srand.py

import time,sys,math
from ctypes import c_int, c_uint
from ctypes import CDLL
# http://www.mscs.dal.ca/~selinger/random/
#implement glibc rand function
libc = CDLL('libc.so.6') # or just use libc :))
def srand(seed):
    srand.r = [0 for _ in range(34)]
    srand.r[0] = c_int(seed).value
    for i in range(1, 31):
        srand.r[i] = (16807 * srand.r[i - 1]) % 2147483647
    for i in range(31, 34):
        srand.r[i] = srand.r[i - 31]
    srand.k = 0
    for _ in range(34, 344):
        rand()


def rand():
    srand.r[srand.k] = srand.r[(srand.k - 31) % 34] + srand.r[(srand.k - 3) % 34]
    r = c_uint(srand.r[srand.k]).value >> 1
    srand.k = (srand.k + 1) % 34
    return r

def search(b):
	now = int(math.floor(time.time()))
	for i in range(-256,256):
		srand(now+i)
		# libc.srand(now+i)
		for x in range(256):
			k = rand()
			# k = libc.rand()
			if k==b:
				return now+i
if __name__ == '__main__':
	print (search(eval(sys.argv[1])))