client/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     md = hashlib.new('ripemd160')
  42     md.update(hashlib.sha256(public_key).digest())
  43     return md.digest()
  44
  45 def public_key_to_bc_address(public_key):
  46     h160 = hash_160(public_key)
  47     return hash_160_to_bc_address(h160)
  48
  49 def hash_160_to_bc_address(h160):
  50     vh160 = chr(addrtype) + h160
  51     h = Hash(vh160)
  52     addr = vh160 + h[0:4]
  53     return b58encode(addr)
  54
  55 def bc_address_to_hash_160(addr):
  56     bytes = b58decode(addr, 25)
  57     return bytes[1:21]
  58
  59 __b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
  60 __b58base = len(__b58chars)
  61
  62 def b58encode(v):
  63     """ encode v, which is a string of bytes, to base58.
  64     """
  65
  66     long_value = 0L
  67     for (i, c) in enumerate(v[::-1]):
  68         long_value += (256**i) * ord(c)
  69
  70     result = ''
  71     while long_value >= __b58base:
  72         div, mod = divmod(long_value, __b58base)
  73         result = __b58chars[mod] + result
  74         long_value = div
  75     result = __b58chars[long_value] + result
  76
  77     # Bitcoin does a little leading-zero-compression:
  78     # leading 0-bytes in the input become leading-1s
  79     nPad = 0
  80     for c in v:
  81         if c == '\0': nPad += 1
  82         else: break
  83
  84     return (__b58chars[0]*nPad) + result
  85
  86 def b58decode(v, length):
  87     """ decode v into a string of len bytes
  88     """
  89     long_value = 0L
  90     for (i, c) in enumerate(v[::-1]):
  91         long_value += __b58chars.find(c) * (__b58base**i)
  92
  93     result = ''
  94     while long_value >= 256:
  95         div, mod = divmod(long_value, 256)
  96         result = chr(mod) + result
  97         long_value = div
  98     result = chr(long_value) + result
  99
 100     nPad = 0
 101     for c in v:
 102         if c == __b58chars[0]: nPad += 1
 103         else: break
 104
 105     result = chr(0)*nPad + result
 106     if length is not None and len(result) != length:
 107         return None
 108
 109     return result
 110
 111
 112 def Hash(data):
 113     return hashlib.sha256(hashlib.sha256(data).digest()).digest()
 114
 115 def EncodeBase58Check(vchIn):
 116     hash = Hash(vchIn)
 117     return b58encode(vchIn + hash[0:4])
 118
 119 def DecodeBase58Check(psz):
 120     vchRet = b58decode(psz, None)
 121     key = vchRet[0:-4]
 122     csum = vchRet[-4:]
 123     hash = Hash(key)
 124     cs32 = hash[0:4]
 125     if cs32 != csum:
 126         return None
 127     else:
 128         return key
 129
 130 def PrivKeyToSecret(privkey):
 131     return privkey[9:9+32]
 132
 133 def SecretToASecret(secret):
 134     vchIn = chr(addrtype+128) + secret
 135     return EncodeBase58Check(vchIn)
 136
 137 def ASecretToSecret(key):
 138     vch = DecodeBase58Check(key)
 139     if vch and vch[0] == chr(addrtype+128):
 140         return vch[1:]
 141     else:
 142         return False
 143
 144 ########### end pywallet functions #######################
 145
 146 # URL decode
 147 _ud = re.compile('%([0-9a-hA-H]{2})', re.MULTILINE)
 148 urldecode = lambda x: _ud.sub(lambda m: chr(int(m.group(1), 16)), x)
 149
 150
 151 def int_to_hex(i, length=1):
 152     s = hex(i)[2:].rstrip('L')
 153     s = "0"*(2*length - len(s)) + s
 154     return s.decode('hex')[::-1].encode('hex')
 155
 156
 157 # AES
 158 EncodeAES = lambda secret, s: base64.b64encode(aes.encryptData(secret,s))
 159 DecodeAES = lambda secret, e: aes.decryptData(secret, base64.b64decode(e))
 160
 161
 162
 163 # secp256k1, http://www.oid-info.com/get/1.3.132.0.10
 164 _p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2FL
 165 _r = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141L
 166 _b = 0x0000000000000000000000000000000000000000000000000000000000000007L
 167 _a = 0x0000000000000000000000000000000000000000000000000000000000000000L
 168 _Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798L
 169 _Gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8L
 170 curve_secp256k1 = ecdsa.ellipticcurve.CurveFp( _p, _a, _b )
 171 generator_secp256k1 = ecdsa.ellipticcurve.Point( curve_secp256k1, _Gx, _Gy, _r )
 172 oid_secp256k1 = (1,3,132,0,10)
 173 SECP256k1 = ecdsa.curves.Curve("SECP256k1", curve_secp256k1, generator_secp256k1, oid_secp256k1 )
 174
 175
 176 def filter(s):
 177     out = re.sub('( [^\n]*|)\n','',s)
 178     out = out.replace(' ','')
 179     out = out.replace('\n','')
 180     return out
 181
 182 def raw_tx( inputs, outputs, for_sig = None ):
 183     s  = int_to_hex(1,4)                                     +   '     version\n'
 184     s += int_to_hex( len(inputs) )                           +   '     number of inputs\n'
 185     for i in range(len(inputs)):
 186         _, _, p_hash, p_index, p_script, pubkey, sig = inputs[i]
 187         s += p_hash.decode('hex')[::-1].encode('hex')        +  '     prev hash\n'
 188         s += int_to_hex(p_index,4)                           +  '     prev index\n'
