1  /*
       2   * Copyright (c) 2013 Red Hat, Inc.
       3   * Author: Tomas Mraz <tmraz@redhat.com>
       4   *
       5   * Redistribution and use in source and binary forms, with or without
       6   * modification, are permitted provided that the following conditions
       7   * are met:
       8   * 1. Redistributions of source code must retain the above copyright
       9   *    notice, and the entire permission notice in its entirety,
      10   *    including the disclaimer of warranties.
      11   * 2. Redistributions in binary form must reproduce the above copyright
      12   *    notice, this list of conditions and the following disclaimer in the
      13   *    documentation and/or other materials provided with the distribution.
      14   * 3. The name of the author may not be used to endorse or promote
      15   *    products derived from this software without specific prior
      16   *    written permission.
      17   *
      18   * ALTERNATIVELY, this product may be distributed under the terms of
      19   * the GNU Public License, in which case the provisions of the GPL are
      20   * required INSTEAD OF the above restrictions.  (This clause is
      21   * necessary due to a potential bad interaction between the GPL and
      22   * the restrictions contained in a BSD-style copyright.)
      23   *
      24   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
      25   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
      26   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
      27   * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
      28   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
      29   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
      30   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      31   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
      32   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
      33   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
      34   * OF THE POSSIBILITY OF SUCH DAMAGE.
      35   */
      36  
      37  #include "config.h"
      38  
      39  #include <stdio.h>
      40  #include <stdlib.h>
      41  #include <string.h>
      42  #include <syslog.h>
      43  #include <errno.h>
      44  #include <unistd.h>
      45  #include <signal.h>
      46  #include <security/_pam_types.h>
      47  #include <security/_pam_macros.h>
      48  #include <security/pam_modutil.h>
      49  #include "opasswd.h"
      50  #include "pam_inline.h"
      51  
      52  
      53  static int
      54  check_history(const char *user, const char *filename, const char *debug)
      55  {
      56    char pass[PAM_MAX_RESP_SIZE + 1];
      57    char *passwords[] = { pass };
      58    int npass;
      59    int dbg = atoi(debug); /* no need to be too fancy here */
      60    int retval;
      61  
      62    /* read the password from stdin (a pipe from the pam_pwhistory module) */
      63    npass = pam_read_passwords(STDIN_FILENO, 1, passwords);
      64  
      65    if (npass != 1)
      66      { /* is it a valid password? */
      67        helper_log_err(LOG_DEBUG, "no password supplied");
      68        return PAM_AUTHTOK_ERR;
      69      }
      70  
      71    retval = check_old_pass(user, pass, filename, dbg);
      72  
      73    pam_overwrite_array(pass);	/* clear memory of the password */
      74  
      75    return retval;
      76  }
      77  
      78  static int
      79  save_history(const char *user, const char *filename, const char *howmany, const char *debug)
      80  {
      81    int num = atoi(howmany);
      82    int dbg = atoi(debug); /* no need to be too fancy here */
      83    int retval;
      84  
      85    retval = save_old_pass(user, num, filename, dbg);
      86  
      87    return retval;
      88  }
      89  
      90  int
      91  main(int argc, char *argv[])
      92  {
      93    const char *option;
      94    const char *user;
      95    const char *filename;
      96  
      97    /*
      98     * we establish that this program is running with non-tty stdin.
      99     * this is to discourage casual use.
     100     */
     101  
     102    if (isatty(STDIN_FILENO) || argc < 5)
     103      {
     104        fprintf(stderr,
     105              "This binary is not designed for running in this way.\n");
     106        return PAM_SYSTEM_ERR;
     107      }
     108  
     109    option = argv[1];
     110    user = argv[2];
     111    filename = argv[3];
     112  
     113    if (strcmp(option, "check") == 0 && argc == 5)
     114      return check_history(user, filename, argv[4]);
     115    else if (strcmp(option, "save") == 0 && argc == 6)
     116      return save_history(user, filename, argv[4], argv[5]);
     117  
     118    fprintf(stderr, "This binary is not designed for running in this way.\n");
     119  
     120    return PAM_SYSTEM_ERR;
     121  }