dist/openpam/lib/pam_get_user.c

   1 /*-
   2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
   3  * Copyright (c) 2004-2007 Dag-Erling Smørgrav
   4  * All rights reserved.
   5  *
   6  * This software was developed for the FreeBSD Project by ThinkSec AS and
   7  * Network Associates Laboratories, the Security Research Division of
   8  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
   9  * ("CBOSS"), as part of the DARPA CHATS research program.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote
  20  *    products derived from this software without specific prior written
  21  *    permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * $Id: pam_get_user.c,v 1.4 2008/01/27 01:23:00 christos Exp $
  36  */
  37
  38 #include <sys/param.h>
  39
  40 #include <stdlib.h>
  41
  42 #include <security/pam_appl.h>
  43 #include <security/openpam.h>
  44
  45 #include "openpam_impl.h"
  46
  47 static const char user_prompt[] = "Login:";
  48
  49 /*
  50  * XSSO 4.2.1
  51  * XSSO 6 page 52
  52  *
  53  * Retrieve user name
  54  */
  55
  56 int
  57 pam_get_user(pam_handle_t *pamh,
  58         const char **user,
  59         const char *prompt)
  60 {
  61         const void *promptp;
  62         char *resp;
  63         int r;
  64
  65         ENTER();
  66         if (pamh == NULL || user == NULL)
  67                 RETURNC(PAM_SYSTEM_ERR);
  68         r = pam_get_item(pamh, PAM_USER, (const void **)user);
  69         if (r == PAM_SUCCESS && *user != NULL)
  70                 RETURNC(PAM_SUCCESS);
  71         if (prompt == NULL) {
  72                 r = pam_get_item(pamh, PAM_USER_PROMPT, &promptp);
  73                 if (r != PAM_SUCCESS || promptp == NULL)
  74                         prompt = user_prompt;
  75                 else
  76                         prompt = promptp;
  77         }
  78         r = pam_prompt(pamh, PAM_PROMPT_ECHO_ON, &resp, "%s", prompt);
  79         if (r != PAM_SUCCESS)
  80                 RETURNC(r);
  81         r = pam_set_item(pamh, PAM_USER, resp);
  82         FREE(resp);
  83         if (r != PAM_SUCCESS)
  84                 RETURNC(r);
  85         r = pam_get_item(pamh, PAM_USER, (const void **)user);
  86         RETURNC(r);
  87         /*NOTREACHED*/
  88 }
  89
  90 /*
  91  * Error codes:
  92  *
  93  *      =pam_get_item
  94  *      =pam_prompt
  95  *      =pam_set_item
  96  *      !PAM_SYMBOL_ERR
  97  */
  98
  99 /**
 100  * The =pam_get_user function returns the name of the target user, as
 101  * specified to =pam_start.
 102  * If no user was specified, nor set using =pam_set_item, =pam_get_user
 103  * will prompt for a user name.
 104  * Either way, a pointer to the user name is stored in the location
 105  * pointed to by the =user argument.
 106  *
 107  * The =prompt argument specifies a prompt to use if no user name is
 108  * cached.
 109  * If it is =NULL, the =PAM_USER_PROMPT will be used.
 110  * If that item is also =NULL, a hardcoded default prompt will be used.
 111  *
 112  * >pam_get_item
 113  * >pam_get_authtok
 114  */