simple payment verification: check targets, use block headers file.
[electrum-nvc.git] / lib / wallet.py
index a45af9d..c3f5984 100644 (file)
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-
-import sys, base64, os, re, hashlib, copy, operator, ast, threading, random
-
-try:
-    import ecdsa  
-    from ecdsa.util import string_to_number, number_to_string
-except:
-    print "python-ecdsa does not seem to be installed. Try 'sudo easy_install ecdsa'"
-    sys.exit(1)
-
-try:
-    import aes
-except:
-    print "AES does not seem to be installed. Try 'sudo easy_install slowaes'"
-    sys.exit(1)
-
-
-############ functions from pywallet ##################### 
-
-addrtype = 0
-
-def hash_160(public_key):
-    try:
-        md = hashlib.new('ripemd160')
-        md.update(hashlib.sha256(public_key).digest())
-        return md.digest()
-    except:
-        import ripemd
-        md = ripemd.new(hashlib.sha256(public_key).digest())
-        return md.digest()
-
-
-def public_key_to_bc_address(public_key):
-    h160 = hash_160(public_key)
-    return hash_160_to_bc_address(h160)
-
-def hash_160_to_bc_address(h160):
-    vh160 = chr(addrtype) + h160
-    h = Hash(vh160)
-    addr = vh160 + h[0:4]
-    return b58encode(addr)
-
-def bc_address_to_hash_160(addr):
-    bytes = b58decode(addr, 25)
-    return bytes[1:21]
-
-__b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
-__b58base = len(__b58chars)
-
-def b58encode(v):
-    """ encode v, which is a string of bytes, to base58.               
-    """
-
-    long_value = 0L
-    for (i, c) in enumerate(v[::-1]):
-        long_value += (256**i) * ord(c)
-
-    result = ''
-    while long_value >= __b58base:
-        div, mod = divmod(long_value, __b58base)
-        result = __b58chars[mod] + result
-        long_value = div
-    result = __b58chars[long_value] + result
-
-    # Bitcoin does a little leading-zero-compression:
-    # leading 0-bytes in the input become leading-1s
-    nPad = 0
-    for c in v:
-        if c == '\0': nPad += 1
-        else: break
-
-    return (__b58chars[0]*nPad) + result
-
-def b58decode(v, length):
-    """ decode v into a string of len bytes
-    """
-    long_value = 0L
-    for (i, c) in enumerate(v[::-1]):
-        long_value += __b58chars.find(c) * (__b58base**i)
-
-    result = ''
-    while long_value >= 256:
-        div, mod = divmod(long_value, 256)
-        result = chr(mod) + result
-        long_value = div
-    result = chr(long_value) + result
-
-    nPad = 0
-    for c in v:
-        if c == __b58chars[0]: nPad += 1
-        else: break
-
-    result = chr(0)*nPad + result
-    if length is not None and len(result) != length:
-        return None
-
-    return result
-
-
-def Hash(data):
-    return hashlib.sha256(hashlib.sha256(data).digest()).digest()
-
-def EncodeBase58Check(vchIn):
-    hash = Hash(vchIn)
-    return b58encode(vchIn + hash[0:4])
-
-def DecodeBase58Check(psz):
-    vchRet = b58decode(psz, None)
-    key = vchRet[0:-4]
-    csum = vchRet[-4:]
-    hash = Hash(key)
-    cs32 = hash[0:4]
-    if cs32 != csum:
-        return None
-    else:
-        return key
-
-def PrivKeyToSecret(privkey):
-    return privkey[9:9+32]
-
-def SecretToASecret(secret):
-    vchIn = chr(addrtype+128) + secret
-    return EncodeBase58Check(vchIn)
-
-def ASecretToSecret(key):
-    vch = DecodeBase58Check(key)
-    if vch and vch[0] == chr(addrtype+128):
-        return vch[1:]
-    else:
-        return False
-
-########### end pywallet functions #######################
+import sys
+import base64
+import os
+import re
+import hashlib
+import copy
+import operator
+import ast
+import threading
+import random
+import aes
+import ecdsa
+import Queue
+import time
+
+from ecdsa.util import string_to_number, number_to_string
+from util import print_error, user_dir, format_satoshis
+from bitcoin import *
 
 # URL decode
 _ud = re.compile('%([0-9a-hA-H]{2})', re.MULTILINE)
 urldecode = lambda x: _ud.sub(lambda m: chr(int(m.group(1), 16)), x)
 
-
-def int_to_hex(i, length=1):
-    s = hex(i)[2:].rstrip('L')
-    s = "0"*(2*length - len(s)) + s
-    return s.decode('hex')[::-1].encode('hex')
-
-
-# AES
+# AES encryption
 EncodeAES = lambda secret, s: base64.b64encode(aes.encryptData(secret,s))
 DecodeAES = lambda secret, e: aes.decryptData(secret, base64.b64decode(e))
 
