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      1 /*	$NetBSD: pam_vprompt.c,v 1.5 2025/09/06 12:33:44 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
      5  * Copyright (c) 2004-2011 Dag-Erling Smrgrav
      6  * All rights reserved.
      7  *
      8  * This software was developed for the FreeBSD Project by ThinkSec AS and
      9  * Network Associates Laboratories, the Security Research Division of
     10  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
     11  * ("CBOSS"), as part of the DARPA CHATS research program.
     12  *
     13  * Redistribution and use in source and binary forms, with or without
     14  * modification, are permitted provided that the following conditions
     15  * are met:
     16  * 1. Redistributions of source code must retain the above copyright
     17  *    notice, this list of conditions and the following disclaimer.
     18  * 2. Redistributions in binary form must reproduce the above copyright
     19  *    notice, this list of conditions and the following disclaimer in the
     20  *    documentation and/or other materials provided with the distribution.
     21  * 3. The name of the author may not be used to endorse or promote
     22  *    products derived from this software without specific prior written
     23  *    permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     35  * SUCH DAMAGE.
     36  */
     37 
     38 #ifdef HAVE_CONFIG_H
     39 # include "config.h"
     40 #endif
     41 
     42 #include <sys/cdefs.h>
     43 __RCSID("$NetBSD: pam_vprompt.c,v 1.5 2025/09/06 12:33:44 riastradh Exp $");
     44 
     45 #include <stdarg.h>
     46 #include <stdio.h>
     47 #include <stdlib.h>
     48 
     49 #include <security/pam_appl.h>
     50 
     51 #include "openpam_impl.h"
     52 
     53 /*
     54  * OpenPAM extension
     55  *
     56  * Call the conversation function
     57  */
     58 
     59 int
     60 pam_vprompt(const pam_handle_t *pamh,
     61 	int style,
     62 	char **resp,
     63 	const char *fmt,
     64 	va_list ap)
     65 {
     66 	char msgbuf[PAM_MAX_MSG_SIZE];
     67 	struct pam_message msg;
     68 	const struct pam_message *msgp;
     69 	struct pam_response *rsp;
     70 	const struct pam_conv *conv;
     71 	const void *convp;
     72 	int r;
     73 
     74 	ENTER();
     75 	r = pam_get_item(pamh, PAM_CONV, &convp);
     76 	if (r != PAM_SUCCESS)
     77 		RETURNC(r);
     78 	conv = convp;
     79 	if (conv == NULL || conv->conv == NULL) {
     80 		openpam_log(PAM_LOG_ERROR, "no conversation function");
     81 		RETURNC(PAM_SYSTEM_ERR);
     82 	}
     83 	vsnprintf(msgbuf, PAM_MAX_MSG_SIZE, fmt, ap);
     84 	msg.msg_style = style;
     85 	msg.msg = msgbuf;
     86 	msgp = &msg;
     87 	rsp = NULL;
     88 	r = (conv->conv)(1, &msgp, &rsp, conv->appdata_ptr);
     89 	*resp = rsp == NULL ? NULL : rsp->resp;
     90 	FREE(rsp);
     91 	RETURNC(r);
     92 }
     93 
     94 /*
     95  * Error codes:
     96  *
     97  *     !PAM_SYMBOL_ERR
     98  *	PAM_SYSTEM_ERR
     99  *	PAM_BUF_ERR
    100  *	PAM_CONV_ERR
    101  */
    102 
    103 /**
    104  * The =pam_vprompt function constructs a string from the =fmt and =ap
    105  * arguments using =vsnprintf, and passes it to the given PAM context's
    106  * conversation function.
    107  *
    108  * The =style argument specifies the type of interaction requested, and
    109  * must be one of the following:
    110  *
    111  *	=PAM_PROMPT_ECHO_OFF:
    112  *		Display the message and obtain the user's response without
    113  *		displaying it.
    114  *	=PAM_PROMPT_ECHO_ON:
    115  *		Display the message and obtain the user's response.
    116  *	=PAM_ERROR_MSG:
    117  *		Display the message as an error message, and do not wait
    118  *		for a response.
    119  *	=PAM_TEXT_INFO:
    120  *		Display the message as an informational message, and do
    121  *		not wait for a response.
    122  *
    123  * A pointer to the response, or =NULL if the conversation function did
    124  * not return one, is stored in the location pointed to by the =resp
    125  * argument.
    126  *
    127  * The message and response should not exceed =PAM_MAX_MSG_SIZE or
    128  * =PAM_MAX_RESP_SIZE, respectively.
    129  * If they do, they may be truncated.
    130  *
    131  * >pam_error
    132  * >pam_info
    133  * >pam_prompt
    134  * >pam_verror
    135  * >pam_vinfo
    136  */
    137