xref: /freebsd/contrib/openpam/lib/libpam/openpam_set_option.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3  * Copyright (c) 2004-2023 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 
36 #ifdef HAVE_CONFIG_H
37 # include "config.h"
38 #endif
39 
40 #include <sys/param.h>
41 
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include <security/pam_appl.h>
47 
48 #include "openpam_impl.h"
49 #include "openpam_asprintf.h"
50 
51 /*
52  * OpenPAM extension
53  *
54  * Sets the value of a module option
55  */
56 
57 int
58 openpam_set_option(pam_handle_t *pamh,
59 	const char *option,
60 	const char *value)
61 {
62 	pam_chain_t *cur;
63 	char *opt, **optv;
64 	size_t len;
65 	int i;
66 
67 	ENTERS(option);
68 	if (pamh == NULL || pamh->current == NULL || option == NULL)
69 		RETURNC(PAM_SYSTEM_ERR);
70 	cur = pamh->current;
71 	for (len = 0; option[len] != '\0'; ++len)
72 		if (option[len] == '=')
73 			break;
74 	for (i = 0; i < cur->optc; ++i) {
75 		if (strncmp(cur->optv[i], option, len) == 0 &&
76 		    (cur->optv[i][len] == '\0' || cur->optv[i][len] == '='))
77 			break;
78 	}
79 	if (value == NULL) {
80 		/* remove */
81 		if (i == cur->optc)
82 			RETURNC(PAM_SUCCESS);
83 		for (free(cur->optv[i]); i < cur->optc; ++i)
84 			cur->optv[i] = cur->optv[i + 1];
85 		cur->optv[i] = NULL;
86 		--cur->optc;
87 		RETURNC(PAM_SUCCESS);
88 	}
89 	if (asprintf(&opt, "%.*s=%s", (int)len, option, value) < 0)
90 		RETURNC(PAM_BUF_ERR);
91 	if (i == cur->optc) {
92 		/* add */
93 		optv = realloc(cur->optv, sizeof(char *) * (cur->optc + 2));
94 		if (optv == NULL) {
95 			FREE(opt);
96 			RETURNC(PAM_BUF_ERR);
97 		}
98 		optv[i] = opt;
99 		optv[i + 1] = NULL;
100 		cur->optv = optv;
101 		++cur->optc;
102 	} else {
103 		/* replace */
104 		FREE(cur->optv[i]);
105 		cur->optv[i] = opt;
106 	}
107 	RETURNC(PAM_SUCCESS);
108 }
109 
110 /*
111  * Error codes:
112  *
113  *	PAM_SYSTEM_ERR
114  *	PAM_BUF_ERR
115  */
116 
117 /**
118  * The =openpam_set_option function sets the specified option in the
119  * context of the currently executing service module.
120  *
121  * >openpam_get_option
122  */
123