 
-
-# secp256k1, http://www.oid-info.com/get/1.3.132.0.10
-_p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2FL
-_r = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141L
-_b = 0x0000000000000000000000000000000000000000000000000000000000000007L
-_a = 0x0000000000000000000000000000000000000000000000000000000000000000L
-_Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798L
-_Gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8L
-curve_secp256k1 = ecdsa.ellipticcurve.CurveFp( _p, _a, _b )
-generator_secp256k1 = ecdsa.ellipticcurve.Point( curve_secp256k1, _Gx, _Gy, _r )
-oid_secp256k1 = (1,3,132,0,10)
-SECP256k1 = ecdsa.curves.Curve("SECP256k1", curve_secp256k1, generator_secp256k1, oid_secp256k1 ) 
-
-
-def filter(s): 
-    out = re.sub('( [^\n]*|)\n','',s)
-    out = out.replace(' ','')
-    out = out.replace('\n','')
-    return out
-
-def raw_tx( inputs, outputs, for_sig = None ):
-    s  = int_to_hex(1,4)                                     +   '     version\n' 
-    s += int_to_hex( len(inputs) )                           +   '     number of inputs\n'
-    for i in range(len(inputs)):
-        _, _, p_hash, p_index, p_script, pubkey, sig = inputs[i]
-        s += p_hash.decode('hex')[::-1].encode('hex')        +  '     prev hash\n'
-        s += int_to_hex(p_index,4)                           +  '     prev index\n'
-        if for_sig is None:
-            sig = sig + chr(1)                               # hashtype
-            script  = int_to_hex( len(sig))                  +  '     push %d bytes\n'%len(sig)
-            script += sig.encode('hex')                      +  '     sig\n'
-            pubkey = chr(4) + pubkey
-            script += int_to_hex( len(pubkey))               +  '     push %d bytes\n'%len(pubkey)
-            script += pubkey.encode('hex')                   +  '     pubkey\n'
-        elif for_sig==i:
-            script = p_script                                +  '     scriptsig \n'
-        else:
-            script=''
-        s += int_to_hex( len(filter(script))/2 )             +  '     script length \n'
-        s += script
-        s += "ffffffff"                                      +  '     sequence\n'
-    s += int_to_hex( len(outputs) )                          +  '     number of outputs\n'
-    for output in outputs:
-        addr, amount = output
-        s += int_to_hex( amount, 8)                          +  '     amount: %d\n'%amount 
-        script = '76a9'                                      # op_dup, op_hash_160
-        script += '14'                                       # push 0x14 bytes
-        script += bc_address_to_hash_160(addr).encode('hex')
-        script += '88ac'                                     # op_equalverify, op_checksig
-        s += int_to_hex( len(filter(script))/2 )             +  '     script length \n'
-        s += script                                          +  '     script \n'
-    s += int_to_hex(0,4)                                     # lock time
-    if for_sig is not None: s += int_to_hex(1, 4)            # hash type
-    return s
-
-
-
-
-def format_satoshis(x, is_diff=False, num_zeros = 0):
-    from decimal import Decimal
-    s = str( Decimal(x) /100000000 )
-    if is_diff and x>0:
-        s = "+" + s
-    if not '.' in s: s += '.'
-    p = s.find('.')
-    s += "0"*( 1 + num_zeros - ( len(s) - p ))
-    s += " "*( 9 - ( len(s) - p ))
-    s = " "*( 5 - ( p )) + s
-    return s
-
-
 from version import ELECTRUM_VERSION, SEED_VERSION
-from interface import DEFAULT_SERVERS
-
-
 
 
 class Wallet:
-    def __init__(self, gui_callback = lambda: None):
+    def __init__(self, config={}):
 
+        self.config = config
         self.electrum_version = ELECTRUM_VERSION
-        self.seed_version = SEED_VERSION
-        self.gui_callback = gui_callback
-
-        self.gap_limit = 5           # configuration
-        self.fee = 100000
-        self.num_zeros = 0
-        self.master_public_key = ''
 
