mission009.py

#!/usr/bin/env python
import string

def srand(s):
  global seed
  seed = s

# microsoft c runtime implementation
def rand():
  global seed
  seed = (seed * 214013 + 2531011) % 2**64

  return (seed >> 16)&0x7fff

def xor(key, val):
    return ''.join(chr(ord(a) ^ ord(b)) for a,b in zip(key,val))

enc = "\x9a\x60\x76\x14\x8b\x36\x5a\x10\x2b\x91\xc4\x6c\xab\x27\x92\x99\xf8\x6a\xec\x5d\x32\x20\x3d\x61\x8f\xc7\xfb\xdd\x02\x72\xbf";

# epoch for 2017-07-18 to 2017-07-20
for k in xrange(1500336000, 1500508800):
  key = ""
  srand(k)

  for i in range(len(enc)):
    r = rand()
    key += chr((r - (0x7F807F81 * r >> 39) - (r >> 31))&0xff)

  plain = xor(key, enc)

  if  all(c in string.printable for c in plain):
    print "Message: %s"%plain
    print "Seed time: %d"%k
    print "Key: %s"%key.encode("hex")
    break