 189         if for_sig is None:
 190             sig = sig + chr(1)                               # hashtype
 191             script  = int_to_hex( len(sig))                  +  '     push %d bytes\n'%len(sig)
 192             script += sig.encode('hex')                      +  '     sig\n'
 193             pubkey = chr(4) + pubkey
 194             script += int_to_hex( len(pubkey))               +  '     push %d bytes\n'%len(pubkey)
 195             script += pubkey.encode('hex')                   +  '     pubkey\n'
 196         elif for_sig==i:
 197             script = p_script                                +  '     scriptsig \n'
 198         else:
 199             script=''
 200         s += int_to_hex( len(filter(script))/2 )             +  '     script length \n'
 201         s += script
 202         s += "ffffffff"                                      +  '     sequence\n'
 203     s += int_to_hex( len(outputs) )                          +  '     number of outputs\n'
 204     for output in outputs:
 205         addr, amount = output
 206         s += int_to_hex( amount, 8)                          +  '     amount: %d\n'%amount
 207         script = '76a9'                                      # op_dup, op_hash_160
 208         script += '14'                                       # push 0x14 bytes
 209         script += bc_address_to_hash_160(addr).encode('hex')
 210         script += '88ac'                                     # op_equalverify, op_checksig
 211         s += int_to_hex( len(filter(script))/2 )             +  '     script length \n'
 212         s += script                                          +  '     script \n'
 213     s += int_to_hex(0,4)                                     # lock time
 214     if for_sig is not None: s += int_to_hex(1, 4)            # hash type
 215     return s
 216
 217
 218
 219
 220 def format_satoshis(x, is_diff=False):
 221     from decimal import Decimal
 222     s = str( Decimal(x) /100000000 )
 223     if is_diff and x>0:
 224         s = "+" + s
 225     if not '.' in s: s += '.'
 226     p = s.find('.')
 227     s += " "*( 9 - ( len(s) - p ))
 228     s = " "*( 5 - ( p )) + s
 229     return s
 230
 231
 232 from version import ELECTRUM_VERSION, SEED_VERSION
 233 from interface import NativeInterface, AsynchronousInterface, HttpInterface, DEFAULT_SERVERS
 234
 235
 236 DEFAULT_PORT = 50000
 237
 238
 239 class Wallet:
 240     def __init__(self):
 241
 242         self.electrum_version = ELECTRUM_VERSION
 243         self.seed_version = SEED_VERSION
 244
 245         self.gap_limit = 5           # configuration
 246         self.fee = 100000
 247         self.master_public_key = ''
 248
 249         # saved fields
 250         self.use_encryption = False
 251         self.addresses = []          # receiving addresses visible for user
 252         self.change_addresses = []   # addresses used as change
 253         self.seed = ''               # encrypted
 254         self.status = {}             # current status of addresses
 255         self.history = {}
 256         self.labels = {}             # labels for addresses and transactions
 257         self.aliases = {}            # aliases for addresses
 258         self.authorities = {}        # trusted addresses
 259
 260         self.receipts = {}           # signed URIs
 261         self.receipt = None          # next receipt
 262         self.addressbook = []        # outgoing addresses, for payments
 263
 264         self.host = random.choice( DEFAULT_SERVERS )         # random choice when the wallet is created
 265         self.port = DEFAULT_PORT
 266
 267         # not saved
 268         self.tx_history = {}
 269
 270         self.imported_keys = {}
 271         self.remote_url = None
 272
 273         self.was_updated = False
 274         self.blocks = 0
 275         self.banner = ''
 276         self.up_to_date_event = threading.Event()
 277         self.up_to_date_event.clear()
 278         self.interface_lock = threading.Lock()
 279         self.tx_event = threading.Event()
 280
 281
 282     def set_server(self, host, port):
 283         if host!= self.host or port!=self.port:
 284             self.host = host
 285             self.port = port
 286             self.interface.is_connected = False  # this exits the polling loop
 287
 288     def set_path(self, wallet_path):
 289
 290         if wallet_path is not None:
 291             self.path = wallet_path
 292         else:
 293             # backward compatibility: look for wallet file in the default data directory
 294             if "HOME" in os.environ:
 295                 wallet_dir = os.path.join( os.environ["HOME"], '.electrum')
 296             elif "LOCALAPPDATA" in os.environ:
 297                 wallet_dir = os.path.join( os.environ["LOCALAPPDATA"], 'Electrum' )
 298             elif "APPDATA" in os.environ:
 299                 wallet_dir = os.path.join( os.environ["APPDATA"], 'Electrum' )
 300             else:
 301                 raise BaseException("No home directory found in environment variables.")
