HashCashExample.py

from hashlib import sha256, sha1
from uuid import uuid4
from os import urandom
from Crypto.Cipher import AES
from binascii import b2a_base64
from ctypes import c_int
import numpy as np

zero = np.uint32(0)
_joiner__ = ':'.encode()
class HashCashClient:
    ver = 1
    bits = 15
    date = b'YYMMDD'
    resource = b'test@localhost'
    extension = str().encode()
    rand = None
    counter = None
    solved = False
    def __init__(self):
        self.populate_counter()
        self.populate_rand()
    def get_str(self):
        return _joiner__.join([str(self.ver).encode(), 
                                    str(self.bits).encode(),
                                    self.date,
                                    self.resource,
                                    self.extension,
                                    self.rand, 
                                    str(self.counter).encode()])
    def populate_rand(self):
        self.rand = b2a_base64(urandom(20), newline=False)
    def populate_counter(self):
        self.counter = int.from_bytes(urandom(4), byteorder='big')
    def solve(self):
        str_repr = None
        count = 0
        while not self.solved:
            str_repr = self.get_str() 
            if np.right_shift(np.fromstring(sha1(str_repr).digest()[0:4], dtype='uint32')[0], 32-self.bits) == 0:
                self.solved = True
                print(count)
            else:
                self.counter += 1
            count += 1
        return str_repr
a = HashCashClient()
t = a.solve()
print(t)
def verify(s):
    dat = {k:v.decode() for k, v in zip(['ver', 'bits', 'date', 'resource', 'extension', 'rand', 'counter'],s.split(b":"))}
    bits = int(dat['bits'])
    return True if np.right_shift(np.fromstring(sha1(s).digest()[0:4], dtype='uint32'), 32-bits) == 0 else False

verify(t)