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       tupdate bip32 derivations, using xpriv and xpub serialization format - electrum - Electrum Bitcoin wallet
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       ---
   DIR commit 328432f5f45ea12a22037adff133cb253c678896
   DIR parent 33b94cd60e5951aeffd0a51e004d3626d9d9a882
  HTML Author: ThomasV <thomasv@gitorious>
       Date:   Mon, 31 Mar 2014 12:00:57 +0200
       
       update bip32 derivations, using xpriv and xpub serialization format
       
       Diffstat:
         M lib/bitcoin.py                      |     172 ++++++++++++++++++-------------
       
       1 file changed, 99 insertions(+), 73 deletions(-)
       ---
   DIR diff --git a/lib/bitcoin.py b/lib/bitcoin.py
       t@@ -452,10 +452,7 @@ class EC_KEY(object):
                str_to_long = string_to_number
        
                P = generator
       -        if len(pubkey)==33: #compressed
       -            pk = Point( curve_secp256k1, str_to_long(pubkey[1:33]), ECC_YfromX(str_to_long(pubkey[1:33]), curve_secp256k1, pubkey[0]=='\x03')[0], _r )
       -        else:
       -            pk = Point( curve_secp256k1, str_to_long(pubkey[1:33]), str_to_long(pubkey[33:65]), _r )
       +        pk = ser_to_point(pubkey)
        
                for i in range(len(msgs)):
                    n = ecdsa.util.randrange( pow(2,256) )
       t@@ -524,17 +521,6 @@ class EC_KEY(object):
        random_seed = lambda n: "%032x"%ecdsa.util.randrange( pow(2,n) )
        BIP32_PRIME = 0x80000000
        
       -def bip32_init(seed):
       -    import hmac
       -    seed = seed.decode('hex')        
       -    I = hmac.new("Bitcoin seed", seed, hashlib.sha512).digest()
       -
       -    master_secret = I[0:32]
       -    master_chain = I[32:]
       -
       -    K, K_compressed = get_pubkeys_from_secret(master_secret)
       -    return master_secret, master_chain, K, K_compressed
       -
        
        def get_pubkeys_from_secret(secret):
            # public key
       t@@ -545,7 +531,6 @@ def get_pubkeys_from_secret(secret):
            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)
       t@@ -554,7 +539,7 @@ def get_pubkeys_from_secret(secret):
        #  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(k, c, n):
       +def CKD_priv(k, c, n):
            import hmac
            from ecdsa.util import string_to_number, number_to_string
            order = generator_secp256k1.order()
       t@@ -577,54 +562,107 @@ def CKD(k, c, n):
        # 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_prime(K, c, n):
       +def CKD_pub(cK, c, n):
            import hmac
            from ecdsa.util import string_to_number, number_to_string
            order = generator_secp256k1.order()
       -
            if n & BIP32_PRIME: raise
       -
       -    K_public_key = ecdsa.VerifyingKey.from_string( K, curve = SECP256k1 )
       -    K_compressed = GetPubKey(K_public_key.pubkey,True)
       -
       -    I = hmac.new(c, K_compressed + rev_hex(int_to_hex(n,4)).decode('hex'), hashlib.sha512).digest()
       -
       +    I = hmac.new(c, cK + rev_hex(int_to_hex(n,4)).decode('hex'), hashlib.sha512).digest()
            curve = SECP256k1
       -    pubkey_point = string_to_number(I[0:32])*curve.generator + K_public_key.pubkey.point
       +    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 )
       -
       -    K_n = public_key.to_string()
       -    K_n_compressed = GetPubKey(public_key.pubkey,True)
            c_n = I[32:]
       +    cK_n = GetPubKey(public_key.pubkey,True)
       +
       +    return cK_n, c_n
       +
       +
       +def parse_xprv(xprv):
       +    xprv = DecodeBase58Check( xprv )
       +    assert len(xprv) == 78
       +    assert xprv[0:4] == "0488ADE4".decode('hex')
       +    depth = ord(xprv[4])
       +    fingerprint = xprv[5:9]
       +    child_number = xprv[9:13]
       +    c = xprv[13:13+32]
       +    k = xprv[13+33:]
       +    K, cK = get_pubkeys_from_secret(k)
       +    key_id = hash_160(cK)
       +    print "keyid", key_id.encode('hex')
       +    print "address", hash_160_to_bc_address(key_id)
       +    print "secret key", SecretToASecret(k, True)
       +
        