 302
 303             if not os.path.exists( wallet_dir ): os.mkdir( wallet_dir )
 304             self.path = os.path.join( wallet_dir, 'electrum.dat' )
 305
 306     def import_key(self, keypair, password):
 307         address, key = keypair.split(':')
 308         if not self.is_valid(address): return False
 309         if address in self.all_addresses(): return False
 310         b = ASecretToSecret( key )
 311         if not b: return False
 312         secexp = int( b.encode('hex'), 16)
 313         private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve=SECP256k1 )
 314         # sanity check
 315         public_key = private_key.get_verifying_key()
 316         if not address == public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() ): return False
 317         self.imported_keys[address] = self.pw_encode( key, password )
 318         return True
 319
 320     def new_seed(self, password):
 321         seed = "%032x"%ecdsa.util.randrange( pow(2,128) )
 322         self.init_mpk(seed)
 323         # encrypt
 324         self.seed = self.pw_encode( seed, password )
 325
 326
 327     def init_mpk(self,seed):
 328         # public key
 329         curve = SECP256k1
 330         secexp = self.stretch_key(seed)
 331         master_private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve = SECP256k1 )
 332         self.master_public_key = master_private_key.get_verifying_key().to_string()
 333
 334     def all_addresses(self):
 335         return self.addresses + self.change_addresses + self.imported_keys.keys()
 336
 337     def is_mine(self, address):
 338         return address in self.all_addresses()
 339
 340     def is_change(self, address):
 341         return address in self.change_addresses
 342
 343     def is_valid(self,addr):
 344         ADDRESS_RE = re.compile('[1-9A-HJ-NP-Za-km-z]{26,}\\Z')
 345         if not ADDRESS_RE.match(addr): return False
 346         try:
 347             h = bc_address_to_hash_160(addr)
 348         except:
 349             return False
 350         return addr == hash_160_to_bc_address(h)
 351
 352     def stretch_key(self,seed):
 353         oldseed = seed
 354         for i in range(100000):
 355             seed = hashlib.sha256(seed + oldseed).digest()
 356         return string_to_number( seed )
 357
 358     def get_sequence(self,n,for_change):
 359         return string_to_number( Hash( "%d:%d:"%(n,for_change) + self.master_public_key ) )
 360
 361     def get_private_key(self, address, password):
 362         """  Privatekey(type,n) = Master_private_key + H(n|S|type)  """
 363         order = generator_secp256k1.order()
 364
 365         if address in self.imported_keys.keys():
 366             b = self.pw_decode( self.imported_keys[address], password )
 367             b = ASecretToSecret( b )
 368             secexp = int( b.encode('hex'), 16)
 369         else:
 370             if address in self.addresses:
 371                 n = self.addresses.index(address)
 372                 for_change = False
 373             elif address in self.change_addresses:
 374                 n = self.change_addresses.index(address)
 375                 for_change = True
 376             else:
 377                 raise BaseException("unknown address")
 378             try:
 379                 seed = self.pw_decode( self.seed, password)
 380             except:
 381                 raise BaseException("Invalid password")
 382             secexp = self.stretch_key(seed)
 383             secexp = ( secexp + self.get_sequence(n,for_change) ) % order
 384
 385         pk = number_to_string(secexp,order)
 386         return pk
 387
 388     def msg_magic(self, message):
 389         return "\x18Bitcoin Signed Message:\n" + chr( len(message) ) + message
 390
 391     def sign_message(self, address, message, password):
 392         private_key = ecdsa.SigningKey.from_string( self.get_private_key(address, password), curve = SECP256k1 )
 393         public_key = private_key.get_verifying_key()
 394         signature = private_key.sign_digest( Hash( self.msg_magic( message ) ), sigencode = ecdsa.util.sigencode_string )
 395         assert public_key.verify_digest( signature, Hash( self.msg_magic( message ) ), sigdecode = ecdsa.util.sigdecode_string)
 396         for i in range(4):
 397             sig = base64.b64encode( chr(27+i) + signature )
 398             try:
 399                 self.verify_message( address, sig, message)
 400                 return sig
 401             except:
 402                 continue
 403         else:
 404             raise BaseException("error: cannot sign message")
 405
 406
 407     def verify_message(self, address, signature, message):
 408         """ See http://www.secg.org/download/aid-780/sec1-v2.pdf for the math """