         # saved fields
-        self.use_encryption = False
-        self.addresses = []          # receiving addresses visible for user
-        self.change_addresses = []   # addresses used as change
-        self.seed = ''               # encrypted
-        self.history = {}
-        self.labels = {}             # labels for addresses and transactions
-        self.aliases = {}            # aliases for addresses
-        self.authorities = {}        # trusted addresses
-        self.frozen_addresses = []
-        
-        self.receipts = {}           # signed URIs
-        self.receipt = None          # next receipt
-        self.addressbook = []        # outgoing addresses, for payments
+        self.seed_version          = config.get('seed_version', SEED_VERSION)
+        self.gap_limit             = config.get('gap_limit', 5)
+        self.use_change            = config.get('use_change',True)
+        self.fee                   = int(config.get('fee',100000))
+        self.num_zeros             = int(config.get('num_zeros',0))
+        self.master_public_key     = config.get('master_public_key','')
+        self.use_encryption        = config.get('use_encryption', False)
+        self.addresses             = config.get('addresses', [])          # receiving addresses visible for user
+        self.change_addresses      = config.get('change_addresses', [])   # addresses used as change
+        self.seed                  = config.get('seed', '')               # encrypted
+        self.history               = config.get('history',{})
+        self.labels                = config.get('labels',{})              # labels for addresses and transactions
+        self.aliases               = config.get('aliases', {})            # aliases for addresses
+        self.authorities           = config.get('authorities', {})        # trusted addresses
+        self.frozen_addresses      = config.get('frozen_addresses',[])
+        self.prioritized_addresses = config.get('prioritized_addresses',[])
+        self.receipts              = config.get('receipts',{})            # signed URIs
+        self.addressbook           = config.get('contacts', [])           # outgoing addresses, for payments
+        self.imported_keys         = config.get('imported_keys',{})
 
         # not saved
+        self.receipt = None          # next receipt
         self.tx_history = {}
-
-        self.imported_keys = {}
-        self.remote_url = None
-
         self.was_updated = True
         self.blocks = -1
         self.banner = ''
 
-        # there is a difference between self.up_to_date and self.is_up_to_date()
-        # self.is_up_to_date() returns true when all requests have been answered and processed
-        # self.up_to_date is true when the wallet is synchronized (stronger requirement)
+        # there is a difference between wallet.up_to_date and interface.is_up_to_date()
+        # interface.is_up_to_date() returns true when all requests have been answered and processed
+        # wallet.up_to_date is true when the wallet is synchronized (stronger requirement)
         self.up_to_date_event = threading.Event()
         self.up_to_date_event.clear()
         self.up_to_date = False
         self.lock = threading.Lock()
         self.tx_event = threading.Event()
 
-        self.pick_random_server()
-
-
-
-    def pick_random_server(self):
-        self.server = random.choice( DEFAULT_SERVERS )         # random choice when the wallet is created
-
-    def is_up_to_date(self):
-        return self.interface.responses.empty() and not self.interface.unanswered_requests
-
-    def set_server(self, server):
-        # raise an error if the format isnt correct
-        a,b,c = server.split(':')
-        b = int(b)
-        assert c in ['t','h','n']
-        # set the server
-        if server != self.server:
-            self.server = server
-            self.save()
-            self.interface.is_connected = False  # this exits the polling loop
-
-    def set_path(self, wallet_path):
-
-        if wallet_path is not None:
-            self.path = wallet_path
-        else:
-            # backward compatibility: look for wallet file in the default data directory
-            if "HOME" in os.environ:
-                wallet_dir = os.path.join( os.environ["HOME"], '.electrum')
-            elif "LOCALAPPDATA" in os.environ:
-                wallet_dir = os.path.join( os.environ["LOCALAPPDATA"], 'Electrum' )
-            elif "APPDATA" in os.environ:
-                wallet_dir = os.path.join( os.environ["APPDATA"], 'Electrum' )
-            else:
-                raise BaseException("No home directory found in environment variables.")
+        self.update_tx_history()
+        if self.seed_version != SEED_VERSION:
+            raise ValueError("This wallet seed is deprecated. Please run upgrade.py for a diagnostic.")
 
-            if not os.path.exists( wallet_dir ): os.mkdir( wallet_dir )
-            self.path = os.path.join( wallet_dir, 'electrum.dat' )
+    def init_up_to_date(self):
+        self.up_to_date_event.clear()
+        self.up_to_date = False
 
     def import_key(self, keypair, password):
         address, key = keypair.split(':')
-        if not self.is_valid(address): return False
-        if address in self.all_addresses(): return False
+        if not self.is_valid(address):
+            raise BaseException('Invalid Bitcoin address')
+        if address in self.all_addresses():
+            raise BaseException('Address already in wallet')
         b = ASecretToSecret( key )
-        if not b: return False
+        if not b: 
+            raise BaseException('Unsupported key format')
         secexp = int( b.encode('hex'), 16)
         private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve=SECP256k1 )
         # sanity check
         public_key = private_key.get_verifying_key()
-        if not address == public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() ): return False
+        if not address == public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() ):
+            raise BaseException('Address does not match private key')
         self.imported_keys[address] = self.pw_encode( key, password )
-        return True
+
 
