/* Verify a passphrase.

   Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or

   modify it under the terms of the GNU General Public License

   as published by the Free Software Foundation; either version 2

   of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, if not, see <http://www.gnu.org/licenses/>.

*/

#include <stdio.h>

#include <string.h>

#include <unistd.h>

#include <crypt.h>

/* @samp{GNU's Not Unix} hashed using SHA-256, MD5, and DES.  */

static const char hash_sha[] =

  "$5$DQ2z5NHf1jNJnChB$kV3ZTR0aUaosujPhLzR84Llo3BsspNSe4/tsp7VoEn6";

static const char hash_md5[] = "$1$A3TxDv41$rtXVTUXl2LkeSV0UU5xxs1";

static const char hash_des[] = "FgkTuF98w5DaI";

int

main(void)

{

  char *phrase;

  int status = 0;

  /* Prompt for a passphrase.  */

  phrase = getpass ("Enter passphrase: ");

  /* Compare against the stored hashes.  Any input that begins with

     @samp{GNU's No} will match the DES hash, but the other two will

     only match @samp{GNU's Not Unix}.  */

  if (strcmp (crypt (phrase, hash_sha), hash_sha))

    {

      puts ("SHA: not ok");

      status = 1;

    }

  else

    puts ("SHA: ok");

  if (strcmp (crypt (phrase, hash_md5), hash_md5))

    {

      puts ("MD5: not ok");

      status = 1;

    }

  else

    puts ("MD5: ok");

  if (strcmp (crypt (phrase, hash_des), hash_des))

    {

      puts ("DES: not ok");

      status = 1;

    }

  else

    puts ("DES: ok");

  return status;

}