 409         from ecdsa import numbertheory, ellipticcurve, util
 410         import msqr
 411         curve = curve_secp256k1
 412         G = generator_secp256k1
 413         order = G.order()
 414         # extract r,s from signature
 415         sig = base64.b64decode(signature)
 416         if len(sig) != 65: raise BaseException("Wrong encoding")
 417         r,s = util.sigdecode_string(sig[1:], order)
 418         recid = ord(sig[0]) - 27
 419         # 1.1
 420         x = r + (recid/2) * order
 421         # 1.3
 422         alpha = ( x * x * x  + curve.a() * x + curve.b() ) % curve.p()
 423         beta = msqr.modular_sqrt(alpha, curve.p())
 424         y = beta if (beta - recid) % 2 == 0 else curve.p() - beta
 425         # 1.4 the constructor checks that nR is at infinity
 426         R = ellipticcurve.Point(curve, x, y, order)
 427         # 1.5 compute e from message:
 428         h = Hash( self.msg_magic( message ) )
 429         e = string_to_number(h)
 430         minus_e = -e % order
 431         # 1.6 compute Q = r^-1 (sR - eG)
 432         inv_r = numbertheory.inverse_mod(r,order)
 433         Q = inv_r * ( s * R + minus_e * G )
 434         public_key = ecdsa.VerifyingKey.from_public_point( Q, curve = SECP256k1 )
 435         # check that Q is the public key
 436         public_key.verify_digest( sig[1:], h, sigdecode = ecdsa.util.sigdecode_string)
 437         # check that we get the original signing address
 438         addr = public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() )
 439         # print addr
 440         if address != addr:
 441             print "bad signature"
 442             raise BaseException("Bad signature")
 443
 444
 445     def create_new_address(self, for_change):
 446         """   Publickey(type,n) = Master_public_key + H(n|S|type)*point  """
 447         curve = SECP256k1
 448         n = len(self.change_addresses) if for_change else len(self.addresses)
 449         z = self.get_sequence(n,for_change)
 450         master_public_key = ecdsa.VerifyingKey.from_string( self.master_public_key, curve = SECP256k1 )
 451         pubkey_point = master_public_key.pubkey.point + z*curve.generator
 452         public_key2 = ecdsa.VerifyingKey.from_public_point( pubkey_point, curve = SECP256k1 )
 453         address = public_key_to_bc_address( '04'.decode('hex') + public_key2.to_string() )
 454         if for_change:
 455             self.change_addresses.append(address)
 456         else:
 457             self.addresses.append(address)
 458
 459         self.history[address] = []
 460         self.status[address] = None
 461         print address
 462         return address
 463
 464
 465
 466     def synchronize(self):
 467         if not self.master_public_key:
 468             return []
 469
 470         new_addresses = []
 471         while True:
 472             if self.change_addresses == []:
 473                 new_addresses.append( self.create_new_address(True) )
 474                 continue
 475             a = self.change_addresses[-1]
 476             if self.history.get(a):
 477                 new_addresses.append( self.create_new_address(True) )
 478             else:
 479                 break
 480
 481         n = self.gap_limit
 482         while True:
 483             if len(self.addresses) < n:
 484                 new_addresses.append( self.create_new_address(False) )
 485                 continue
 486             if map( lambda a: self.history.get(a), self.addresses[-n:] ) == n*[[]]:
 487                 break
 488             else:
 489                 new_addresses.append( self.create_new_address(False) )
 490
 491         if self.remote_url:
 492             num = self.get_remote_number()
 493             while len(self.addresses)<num:
 494                 new_addresses.append( self.create_new_address(False) )
 495
 496         return new_addresses
 497
 498
 499     def get_remote_number(self):
 500         import jsonrpclib
 501         server = jsonrpclib.Server(self.remote_url)
 502         out = server.getnum()
 503         return out
 504
 505     def get_remote_mpk(self):
 506         import jsonrpclib
 507         server = jsonrpclib.Server(self.remote_url)
 508         out = server.getkey()
 509         return out
 510
 511     def is_found(self):
 512         return (len(self.change_addresses) > 1 ) or ( len(self.addresses) > self.gap_limit )
 513
 514     def fill_addressbook(self):
 515         for tx in self.tx_history.values():
 516             if tx['value']<0:
 517                 for i in tx['outputs']:
 518                     if not self.is_mine(i) and i not in self.addressbook:
 519                         self.addressbook.append(i)
 520         # redo labels
 521         self.update_tx_labels()
 522
 523
 524     def save(self):
