@@@ tvec doc wip

[mLib] / hash / t / unihash-testgen

#! /usr/bin/python
### -*-python-*-
###
### Generate test vectors for universal hashing.

import sys as SYS
if SYS.version_info >= (3,): xrange = range

MOD = 0x104c11db7

def gfmul(x, y):
  a = 0
  while y > 0:
    if y & 1: a ^= x
    if x & 0x80000000: x = (x << 1) ^ MOD
    else: x <<= 1
    y >>= 1
  return a

def hashtest(k, m):
  h = k
  for ch in m: h = gfmul(h ^ ord(ch), k)
  print('')
  print('k = 0x%08x' % k)
  print('m = "%s"' % m)
  print('h = 0x%08x' % h)

print('''\
;;; -*-conf-*- Test vectors for universal hashing
;;;   [generated]

[unihash]''')

for k, m in [(0x00000000, 'anything you like'),
             (0x12345678, 'an exaple test string'),
             (0xb8a171f0, 'The quick brown fox jumps over the lazy dog.'),
             (0xcc825ed5, 'Jackdaws love my big sphinx of quartz.'),
             (0x16e98e46, 'Waltz, bad nymph, for quick jigs vex!'),
             (0x2940521b, 'A man, a plan, a canal: Panama!')]:
  hashtest(k, m)

k, m = 0x94b22a73, 0xbb7b1fef
for i in xrange(48):
  hashtest(k, "If we don't succeed, we run the risk of failure.")
  k = gfmul(k, m)