import random
import os
from Crypto.Util import number

random.seed(os.getpid())

def randfunction(N):
    # N is in bytes
    # pycrypto expects a string
    l = []
    while N > 0:
        l.append(chr(random.getrandbits(8)))
        N -= 1
    return "".join(l)

p = number.getPrime(512, randfunction)
q = number.getPrime(512, randfunction)
n = p*q