1  """
 2  Calculates bitcoin and testnet address from pubkey
 3  """
 4  
 5  import hashlib
 6  
 7  from debug import logger
 8  from pyelliptic import arithmetic
 9  
10  
11  def calculateBitcoinAddressFromPubkey(pubkey):
12      """Calculate bitcoin address from given pubkey (65 bytes long hex string)"""
13      if len(pubkey) != 65:
14          logger.error('Could not calculate Bitcoin address from pubkey because'
15                       ' function was passed a pubkey that was'
16                       ' %i bytes long rather than 65.', len(pubkey))
17          return "error"
18      ripe = hashlib.new('ripemd160')
19      sha = hashlib.new('sha256')
20      sha.update(pubkey)
21      ripe.update(sha.digest())
22      ripeWithProdnetPrefix = '\x00' + ripe.digest()
23  
24      checksum = hashlib.sha256(hashlib.sha256(
25          ripeWithProdnetPrefix).digest()).digest()[:4]
26      binaryBitcoinAddress = ripeWithProdnetPrefix + checksum
27      numberOfZeroBytesOnBinaryBitcoinAddress = 0
28      while binaryBitcoinAddress[0] == '\x00':
29          numberOfZeroBytesOnBinaryBitcoinAddress += 1
30          binaryBitcoinAddress = binaryBitcoinAddress[1:]
31      base58encoded = arithmetic.changebase(binaryBitcoinAddress, 256, 58)
32      return "1" * numberOfZeroBytesOnBinaryBitcoinAddress + base58encoded
33  
34  
35  def calculateTestnetAddressFromPubkey(pubkey):
36      """This function expects that pubkey begin with the testnet prefix"""
37      if len(pubkey) != 65:
38          logger.error('Could not calculate Bitcoin address from pubkey because'
39                       ' function was passed a pubkey that was'
40                       ' %i bytes long rather than 65.', len(pubkey))
41          return "error"
42      ripe = hashlib.new('ripemd160')
43      sha = hashlib.new('sha256')
44      sha.update(pubkey)
45      ripe.update(sha.digest())
46      ripeWithProdnetPrefix = '\x6F' + ripe.digest()
47  
48      checksum = hashlib.sha256(hashlib.sha256(
49          ripeWithProdnetPrefix).digest()).digest()[:4]
50      binaryBitcoinAddress = ripeWithProdnetPrefix + checksum
51      numberOfZeroBytesOnBinaryBitcoinAddress = 0
52      while binaryBitcoinAddress[0] == '\x00':
53          numberOfZeroBytesOnBinaryBitcoinAddress += 1
54          binaryBitcoinAddress = binaryBitcoinAddress[1:]
55      base58encoded = arithmetic.changebase(binaryBitcoinAddress, 256, 58)
56      return "1" * numberOfZeroBytesOnBinaryBitcoinAddress + base58encoded