700                 except:
 701                     raise BaseException("Invalid password")
 702             return d
 703         else:
 704             return s
 705
 706     def get_status(self, address):
 707         h = self.history.get(address)
 708         if not h:
 709             status = None
 710         else:
 711             lastpoint = h[-1]
 712             status = lastpoint['block_hash']
 713             if status == 'mempool':
 714                 status = status + ':%d'% len(h)
 715         return status
 716
 717     def receive_status_callback(self, addr, status):
 718         with self.lock:
 719             if self.get_status(addr) != status:
 720                 #print "updating status for", addr, status
 721                 self.addresses_waiting_for_history.append(addr)
 722                 self.interface.get_history(addr)
 723             if addr in self.addresses_waiting_for_status:
 724                 self.addresses_waiting_for_status.remove(addr)
 725
 726     def receive_history_callback(self, addr, data):
 727         #print "updating history for", addr
 728         with self.lock:
 729             self.history[addr] = data
 730             self.update_tx_history()
 731             self.save()
 732             if addr in self.addresses_waiting_for_history: self.addresses_waiting_for_history.remove(addr)
 733
 734     def get_tx_history(self):
 735         lines = self.tx_history.values()
 736         lines = sorted(lines, key=operator.itemgetter("timestamp"))
 737         return lines
 738
 739     def update_tx_history(self):
 740         self.tx_history= {}
 741         for addr in self.all_addresses():
 742             h = self.history.get(addr)
 743             if h is None: continue
 744             for tx in h:
 745                 tx_hash = tx['tx_hash']
 746                 line = self.tx_history.get(tx_hash)
 747                 if not line:
 748                     self.tx_history[tx_hash] = copy.copy(tx)
 749                     line = self.tx_history.get(tx_hash)
 750                 else:
 751                     line['value'] += tx['value']
 752                 if line['height'] == 0:
 753                     line['timestamp'] = 1e12
 754         self.update_tx_labels()
 755
 756     def update_tx_labels(self):
 757         for tx in self.tx_history.values():
 758             default_label = ''
 759             if tx['value']<0:
 760                 for o_addr in tx['outputs']:
 761                     if not self.is_change(o_addr):
 762                         dest_label = self.labels.get(o_addr)
 763                         if dest_label:
 764                             default_label = 'to: ' + dest_label
 765                         else:
 766                             default_label = 'to: ' + o_addr
 767             else:
 768                 for o_addr in tx['outputs']:
 769                     if self.is_mine(o_addr) and not self.is_change(o_addr):
 770                         dest_label = self.labels.get(o_addr)
 771                         if dest_label:
 772                             default_label = 'at: ' + dest_label
 773                         else:
 774                             default_label = 'at: ' + o_addr
 775             tx['default_label'] = default_label
 776
 777     def mktx(self, to_address, amount, label, password, fee=None, change_addr=None, from_addr= None):
 778         if not self.is_valid(to_address):
 779             raise BaseException("Invalid address")
 780         inputs, total, fee = self.choose_tx_inputs( amount, fee, from_addr )
 781         if not inputs:
 782             raise BaseException("Not enough funds")
 783         outputs = self.choose_tx_outputs( to_address, amount, fee, total, change_addr )
 784         s_inputs = self.sign_inputs( inputs, outputs, password )
 785
 786         tx = filter( raw_tx( s_inputs, outputs ) )
 787         if to_address not in self.addressbook:
 788             self.addressbook.append(to_address)
 789         if label:
 790             tx_hash = Hash(tx.decode('hex') )[::-1].encode('hex')
 791             self.labels[tx_hash] = label
 792
 793         return tx
 794
 795     def sendtx(self, tx):
 796         tx_hash = Hash(tx.decode('hex') )[::-1].encode('hex')
 797         self.tx_event.clear()
 798         self.interface.send([('blockchain.transaction.broadcast', [tx])])
 799         self.tx_event.wait()
 800         out = self.tx_result
 801         if out != tx_hash:
 802             return False, "error: " + out
 803         if self.receipt:
 804             self.receipts[tx_hash] = self.receipt
 805             self.receipt = None
 806         return True, out
 807
 808
 809     def read_alias(self, alias):
 810         # this might not be the right place for this function.
