return error status for payment requests
[electrum-nvc.git] / lib / bitcoin.py
index eb20500..d7ed754 100644 (file)
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 #!/usr/bin/env python
 #
 # Electrum - lightweight Bitcoin client
 
 
 import hashlib, base64, ecdsa, re
+import hmac
+import aes
+from util import print_error
+
+# AES encryption
+EncodeAES = lambda secret, s: base64.b64encode(aes.encryptData(secret,s))
+DecodeAES = lambda secret, e: aes.decryptData(secret, base64.b64decode(e))
+
+def pw_encode(s, password):
+    if password:
+        secret = Hash(password)
+        return EncodeAES(secret, s.encode("utf8"))
+    else:
+        return s
+
+def pw_decode(s, password):
+    if password is not None:
+        secret = Hash(password)
+        try:
+            d = DecodeAES(secret, s).decode("utf8")
+        except Exception:
+            raise Exception('Invalid password')
+        return d
+    else:
+        return s
+
+
+
 
 
 def rev_hex(s):
@@ -29,6 +58,7 @@ def int_to_hex(i, length=1):
     return rev_hex(s)
 
 def var_int(i):
+    # https://en.bitcoin.it/wiki/Protocol_specification#Variable_length_integer
     if i<0xfd:
         return int_to_hex(i)
     elif i<=0xffff:
@@ -38,10 +68,54 @@ def var_int(i):
     else:
         return "ff"+int_to_hex(i,8)
 
+def op_push(i):
+    if i<0x4c:
+        return int_to_hex(i)
+    elif i<0xff:
+        return '4c' + int_to_hex(i)
+    elif i<0xffff:
+        return '4d' + int_to_hex(i,2)
+    else:
+        return '4e' + int_to_hex(i,4)
+    
+
+
+def sha256(x):
+    return hashlib.sha256(x).digest()
+
+def Hash(x):
+    if type(x) is unicode: x=x.encode('utf-8')
+    return sha256(sha256(x))
 
-Hash = lambda x: hashlib.sha256(hashlib.sha256(x).digest()).digest()
 hash_encode = lambda x: x[::-1].encode('hex')
 hash_decode = lambda x: x.decode('hex')[::-1]
+hmac_sha_512 = lambda x,y: hmac.new(x, y, hashlib.sha512).digest()
+
+def mnemonic_to_seed(mnemonic, passphrase):
+    from pbkdf2 import PBKDF2
+    import hmac
+    PBKDF2_ROUNDS = 2048
+    return PBKDF2(mnemonic, 'mnemonic' + passphrase, iterations = PBKDF2_ROUNDS, macmodule = hmac, digestmodule = hashlib.sha512).read(64)
+
+from version import SEED_PREFIX
+is_new_seed = lambda x: hmac_sha_512("Seed version", x.encode('utf8')).encode('hex')[0:2].startswith(SEED_PREFIX)
+
+def is_old_seed(seed):
+    import mnemonic
+    words = seed.strip().split()
+    try:
+        mnemonic.mn_decode(words)
+        uses_electrum_words = True
+    except Exception:
+        uses_electrum_words = False
+
+    try:
+        seed.decode('hex')
+        is_hex = (len(seed) == 32)
+    except Exception:
+        is_hex = False
+         
+    return is_hex or (uses_electrum_words and len(words) == 12)
 
 
 # pywallet openssl private key implementation
@@ -69,22 +143,22 @@ def i2d_ECPrivateKey(pkey, compressed=False):
               '%064x' % _r + \
               '020101a144034200'
         
-    return key.decode('hex') + i2o_ECPublicKey(pkey, compressed)
+    return key.decode('hex') + i2o_ECPublicKey(pkey.pubkey, compressed)
     
