mdw@git.distorted.org.uk Git - mLib/blob - hash/t/unihash-testgen.py

   1 #! /usr/bin/python
   2 ### -*-python-*-
   3 ###
   4 ### Generate test vectors for universal hashing.
   5
   6 import sys as SYS
   7 if SYS.version_info >= (3,): xrange = range
   8
   9 MOD = 0x104c11db7
  10
  11 def gfmul(x, y):
  12   a = 0
  13   while y > 0:
  14     if y & 1: a ^= x
  15     if x & 0x80000000: x = (x << 1) ^ MOD
  16     else: x <<= 1
  17     y >>= 1
  18   return a
  19
  20 def hashtest(k, m):
  21   h = k
  22   for ch in m: h = gfmul(h ^ ord(ch), k)
  23   print('')
  24   print('k = 0x%08x' % k)
  25   print('m = "%s"' % m)
  26   print('h = 0x%08x' % h)
  27
  28 print('''\
  29 ;;; -*-conf-*- Test vectors for universal hashing
  30 ;;;   [generated]
  31
  32 [unihash]''')
  33
  34 for k, m in [(0x00000000, 'anything you like'),
  35              (0x12345678, 'an exaple test string'),
  36              (0xb8a171f0, 'The quick brown fox jumps over the lazy dog.'),
  37              (0xcc825ed5, 'Jackdaws love my big sphinx of quartz.'),
  38              (0x16e98e46, 'Waltz, bad nymph, for quick jigs vex!'),
  39              (0x2940521b, 'A man, a plan, a canal: Panama!')]:
  40   hashtest(k, m)
  41
  42 k, m = 0x94b22a73, 0xbb7b1fef
  43 for i in xrange(48):
  44   hashtest(k, "If we don't succeed, we run the risk of failure.")
  45   k = gfmul(k, m)