1 /*-
2 * Copyright 2000 James Bloom
3 * All rights reserved.
4 * Based upon code Copyright 1998 Juniper Networks, Inc.
5 * Copyright (c) 2001-2003 Networks Associates Technology, Inc.
6 * All rights reserved.
7 *
8 * Portions of this software were developed for the FreeBSD Project by
9 * ThinkSec AS and NAI Labs, the Security Research Division of Network
10 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
11 * ("CBOSS"), as part of the DARPA CHATS research program.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote
22 * products derived from this software without specific prior written
23 * permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD: stable/10/lib/libpam/modules/pam_opie/pam_opie.c 270125 2014-08-18 03:06:49Z ache $");
40
41 #include <sys/types.h>
42 #include <opie.h>
43 #include <pwd.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48
49 #define PAM_SM_AUTH
50
51 #include <security/pam_appl.h>
52 #include <security/pam_modules.h>
53 #include <security/pam_mod_misc.h>
54
55 #define PAM_OPT_NO_FAKE_PROMPTS "no_fake_prompts"
56
57 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)58 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
59 int argc __unused, const char *argv[] __unused)
60 {
61 struct opie opie;
62 struct passwd *pwd;
63 int retval, i;
64 const char *(promptstr[]) = { "%s\nPassword: ", "%s\nPassword [echo on]: "};
65 char challenge[OPIE_CHALLENGE_MAX + 1];
66 char principal[OPIE_PRINCIPAL_MAX];
67 const char *user;
68 char *response;
69 int style;
70
71 user = NULL;
72 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) {
73 if ((pwd = getpwnam(getlogin())) == NULL)
74 return (PAM_AUTH_ERR);
75 user = pwd->pw_name;
76 }
77 else {
78 retval = pam_get_user(pamh, &user, NULL);
79 if (retval != PAM_SUCCESS)
80 return (retval);
81 }
82
83 PAM_LOG("Got user: %s", user);
84
85 /*
86 * Watch out: libopie feels entitled to truncate the user name
87 * passed to it if it's longer than OPIE_PRINCIPAL_MAX, which is
88 * not uncommon in Windows environments.
89 */
90 if (strlen(user) >= sizeof(principal))
91 return (PAM_AUTH_ERR);
92 strlcpy(principal, user, sizeof(principal));
93
94 /*
95 * Don't call the OPIE atexit() handler when our program exits,
96 * since the module has been unloaded and we will SEGV.
97 */
98 opiedisableaeh();
99
100 /*
101 * If the no_fake_prompts option was given, and the user
102 * doesn't have an OPIE key, just fail rather than present the
103 * user with a bogus OPIE challenge.
104 */
105 if (opiechallenge(&opie, principal, challenge) != 0 &&
106 openpam_get_option(pamh, PAM_OPT_NO_FAKE_PROMPTS))
107 return (PAM_AUTH_ERR);
108
109 /*
110 * It doesn't make sense to use a password that has already been
111 * typed in, since we haven't presented the challenge to the user
112 * yet, so clear the stored password.
113 */
114 pam_set_item(pamh, PAM_AUTHTOK, NULL);
115
116 style = PAM_PROMPT_ECHO_OFF;
117 for (i = 0; i < 2; i++) {
118 retval = pam_prompt(pamh, style, &response,
119 promptstr[i], challenge);
120 if (retval != PAM_SUCCESS) {
121 opieunlock();
122 return (retval);
123 }
124
125 PAM_LOG("Completed challenge %d: %s", i, response);
126
127 if (response[0] != '\0')
128 break;
129
130 /* Second time round, echo the password */
131 style = PAM_PROMPT_ECHO_ON;
132 }
133
134 pam_set_item(pamh, PAM_AUTHTOK, response);
135
136 /*
137 * Opieverify is supposed to return -1 only if an error occurs.
138 * But it returns -1 even if the response string isn't in the form
139 * it expects. Thus we can't log an error and can only check for
140 * success or lack thereof.
141 */
142 retval = opieverify(&opie, response);
143 free(response);
144 return (retval == 0 ? PAM_SUCCESS : PAM_AUTH_ERR);
145 }
146
147 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)148 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
149 int argc __unused, const char *argv[] __unused)
150 {
151
152 return (PAM_SUCCESS);
153 }
154
155 PAM_MODULE_ENTRY("pam_opie");
156