manual/examples/testpass.c

   1 /* Verify a passphrase.
   2    Copyright (C) 1991-2020 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU General Public License
   6    as published by the Free Software Foundation; either version 2
   7    of the License, or (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, see <https://www.gnu.org/licenses/>.
  16 */
  17
  18 #include <stdio.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <crypt.h>
  22
  23 /* @samp{GNU's Not Unix} hashed using SHA-256, MD5, and DES.  */
  24 static const char hash_sha[] =
  25   "$5$DQ2z5NHf1jNJnChB$kV3ZTR0aUaosujPhLzR84Llo3BsspNSe4/tsp7VoEn6";
  26 static const char hash_md5[] = "$1$A3TxDv41$rtXVTUXl2LkeSV0UU5xxs1";
  27 static const char hash_des[] = "FgkTuF98w5DaI";
  28
  29 int
  30 main(void)
  31 {
  32   char *phrase;
  33   int status = 0;
  34
  35   /* Prompt for a passphrase.  */
  36   phrase = getpass ("Enter passphrase: ");
  37
  38   /* Compare against the stored hashes.  Any input that begins with
  39      @samp{GNU's No} will match the DES hash, but the other two will
  40      only match @samp{GNU's Not Unix}.  */
  41
  42   if (strcmp (crypt (phrase, hash_sha), hash_sha))
  43     {
  44       puts ("SHA: not ok");
  45       status = 1;
  46     }
  47   else
  48     puts ("SHA: ok");
  49
  50   if (strcmp (crypt (phrase, hash_md5), hash_md5))
  51     {
  52       puts ("MD5: not ok");
  53       status = 1;
  54     }
  55   else
  56     puts ("MD5: ok");
  57
  58   if (strcmp (crypt (phrase, hash_des), hash_des))
  59     {
  60       puts ("DES: not ok");
  61       status = 1;
  62     }
  63   else
  64     puts ("DES: ok");
  65
  66   return status;
  67 }