/*
 * Copyright (c) 2008 Sebastiaan Indesteege
 *                              <sebastiaan.indesteege@esat.kuleuven.be>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * Example collision pair for EnRUPT-256, using the defaults for the other
 * tunable parameters. This file should be linked with the reference
 * implementation of EnRUPT.
 *
 * 2008-11-06, Sebastiaan Indesteege, COSIC, Katholieke Universiteit Leuven
 */

#include "EnRUPT_ref.h"

#include <err.h>
#include <stdio.h>
#include <stdint.h>

#define HASHBITLEN 256
#define LEN 48*8

static const uint8_t m1[] = {
  0x13, 0xc8, 0x4b, 0x45, 0x62, 0x70, 0x17, 0x6e, 0x04, 0xf9, 0x31, 0x7e,
  0xc3, 0x6c, 0xe7, 0xd3, 0xe1, 0x21, 0x78, 0x6a, 0x34, 0x74, 0x11, 0x19,
  0x7f, 0x64, 0xa3, 0xc9, 0x40, 0x07, 0x75, 0x76, 0xa1, 0x4f, 0x90, 0x86,
  0xfd, 0xc7, 0x33, 0x4a, 0x41, 0x3a, 0x76, 0x91, 0x96, 0x06, 0x2c, 0xa1
};

static const uint8_t m2[] = {
  0x13, 0xc8, 0x4b, 0x45, 0x6a, 0x70, 0x17, 0x6e, 0x04, 0xf9, 0x31, 0x5c,
  0x43, 0x6c, 0xe7, 0xd3, 0xe1, 0x21, 0x78, 0x48, 0xbc, 0x74, 0x11, 0x19,
  0x7f, 0x64, 0xa3, 0xcb, 0x48, 0x07, 0x75, 0x76, 0xa1, 0x4f, 0x90, 0x84,
  0xfd, 0xc7, 0x33, 0x4a, 0x41, 0x3a, 0x76, 0x93, 0x96, 0x06, 0x2c, 0xa1
};

uint8_t h1[HASHBITLEN/8];
uint8_t h2[HASHBITLEN/8];

void printbytes(uint8_t const *p, int n)
{
  int i;
  for (i=0; i!=n; ++i)
    printf("%02x", p[i]);
  printf("\n");
}

int main()
{
  int i;

  printf("Example collision pair for EnRUPT-256\n");
  printf("2008-11-06, Sebastiaan Indesteege, COSIC, Katholieke Universiteit Leuven\n\n");

  /* Hash first mesage */
  if (Hash(HASHBITLEN, m1, LEN, h1) != SUCCESS)
    errx(1, "Hashing failed!");
  printf("m1 = ");
  printbytes(m1, LEN/8);
  printf("EnRUPT-256(m1) = ");
  printbytes(h1, HASHBITLEN/8);
  printf("\n");

  /* Hash second mesage */
  if (Hash(HASHBITLEN, m2, LEN, h2) != SUCCESS)
    errx(1, "Hashing failed!");
  printf("m2 = ");
  printbytes(m2, LEN/8);
  printf("EnRUPT-256(m2) = ");
  printbytes(h2, HASHBITLEN/8);
  printf("\n");

  /* Verify collision */
  for (i=0; i!=32; ++i) {
    if (h1[i] != h2[i]) {
      printf("ERROR: m1 and m2 do NOT collide\n");
      return 1;
    }
  }
  printf("m1 and m2 collide!\n\n");

  return 0;
}