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('  0x%08x "%s" 0x%08x;' % (k, m, h))
  24
  25 print('''\
  26 ### Test vectors for universal hashing
  27 ###   [generated]
  28
  29 hash {''')
  30
  31 for k, m in [(0x00000000, 'anything you like'),
  32              (0x12345678, 'an exaple test string'),
  33              (0xb8a171f0, 'The quick brown fox jumps over the lazy dog.'),
  34              (0x2940521b, 'A man, a plan, a canal: Panama!')]:
  35   hashtest(k, m)
  36
  37 k, m = 0x94b22a73, 0xbb7b1fef
  38 for i in xrange(48):
  39   hashtest(k, "If we don't succeed, we run the risk of failure.")
  40   k = gfmul(k, m)
  41
  42 print('}')