1 /* $NetBSD: pam_passwd.c,v 1.7 2021/09/10 21:52:18 rillig Exp $ */
2
3 /*-
4 * Copyright (c) 2002 Networks Associates Technologies, Inc.
5 * All rights reserved.
6 *
7 * This software was developed for the FreeBSD Project by ThinkSec AS and
8 * NAI Labs, the Security Research Division of Network Associates, Inc.
9 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
10 * 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/usr.bin/passwd/passwd.c,v 1.23 2003/04/18 21:27:09 nectar Exp $");
40 #else
41 __RCSID("$NetBSD: pam_passwd.c,v 1.7 2021/09/10 21:52:18 rillig Exp $");
42 #endif
43
44 #include <sys/param.h>
45
46 #include <err.h>
47 #include <pwd.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <syslog.h>
51 #include <unistd.h>
52
53 #include "extern.h"
54
55 #include <security/pam_appl.h>
56 #include <security/openpam.h>
57
58 static pam_handle_t *pamh;
59 static struct pam_conv pamc = {
60 openpam_ttyconv,
61 NULL
62 };
63
64 #define pam_check(msg) \
65 do { \
66 if (pam_err != PAM_SUCCESS) { \
67 warnx("%s: %s", (msg), pam_strerror(pamh, pam_err)); \
68 goto end; \
69 } \
70 } while (0)
71
72 void
pwpam_process(const char * username,int argc,char ** argv)73 pwpam_process(const char *username, int argc, char **argv)
74 {
75 int ch, pam_err;
76 char hostname[MAXHOSTNAMELEN + 1];
77
78 /* details about the invoking user for logging */
79 const uid_t i_uid = getuid();
80 const struct passwd *const i_pwd = getpwuid(i_uid);
81 const char *const i_username = (i_pwd && i_pwd->pw_name)
82 ? i_pwd->pw_name : "(null)";
83
84 while ((ch = getopt(argc, argv, "")) != -1) {
85 switch (ch) {
86 default:
87 usage();
88 /* NOTREACHED */
89 }
90 }
91
92 argc -= optind;
93 argv += optind;
94
95 switch (argc) {
96 case 0:
97 /* username already provided */
98 break;
99 case 1:
100 username = argv[0];
101 break;
102 default:
103 usage();
104 /* NOTREACHED */
105 }
106
107 (void)printf("Changing password for %s.\n", username);
108
109 /* initialize PAM -- always use the program name "passwd" */
110 pam_err = pam_start("passwd", username, &pamc, &pamh);
111 if (pam_err != PAM_SUCCESS)
112 errx(1, "unable to start PAM session: %s",
113 pam_strerror(NULL, pam_err));
114
115 pam_err = pam_set_item(pamh, PAM_TTY, ttyname(STDERR_FILENO));
116 pam_check("unable to set TTY");
117
118 (void)gethostname(hostname, sizeof hostname);
119 pam_err = pam_set_item(pamh, PAM_RHOST, hostname);
120 pam_check("unable to set RHOST");
121
122 pam_err = pam_set_item(pamh, PAM_RUSER, getlogin());
123 pam_check("unable to set RUSER");
124
125 /* set new password */
126 pam_err = pam_chauthtok(pamh, 0);
127 if (pam_err != PAM_SUCCESS) {
128 if (pam_err == PAM_PERM_DENIED) {
129 syslog(LOG_AUTH | LOG_NOTICE,
130 "user %s (UID %lu) failed to change the "
131 "PAM authentication token of user %s: %s",
132 i_username, (unsigned long)i_uid, username,
133 pam_strerror(pamh, pam_err));
134 }
135 printf("Unable to change auth token: %s\n",
136 pam_strerror(pamh, pam_err));
137 } else {
138 syslog(LOG_AUTH | LOG_INFO,
139 "user %s (UID %lu) successfully changed the "
140 "PAM authentication token of user %s",
141 i_username, (unsigned long)i_uid, username);
142 }
143
144 end:
145 pam_end(pamh, pam_err);
146 if (pam_err == PAM_SUCCESS)
147 return;
148 exit(1);
149 }
150