-def i2o_ECPublicKey(pkey, compressed=False):
+def i2o_ECPublicKey(pubkey, compressed=False):
     # public keys are 65 bytes long (520 bits)
     # 0x04 + 32-byte X-coordinate + 32-byte Y-coordinate
     # 0x00 = point at infinity, 0x02 and 0x03 = compressed, 0x04 = uncompressed
     # compressed keys: <sign> <x> where <sign> is 0x02 if y is even and 0x03 if y is odd
     if compressed:
-        if pkey.pubkey.point.y() & 1:
-            key = '03' + '%064x' % pkey.pubkey.point.x()
+        if pubkey.point.y() & 1:
+            key = '03' + '%064x' % pubkey.point.x()
         else:
-            key = '02' + '%064x' % pkey.pubkey.point.x()
+            key = '02' + '%064x' % pubkey.point.x()
     else:
         key = '04' + \
-              '%064x' % pkey.pubkey.point.x() + \
-              '%064x' % pkey.pubkey.point.y()
+              '%064x' % pubkey.point.x() + \
+              '%064x' % pubkey.point.y()
             
     return key.decode('hex')
             
@@ -93,17 +167,15 @@ def i2o_ECPublicKey(pkey, compressed=False):
                                                 
             
 ############ functions from pywallet ##################### 
-            
-addrtype = 0
 
 def hash_160(public_key):
     try:
         md = hashlib.new('ripemd160')
-        md.update(hashlib.sha256(public_key).digest())
+        md.update(sha256(public_key))
         return md.digest()
-    except:
+    except Exception:
         import ripemd
-        md = ripemd.new(hashlib.sha256(public_key).digest())
+        md = ripemd.new(sha256(public_key))
         return md.digest()
 
 
@@ -111,7 +183,7 @@ 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):
+def hash_160_to_bc_address(h160, addrtype = 0):
     vh160 = chr(addrtype) + h160
     h = Hash(vh160)
     addr = vh160 + h[0:4]
@@ -119,17 +191,8 @@ def hash_160_to_bc_address(h160):
 
 def bc_address_to_hash_160(addr):
     bytes = b58decode(addr, 25)
-    return bytes[1:21]
+    return ord(bytes[0]), bytes[1:21]
 
-def encode_point(pubkey, compressed=False):
-    order = generator_secp256k1.order()
-    p = pubkey.pubkey.point
-    x_str = ecdsa.util.number_to_string(p.x(), order)
-    y_str = ecdsa.util.number_to_string(p.y(), order)
-    if compressed:
-        return chr(2 + (p.y() & 1)) + x_str
-    else:
-        return chr(4) + pubkey.to_string() #x_str + y_str
 
 __b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 __b58base = len(__b58chars)
@@ -200,12 +263,12 @@ def DecodeBase58Check(psz):
 def PrivKeyToSecret(privkey):
     return privkey[9:9+32]
 
-def SecretToASecret(secret, compressed=False):
+def SecretToASecret(secret, compressed=False, addrtype=0):
     vchIn = chr((addrtype+128)&255) + secret
     if compressed: vchIn += '\01'
     return EncodeBase58Check(vchIn)
 
-def ASecretToSecret(key):
+def ASecretToSecret(key, addrtype=0):
     vch = DecodeBase58Check(key)
     if vch and vch[0] == chr((addrtype+128)&255):
         return vch[1:]
@@ -217,11 +280,10 @@ def regenerate_key(sec):
     if not b:
         return False
     b = b[0:32]
-    secret = int('0x' + b.encode('hex'), 16)
-    return EC_KEY(secret)
+    return EC_KEY(b)
 
-def GetPubKey(pkey, compressed=False):
-    return i2o_ECPublicKey(pkey, compressed)
+def GetPubKey(pubkey, compressed=False):
+    return i2o_ECPublicKey(pubkey, compressed)
 
 def GetPrivKey(pkey, compressed=False):
     return i2d_ECPrivateKey(pkey, compressed)
@@ -233,67 +295,492 @@ def is_compressed(sec):
     b = ASecretToSecret(sec)
     return len(b) == 33
 
