dist/openpam/lib/pam_vprompt.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_vprompt.c,v 1.4 2008/01/27 01:23:01 christos Exp $
  36  */
  37
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41
  42 #include <security/pam_appl.h>
  43
  44 #include "openpam_impl.h"
  45
  46 /*
  47  * OpenPAM extension
  48  *
  49  * Call the conversation function
  50  */
  51
  52 int
  53 pam_vprompt(const pam_handle_t *pamh,
  54         int style,
  55         char **resp,
  56         const char *fmt,
  57         va_list ap)
  58 {
  59         char msgbuf[PAM_MAX_MSG_SIZE];
  60         struct pam_message msg;
  61         const struct pam_message *msgp;
  62         struct pam_response *rsp;
  63         const struct pam_conv *conv;
  64         const void *convp;
  65         int r;
  66
  67         ENTER();
  68         r = pam_get_item(pamh, PAM_CONV, &convp);
  69         if (r != PAM_SUCCESS)
  70                 RETURNC(r);
  71         conv = convp;
  72         if (conv == NULL || conv->conv == NULL) {
  73                 openpam_log(PAM_LOG_ERROR, "no conversation function");
  74                 RETURNC(PAM_SYSTEM_ERR);
  75         }
  76         vsnprintf(msgbuf, (size_t)PAM_MAX_MSG_SIZE, fmt, ap);
  77         msg.msg_style = style;
  78         msg.msg = msgbuf;
  79         msgp = &msg;
  80         rsp = NULL;
  81         r = (conv->conv)(1, &msgp, &rsp, conv->appdata_ptr);
  82         *resp = rsp == NULL ? NULL : rsp->resp;
  83         FREE(rsp);
  84         RETURNC(r);
  85         /*NOTREACHED*/
  86 }
  87
  88 /*
  89  * Error codes:
  90  *
  91  *     !PAM_SYMBOL_ERR
  92  *      PAM_SYSTEM_ERR
  93  *      PAM_BUF_ERR
  94  *      PAM_CONV_ERR
  95  */
  96
  97 /**
  98  * The =pam_vprompt function constructs a string from the =fmt and =ap
  99  * arguments using =vsnprintf, and passes it to the given PAM context's
 100  * conversation function.
 101  *
 102  * The =style argument specifies the type of interaction requested, and
 103  * must be one of the following:
 104  *
 105  *      =PAM_PROMPT_ECHO_OFF:
 106  *              Display the message and obtain the user's response without
 107  *              displaying it.
 108  *      =PAM_PROMPT_ECHO_ON:
 109  *              Display the message and obtain the user's response.
 110  *      =PAM_ERROR_MSG:
 111  *              Display the message as an error message, and do not wait
 112  *              for a response.
 113  *      =PAM_TEXT_INFO:
 114  *              Display the message as an informational message, and do
 115  *              not wait for a response.
 116  *
 117  * A pointer to the response, or =NULL if the conversation function did
 118  * not return one, is stored in the location pointed to by the =resp
 119  * argument.
 120  *
 121  * The message and response should not exceed =PAM_MAX_MSG_SIZE or
 122  * =PAM_MAX_RESP_SIZE, respectively.
 123  * If they do, they may be truncated.
 124  *
 125  * >pam_error
 126  * >pam_info
 127  * >pam_prompt
 128  * >pam_verror
 129  * >pam_vinfo
 130  */