       -    return K_n, K_n_compressed, c_n
       +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(k, c, branch, sequence):
       +def bip32_private_derivation(xprv, branch, sequence):
       +    xprv = DecodeBase58Check( xprv ) 
       +    assert len(xprv) == 78
       +    assert xprv[0:4] == "0488ADE4".decode('hex')
            assert sequence.startswith(branch)
       +    depth = ord(xprv[4])
       +    fingerprint = xprv[5:9]
       +    child_number = xprv[9:13]
       +    c = xprv[13:13+32]
       +    k = xprv[13+33:]
            sequence = sequence[len(branch):]
            for n in sequence.split('/'):
                if n == '': continue
       -        n = int(n[:-1]) + BIP32_PRIME if n[-1] == "'" else int(n)
       -        k, c = CKD(k, c, n)
       -    K, K_compressed = get_pubkeys_from_secret(k)
       -    return k.encode('hex'), c.encode('hex'), K.encode('hex'), K_compressed.encode('hex')
       +        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(c, K, branch, sequence):
       +
       +def bip32_public_derivation(xpub, branch, sequence):
       +    xpub = DecodeBase58Check( xpub ) 
       +    assert len(xpub) == 78
       +    assert xpub[0:4] == "0488B21E".decode('hex')
            assert sequence.startswith(branch)
       +    depth = ord(xpub[4])
       +    fingerprint = xpub[5:9]
       +    child_number = xpub[9:13]
       +    c = xpub[13:13+32]
       +    cK = xpub[13+32:]
            sequence = sequence[len(branch):]
            for n in sequence.split('/'):
       -        n = int(n)
       -        K, cK, c = CKD_prime(K, c, n)
       +        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)
       +
        
       -    return c.encode('hex'), K.encode('hex'), cK.encode('hex')
        
        
        def bip32_private_key(sequence, k, chain):
            for i in sequence:
       -        k, chain = CKD(k, chain, i)
       +        k, chain = CKD_priv(k, chain, i)
            return SecretToASecret(k, True)
        
        
       t@@ -642,41 +680,28 @@ def test_bip32(seed, sequence):
            see https://en.bitcoin.it/wiki/BIP_0032_TestVectors
            """
        
       -    master_secret, master_chain, master_public_key, master_public_key_compressed = bip32_init(seed)
       -        
       -    print "secret key", master_secret.encode('hex')
       -    print "chain code", master_chain.encode('hex')
       -
       -    key_id = hash_160(master_public_key_compressed)
       -    print "keyid", key_id.encode('hex')
       -    print "base58"
       -    print "address", hash_160_to_bc_address(key_id)
       -    print "secret key", SecretToASecret(master_secret, True)
       +    xprv, xpub = bip32_root(seed)
       +    print xpub
       +    print xprv
       +    #parse_xprv(xprv)
        
       -    k = master_secret
       -    c = master_chain
       -
       -    s = ['m']
       +    assert sequence[0:2] == "m/"
       +    path = 'm'
       +    sequence = sequence[2:]
            for n in sequence.split('/'):
       -        s.append(n)
       -        print "Chain [%s]" % '/'.join(s)
       +        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
                
       -        n = int(n[:-1]) + BIP32_PRIME if n[-1] == "'" else int(n)
       -        k0, c0 = CKD(k, c, n)
       -        K0, K0_compressed = get_pubkeys_from_secret(k0)
       -
       -        print "* Identifier"
       -        print "  * (main addr)", hash_160_to_bc_address(hash_160(K0_compressed))
        
       -        print "* Secret Key"
       -        print "  * (hex)", k0.encode('hex')
       -        print "  * (wif)", SecretToASecret(k0, True)
       +        path = child_path
       +        print path
       +        print xpub
       +        print xprv
        
       -        print "* Chain Code"
       -        print "   * (hex)", c0.encode('hex')
       -
       -        k = k0
       -        c = c0
            print "----"
        
                
       t@@ -709,7 +734,8 @@ def test_crypto():
        
        
        if __name__ == '__main__':
       -    test_crypto()
       -    #test_bip32("000102030405060708090a0b0c0d0e0f", "0'/1/2'/2/1000000000")
       -    #test_bip32("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542","0/2147483647'/1/2147483646'/2")
       +    #test_crypto()
       +    test_bip32("000102030405060708090a0b0c0d0e0f", "m/0'/1/2'/2/1000000000")
       +    test_bip32("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542","m/0/2147483647'/1/2147483646'/2")
       +