     def new_seed(self, password):
         seed = "%032x"%ecdsa.util.randrange( pow(2,128) )
@@ -353,7 +128,7 @@ class Wallet:
         curve = SECP256k1
         secexp = self.stretch_key(seed)
         master_private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve = SECP256k1 )
-        self.master_public_key = master_private_key.get_verifying_key().to_string()
+        self.master_public_key = master_private_key.get_verifying_key().to_string().encode('hex')
 
     def all_addresses(self):
         return self.addresses + self.change_addresses + self.imported_keys.keys()
@@ -380,7 +155,12 @@ class Wallet:
         return string_to_number( seed )
 
     def get_sequence(self,n,for_change):
-        return string_to_number( Hash( "%d:%d:"%(n,for_change) + self.master_public_key ) )
+        return string_to_number( Hash( "%d:%d:"%(n,for_change) + self.master_public_key.decode('hex') ) )
+
+    def get_private_key_base58(self, address, password):
+        pk = self.get_private_key(address, password)
+        if pk is None: return None
+        return SecretToASecret( pk )
 
     def get_private_key(self, address, password):
         """  Privatekey(type,n) = Master_private_key + H(n|S|type)  """
@@ -388,6 +168,7 @@ class Wallet:
         
         if address in self.imported_keys.keys():
             b = self.pw_decode( self.imported_keys[address], password )
+            if not b: return None
             b = ASecretToSecret( b )
             secexp = int( b.encode('hex'), 16)
         else:
@@ -403,6 +184,7 @@ class Wallet:
                 seed = self.pw_decode( self.seed, password)
             except:
                 raise BaseException("Invalid password")
+            if not seed: return None
             secexp = self.stretch_key(seed)
             secexp = ( secexp + self.get_sequence(n,for_change) ) % order
 
@@ -426,8 +208,8 @@ class Wallet:
                 continue
         else:
             raise BaseException("error: cannot sign message")
-        
-            
+
+
     def verify_message(self, address, signature, message):
         """ See http://www.secg.org/download/aid-780/sec1-v2.pdf for the math """
         from ecdsa import numbertheory, ellipticcurve, util
@@ -439,7 +221,16 @@ class Wallet:
         sig = base64.b64decode(signature)
         if len(sig) != 65: raise BaseException("Wrong encoding")
         r,s = util.sigdecode_string(sig[1:], order)
-        recid = ord(sig[0]) - 27
+        nV = ord(sig[0])
+        if nV < 27 or nV >= 35:
+            raise BaseException("Bad encoding")
+        if nV >= 31:
+            compressed = True
+            nV -= 4
+        else:
+            compressed = False
+
+        recid = nV - 27
         # 1.1
         x = r + (recid/2) * order
         # 1.3
@@ -459,31 +250,69 @@ class Wallet:
         # check that Q is the public key
         public_key.verify_digest( sig[1:], h, sigdecode = ecdsa.util.sigdecode_string)
         # check that we get the original signing address
-        addr = public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() )
-        # print addr
+        addr = public_key_to_bc_address( encode_point(public_key, compressed) )
         if address != addr:
-            print "bad signature"
             raise BaseException("Bad signature")
     
 
     def create_new_address(self, for_change):
-        """   Publickey(type,n) = Master_public_key + H(n|S|type)*point  """
-        curve = SECP256k1
         n = len(self.change_addresses) if for_change else len(self.addresses)
-        z = self.get_sequence(n,for_change)
-        master_public_key = ecdsa.VerifyingKey.from_string( self.master_public_key, curve = SECP256k1 )
-        pubkey_point = master_public_key.pubkey.point + z*curve.generator
-        public_key2 = ecdsa.VerifyingKey.from_public_point( pubkey_point, curve = SECP256k1 )
-        address = public_key_to_bc_address( '04'.decode('hex') + public_key2.to_string() )
+        address = self.get_new_address(n, for_change)
         if for_change:
             self.change_addresses.append(address)
         else:
             self.addresses.append(address)
-
         self.history[address] = []
+        return address
+        
+    def get_new_address(self, n, for_change):
+        """   Publickey(type,n) = Master_public_key + H(n|S|type)*point  """
+        curve = SECP256k1
+        z = self.get_sequence(n, for_change)
+        master_public_key = ecdsa.VerifyingKey.from_string( self.master_public_key.decode('hex'), curve = SECP256k1 )
+        pubkey_point = master_public_key.pubkey.point + z*curve.generator
+        public_key2 = ecdsa.VerifyingKey.from_public_point( pubkey_point, curve = SECP256k1 )
+        address = public_key_to_bc_address( '04'.decode('hex') + public_key2.to_string() )
         print address
         return address
+                                                                      
 