 525         s = {
 526             'seed_version':self.seed_version,
 527             'use_encryption':self.use_encryption,
 528             'master_public_key': self.master_public_key.encode('hex'),
 529             'fee':self.fee,
 530             'host':self.host,
 531             'port':self.port,
 532             'seed':self.seed,
 533             'addresses':self.addresses,
 534             'change_addresses':self.change_addresses,
 535             'status':self.status,
 536             'history':self.history,
 537             'labels':self.labels,
 538             'contacts':self.addressbook,
 539             'imported_keys':self.imported_keys,
 540             'aliases':self.aliases,
 541             'authorities':self.authorities,
 542             'receipts':self.receipts,
 543             }
 544         f = open(self.path,"w")
 545         f.write( repr(s) )
 546         f.close()
 547
 548     def read(self):
 549         import interface
 550
 551         upgrade_msg = """This wallet seed is deprecated. Please run upgrade.py for a diagnostic."""
 552         self.file_exists = False
 553         try:
 554             f = open(self.path,"r")
 555             data = f.read()
 556             f.close()
 557         except:
 558             return
 559         try:
 560             d = ast.literal_eval( data )
 561             self.seed_version = d.get('seed_version')
 562             self.master_public_key = d.get('master_public_key').decode('hex')
 563             self.use_encryption = d.get('use_encryption')
 564             self.fee = int( d.get('fee') )
 565             self.seed = d.get('seed')
 566             self.host = d.get('host')
 567             self.port = d.get('port')
 568             blocks = d.get('blocks')
 569             self.addresses = d.get('addresses')
 570             self.change_addresses = d.get('change_addresses')
 571             self.status = d.get('status')
 572             self.history = d.get('history')
 573             self.labels = d.get('labels')
 574             self.addressbook = d.get('contacts')
 575             self.imported_keys = d.get('imported_keys',{})
 576             self.aliases = d.get('aliases',{})
 577             self.authorities = d.get('authorities',{})
 578             self.receipts = d.get('receipts',{})
 579         except:
 580             raise BaseException("cannot read wallet file")
 581
 582         self.update_tx_history()
 583
 584         if self.seed_version != SEED_VERSION:
 585             raise BaseException(upgrade_msg)
 586
 587         if self.remote_url: assert self.master_public_key.encode('hex') == self.get_remote_mpk()
 588
 589         self.file_exists = True
 590         #self.interface = interface.start_interface(self)
 591
 592
 593
 594     def get_addr_balance(self, addr):
 595         if self.is_mine(addr):
 596             h = self.history.get(addr)
 597         else:
 598             h = self.interface.retrieve_history(addr)
 599         if not h: return 0,0
 600         c = u = 0
 601         for item in h:
 602             v = item['value']
 603             if item['height']:
 604                 c += v
 605             else:
 606                 u += v
 607         return c, u
 608
 609     def get_balance(self):
 610         conf = unconf = 0
 611         for addr in self.all_addresses():
 612             c, u = self.get_addr_balance(addr)
 613             conf += c
 614             unconf += u
 615         return conf, unconf
 616
 617
 618     def choose_tx_inputs( self, amount, fixed_fee, from_addr = None ):
 619         """ todo: minimize tx size """
 620         total = 0
 621         fee = self.fee if fixed_fee is None else fixed_fee
 622
 623         coins = []
 624         domain = [from_addr] if from_addr else self.all_addresses()
 625         for addr in domain:
 626             h = self.history.get(addr)
 627             if h is None: continue
 628             for item in h:
 629                 if item.get('raw_scriptPubKey'):
 630                     coins.append( (addr,item))
 631
 632         coins = sorted( coins, key = lambda x: x[1]['nTime'] )
 633         inputs = []
 634         for c in coins:
 635             addr, item = c
 636             v = item.get('value')
 637             total += v
 638             inputs.append((addr, v, item['tx_hash'], item['pos'], item['raw_scriptPubKey'], None, None) )
 639             fee = self.fee*len(inputs) if fixed_fee is None else fixed_fee
 640             if total >= amount + fee: break
 641         else:
 642             #print "not enough funds: %d %d"%(total, fee)
 643             inputs = []
 644         return inputs, total, fee
 645
 646     def choose_tx_outputs( self, to_addr, amount, fee, total, change_addr=None ):
 647         outputs = [ (to_addr, amount) ]
