1 /* $NetBSD: pam_group.c,v 1.12 2009/03/08 19:38:03 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2003 Networks Associates Technology, Inc.
5 * All rights reserved.
6 *
7 * Portions of this software were developed for the FreeBSD Project by
8 * ThinkSec AS and NAI Labs, the Security Research Division of Network
9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
10 * ("CBOSS"), as part of the DARPA CHATS research program.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote
21 * products derived from this software without specific prior written
22 * permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/cdefs.h>
38 #ifdef __FreeBSD__
39 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_group/pam_group.c,v 1.4 2003/12/11 13:55:15 des Exp $");
40 #else
41 __RCSID("$NetBSD: pam_group.c,v 1.12 2009/03/08 19:38:03 christos Exp $");
42 #endif
43
44 #include <sys/types.h>
45
46 #include <grp.h>
47 #include <pwd.h>
48 #include <stdarg.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 #include <login_cap.h>
54
55 #define PAM_SM_AUTH
56
57 #include <security/pam_appl.h>
58 #include <security/pam_modules.h>
59 #include <security/pam_mod_misc.h>
60 #include <security/openpam.h>
61
62 static int authenticate(pam_handle_t *, struct passwd *, int);
63
64 #define PASSWORD_PROMPT "%s's password:"
65
66 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)67 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
68 int argc __unused, const char *argv[] __unused)
69 {
70 const char *group, *user;
71 const void *ruser;
72 char *const *list;
73 struct passwd *pwd, pwres;
74 struct group *grp, grres;
75 int pam_err, auth;
76 char *promptresp = NULL;
77 char pwbuf[1024];
78 char grbuf[1024];
79
80 /* get target account */
81 if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
82 user == NULL ||
83 getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
84 pwd == NULL)
85 return (PAM_AUTH_ERR);
86 if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
87 return (PAM_IGNORE);
88
89 /* get applicant */
90 if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS ||
91 ruser == NULL ||
92 getpwnam_r(ruser, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
93 pwd == NULL)
94 return (PAM_AUTH_ERR);
95
96 auth = openpam_get_option(pamh, "authenticate") != NULL;
97
98 /* get regulating group */
99 if ((group = openpam_get_option(pamh, "group")) == NULL)
100 group = "wheel";
101 if (getgrnam_r(group, &grres, grbuf, sizeof(grbuf), &grp) != 0 ||
102 grp == NULL || grp->gr_mem == NULL)
103 goto failed;
104
105 /* check if the group is empty */
106 if (*grp->gr_mem == NULL)
107 goto failed;
108
109 /* check membership */
110 if (pwd->pw_gid == grp->gr_gid)
111 goto found;
112 for (list = grp->gr_mem; *list != NULL; ++list)
113 if (strcmp(*list, pwd->pw_name) == 0)
114 goto found;
115
116 not_found:
117 if (openpam_get_option(pamh, "deny"))
118 return (PAM_SUCCESS);
119 if (!auth) {
120 pam_err = pam_prompt(pamh, PAM_ERROR_MSG, &promptresp,
121 "%s: You are not listed in the correct secondary group"
122 " (%s) to %s %s.", getprogname(), group, getprogname(),
123 user);
124 if (pam_err == PAM_SUCCESS && promptresp)
125 free(promptresp);
126 }
127 return (PAM_AUTH_ERR);
128 found:
129 if (auth)
130 if ((pam_err = authenticate(pamh, pwd, flags)) != PAM_SUCCESS)
131 return pam_err;
132
133 if (openpam_get_option(pamh, "deny"))
134 return (PAM_AUTH_ERR);
135 return (PAM_SUCCESS);
136 failed:
137 if (openpam_get_option(pamh, "fail_safe"))
138 goto found;
139 else
140 goto not_found;
141 }
142
143 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)144 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
145 int argc __unused, const char *argv[] __unused)
146 {
147
148 return (PAM_SUCCESS);
149 }
150
151 static int
authenticate(pam_handle_t * pamh,struct passwd * pwd,int flags)152 authenticate(pam_handle_t *pamh, struct passwd *pwd, int flags)
153 {
154 int retval;
155 login_cap_t *lc;
156 const char *pass;
157 char password_prompt[80];
158
159 (void) snprintf(password_prompt, sizeof(password_prompt),
160 PASSWORD_PROMPT, pwd->pw_name);
161 lc = login_getpwclass(pwd);
162 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, password_prompt);
163 login_close(lc);
164
165 if (retval != PAM_SUCCESS)
166 return retval;
167 PAM_LOG("Got password");
168 if (strcmp(crypt(pass, pwd->pw_passwd), pwd->pw_passwd) == 0)
169 return PAM_SUCCESS;
170
171 PAM_VERBOSE_ERROR("UNIX authentication refused");
172 return PAM_AUTH_ERR;
173 }
174
175
176 PAM_MODULE_ENTRY("pam_group");
177