+    def change_gap_limit(self, value):
+        if value >= self.gap_limit:
+            self.gap_limit = value
+            self.save()
+            self.interface.poke()
+            return True
+
+        elif value >= self.min_acceptable_gap():
+            k = self.num_unused_trailing_addresses()
+            n = len(self.addresses) - k + value
+            self.addresses = self.addresses[0:n]
+            self.gap_limit = value
+            self.save()
+            return True
+        else:
+            return False
+
+    def num_unused_trailing_addresses(self):
+        k = 0
+        for a in self.addresses[::-1]:
+            if self.history.get(a):break
+            k = k + 1
+        return k
+
+    def min_acceptable_gap(self):
+        # fixme: this assumes wallet is synchronized
+        n = 0
+        nmax = 0
+        k = self.num_unused_trailing_addresses()
+        for a in self.addresses[0:-k]:
+            if self.history.get(a):
+                n = 0
+            else:
+                n += 1
+                if n > nmax: nmax = n
+        return nmax + 1
 
 
     def synchronize(self):
@@ -511,26 +340,9 @@ class Wallet:
             else:
                 new_addresses.append( self.create_new_address(False) )
 
-        if self.remote_url:
-            num = self.get_remote_number()
-            while len(self.addresses)<num:
-                new_addresses.append( self.create_new_address(False) )
-
         return new_addresses
 
 
-    def get_remote_number(self):
-        import jsonrpclib
-        server = jsonrpclib.Server(self.remote_url)
-        out = server.getnum()
-        return out
-
-    def get_remote_mpk(self):
-        import jsonrpclib
-        server = jsonrpclib.Server(self.remote_url)
-        out = server.getkey()
-        return out
-
     def is_found(self):
         return (len(self.change_addresses) > 1 ) or ( len(self.addresses) > self.gap_limit )
 
@@ -544,75 +356,10 @@ class Wallet:
         self.update_tx_labels()
 
 
-    def save(self):
-        s = {
-            'seed_version':self.seed_version,
-            'use_encryption':self.use_encryption,
-            'master_public_key': self.master_public_key.encode('hex'),
-            'fee':self.fee,
-            'server':self.server,
-            'seed':self.seed,
-            'addresses':self.addresses,
-            'change_addresses':self.change_addresses,
-            'history':self.history, 
-            'labels':self.labels,
-            'contacts':self.addressbook,
-            'imported_keys':self.imported_keys,
-            'aliases':self.aliases,
-            'authorities':self.authorities,
-            'receipts':self.receipts,
-            'num_zeros':self.num_zeros,
-            'frozen_addresses':self.frozen_addresses,
-            }
-        f = open(self.path,"w")
-        f.write( repr(s) )
-        f.close()
-
-    def read(self):
-        import interface
-
-        upgrade_msg = """This wallet seed is deprecated. Please run upgrade.py for a diagnostic."""
-        self.file_exists = False
-        try:
-            f = open(self.path,"r")
-            data = f.read()
-            f.close()
-        except:
-            return
-        data = interface.old_to_new(data)
-        try:
-            d = ast.literal_eval( data )
-            self.seed_version = d.get('seed_version')
-            self.master_public_key = d.get('master_public_key').decode('hex')
-            self.use_encryption = d.get('use_encryption')
-            self.fee = int( d.get('fee') )
-            self.seed = d.get('seed')
-            self.server = d.get('server')
-            #blocks = d.get('blocks')
-            self.addresses = d.get('addresses')
-            self.change_addresses = d.get('change_addresses')
-            self.history = d.get('history')
-            self.labels = d.get('labels')
-            self.addressbook = d.get('contacts')
-            self.imported_keys = d.get('imported_keys',{})
-            self.aliases = d.get('aliases',{})
-            self.authorities = d.get('authorities',{})
-            self.receipts = d.get('receipts',{})
-            self.num_zeros = d.get('num_zeros',0)
-            self.frozen_addresses = d.get('frozen_addresses',[])
-        except:
-            raise BaseException("cannot read wallet file")
-
-        self.update_tx_history()
-
-        if self.seed_version != SEED_VERSION:
-            raise BaseException(upgrade_msg)
-
-        if self.remote_url: assert self.master_public_key.encode('hex') == self.get_remote_mpk()
-
-        self.file_exists = True
-
-
+    def get_address_flags(self, addr):
+        flags = "C" if self.is_change(addr) else "I" if addr in self.imported_keys.keys() else "-" 
+        flags += "F" if addr in self.frozen_addresses else "P" if addr in self.prioritized_addresses else "-"
+        return flags
         
 
     def get_addr_balance(self, addr):
@@ -642,10 +389,14 @@ class Wallet:
         fee = self.fee if fixed_fee is None else fixed_fee
 
         coins = []
+        prioritized_coins = []
         domain = [from_addr] if from_addr else self.all_addresses()
         for i in self.frozen_addresses:
             if i in domain: domain.remove(i)
 