+
+def public_key_from_private_key(sec):
+    # rebuild public key from private key, compressed or uncompressed
+    pkey = regenerate_key(sec)
+    assert pkey
+    compressed = is_compressed(sec)
+    public_key = GetPubKey(pkey.pubkey, compressed)
+    return public_key.encode('hex')
+
+
+def address_from_private_key(sec):
+    public_key = public_key_from_private_key(sec)
+    address = public_key_to_bc_address(public_key.decode('hex'))
+    return address
+
+
+def is_valid(addr):
+    return is_address(addr)
+
+
+def is_address(addr):
+    ADDRESS_RE = re.compile('[1-9A-HJ-NP-Za-km-z]{26,}\\Z')
+    if not ADDRESS_RE.match(addr): return False
+    try:
+        addrtype, h = bc_address_to_hash_160(addr)
+    except Exception:
+        return False
+    return addr == hash_160_to_bc_address(h, addrtype)
+
+
+def is_private_key(key):
+    try:
+        k = ASecretToSecret(key) 
+        return k is not False
+    except:
+        return False
+
+
 ########### end pywallet functions #######################
 
-# 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 ) 
+try:
+    from ecdsa.ecdsa import curve_secp256k1, generator_secp256k1
+except Exception:
+    print "cannot import ecdsa.curve_secp256k1. You probably need to upgrade ecdsa.\nTry: sudo pip install --upgrade ecdsa"
+    exit()
+
+from ecdsa.curves import SECP256k1
+from ecdsa.ellipticcurve import Point
+from ecdsa.util import string_to_number, number_to_string
+
+def msg_magic(message):
+    varint = var_int(len(message))
+    encoded_varint = "".join([chr(int(varint[i:i+2], 16)) for i in xrange(0, len(varint), 2)])
+    return "\x18Bitcoin Signed Message:\n" + encoded_varint + message
+
+
+def verify_message(address, signature, message):
+    try:
+        EC_KEY.verify_message(address, signature, message)
+        return True
+    except Exception as e:
+        print_error("Verification error: {0}".format(e))
+        return False
+
+
+def encrypt_message(message, pubkey):
+    return EC_KEY.encrypt_message(message, pubkey.decode('hex'))
+
+
+def chunks(l, n):
+    return [l[i:i+n] for i in xrange(0, len(l), n)]
+
+
+def ECC_YfromX(x,curved=curve_secp256k1, odd=True):
+    _p = curved.p()
+    _a = curved.a()
+    _b = curved.b()
+    for offset in range(128):
+        Mx = x + offset
+        My2 = pow(Mx, 3, _p) + _a * pow(Mx, 2, _p) + _b % _p
+        My = pow(My2, (_p+1)/4, _p )
+
+        if curved.contains_point(Mx,My):
+            if odd == bool(My&1):
+                return [My,offset]
+            return [_p-My,offset]
+    raise Exception('ECC_YfromX: No Y found')
+
+def private_header(msg,v):
+    assert v<1, "Can't write version %d private header"%v
+    r = ''
+    if v==0:
+        r += ('%08x'%len(msg)).decode('hex')
+        r += sha256(msg)[:2]
+    return ('%02x'%v).decode('hex') + ('%04x'%len(r)).decode('hex') + r
+
+def public_header(pubkey,v):
+    assert v<1, "Can't write version %d public header"%v
+    r = ''
+    if v==0:
+        r = sha256(pubkey)[:2]
+    return '\x6a\x6a' + ('%02x'%v).decode('hex') + ('%04x'%len(r)).decode('hex') + r
+
+
+def negative_point(P):
+    return Point( P.curve(), P.x(), -P.y(), P.order() )
+
+
+def point_to_ser(P, comp=True ):
+    if comp:
+        return ( ('%02x'%(2+(P.y()&1)))+('%064x'%P.x()) ).decode('hex')
+    return ( '04'+('%064x'%P.x())+('%064x'%P.y()) ).decode('hex')
+
+
+def ser_to_point(Aser):
+    curve = curve_secp256k1
+    generator = generator_secp256k1
+    _r  = generator.order()
+    assert Aser[0] in ['\x02','\x03','\x04']
+    if Aser[0] == '\x04':
+        return Point( curve, str_to_long(Aser[1:33]), str_to_long(Aser[33:]), _r )
+    Mx = string_to_number(Aser[1:])
+    return Point( curve, Mx, ECC_YfromX(Mx, curve, Aser[0]=='\x03')[0], _r )
+
+
 