 811         import urllib
 812
 813         m1 = re.match('([\w\-\.]+)@((\w[\w\-]+\.)+[\w\-]+)', alias)
 814         m2 = re.match('((\w[\w\-]+\.)+[\w\-]+)', alias)
 815         if m1:
 816             url = 'http://' + m1.group(2) + '/bitcoin.id/' + m1.group(1)
 817         elif m2:
 818             url = 'http://' + alias + '/bitcoin.id'
 819         else:
 820             return ''
 821         try:
 822             lines = urllib.urlopen(url).readlines()
 823         except:
 824             return ''
 825
 826         # line 0
 827         line = lines[0].strip().split(':')
 828         if len(line) == 1:
 829             auth_name = None
 830             target = signing_addr = line[0]
 831         else:
 832             target, auth_name, signing_addr, signature = line
 833             msg = "alias:%s:%s:%s"%(alias,target,auth_name)
 834             print msg, signature
 835             self.verify_message(signing_addr, signature, msg)
 836
 837         # other lines are signed updates
 838         for line in lines[1:]:
 839             line = line.strip()
 840             if not line: continue
 841             line = line.split(':')
 842             previous = target
 843             print repr(line)
 844             target, signature = line
 845             self.verify_message(previous, signature, "alias:%s:%s"%(alias,target))
 846
 847         if not self.is_valid(target):
 848             raise BaseException("Invalid bitcoin address")
 849
 850         return target, signing_addr, auth_name
 851
 852     def update_password(self, seed, new_password):
 853         if new_password == '': new_password = None
 854         self.use_encryption = (new_password != None)
 855         self.seed = self.pw_encode( seed, new_password)
 856         for k in self.imported_keys.keys():
 857             a = self.imported_keys[k]
 858             b = self.pw_decode(a, password)
 859             c = self.pw_encode(b, new_password)
 860             self.imported_keys[k] = c
 861         self.save()
 862
 863     def get_alias(self, alias, interactive = False, show_message=None, question = None):
 864         try:
 865             target, signing_address, auth_name = self.read_alias(alias)
 866         except BaseException, e:
 867             # raise exception if verify fails (verify the chain)
 868             if interactive:
 869                 show_message("Alias error: " + e.message)
 870             return
 871
 872         print target, signing_address, auth_name
 873
 874         if auth_name is None:
 875             a = self.aliases.get(alias)
 876             if not a:
 877                 msg = "Warning: the alias '%s' is self-signed.\nThe signing address is %s.\n\nDo you want to add this alias to your list of contacts?"%(alias,signing_address)
 878                 if interactive and question( msg ):
 879                     self.aliases[alias] = (signing_address, target)
 880                 else:
 881                     target = None
 882             else:
 883                 if signing_address != a[0]:
 884                     msg = "Warning: the key of alias '%s' has changed since your last visit! It is possible that someone is trying to do something nasty!!!\nDo you accept to change your trusted key?"%alias
 885                     if interactive and question( msg ):
 886                         self.aliases[alias] = (signing_address, target)
 887                     else:
 888                         target = None
 889         else:
 890             if signing_address not in self.authorities.keys():
 891                 msg = "The alias: '%s' links to %s\n\nWarning: this alias was signed by an unknown key.\nSigning authority: %s\nSigning address: %s\n\nDo you want to add this key to your list of trusted keys?"%(alias,target,auth_name,signing_address)
 892                 if interactive and question( msg ):
 893                     self.authorities[signing_address] = auth_name
 894                 else:
 895                     target = None
 896
 897         if target:
 898             self.aliases[alias] = (signing_address, target)
 899
 900         return target
 901
 902
 903     def parse_url(self, url, show_message, question):
 904         o = url[8:].split('?')
 905         address = o[0]
 906         if len(o)>1:
 907             params = o[1].split('&')
 908         else:
 909             params = []
 910
 911         amount = label = message = signature = identity = ''
 912         for p in params:
 913             k,v = p.split('=')
 914             uv = urldecode(v)
 915             if k == 'amount': amount = uv
 916             elif k == 'message': message = uv
 917             elif k == 'label': label = uv
 918             elif k == 'signature':
 919                 identity, signature = uv.split(':')
 920                 url = url.replace('&%s=%s'%(k,v),'')
 921             else:
 922                 print k,v
 923
 924         if signature:
 925             if re.match('^(|([\w\-\.]+)@)((\w[\w\-]+\.)+[\w\-]+)$', identity):
 926                 signing_address = self.get_alias(identity, True, show_message, question)
 927             elif self.is_valid(identity):
 928                 signing_address = identity
 929             else:
 930                 signing_address = None
 931             if not signing_address:
 932                 return
 933             try:
 934                 self.verify_message(signing_address, signature, url )
 935                 self.receipt = (signing_address, signature, url)
 936             except:
 937                 show_message('Warning: the URI contains a bad signature.\nThe identity of the recipient cannot be verified.')
 938                 address = amount = label = identity = message = ''
 939
 940         if re.match('^(|([\w\-\.]+)@)((\w[\w\-]+\.)+[\w\-]+)$', address):
 941             payto_address = self.get_alias(address, True, show_message, question)
 942             if payto_address:
 943                 address = address + ' <' + payto_address + '>'
 944
 945         return address, amount, label, message, signature, identity, url
 946
 947
 948     def update(self):
 949         self.interface.poke()
 950         self.up_to_date_event.wait()
 951
 952
 953