xref: /freebsd/lib/libpam/modules/pam_unix/pam_unix.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
1 /*-
2  * Copyright 1998 Juniper Networks, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  *	$FreeBSD$
27  */
28 
29 #include <sys/types.h>
30 #include <sys/time.h>
31 #include <login_cap.h>
32 #include <pwd.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <stdio.h>
36 #include <unistd.h>
37 
38 #define PAM_SM_AUTH
39 #define PAM_SM_ACCOUNT
40 #include <security/pam_modules.h>
41 
42 #include "pam_mod_misc.h"
43 
44 #define PASSWORD_PROMPT	"Password:"
45 
46 /*
47  * authentication management
48  */
49 
50 PAM_EXTERN int
51 pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc,
52     const char **argv)
53 {
54 	int retval;
55 	const char *user;
56 	const char *password;
57 	struct passwd *pwd;
58 	char *encrypted;
59 	int options;
60 	int i;
61 
62 	options = 0;
63 	for (i = 0;  i < argc;  i++)
64 		pam_std_option(&options, argv[i]);
65 	if ((retval = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS)
66 		return retval;
67 	if ((retval = pam_get_pass(pamh, &password, PASSWORD_PROMPT,
68 	    options)) != PAM_SUCCESS)
69 		return retval;
70 	if ((pwd = getpwnam(user)) != NULL) {
71 		encrypted = crypt(password, pwd->pw_passwd);
72 		if (password[0] == '\0' && pwd->pw_passwd[0] != '\0')
73 			encrypted = ":";
74 
75 		retval = strcmp(encrypted, pwd->pw_passwd) == 0 ?
76 		    PAM_SUCCESS : PAM_AUTH_ERR;
77 	} else {
78 		/*
79 		 * User unknown.  Encrypt anyway so that it takes the
80 		 * same amount of time.
81 		 */
82 		crypt(password, "xx");
83 		retval = PAM_AUTH_ERR;
84 	}
85 	/*
86 	 * The PAM infrastructure will obliterate the cleartext
87 	 * password before returning to the application.
88 	 */
89 	return retval;
90 }
91 
92 PAM_EXTERN int
93 pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv)
94 {
95 	return PAM_SUCCESS;
96 }
97 
98 /*
99  * account management
100  *
101  * check pw_change and pw_expire fields
102  */
103 PAM_EXTERN
104 int pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
105 		     int argc, const char **argv)
106 {
107 	const char *user;
108 	struct passwd *pw;
109 	struct timeval tp;
110 	time_t warntime;
111 	login_cap_t *lc = NULL;
112 	char buf[128];
113 	int retval;
114 
115 	retval = pam_get_item(pamh, PAM_USER, (const void **)&user);
116 	if (retval != PAM_SUCCESS || user == NULL)
117 		/* some implementations return PAM_SUCCESS here */
118 		return PAM_USER_UNKNOWN;
119 
120 	if ((pw = getpwnam(user)) == NULL)
121 		return PAM_USER_UNKNOWN;
122 
123 	retval = PAM_SUCCESS;
124 	lc = login_getpwclass(pw);
125 
126 	if (pw->pw_change || pw->pw_expire)
127 		gettimeofday(&tp, NULL);
128 
129 #define DEFAULT_WARN  (2L * 7L * 86400L)  /* Two weeks */
130 
131 	warntime = login_getcaptime(lc, "warnpassword", DEFAULT_WARN,
132 	    DEFAULT_WARN);
133 
134 	if (pw->pw_change) {
135 		if (tp.tv_sec >= pw->pw_change)
136 			/* some implementations return PAM_AUTHTOK_EXPIRED */
137 			retval = PAM_NEW_AUTHTOK_REQD;
138 		else if (pw->pw_change - tp.tv_sec < warntime) {
139 			snprintf(buf, sizeof(buf),
140 			    "Warning: your password expires on %s",
141 			    ctime(&pw->pw_change));
142 			pam_prompt(pamh, PAM_ERROR_MSG, buf, NULL);
143 		}
144 	}
145 
146 	warntime = login_getcaptime(lc, "warnexpire", DEFAULT_WARN,
147 	    DEFAULT_WARN);
148 
149 	if (pw->pw_expire) {
150 		if (tp.tv_sec >= pw->pw_expire)
151 			retval = PAM_ACCT_EXPIRED;
152 		else if (pw->pw_expire - tp.tv_sec < warntime) {
153 			snprintf(buf, sizeof(buf),
154 			    "Warning: your account expires on %s",
155 			    ctime(&pw->pw_expire));
156 			pam_prompt(pamh, PAM_ERROR_MSG, buf, NULL);
157 		}
158 	}
159 
160 	login_close(lc);
161 	return retval;
162 }
163 
164 PAM_MODULE_ENTRY("pam_unix");
165