 class EC_KEY(object):
-    def __init__( self, secret ):
+    def __init__( self, k ):
+        secret = string_to_number(k)
         self.pubkey = ecdsa.ecdsa.Public_key( generator_secp256k1, generator_secp256k1 * secret )
         self.privkey = ecdsa.ecdsa.Private_key( self.pubkey, secret )
         self.secret = secret
+
+    def get_public_key(self, compressed=True):
+        return point_to_ser(self.pubkey.point, compressed).encode('hex')
+
+    def sign_message(self, message, compressed, address):
+        private_key = ecdsa.SigningKey.from_secret_exponent( self.secret, curve = SECP256k1 )
+        public_key = private_key.get_verifying_key()
+        signature = private_key.sign_digest_deterministic( Hash( msg_magic(message) ), hashfunc=hashlib.sha256, sigencode = ecdsa.util.sigencode_string )
+        assert public_key.verify_digest( signature, Hash( msg_magic(message) ), sigdecode = ecdsa.util.sigdecode_string)
+        for i in range(4):
+            sig = base64.b64encode( chr(27 + i + (4 if compressed else 0)) + signature )
+            try:
+                self.verify_message( address, sig, message)
+                return sig
+            except Exception:
+                continue
+        else:
+            raise Exception("error: cannot sign message")
+
+
+    @classmethod
+    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, util
+        import msqr
+        curve = curve_secp256k1
+        G = generator_secp256k1
+        order = G.order()
+        # extract r,s from signature
+        sig = base64.b64decode(signature)
+        if len(sig) != 65: raise Exception("Wrong encoding")
+        r,s = util.sigdecode_string(sig[1:], order)
+        nV = ord(sig[0])
+        if nV < 27 or nV >= 35:
+            raise Exception("Bad encoding")
+        if nV >= 31:
+            compressed = True
+            nV -= 4
+        else:
+            compressed = False
+
+        recid = nV - 27
+        # 1.1
+        x = r + (recid/2) * order
+        # 1.3
+        alpha = ( x * x * x  + curve.a() * x + curve.b() ) % curve.p()
+        beta = msqr.modular_sqrt(alpha, curve.p())
+        y = beta if (beta - recid) % 2 == 0 else curve.p() - beta
+        # 1.4 the constructor checks that nR is at infinity
+        R = Point(curve, x, y, order)
+        # 1.5 compute e from message:
+        h = Hash( msg_magic(message) )
+        e = string_to_number(h)
+        minus_e = -e % order
+        # 1.6 compute Q = r^-1 (sR - eG)
+        inv_r = numbertheory.inverse_mod(r,order)
+        Q = inv_r * ( s * R + minus_e * G )
+        public_key = ecdsa.VerifyingKey.from_public_point( Q, curve = SECP256k1 )
+        # 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( point_to_ser(public_key.pubkey.point, compressed) )
+        if address != addr:
+            raise Exception("Bad signature")
+
+
+    # ecdsa encryption/decryption methods
+    # credits: jackjack, https://github.com/jackjack-jj/jeeq
+
+    @classmethod
+    def encrypt_message(self, message, pubkey):
+        generator = generator_secp256k1
+        curved = curve_secp256k1
+        r = ''
+        msg = private_header(message,0) + message
+        msg = msg + ('\x00'*( 32-(len(msg)%32) ))
+        msgs = chunks(msg,32)
+
+        _r  = generator.order()
+        str_to_long = string_to_number
+
+        P = generator
+        pk = ser_to_point(pubkey)
+
+        for i in range(len(msgs)):
+            n = ecdsa.util.randrange( pow(2,256) )
+            Mx = str_to_long(msgs[i])
+            My, xoffset = ECC_YfromX(Mx, curved)
+            M = Point( curved, Mx+xoffset, My, _r )
+            T = P*n
+            U = pk*n + M
+            toadd = point_to_ser(T) + point_to_ser(U)