+        for i in self.prioritized_addresses:
+            if i in domain: domain.remove(i)
+
         for addr in domain:
             h = self.history.get(addr)
             if h is None: continue
@@ -654,7 +405,19 @@ class Wallet:
                     coins.append( (addr,item))
 
         coins = sorted( coins, key = lambda x: x[1]['timestamp'] )
+
+        for addr in self.prioritized_addresses:
+            h = self.history.get(addr)
+            if h is None: continue
+            for item in h:
+                if item.get('raw_output_script'):
+                    prioritized_coins.append( (addr,item))
+
+        prioritized_coins = sorted( prioritized_coins, key = lambda x: x[1]['timestamp'] )
+
         inputs = []
+        coins = prioritized_coins + coins
+
         for c in coins: 
             addr, item = c
             v = item.get('value')
@@ -663,7 +426,7 @@ class Wallet:
             fee = self.fee*len(inputs) if fixed_fee is None else fixed_fee
             if total >= amount + fee: break
         else:
-            #print "not enough funds: %d %d"%(total, fee)
+            #print "not enough funds: %s %s"%(format_satoshis(total), format_satoshis(fee))
             inputs = []
         return inputs, total, fee
 
@@ -705,13 +468,14 @@ class Wallet:
                 try:
                     d.decode('hex')
                 except:
-                    raise BaseException("Invalid password")
+                    raise ValueError("Invalid password")
             return d
         else:
             return s
 
     def get_status(self, address):
-        h = self.history.get(address)
+        with self.lock:
+            h = self.history.get(address)
         if not h:
             status = None
         else:
@@ -721,11 +485,6 @@ class Wallet:
                 status = status + ':%d'% len(h)
         return status
 
-    def receive_status_callback(self, addr, status):
-        with self.lock:
-            if self.get_status(addr) != status:
-                #print "updating status for", addr, status
-                self.interface.get_history(addr)
 
     def receive_history_callback(self, addr, data): 
         #print "updating history for", addr
@@ -735,10 +494,26 @@ class Wallet:
             self.save()
 
     def get_tx_history(self):
-        lines = self.tx_history.values()
+        with self.lock:
+            lines = self.tx_history.values()
         lines = sorted(lines, key=operator.itemgetter("timestamp"))
         return lines
 
+    def get_tx_hashes(self):
+        with self.lock:
+            hashes = self.tx_history.keys()
+        return hashes
+
+    def get_transactions_at_height(self, height):
+        with self.lock:
+            values = self.tx_history.values()[:]
+
+        out = []
+        for tx in values:
+            if tx['height'] == height:
+                out.append(tx['tx_hash'])
+        return out
+
     def update_tx_history(self):
         self.tx_history= {}
         for addr in self.all_addresses():
@@ -761,28 +536,42 @@ class Wallet:
             default_label = ''
             if tx['value']<0:
                 for o_addr in tx['outputs']:
-                    if not self.is_change(o_addr):
-                        dest_label = self.labels.get(o_addr)
-                        if dest_label:
-                            default_label = 'to: ' + dest_label
-                        else:
-                            default_label = 'to: ' + o_addr
+                    if not self.is_mine(o_addr):
+                        try:
+                            default_label = self.labels[o_addr]
+                        except KeyError:
+                            default_label = o_addr
             else:
                 for o_addr in tx['outputs']:
                     if self.is_mine(o_addr) and not self.is_change(o_addr):
-                        dest_label = self.labels.get(o_addr)
-                        if dest_label:
-                            default_label = 'at: ' + dest_label
-                        else:
-                            default_label = 'at: ' + o_addr
+                        break
+                else:
+                    for o_addr in tx['outputs']:
+                        if self.is_mine(o_addr):
+                            break
+                    else:
+                        o_addr = None
+
+                if o_addr:
+                    dest_label = self.labels.get(o_addr)
+                    try:
+                        default_label = self.labels[o_addr]
+                    except KeyError:
+                        default_label = o_addr
+
             tx['default_label'] = default_label
 
     def mktx(self, to_address, amount, label, password, fee=None, change_addr=None, from_addr= None):
         if not self.is_valid(to_address):
-            raise BaseException("Invalid address")
+            raise ValueError("Invalid address")
         inputs, total, fee = self.choose_tx_inputs( amount, fee, from_addr )
         if not inputs:
-            raise BaseException("Not enough funds")
+            raise ValueError("Not enough funds")
+
+        if not self.use_change and not change_addr:
+            change_addr = inputs[0][0]
+            print "Sending change to", change_addr
+
         outputs = self.choose_tx_outputs( to_address, amount, fee, total, change_addr )
         s_inputs = self.sign_inputs( inputs, outputs, password )
 