 648         change_amount = total - ( amount + fee )
 649         if change_amount != 0:
 650             # normally, the update thread should ensure that the last change address is unused
 651             if not change_addr:
 652                 change_addr = self.change_addresses[-1]
 653             outputs.append( ( change_addr,  change_amount) )
 654         return outputs
 655
 656     def sign_inputs( self, inputs, outputs, password ):
 657         s_inputs = []
 658         for i in range(len(inputs)):
 659             addr, v, p_hash, p_pos, p_scriptPubKey, _, _ = inputs[i]
 660             private_key = ecdsa.SigningKey.from_string( self.get_private_key(addr, password), curve = SECP256k1 )
 661             public_key = private_key.get_verifying_key()
 662             pubkey = public_key.to_string()
 663             tx = filter( raw_tx( inputs, outputs, for_sig = i ) )
 664             sig = private_key.sign_digest( Hash( tx.decode('hex') ), sigencode = ecdsa.util.sigencode_der )
 665             assert public_key.verify_digest( sig, Hash( tx.decode('hex') ), sigdecode = ecdsa.util.sigdecode_der)
 666             s_inputs.append( (addr, v, p_hash, p_pos, p_scriptPubKey, pubkey, sig) )
 667         return s_inputs
 668
 669     def pw_encode(self, s, password):
 670         if password:
 671             secret = Hash(password)
 672             return EncodeAES(secret, s)
 673         else:
 674             return s
 675
 676     def pw_decode(self, s, password):
 677         if password is not None:
 678             secret = Hash(password)
 679             d = DecodeAES(secret, s)
 680             if s == self.seed:
 681                 try:
 682                     d.decode('hex')
 683                 except:
 684                     raise BaseException("Invalid password")
 685             return d
 686         else:
 687             return s
 688
 689     def receive_status_callback(self, addr, status):
 690         if self.status.get(addr) != status:
 691             #print "updating status for", addr, repr(self.status.get(addr)), repr(status)
 692             self.status[addr] = status
 693             self.interface.get_history(addr)
 694
 695     def receive_history_callback(self, addr, data):
 696         #print "updating history for", addr
 697         self.history[addr] = data
 698         self.update_tx_history()
 699         self.save()
 700
 701     def get_tx_history(self):
 702         lines = self.tx_history.values()
 703         lines = sorted(lines, key=operator.itemgetter("nTime"))
 704         return lines
 705
 706     def update_tx_history(self):
 707         self.tx_history= {}
 708         for addr in self.all_addresses():
 709             h = self.history.get(addr)
 710             if h is None: continue
 711             for tx in h:
 712                 tx_hash = tx['tx_hash']
 713                 line = self.tx_history.get(tx_hash)
 714                 if not line:
 715                     self.tx_history[tx_hash] = copy.copy(tx)
 716                     line = self.tx_history.get(tx_hash)
 717                 else:
 718                     line['value'] += tx['value']
 719                 if line['height'] == 0:
 720                     line['nTime'] = 1e12
 721         self.update_tx_labels()
 722
 723     def update_tx_labels(self):
 724         for tx in self.tx_history.values():
 725             default_label = ''
 726             if tx['value']<0:
 727                 for o_addr in tx['outputs']:
 728                     if not self.is_change(o_addr):
 729                         dest_label = self.labels.get(o_addr)
 730                         if dest_label:
 731                             default_label = 'to: ' + dest_label
 732                         else:
 733                             default_label = 'to: ' + o_addr
 734             else:
 735                 for o_addr in tx['outputs']:
 736                     if self.is_mine(o_addr) and not self.is_change(o_addr):
 737                         dest_label = self.labels.get(o_addr)
 738                         if dest_label:
 739                             default_label = 'at: ' + dest_label
 740                         else:
 741                             default_label = 'at: ' + o_addr
 742             tx['default_label'] = default_label
 743
 744     def mktx(self, to_address, amount, label, password, fee=None, change_addr=None, from_addr= None):
 745         if not self.is_valid(to_address):
 746             raise BaseException("Invalid address")
 747         inputs, total, fee = self.choose_tx_inputs( amount, fee, from_addr )
 748         if not inputs:
 749             raise BaseException("Not enough funds")
 750         outputs = self.choose_tx_outputs( to_address, amount, fee, total, change_addr )