+            toadd = chr(ord(toadd[0])-2 + 2*xoffset) + toadd[1:]
+            r += toadd
+
+        return base64.b64encode(public_header(pubkey,0) + r)
+
+
+    def decrypt_message(self, enc):
+        G = generator_secp256k1
+        curved = curve_secp256k1
+        pvk = self.secret
+        pubkeys = [point_to_ser(G*pvk,True), point_to_ser(G*pvk,False)]
+        enc = base64.b64decode(enc)
+        str_to_long = string_to_number
+
+        assert enc[:2]=='\x6a\x6a'
+
+        phv = str_to_long(enc[2])
+        assert phv==0, "Can't read version %d public header"%phv
+        hs = str_to_long(enc[3:5])
+        public_header=enc[5:5+hs]
+        checksum_pubkey=public_header[:2]
+        address=filter(lambda x:sha256(x)[:2]==checksum_pubkey, pubkeys)
+        assert len(address)>0, 'Bad private key'
+        address=address[0]
+        enc=enc[5+hs:]
+        r = ''
+        for Tser,User in map(lambda x:[x[:33],x[33:]], chunks(enc,66)):
+            ots = ord(Tser[0])
+            xoffset = ots>>1
+            Tser = chr(2+(ots&1))+Tser[1:]
+            T = ser_to_point(Tser)
+            U = ser_to_point(User)
+            V = T*pvk
+            Mcalc = U + negative_point(V)
+            r += ('%064x'%(Mcalc.x()-xoffset)).decode('hex')
+
+        pvhv = str_to_long(r[0])
+        assert pvhv==0, "Can't read version %d private header"%pvhv
+        phs = str_to_long(r[1:3])
+        private_header = r[3:3+phs]
+        size = str_to_long(private_header[:4])
+        checksum = private_header[4:6]
+        r = r[3+phs:]
+
+        msg = r[:size]
+        hashmsg = sha256(msg)[:2]
+        checksumok = hashmsg==checksum
+
+        return [msg, checksumok, address]
+
+
+
+
+
+###################################### BIP32 ##############################
+
+random_seed = lambda n: "%032x"%ecdsa.util.randrange( pow(2,n) )
+BIP32_PRIME = 0x80000000
+
+
+def get_pubkeys_from_secret(secret):
+    # public key
+    private_key = ecdsa.SigningKey.from_string( secret, curve = SECP256k1 )
+    public_key = private_key.get_verifying_key()
+    K = public_key.to_string()
+    K_compressed = GetPubKey(public_key.pubkey,True)
+    return K, K_compressed
+
+
+# Child private key derivation function (from master private key)
+# k = master private key (32 bytes)
+# c = master chain code (extra entropy for key derivation) (32 bytes)
+# n = the index of the key we want to derive. (only 32 bits will be used)
+# If n is negative (i.e. the 32nd bit is set), the resulting private key's
+#  corresponding public key can NOT be determined without the master private key.
+# However, if n is positive, the resulting private key's corresponding
+#  public key can be determined without the master private key.
+def CKD_priv(k, c, n):
+    is_prime = n & BIP32_PRIME
+    return _CKD_priv(k, c, rev_hex(int_to_hex(n,4)).decode('hex'), is_prime)
+
+def _CKD_priv(k, c, s, is_prime):
+    import hmac
+    from ecdsa.util import string_to_number, number_to_string
+    order = generator_secp256k1.order()
+    keypair = EC_KEY(k)
+    cK = GetPubKey(keypair.pubkey,True)
+    data = chr(0) + k + s if is_prime else cK + s
+    I = hmac.new(c, data, hashlib.sha512).digest()
+    k_n = number_to_string( (string_to_number(I[0:32]) + string_to_number(k)) % order , order )
+    c_n = I[32:]
+    return k_n, c_n
+
+# Child public key derivation function (from public key only)
+# K = master public key 
+# c = master chain code
+# n = index of key we want to derive
+# This function allows us to find the nth public key, as long as n is 
+#  non-negative. If n is negative, we need the master private key to find it.
+def CKD_pub(cK, c, n):
+    if n & BIP32_PRIME: raise
+    return _CKD_pub(cK, c, rev_hex(int_to_hex(n,4)).decode('hex'))
+