@@ -796,10 +585,19 @@ class Wallet:
         return tx
 
     def sendtx(self, tx):
-        tx_hash = Hash(tx.decode('hex') )[::-1].encode('hex')
+        # synchronous
+        h = self.send_tx(tx)
+        self.tx_event.wait()
+        self.receive_tx(h)
+
+    def send_tx(self, tx):
+        # asynchronous
         self.tx_event.clear()
+        tx_hash = Hash(tx.decode('hex') )[::-1].encode('hex')
         self.interface.send([('blockchain.transaction.broadcast', [tx])])
-        self.tx_event.wait()
+        return tx_hash
+
+    def receive_tx(self,tx_hash):
         out = self.tx_result 
         if out != tx_hash:
             return False, "error: " + out
@@ -816,9 +614,9 @@ class Wallet:
         m1 = re.match('([\w\-\.]+)@((\w[\w\-]+\.)+[\w\-]+)', alias)
         m2 = re.match('((\w[\w\-]+\.)+[\w\-]+)', alias)
         if m1:
-            url = 'http://' + m1.group(2) + '/bitcoin.id/' + m1.group(1) 
+            url = 'https://' + m1.group(2) + '/bitcoin.id/' + m1.group(1) 
         elif m2:
-            url = 'http://' + alias + '/bitcoin.id'
+            url = 'https://' + alias + '/bitcoin.id'
         else:
             return ''
         try:
@@ -848,17 +646,17 @@ class Wallet:
             self.verify_message(previous, signature, "alias:%s:%s"%(alias,target))
 
         if not self.is_valid(target):
-            raise BaseException("Invalid bitcoin address")
+            raise ValueError("Invalid bitcoin address")
 
         return target, signing_addr, auth_name
 
-    def update_password(self, seed, new_password):
+    def update_password(self, seed, old_password, new_password):
         if new_password == '': new_password = None
         self.use_encryption = (new_password != None)
         self.seed = self.pw_encode( seed, new_password)
         for k in self.imported_keys.keys():
             a = self.imported_keys[k]
-            b = self.pw_decode(a, password)
+            b = self.pw_decode(a, old_password)
             c = self.pw_encode(b, new_password)
             self.imported_keys[k] = c
         self.save()
@@ -869,7 +667,7 @@ class Wallet:
         except BaseException, e:
             # raise exception if verify fails (verify the chain)
             if interactive:
-                show_message("Alias error: " + e.message)
+                show_message("Alias error: " + str(e))
             return
 
         print target, signing_address, auth_name
@@ -924,6 +722,12 @@ class Wallet:
             else: 
                 print k,v
 
+        if label and self.labels.get(address) != label:
+            if question('Give label "%s" to address %s ?'%(label,address)):
+                if address not in self.addressbook and address not in self.all_addresses(): 
+                    self.addressbook.append(address)
+                self.labels[address] = label
+
         if signature:
             if re.match('^(|([\w\-\.]+)@)((\w[\w\-]+\.)+[\w\-]+)$', identity):
                 signing_address = self.get_alias(identity, True, show_message, question)
@@ -949,15 +753,190 @@ class Wallet:
 
