PyBitmessage/src/helper_bitcoin.py

57 lines
2.2 KiB
Python

"""
Calculates bitcoin and testnet address from pubkey
"""
import hashlib
from debug import logger
from pyelliptic import arithmetic
def calculateBitcoinAddressFromPubkey(pubkey):
"""Calculate bitcoin address from given pubkey (65 bytes long hex string)"""
if len(pubkey) != 65:
logger.error('Could not calculate Bitcoin address from pubkey because'
' function was passed a pubkey that was'
' %i bytes long rather than 65.', len(pubkey))
return "error"
ripe = hashlib.new('ripemd160')
sha = hashlib.new('sha256')
sha.update(pubkey)
ripe.update(sha.digest())
ripeWithProdnetPrefix = '\x00' + ripe.digest()
checksum = hashlib.sha256(hashlib.sha256(
ripeWithProdnetPrefix).digest()).digest()[:4]
binaryBitcoinAddress = ripeWithProdnetPrefix + checksum
numberOfZeroBytesOnBinaryBitcoinAddress = 0
while binaryBitcoinAddress[0] == '\x00':
numberOfZeroBytesOnBinaryBitcoinAddress += 1
binaryBitcoinAddress = binaryBitcoinAddress[1:]
base58encoded = arithmetic.changebase(binaryBitcoinAddress, 256, 58)
return "1" * numberOfZeroBytesOnBinaryBitcoinAddress + base58encoded
def calculateTestnetAddressFromPubkey(pubkey):
"""This function expects that pubkey begin with the testnet prefix"""
if len(pubkey) != 65:
logger.error('Could not calculate Bitcoin address from pubkey because'
' function was passed a pubkey that was'
' %i bytes long rather than 65.', len(pubkey))
return "error"
ripe = hashlib.new('ripemd160')
sha = hashlib.new('sha256')
sha.update(pubkey)
ripe.update(sha.digest())
ripeWithProdnetPrefix = '\x6F' + ripe.digest()
checksum = hashlib.sha256(hashlib.sha256(
ripeWithProdnetPrefix).digest()).digest()[:4]
binaryBitcoinAddress = ripeWithProdnetPrefix + checksum
numberOfZeroBytesOnBinaryBitcoinAddress = 0
while binaryBitcoinAddress[0] == '\x00':
numberOfZeroBytesOnBinaryBitcoinAddress += 1
binaryBitcoinAddress = binaryBitcoinAddress[1:]
base58encoded = arithmetic.changebase(binaryBitcoinAddress, 256, 58)
return "1" * numberOfZeroBytesOnBinaryBitcoinAddress + base58encoded