xref: /titanic_44/usr/src/lib/pam_modules/roles/roles.c (revision 3fdcff3d33a8e780f29abef9af443fbe975a1d41)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <syslog.h>
27 #include <pwd.h>
28 #include <unistd.h>
29 #include <strings.h>
30 #include <security/pam_appl.h>
31 #include <security/pam_modules.h>
32 #include <libintl.h>
33 #include <pwd.h>
34 #include <user_attr.h>
35 #include <secdb.h>
36 #include <nss_dbdefs.h>
37 #include <security/pam_impl.h>
38 
39 static int roleinlist();
40 
41 /*
42  * pam_sm_acct_mgmt():
43  *	Account management module
44  *	This module disallows roles for primary logins and adds special
45  *	checks to allow roles for secondary logins.
46  */
47 
48 /*ARGSUSED*/
49 int
pam_sm_acct_mgmt(pam_handle_t * pamh,int flags,int argc,const char ** argv)50 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
51 {
52 	uid_t uid;
53 	userattr_t *user_entry;
54 	char	*kva_value;
55 	char	*username;
56 	char	*auser;
57 	char	*rhost;
58 	char messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
59 	struct passwd *pw_entry, pwd;
60 	char buf[NSS_BUFLEN_PASSWD];
61 
62 	int i;
63 	int debug = 0;
64 	int allow_remote = 0;
65 
66 	(void) pam_get_item(pamh, PAM_USER, (void **)&username);
67 	(void) pam_get_item(pamh, PAM_AUSER, (void **)&auser);
68 	(void) pam_get_item(pamh, PAM_RHOST, (void **)&rhost);
69 
70 	for (i = 0; i < argc; i++) {
71 		if (strcmp(argv[i], "allow_remote") == 0) {
72 			allow_remote = 1;
73 		} else if (strcmp(argv[i], "debug") == 0) {
74 			debug = 1;
75 		} else {
76 			__pam_log(LOG_AUTH | LOG_ERR,
77 			    "pam_roles:pam_sm_acct_mgmt: illegal module "
78 			    "option %s", argv[i]);
79 		}
80 	}
81 
82 	if (debug) {
83 		char	*ruser;
84 		char	*service;
85 
86 		(void) pam_get_item(pamh, PAM_RUSER, (void **)&ruser);
87 		(void) pam_get_item(pamh, PAM_SERVICE, (void **)&service);
88 		__pam_log(LOG_AUTH | LOG_DEBUG, "pam_roles:pam_sm_acct_mgmt: "
89 		    "service = %s, allow_remote = %d, user = %s auser = %s "
90 		    "ruser = %s rhost = %s\n", (service) ? service : "not set",
91 		    allow_remote, (username) ? username : "not set",
92 		    (auser) ? auser: "not set", (ruser) ? ruser: "not set",
93 		    (rhost) ? rhost: "not set");
94 	}
95 
96 	if (username == NULL)
97 		return (PAM_USER_UNKNOWN);
98 
99 	/* stop masquerades by mapping username to uid to username */
100 
101 	if ((pw_entry = getpwnam_r(username, &pwd, buf, sizeof (buf))) == NULL)
102 		return (PAM_USER_UNKNOWN);
103 	if ((pw_entry = getpwuid_r(pw_entry->pw_uid, &pwd, buf,
104 	    sizeof (buf))) == NULL)
105 		return (PAM_USER_UNKNOWN);
106 	/*
107 	 * If there's no user_attr entry for the primary user or it's not a
108 	 * role, no further checks are needed.
109 	 */
110 
111 	if (((user_entry = getusernam(pw_entry->pw_name)) == NULL) ||
112 	    ((kva_value = kva_match((kva_t *)user_entry->attr,
113 	    USERATTR_TYPE_KW)) == NULL) ||
114 	    ((strcmp(kva_value, USERATTR_TYPE_NONADMIN_KW) != 0) &&
115 	    (strcmp(kva_value, USERATTR_TYPE_ADMIN_KW) != 0))) {
116 		free_userattr(user_entry);
117 		return (PAM_IGNORE);
118 	}
119 	free_userattr(user_entry);
120 
121 	/* username is a role */
122 
123 	if (strcmp(username, pw_entry->pw_name) != 0) {
124 		__pam_log(LOG_AUTH | LOG_ALERT,
125 		    "pam_roles:pam_sm_acct_mgmt: user name %s "
126 		    "maps to user id %d which is user name %s",
127 		    username, pw_entry->pw_uid, pw_entry->pw_name);
128 
129 	}
130 
131 	/* Who's the user requesting the role? */
132 
133 	if (auser != NULL && *auser != '\0') {
134 		/* authenticated requesting user */
135 
136 		user_entry = getusernam(auser);
137 	} else {
138 		/* user is implied by real UID */
139 
140 		if ((uid = getuid()) == 0) {
141 			/*
142 			 * Root user_attr entry cannot have roles.
143 			 * Force error and deny access.
144 			 */
145 			user_entry = NULL;
146 		} else {
147 			if ((pw_entry = getpwuid_r(uid, &pwd, buf,
148 			    sizeof (buf))) == NULL) {
149 				return (PAM_USER_UNKNOWN);
150 			}
151 			user_entry = getusernam(pw_entry->pw_name);
152 		}
153 	}
154 
155 	if ((rhost != NULL && *rhost != '\0') &&
156 	    allow_remote == 0) {
157 		/* don't allow remote roles for this service */
158 
159 		free_userattr(user_entry);
160 		return (PAM_PERM_DENIED);
161 	}
162 
163 	/*
164 	 * If the original user does not have a user_attr entry or isn't
165 	 * assigned the role being assumed, fail.
166 	 */
167 
168 	if ((user_entry == NULL) ||
169 	    ((kva_value = kva_match((kva_t *)user_entry->attr,
170 	    USERATTR_ROLES_KW)) == NULL) ||
171 	    (roleinlist(kva_value, username) == 0)) {
172 		free_userattr(user_entry);
173 		(void) strlcpy(messages[0], dgettext(TEXT_DOMAIN,
174 		    "Roles can only be assumed by authorized users"),
175 		    sizeof (messages[0]));
176 		(void) __pam_display_msg(pamh, PAM_ERROR_MSG, 1, messages,
177 		    NULL);
178 		return (PAM_PERM_DENIED);
179 	}
180 
181 	free_userattr(user_entry);
182 	return (PAM_IGNORE);
183 }
184 
185 int
roleinlist(char * list,char * role)186 roleinlist(char *list, char *role)
187 {
188 	char *lasts = (char *)NULL;
189 	char *rolename = (char *)strtok_r(list, ",", &lasts);
190 
191 	while (rolename) {
192 		if (strcmp(rolename, role) == 0)
193 			return (1);
194 		else
195 			rolename = (char *)strtok_r(NULL, ",", &lasts);
196 	}
197 	return (0);
198 }
199