 751         s_inputs = self.sign_inputs( inputs, outputs, password )
 752
 753         tx = filter( raw_tx( s_inputs, outputs ) )
 754         if to_address not in self.addressbook:
 755             self.addressbook.append(to_address)
 756         if label:
 757             tx_hash = Hash(tx.decode('hex') )[::-1].encode('hex')
 758             self.labels[tx_hash] = label
 759
 760         return tx
 761
 762     def sendtx(self, tx):
 763         tx_hash = Hash(tx.decode('hex') )[::-1].encode('hex')
 764         self.tx_event.clear()
 765         self.interface.send([('transaction.broadcast', [tx])])
 766         self.tx_event.wait()
 767         out = self.tx_result
 768         if out != tx_hash:
 769             return False, "error: " + out
 770         if self.receipt:
 771             self.receipts[tx_hash] = self.receipt
 772             self.receipt = None
 773         return True, out
 774
 775
 776     def read_alias(self, alias):
 777         # this might not be the right place for this function.
 778         import urllib
 779
 780         m1 = re.match('([\w\-\.]+)@((\w[\w\-]+\.)+[\w\-]+)', alias)
 781         m2 = re.match('((\w[\w\-]+\.)+[\w\-]+)', alias)
 782         if m1:
 783             url = 'http://' + m1.group(2) + '/bitcoin.id/' + m1.group(1)
 784         elif m2:
 785             url = 'http://' + alias + '/bitcoin.id'
 786         else:
 787             return ''
 788         try:
 789             lines = urllib.urlopen(url).readlines()
 790         except:
 791             return ''
 792
 793         # line 0
 794         line = lines[0].strip().split(':')
 795         if len(line) == 1:
 796             auth_name = None
 797             target = signing_addr = line[0]
 798         else:
 799             target, auth_name, signing_addr, signature = line
 800             msg = "alias:%s:%s:%s"%(alias,target,auth_name)
 801             print msg, signature
 802             self.verify_message(signing_addr, signature, msg)
 803
 804         # other lines are signed updates
 805         for line in lines[1:]:
 806             line = line.strip()
 807             if not line: continue
 808             line = line.split(':')
 809             previous = target
 810             print repr(line)
 811             target, signature = line
 812             self.verify_message(previous, signature, "alias:%s:%s"%(alias,target))
 813
 814         if not self.is_valid(target):
 815             raise BaseException("Invalid bitcoin address")
 816
 817         return target, signing_addr, auth_name
 818
 819     def update_password(self, seed, new_password):
 820         self.use_encryption = (new_password != '')
 821         self.seed = self.pw_encode( seed, new_password)
 822         for k in self.imported_keys.keys():
 823             a = self.imported_keys[k]
 824             b = self.pw_decode(a, password)
 825             c = self.pw_encode(b, new_password)
 826             self.imported_keys[k] = c
 827         self.save()
 828
 829     def get_alias(self, alias, interactive = False, show_message=None, question = None):
 830         try:
 831             target, signing_address, auth_name = self.read_alias(alias)
 832         except BaseException, e:
 833             # raise exception if verify fails (verify the chain)
 834             if interactive:
 835                 show_message("Alias error: " + e.message)
 836             return
 837
 838         print target, signing_address, auth_name
 839
 840         if auth_name is None:
 841             a = self.aliases.get(alias)
 842             if not a:
 843                 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)
 844                 if interactive and question( msg ):
 845                     self.aliases[alias] = (signing_address, target)
 846                 else:
 847                     target = None
 848             else:
 849                 if signing_address != a[0]:
 850                     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
 851                     if interactive and question( msg ):
 852                         self.aliases[alias] = (signing_address, target)
 853                     else:
 854                         target = None
 855         else:
 856             if signing_address not in self.authorities.keys():
 857                 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)
 858                 if interactive and question( msg ):
 859                     self.authorities[signing_address] = auth_name
 860                 else:
 861                     target = None
 862
 863         if target:
 864             self.aliases[alias] = (signing_address, target)
 865
 866         return target
 867
 868
 869     def parse_url(self, url, show_message, question):
 870         o = url[8:].split('?')