+# helper function, callable with arbitrary string
+def _CKD_pub(cK, c, s):
+    import hmac
+    from ecdsa.util import string_to_number, number_to_string
+    order = generator_secp256k1.order()
+    I = hmac.new(c, cK + s, hashlib.sha512).digest()
+    curve = SECP256k1
+    pubkey_point = string_to_number(I[0:32])*curve.generator + ser_to_point(cK)
+    public_key = ecdsa.VerifyingKey.from_public_point( pubkey_point, curve = SECP256k1 )
+    c_n = I[32:]
+    cK_n = GetPubKey(public_key.pubkey,True)
+    return cK_n, c_n
+
+
+
+def deserialize_xkey(xkey):
+    xkey = DecodeBase58Check(xkey) 
+    assert len(xkey) == 78
+    assert xkey[0:4].encode('hex') in ["0488ade4", "0488b21e"]
+    depth = ord(xkey[4])
+    fingerprint = xkey[5:9]
+    child_number = xkey[9:13]
+    c = xkey[13:13+32]
+    if xkey[0:4].encode('hex') == "0488ade4":
+        K_or_k = xkey[13+33:]
+    else:
+        K_or_k = xkey[13+32:]
+    return depth, fingerprint, child_number, c, K_or_k
+
+
+
+def bip32_root(seed):
+    import hmac
+    seed = seed.decode('hex')        
+    I = hmac.new("Bitcoin seed", seed, hashlib.sha512).digest()
+    master_k = I[0:32]
+    master_c = I[32:]
+    K, cK = get_pubkeys_from_secret(master_k)
+    xprv = ("0488ADE4" + "00" + "00000000" + "00000000").decode("hex") + master_c + chr(0) + master_k
+    xpub = ("0488B21E" + "00" + "00000000" + "00000000").decode("hex") + master_c + cK
+    return EncodeBase58Check(xprv), EncodeBase58Check(xpub)
+
+
+
+def bip32_private_derivation(xprv, branch, sequence):
+    depth, fingerprint, child_number, c, k = deserialize_xkey(xprv)
+    assert sequence.startswith(branch)
+    sequence = sequence[len(branch):]
+    for n in sequence.split('/'):
+        if n == '': continue
+        i = int(n[:-1]) + BIP32_PRIME if n[-1] == "'" else int(n)
+        parent_k = k
+        k, c = CKD_priv(k, c, i)
+        depth += 1
+
+    _, parent_cK = get_pubkeys_from_secret(parent_k)
+    fingerprint = hash_160(parent_cK)[0:4]
+    child_number = ("%08X"%i).decode('hex')
+    K, cK = get_pubkeys_from_secret(k)
+    xprv = "0488ADE4".decode('hex') + chr(depth) + fingerprint + child_number + c + chr(0) + k
+    xpub = "0488B21E".decode('hex') + chr(depth) + fingerprint + child_number + c + cK
+    return EncodeBase58Check(xprv), EncodeBase58Check(xpub)
+
+
+
+def bip32_public_derivation(xpub, branch, sequence):
+    depth, fingerprint, child_number, c, cK = deserialize_xkey(xpub)
+    assert sequence.startswith(branch)
+    sequence = sequence[len(branch):]
+    for n in sequence.split('/'):
+        if n == '': continue
+        i = int(n)
+        parent_cK = cK
+        cK, c = CKD_pub(cK, c, i)
+        depth += 1
+
+    fingerprint = hash_160(parent_cK)[0:4]
+    child_number = ("%08X"%i).decode('hex')
+    xpub = "0488B21E".decode('hex') + chr(depth) + fingerprint + child_number + c + cK
+    return EncodeBase58Check(xpub)
+
+
+
+
+def bip32_private_key(sequence, k, chain):
+    for i in sequence:
+        k, chain = CKD_priv(k, chain, i)
+    return SecretToASecret(k, True)
+
+
+
+
+################################## transactions
+
+MIN_RELAY_TX_FEE = 1000
+
+
+
+def test_bip32(seed, sequence):
+    """
+    run a test vector,
+    see https://en.bitcoin.it/wiki/BIP_0032_TestVectors
+    """
+
+    xprv, xpub = bip32_root(seed)
+    print xpub
+    print xprv
+
+    assert sequence[0:2] == "m/"
+    path = 'm'
+    sequence = sequence[2:]
+    for n in sequence.split('/'):
+        child_path = path + '/' + n
+        if n[-1] != "'":
+            xpub2 = bip32_public_derivation(xpub, path, child_path)
+        xprv, xpub = bip32_private_derivation(xprv, path, child_path)
+        if n[-1] != "'":
+            assert xpub == xpub2
         
