xref: /illumos-gate/usr/src/lib/pam_modules/sample/sample_acct_mgmt.c (revision cbea7aca3fd7787405cbdbd93752998f03dfc25f)
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  * Copyright (c) 2016 by Delphix. All rights reserved.
25  * Copyright 2023 OmniOS Community Edition (OmniOSce) Association.
26  */
27 
28 #include <syslog.h>
29 #include <pwd.h>
30 #include <unistd.h>
31 #include <strings.h>
32 #include <security/pam_appl.h>
33 #include <security/pam_modules.h>
34 #include <libintl.h>
35 
36 static int parse_allow_name(const char *, char *);
37 
38 /*
39  * pam_sm_acct_mgmt	main account managment routine.
40  *			XXX: The routine just prints out a warning message.
41  *			     It may need to force the user to change their
42  *			     passwd.
43  */
44 
45 int
pam_sm_acct_mgmt(pam_handle_t * pamh,int flags,int argc,const char ** argv)46 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
47 {
48 	const char *user;
49 	const char *pg;
50 	int i;
51 	int debug __unused = 0;
52 	int nowarn __unused = 0;
53 	int error = 0;
54 
55 	if (argc == 0)
56 		return (PAM_SUCCESS);
57 
58 	if (pam_get_item(pamh, PAM_USER, (const void **)&user) != PAM_SUCCESS)
59 		return (PAM_SERVICE_ERR);
60 
61 	if (pam_get_item(pamh, PAM_SERVICE, (const void **)&pg) != PAM_SUCCESS)
62 		return (PAM_SERVICE_ERR);
63 
64 	/*
65 	 * kludge alert. su needs to be handled specially for allow policy.
66 	 * we want to use the policy of the current user not the "destination"
67 	 * user. This will enable us to prevent su to root but not to rlogin,
68 	 * telnet, rsh, ftp to root.
69 	 *
70 	 * description of problem: user name is the "destination" name. not
71 	 * the current name. The allow policy needs to be applied to the
72 	 * current name in the case of su. user is "root" in this case and
73 	 * we will be getting the root policy instead of the user policy.
74 	 */
75 	if (strcmp(pg, "su") == 0) {
76 		struct passwd *pw;
77 		uid_t uid;
78 		uid = getuid();
79 		pw = getpwuid(uid);
80 		if (pw == NULL)
81 			return (PAM_SYSTEM_ERR);
82 		user = pw->pw_name;
83 	}
84 
85 	if (user == 0 || *user == '\0' || (strcmp(user, "root") == 0))
86 		return (PAM_SUCCESS);
87 
88 	for (i = 0; i < argc; i++) {
89 		if (strcasecmp(argv[i], "debug") == 0)
90 			debug = 1;
91 		else if (strcasecmp(argv[i], "nowarn") == 0) {
92 			nowarn = 1;
93 			flags = flags | PAM_SILENT;
94 		} else if (strncmp(argv[i], "allow=", 6) == 0)
95 			error |= parse_allow_name(user, (char *)(argv[i]+6));
96 		else
97 			syslog(LOG_DEBUG, "illegal option %s", argv[i]);
98 	}
99 	return (error?PAM_SUCCESS:PAM_AUTH_ERR);
100 }
101 
102 static char *getname();
103 
104 static int
parse_allow_name(const char * who,char * cp)105 parse_allow_name(const char *who, char *cp)
106 {
107 	char name[256];
108 
109 	/* catch "allow=" */
110 	if (*cp == '\0')
111 		return (0);
112 	while (cp) {
113 		cp = getname(cp, name);
114 		/* catch things such as =, and ,, */
115 		if (*name == '\0')
116 			continue;
117 		if (strcmp(who, name) == 0)
118 			return (1);
119 	}
120 	return (0);
121 }
122 
123 static char *
getname(char * cp,char * name)124 getname(char *cp, char *name)
125 {
126 	/* force name to be initially null string */
127 	*name = '\0';
128 
129 	/* end of string? */
130 	if (*cp == '\0')
131 		return ((char *)0);
132 	while (*cp) {
133 		/* end of name? */
134 		if (*cp == ',' || *cp == '\0')
135 			break;
136 		*name++ = *cp++;
137 	}
138 	/* make name into string */
139 	*name++ = '\0';
140 	return ((*cp == '\0')? (char *)0 : ++cp);
141 }
142