xref: /illumos-gate/usr/src/lib/pam_modules/dial_auth/dial_auth.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <crypt.h>
27 #include <pwd.h>
28 #include <shadow.h>
29 #include <string.h>
30 #include <stdlib.h>
31 #include <syslog.h>
32 #include <security/pam_appl.h>
33 #include <security/pam_modules.h>
34 #include "../../libpam/pam_impl.h"
35 
36 #include <libintl.h>
37 
38 /*
39  * Various useful files and string constants
40  */
41 #define	DIAL_FILE	"/etc/dialups"
42 #define	DPASS_FILE	"/etc/d_passwd"
43 #define	SHELL		"/usr/bin/sh"
44 #define	SCPYN(a, b)	(void) strncpy(a, b, sizeof (a))
45 
46 /*
47  * pam_sm_authenticate	- This is the top level function in the
48  *			module called by pam_auth_port in the framework
49  *			Returns: PAM_AUTH_ERR on failure, 0 on success
50  */
51 /*ARGSUSED*/
52 int
53 pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv)
54 {
55 	char	*ttyn, *user;
56 	FILE 	*fp;
57 	char 	defpass[30];
58 	char	line[80];
59 	char 	*p1 = NULL, *p2 = NULL;
60 	struct passwd 	pwd;
61 	char	pwd_buffer[1024];
62 	char	*password = NULL;
63 	int	retcode;
64 	int	i;
65 	int	debug = 0;
66 	int	res;
67 
68 	for (i = 0; i < argc; i++) {
69 		if (strcasecmp(argv[i], "debug") == 0)
70 			debug = 1;
71 		else
72 			syslog(LOG_DEBUG, "illegal option %s", argv[i]);
73 	}
74 
75 	if ((retcode = pam_get_user(pamh, &user, NULL))
76 					!= PAM_SUCCESS ||
77 	    (retcode = pam_get_item(pamh, PAM_TTY, (void **)&ttyn))
78 					!= PAM_SUCCESS)
79 		return (retcode);
80 
81 	if (debug) {
82 		syslog(LOG_DEBUG,
83 			"Dialpass authenticate user = %s, ttyn = %s",
84 			user ? user : "NULL", ttyn ? ttyn : "NULL");
85 	}
86 
87 	if (ttyn == NULL || *ttyn == '\0') {
88 		char *service;
89 
90 		(void) pam_get_item(pamh, PAM_SERVICE, (void **)&service);
91 		syslog(LOG_ERR, "pam_dial_auth: terminal-device not specified"
92 		    "by %s, returning %s.", service,
93 		    pam_strerror(pamh, PAM_SERVICE_ERR));
94 		return (PAM_SERVICE_ERR);
95 	}
96 	if (getpwnam_r(user, &pwd, pwd_buffer, sizeof (pwd_buffer)) == NULL)
97 		return (PAM_USER_UNKNOWN);
98 
99 	if ((fp = fopen(DIAL_FILE, "rF")) == NULL)
100 		return (PAM_IGNORE);
101 
102 	while ((p1 = fgets(line, sizeof (line), fp)) != NULL) {
103 		while (*p1 != '\n' && *p1 != ' ' && *p1 != '\t')
104 			p1++;
105 		*p1 = '\0';
106 		if (strcmp(line, ttyn) == 0)
107 			break;
108 	}
109 
110 	(void) fclose(fp);
111 
112 	if ((fp = fopen(DPASS_FILE, "rF")) == NULL) {
113 		syslog(LOG_ERR, "pam_dial_auth: %s without %s, returning %s.",
114 		    DIAL_FILE, DPASS_FILE,
115 		    pam_strerror(pamh, PAM_SYSTEM_ERR));
116 		(void) memset(line, 0, sizeof (line));
117 		return (PAM_SYSTEM_ERR);
118 	}
119 
120 	if (p1 == NULL) {
121 		(void) fclose(fp);
122 		(void) memset(line, 0, sizeof (line));
123 		return (PAM_IGNORE);
124 	}
125 
126 	defpass[0] = '\0';
127 
128 	while ((p1 = fgets(line, sizeof (line)-1, fp)) != NULL) {
129 		while (*p1 && *p1 != ':')
130 			p1++;
131 		*p1++ = '\0';
132 		p2 = p1;
133 		while (*p1 && *p1 != ':')
134 			p1++;
135 		*p1 = '\0';
136 		if (pwd.pw_shell != NULL && strcmp(pwd.pw_shell, line) == 0)
137 			break;
138 
139 		if (strcmp(SHELL, line) == 0)
140 			SCPYN(defpass, p2);
141 		p2 = NULL;
142 	}
143 
144 	(void) memset(line, 0, sizeof (line));
145 	(void) fclose(fp);
146 
147 	if (p2 == NULL)
148 		p2 = defpass;
149 
150 	if (*p2 != '\0') {
151 		res = __pam_get_authtok(pamh, PAM_PROMPT, PAM_AUTHTOK,
152 		    dgettext(TEXT_DOMAIN, "Dialup Password: "), &password);
153 
154 		if (res != PAM_SUCCESS) {
155 			return (res);
156 		}
157 
158 		if (strcmp(crypt(password, p2), p2) != 0) {
159 			(void) memset(password, 0, strlen(password));
160 			free(password);
161 			return (PAM_AUTH_ERR);
162 		}
163 		(void) memset(password, 0, strlen(password));
164 		free(password);
165 	}
166 
167 	return (PAM_SUCCESS);
168 }
169 
170 /*
171  * dummy pam_sm_setcred - does nothing
172  */
173 /*ARGSUSED*/
174 int
175 pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv)
176 {
177 	return (PAM_IGNORE);
178 }
179