 871         address = o[0]
 872         if len(o)>1:
 873             params = o[1].split('&')
 874         else:
 875             params = []
 876
 877         amount = label = message = signature = identity = ''
 878         for p in params:
 879             k,v = p.split('=')
 880             uv = urldecode(v)
 881             if k == 'amount': amount = uv
 882             elif k == 'message': message = uv
 883             elif k == 'label': label = uv
 884             elif k == 'signature':
 885                 identity, signature = uv.split(':')
 886                 url = url.replace('&%s=%s'%(k,v),'')
 887             else:
 888                 print k,v
 889
 890         if signature:
 891             if re.match('^(|([\w\-\.]+)@)((\w[\w\-]+\.)+[\w\-]+)$', identity):
 892                 signing_address = self.get_alias(identity, True, show_message, question)
 893             elif self.is_valid(identity):
 894                 signing_address = identity
 895             else:
 896                 signing_address = None
 897             if not signing_address:
 898                 return
 899             try:
 900                 self.verify_message(signing_address, signature, url )
 901                 self.receipt = (signing_address, signature, url)
 902             except:
 903                 show_message('Warning: the URI contains a bad signature.\nThe identity of the recipient cannot be verified.')
 904                 address = amount = label = identity = message = ''
 905
 906         if re.match('^(|([\w\-\.]+)@)((\w[\w\-]+\.)+[\w\-]+)$', address):
 907             payto_address = self.get_alias(address, True, show_message, question)
 908             if payto_address:
 909                 address = address + ' <' + payto_address + '>'
 910
 911         return address, amount, label, message, signature, identity, url
 912
 913
 914
 915     def handle_response(self, r):
 916         if r is None:
 917             return
 918
 919         method = r['method']
 920         params = r['params']
 921         result = r['result']
 922
 923         if method == 'server.banner':
 924             self.banner = result
 925             self.was_updated = True
 926
 927         elif method == 'session.poll':
 928             # native poll
 929             blocks, changed_addresses = result
 930             if blocks == -1: raise BaseException("session not found")
 931             self.blocks = int(blocks)
 932             if changed_addresses:
 933                 self.was_updated = True
 934                 for addr, status in changed_addresses.items():
 935                     self.receive_status_callback(addr, status)
 936
 937         elif method == 'server.peers':
 938             self.interface.servers = map( lambda x:x[1], result )
 939
 940         elif method == 'address.subscribe':
 941             addr = params[-1]
 942             self.receive_status_callback(addr, result)
 943
 944         elif method == 'address.get_history':
 945             addr = params[0]
 946             self.receive_history_callback(addr, result)
 947             self.was_updated = True
 948
 949         elif method == 'transaction.broadcast':
 950             self.tx_result = result
 951             self.tx_event.set()
 952
 953         elif method == 'numblocks.subscribe':
 954             self.blocks = result
 955
 956         elif method == 'client.version':
 957             pass
 958
 959         else:
 960             print "unknown message:", method, params, result
 961
 962
 963     def update(self):
 964         self.up_to_date_event.wait()
 965
 966
 967     def run(self):
 968         while self.interface.is_connected:
 969             new_addresses = self.synchronize()
 970             self.interface.subscribe(new_addresses)
 971             if self.interface.is_up_to_date() and not new_addresses:
 972                 self.up_to_date = True
 973                 self.up_to_date_event.set()
 974             else:
 975                 self.up_to_date = False
 976
 977             response = self.interface.responses.get(True,100000000000) # workaround so that it can be keyboard interrupted
 978             self.handle_response(response)
 979
 980     def start_interface(self):
 981         if self.port == 50000:
 982             InterfaceClass = NativeInterface
 983         elif self.port == 50001:
 984             InterfaceClass = AsynchronousInterface
 985         elif self.port in [80, 81, 8080, 8081]:
 986             InterfaceClass = HttpInterface
 987         else:
 988             print "unknown port number: %d. using native protocol."%self.port
 989             InterfaceClass = NativeInterface
 990
 991         self.interface = InterfaceClass(self.host, self.port)
 992         addresses = self.all_addresses()
 993         version = self.electrum_version
 994         self.interface.start_session(addresses,version)
 995
 996