1  /*
       2   * Redistribution and use in source and binary forms, with or without
       3   * modification, are permitted provided that the following conditions
       4   * are met:
       5   * 1. Redistributions of source code must retain the above copyright
       6   *    notice, and the entire permission notice in its entirety,
       7   *    including the disclaimer of warranties.
       8   * 2. Redistributions in binary form must reproduce the above copyright
       9   *    notice, this list of conditions and the following disclaimer in the
      10   *    documentation and/or other materials provided with the distribution.
      11   * 3. The name of the author may not be used to endorse or promote
      12   *    products derived from this software without specific prior
      13   *    written permission.
      14   *
      15   * ALTERNATIVELY, this product may be distributed under the terms of
      16   * the GNU Public License, in which case the provisions of the GPL are
      17   * required INSTEAD OF the above restrictions.  (This clause is
      18   * necessary due to a potential bad interaction between the GPL and
      19   * the restrictions contained in a BSD-style copyright.)
      20   *
      21   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
      22   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
      23   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
      24   * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
      25   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
      26   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
      27   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      28   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
      29   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
      30   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
      31   * OF THE POSSIBILITY OF SUCH DAMAGE.
      32   */
      33  
      34  #include "config.h"
      35  
      36  #include <stdio.h>
      37  #include <stdlib.h>
      38  #include <unistd.h>
      39  #include <stdarg.h>
      40  #include <errno.h>
      41  
      42  #include <security/pam_modules.h>
      43  #include <security/pam_ext.h>
      44  
      45  #include "pam_private.h"
      46  #include "pam_inline.h"
      47  
      48  int
      49  pam_vprompt (pam_handle_t *pamh, int style, char **response,
      50  	     const char *fmt, va_list args)
      51  {
      52    struct pam_message msg;
      53    struct pam_response *pam_resp = NULL;
      54    const struct pam_message *pmsg;
      55    const struct pam_conv *conv;
      56    const void *convp;
      57    char *msgbuf;
      58    int retval;
      59  
      60    if (response)
      61      *response = NULL;
      62  
      63    retval = pam_get_item (pamh, PAM_CONV, &convp);
      64    if (retval != PAM_SUCCESS)
      65      return retval;
      66    conv = convp;
      67    if (conv == NULL || conv->conv == NULL)
      68      {
      69        pam_syslog (pamh, LOG_ERR, "no conversation function");
      70        return PAM_SYSTEM_ERR;
      71      }
      72  
      73    if (vasprintf (&msgbuf, fmt, args) < 0)
      74      {
      75        pam_syslog (pamh, LOG_ERR, "vasprintf: %m");
      76        return PAM_BUF_ERR;
      77      }
      78  
      79    msg.msg_style = style;
      80    msg.msg = msgbuf;
      81    pmsg = &msg;
      82  
      83    retval = conv->conv (1, &pmsg, &pam_resp, conv->appdata_ptr);
      84    if (retval != PAM_SUCCESS && pam_resp != NULL)
      85      pam_syslog(pamh, LOG_WARNING,
      86        "unexpected response from failed conversation function");
      87    if (response)
      88      *response = pam_resp == NULL ? NULL : pam_resp->resp;
      89    else if (pam_resp && pam_resp->resp)
      90      {
      91        pam_overwrite_string (pam_resp->resp);
      92        _pam_drop (pam_resp->resp);
      93      }
      94    pam_overwrite_string (msgbuf);
      95    _pam_drop (pam_resp);
      96    free (msgbuf);
      97    if (retval != PAM_SUCCESS)
      98      pam_syslog (pamh, LOG_ERR, "conversation failed");
      99  
     100    return retval;
     101  }
     102  
     103  int
     104  pam_prompt (pam_handle_t *pamh, int style, char **response,
     105  	    const char *fmt, ...)
     106  {
     107    va_list args;
     108    int retval;
     109  
     110    va_start (args, fmt);
     111    retval = pam_vprompt (pamh, style, response, fmt, args);
     112    va_end (args);
     113  
     114    return retval;
     115  }