 
     def update(self):
-        self.interface.poke()
-        self.up_to_date_event.wait()
+        self.interface.poke('synchronizer')
+        self.up_to_date_event.wait(10000000000)
+
+
+    def freeze(self,addr):
+        if addr in self.all_addresses() and addr not in self.frozen_addresses:
+            self.unprioritize(addr)
+            self.frozen_addresses.append(addr)
+            self.config.set_key('frozen_addresses', self.frozen_addresses, True)
+            return True
+        else:
+            return False
+
+    def unfreeze(self,addr):
+        if addr in self.all_addresses() and addr in self.frozen_addresses:
+            self.frozen_addresses.remove(addr)
+            self.config.set_key('frozen_addresses', self.frozen_addresses, True)
+            return True
+        else:
+            return False
+
+    def prioritize(self,addr):
+        if addr in self.all_addresses() and addr not in self.prioritized_addresses:
+            self.unfreeze(addr)
+            self.prioritized_addresses.append(addr)
+            self.config.set_key('prioritized_addresses', self.prioritized_addresses, True)
+            return True
+        else:
+            return False
+
+    def unprioritize(self,addr):
+        if addr in self.all_addresses() and addr in self.prioritized_addresses:
+            self.prioritized_addresses.remove(addr)
+            self.config.set_key('prioritized_addresses', self.prioritized_addresses, True)
+            return True
+        else:
+            return False
+
+    def save(self):
+        s = {
+            'seed_version': self.seed_version,
+            'use_encryption': self.use_encryption,
+            'use_change': self.use_change,
+            'master_public_key': self.master_public_key,
+            'fee': self.fee,
+            'seed': self.seed,
+            'addresses': self.addresses,
+            'change_addresses': self.change_addresses,
+            'history': self.history, 
+            'labels': self.labels,
+            'contacts': self.addressbook,
+            'imported_keys': self.imported_keys,
+            'aliases': self.aliases,
+            'authorities': self.authorities,
+            'receipts': self.receipts,
+            'num_zeros': self.num_zeros,
+            'frozen_addresses': self.frozen_addresses,
+            'prioritized_addresses': self.prioritized_addresses,
+            'gap_limit': self.gap_limit,
+        }
+        for k, v in s.items():
+            self.config.set_key(k,v)
+        self.config.save()
+
+
+
+
+
+
+class WalletSynchronizer(threading.Thread):
+
+
+    def __init__(self, wallet, config):
+        threading.Thread.__init__(self)
+        self.daemon = True
+        self.wallet = wallet
+        self.interface = self.wallet.interface
+        self.interface.register_channel('synchronizer')
+        self.wallet.interface.register_callback('connected', self.wallet.init_up_to_date)
+        self.wallet.interface.register_callback('connected', lambda: self.interface.send([('server.banner',[])],'synchronizer') )
+
+    def synchronize_wallet(self):
+        new_addresses = self.wallet.synchronize()
+        if new_addresses:
+            self.subscribe_to_addresses(new_addresses)
+            
+        if self.interface.is_up_to_date('synchronizer'):
+            if not self.wallet.up_to_date:
+                self.wallet.up_to_date = True
+                self.wallet.was_updated = True
+                self.wallet.up_to_date_event.set()
+        else:
+            if self.wallet.up_to_date:
+                self.wallet.up_to_date = False
+                self.wallet.was_updated = True
+
 
 
-    def start_session(self, interface):
-        self.interface = interface
-        self.interface.send([('server.banner',[]), ('blockchain.numblocks.subscribe',[]), ('server.peers.subscribe',[])])
-        self.interface.subscribe(self.all_addresses())
+    def subscribe_to_addresses(self, addresses):
+        messages = []
+        for addr in addresses:
+            messages.append(('blockchain.address.subscribe', [addr]))
+        self.interface.send( messages, 'synchronizer')
 
 
+    def run(self):
+
+        # wait until we are connected, in case the user is not connected
+        while not self.interface.is_connected:
+            time.sleep(1)
+        
+        # request banner, because 'connected' event happens before this thread is started
+        self.interface.send([('server.banner',[])],'synchronizer')
+
+        # subscriptions
+        self.interface.send([('blockchain.numblocks.subscribe',[])], 'synchronizer')
+        self.interface.send([('server.peers.subscribe',[])],'synchronizer')
+        self.subscribe_to_addresses(self.wallet.all_addresses())
+
+        while True:
+            # 1. send new requests
+            self.synchronize_wallet()
+
+            if self.wallet.was_updated:
+                self.interface.trigger_callback('updated')
+                self.wallet.was_updated = False
+
+            # 2. get a response
+            r = self.interface.get_response('synchronizer')
+            if not r: continue
+
+            # 3. handle response
+            method = r['method']
+            params = r['params']
+            result = r['result']
+
+            if method == 'blockchain.address.subscribe':
+                addr = params[0]
+                if self.wallet.get_status(addr) != result:
+                    self.interface.send([('blockchain.address.get_history', [address] )])
+                            
+            elif method == 'blockchain.address.get_history':
+                addr = params[0]
+                self.wallet.receive_history_callback(addr, result)
+                self.wallet.was_updated = True
+
+            elif method == 'blockchain.transaction.broadcast':
+                self.wallet.tx_result = result
+                self.wallet.tx_event.set()
+
+            elif method == 'blockchain.numblocks.subscribe':
+                self.wallet.blocks = result
+                self.wallet.was_updated = True
+
+            elif method == 'server.version':
+                pass
+
+            elif method == 'server.peers.subscribe':
+                servers = []
+                for item in result:
+                    s = []
+                    host = item[1]
+                    ports = []
+                    version = None
+                    if len(item) > 2:
+                        for v in item[2]:
+                            if re.match("[stgh]\d+", v):
+                                ports.append((v[0], v[1:]))
+                            if re.match("v(.?)+", v):
+                                version = v[1:]
+                    if ports and version:
+                        servers.append((host, ports))
+                self.interface.servers = servers
+                self.interface.trigger_callback('peers')
+
+            elif method == 'server.banner':
+                self.wallet.banner = result
+                self.wallet.was_updated = True
+
+            else:
+                print_error("Error: Unknown message:" + method + ", " + repr(params) + ", " + repr(result) )
+
+            if self.wallet.was_updated:
+                self.interface.trigger_callback('updated')
+                self.wallet.was_updated = False