xref: /freebsd/contrib/openpam/modules/pam_unix/pam_unix.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*-
2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3  * Copyright (c) 2004-2015 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 <pwd.h>
43 #include <stdlib.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #ifdef HAVE_CRYPT_H
49 # include <crypt.h>
50 #endif
51 
52 #include <security/pam_modules.h>
53 #include <security/pam_appl.h>
54 
55 #ifndef OPENPAM
56 static char password_prompt[] = "Password:";
57 #endif
58 
59 #ifndef PAM_EXTERN
60 #define PAM_EXTERN
61 #endif
62 
63 PAM_EXTERN int
64 pam_sm_authenticate(pam_handle_t *pamh, int flags,
65 	int argc, const char *argv[])
66 {
67 #ifndef OPENPAM
68 	struct pam_conv *conv;
69 	struct pam_message msg;
70 	const struct pam_message *msgp;
71 	struct pam_response *resp;
72 #endif
73 	struct passwd *pwd;
74 	const char *user;
75 	const char *crypt_password, *password;
76 	int pam_err, retry;
77 
78 	(void)argc;
79 	(void)argv;
80 
81 	/* identify user */
82 	if ((pam_err = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS)
83 		return (pam_err);
84 	if ((pwd = getpwnam(user)) == NULL)
85 		return (PAM_USER_UNKNOWN);
86 
87 	/* get password */
88 #ifndef OPENPAM
89 	pam_err = pam_get_item(pamh, PAM_CONV, (const void **)&conv);
90 	if (pam_err != PAM_SUCCESS)
91 		return (PAM_SYSTEM_ERR);
92 	msg.msg_style = PAM_PROMPT_ECHO_OFF;
93 	msg.msg = password_prompt;
94 	msgp = &msg;
95 #endif
96 	for (retry = 0; retry < 3; ++retry) {
97 #ifdef OPENPAM
98 		pam_err = pam_get_authtok(pamh, PAM_AUTHTOK,
99 		    &password, NULL);
100 #else
101 		resp = NULL;
102 		pam_err = (*conv->conv)(1, &msgp, &resp, conv->appdata_ptr);
103 		if (resp != NULL) {
104 			if (pam_err == PAM_SUCCESS)
105 				password = resp->resp;
106 			else
107 				free(resp->resp);
108 			free(resp);
109 		}
110 #endif
111 		if (pam_err == PAM_SUCCESS)
112 			break;
113 	}
114 	if (pam_err == PAM_CONV_ERR)
115 		return (pam_err);
116 	if (pam_err != PAM_SUCCESS)
117 		return (PAM_AUTH_ERR);
118 
119 	/* compare passwords */
120 	if ((!pwd->pw_passwd[0] && (flags & PAM_DISALLOW_NULL_AUTHTOK)) ||
121 	    (crypt_password = crypt(password, pwd->pw_passwd)) == NULL ||
122 	    strcmp(crypt_password, pwd->pw_passwd) != 0)
123 		pam_err = PAM_AUTH_ERR;
124 	else
125 		pam_err = PAM_SUCCESS;
126 #ifndef OPENPAM
127 	free(password);
128 #endif
129 	return (pam_err);
130 }
131 
132 PAM_EXTERN int
133 pam_sm_setcred(pam_handle_t *pamh, int flags,
134 	int argc, const char *argv[])
135 {
136 
137 	(void)pamh;
138 	(void)flags;
139 	(void)argc;
140 	(void)argv;
141 	return (PAM_SUCCESS);
142 }
143 
144 PAM_EXTERN int
145 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
146 	int argc, const char *argv[])
147 {
148 
149 	(void)pamh;
150 	(void)flags;
151 	(void)argc;
152 	(void)argv;
153 	return (PAM_SUCCESS);
154 }
155 
156 PAM_EXTERN int
157 pam_sm_open_session(pam_handle_t *pamh, int flags,
158 	int argc, const char *argv[])
159 {
160 
161 	(void)pamh;
162 	(void)flags;
163 	(void)argc;
164 	(void)argv;
165 	return (PAM_SUCCESS);
166 }
167 
168 PAM_EXTERN int
169 pam_sm_close_session(pam_handle_t *pamh, int flags,
170 	int argc, const char *argv[])
171 {
172 
173 	(void)pamh;
174 	(void)flags;
175 	(void)argc;
176 	(void)argv;
177 	return (PAM_SUCCESS);
178 }
179 
180 PAM_EXTERN int
181 pam_sm_chauthtok(pam_handle_t *pamh, int flags,
182 	int argc, const char *argv[])
183 {
184 
185 	(void)pamh;
186 	(void)flags;
187 	(void)argc;
188 	(void)argv;
189 	return (PAM_SERVICE_ERR);
190 }
191 
192 #ifdef PAM_MODULE_ENTRY
193 PAM_MODULE_ENTRY("pam_unix");
194 #endif
195