 
+        path = child_path
+        print path
+        print xpub
+        print xprv
 
-def filter(s): 
-    out = re.sub('( [^\n]*|)\n','',s)
-    out = out.replace(' ','')
-    out = out.replace('\n','')
-    return out
-
-# https://en.bitcoin.it/wiki/Protocol_specification#Variable_length_integer
-def raw_tx( inputs, outputs, for_sig = None ):
-    s  = int_to_hex(1,4)                                     +   '     version\n' 
-    s += var_int( 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'
-            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 += var_int( len(filter(script))/2 )                +  '     script length \n'
-        s += script
-        s += "ffffffff"                                      +  '     sequence\n'
-    s += var_int( 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 += var_int( 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
+    print "----"
+
+        
+
+def test_crypto():
+
+    G = generator_secp256k1
+    _r  = G.order()
+    pvk = ecdsa.util.randrange( pow(2,256) ) %_r
+
+    Pub = pvk*G
+    pubkey_c = point_to_ser(Pub,True)
+    pubkey_u = point_to_ser(Pub,False)
+    addr_c = public_key_to_bc_address(pubkey_c)
+    addr_u = public_key_to_bc_address(pubkey_u)
+
+    print "Private key            ", '%064x'%pvk
+    print "Compressed public key  ", pubkey_c.encode('hex')
+    print "Uncompressed public key", pubkey_u.encode('hex')
+
+    message = "Chancellor on brink of second bailout for banks"
+    enc = EC_KEY.encrypt_message(message,pubkey_c)
+    eck = EC_KEY(number_to_string(pvk,_r))
+    dec = eck.decrypt_message(enc)
+    print "decrypted", dec
+
+    signature = eck.sign_message(message, True, addr_c)
+    print signature
+    EC_KEY.verify_message(addr_c, signature, message)
+
+
+if __name__ == '__main__':
+    #test_crypto()
+    test_bip32("000102030405060708090a0b0c0d0e0f", "m/0'/1/2'/2/1000000000")
+    test_bip32("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542","m/0/2147483647'/1/2147483646'/2")