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      1 /*	$NetBSD: openpam_set_option.c,v 1.4 2023/06/30 21:46:20 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
      5  * Copyright (c) 2004-2023 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: openpam_set_option.c,v 1.4 2023/06/30 21:46:20 christos Exp $");
     44 
     45 #include <sys/param.h>
     46 
     47 #include <stdio.h>
     48 #include <stdlib.h>
     49 #include <string.h>
     50 
     51 #include <security/pam_appl.h>
     52 
     53 #include "openpam_impl.h"
     54 #include "openpam_asprintf.h"
     55 
     56 /*
     57  * OpenPAM extension
     58  *
     59  * Sets the value of a module option
     60  */
     61 
     62 int
     63 openpam_set_option(pam_handle_t *pamh,
     64 	const char *option,
     65 	const char *value)
     66 {
     67 	pam_chain_t *cur;
     68 	char *opt, **optv;
     69 	size_t len;
     70 	int i;
     71 
     72 	ENTERS(option);
     73 	if (pamh == NULL || pamh->current == NULL || option == NULL)
     74 		RETURNC(PAM_SYSTEM_ERR);
     75 	cur = pamh->current;
     76 	for (len = 0; option[len] != '\0'; ++len)
     77 		if (option[len] == '=')
     78 			break;
     79 	for (i = 0; i < cur->optc; ++i) {
     80 		if (strncmp(cur->optv[i], option, len) == 0 &&
     81 		    (cur->optv[i][len] == '\0' || cur->optv[i][len] == '='))
     82 			break;
     83 	}
     84 	if (value == NULL) {
     85 		/* remove */
     86 		if (i == cur->optc)
     87 			RETURNC(PAM_SUCCESS);
     88 		for (free(cur->optv[i]); i < cur->optc; ++i)
     89 			cur->optv[i] = cur->optv[i + 1];
     90 		cur->optv[i] = NULL;
     91 		--cur->optc;
     92 		RETURNC(PAM_SUCCESS);
     93 	}
     94 	if (asprintf(&opt, "%.*s=%s", (int)len, option, value) < 0)
     95 		RETURNC(PAM_BUF_ERR);
     96 	if (i == cur->optc) {
     97 		/* add */
     98 		optv = realloc(cur->optv,
     99 		    sizeof(*optv) * ((size_t)cur->optc + 2));
    100 		if (optv == NULL) {
    101 			FREE(opt);
    102 			RETURNC(PAM_BUF_ERR);
    103 		}
    104 		optv[i] = opt;
    105 		optv[i + 1] = NULL;
    106 		cur->optv = optv;
    107 		++cur->optc;
    108 	} else {
    109 		/* replace */
    110 		FREE(cur->optv[i]);
    111 		cur->optv[i] = opt;
    112 	}
    113 	RETURNC(PAM_SUCCESS);
    114 }
    115 
    116 /*
    117  * Error codes:
    118  *
    119  *	PAM_SYSTEM_ERR
    120  *	PAM_BUF_ERR
    121  */
    122 
    123 /**
    124  * The =openpam_set_option function sets the specified option in the
    125  * context of the currently executing service module.
    126  *
    127  * >openpam_get_option
    128  */
    129