xref: /illumos-gate/usr/src/lib/pam_modules/sample/sample_authenticate.c (revision d48be21240dfd051b689384ce2b23479d757f2d8)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <security/pam_appl.h>
28 #include <security/pam_modules.h>
29 #include <string.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <sys/types.h>
33 #include <pwd.h>
34 #include <syslog.h>
35 #include <libintl.h>
36 
37 #include "sample_utils.h"
38 
39 /*
40  *
41  * Sample module for pam_sm_authenticate.
42  *
43  * options -
44  *
45  *	debug
46  *	use_first_pass
47  *	try_first_pass
48  *	first_pass_good  (first password is always good when used with use/try)
49  *	first_pass_bad   (first password is always bad when used with use/try)
50  *	pass=foobar	 (set good password to "foobar". default good password
51  *			 is test)
52  *	always_fail	 always return PAM_AUTH_ERR
53  *	always_succeed   always return PAM_SUCCESS
54  *	always_ignore
55  *
56  *
57  */
58 
59 /*
60  * pam_sm_authenticate		- Authenticate user
61  */
62 /*ARGSUSED*/
63 int
64 pam_sm_authenticate(
65 	pam_handle_t		*pamh,
66 	int 			flags,
67 	int			argc,
68 	const char		**argv)
69 {
70 	char			*user;
71 	struct pam_conv 	*pam_convp;
72 	int			err, result = PAM_AUTH_ERR;
73 	struct pam_response 	*ret_resp = (struct pam_response *)0;
74 	char 			messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
75 	int			debug = 0;
76 	int			try_first_pass = 0;
77 	int			use_first_pass = 0;
78 	int			first_pass_good = 0;
79 	int			first_pass_bad = 0;
80 	int			i, num_msg;
81 	char			*firstpass, *password;
82 	char			the_password[64];
83 
84 	if (debug)
85 		syslog(LOG_DEBUG, "Sample Authentication\n");
86 
87 	(void) strcpy(the_password, "test");
88 
89 	for (i = 0; i < argc; i++) {
90 		if (strcmp(argv[i], "debug") == 0)
91 			debug = 1;
92 		else if (strcmp(argv[i], "try_first_pass") == 0)
93 			try_first_pass = 1;
94 		else if (strcmp(argv[i], "first_pass_good") == 0)
95 			first_pass_good = 1;
96 		else if (strcmp(argv[i], "first_pass_bad") == 0)
97 			first_pass_bad = 1;
98 		else if (strcmp(argv[i], "use_first_pass") == 0)
99 			use_first_pass = 1;
100 		else if (strcmp(argv[i], "always_fail") == 0)
101 			return (PAM_AUTH_ERR);
102 		else if (strcmp(argv[i], "always_succeed") == 0)
103 			return (PAM_SUCCESS);
104 		else if (strcmp(argv[i], "always_ignore") == 0)
105 			return (PAM_IGNORE);
106 		else if (sscanf(argv[i], "pass=%64s", the_password) == 1) {
107 			/*EMPTY*/;
108 		}
109 		else
110 			syslog(LOG_DEBUG, "illegal scheme option %s", argv[i]);
111 	}
112 
113 	err = pam_get_user(pamh, &user, NULL);
114 	if (err != PAM_SUCCESS)
115 		return (err);
116 
117 	err = pam_get_item(pamh, PAM_CONV, (void**) &pam_convp);
118 	if (err != PAM_SUCCESS)
119 		return (err);
120 
121 	(void) pam_get_item(pamh, PAM_AUTHTOK, (void **) &firstpass);
122 
123 	if (firstpass && (use_first_pass || try_first_pass)) {
124 
125 		if ((first_pass_good ||
126 			strncmp(firstpass, the_password,
127 				strlen(the_password)) == 0) &&
128 				!first_pass_bad) {
129 					result = PAM_SUCCESS;
130 					goto out;
131 		}
132 		if (use_first_pass) goto out;
133 	}
134 
135 	/*
136 	 * Get the password from the user
137 	 */
138 	if (firstpass) {
139 		(void) snprintf(messages[0], sizeof (messages[0]),
140 			dgettext(TEXT_DOMAIN, "TEST Password: "));
141 	} else {
142 		(void) snprintf(messages[0], sizeof (messages[0]),
143 			dgettext(TEXT_DOMAIN, "Password: "));
144 	}
145 	num_msg = 1;
146 	err = __get_authtok(pam_convp->conv,
147 				num_msg, messages, NULL, &ret_resp);
148 
149 	if (err != PAM_SUCCESS) {
150 		result = err;
151 		goto out;
152 	}
153 
154 	password = ret_resp->resp;
155 
156 	if (password == NULL) {
157 		result = PAM_AUTH_ERR;
158 		goto out;
159 	}
160 
161 	/* one last ditch attempt to "login" to TEST */
162 
163 	if (strncmp(password, the_password, strlen(the_password)) == 0) {
164 		result = PAM_SUCCESS;
165 		if (firstpass == NULL) {
166 			/* this is the first password, stash it away */
167 			(void) pam_set_item(pamh, PAM_AUTHTOK, password);
168 		}
169 	}
170 
171 out:
172 	if (num_msg > 0) {
173 		if (ret_resp != 0) {
174 			if (ret_resp->resp != 0) {
175 				/* avoid leaving password cleartext around */
176 				(void) memset(ret_resp->resp, 0,
177 					strlen(ret_resp->resp));
178 			}
179 			__free_resp(num_msg, ret_resp);
180 			ret_resp = 0;
181 		}
182 	}
183 
184 	return (result);
185 }
186