xref: /freebsd/usr.bin/passwd/passwd.c (revision ab40f58ccfe6c07ebefddc72f4661a52fe746353)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 
42 #include <err.h>
43 #include <pwd.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <syslog.h>
47 #include <unistd.h>
48 
49 #include <security/pam_appl.h>
50 #include <security/openpam.h>
51 
52 static pam_handle_t *pamh;
53 static struct pam_conv pamc = {
54 	openpam_ttyconv,
55 	NULL
56 };
57 
58 static char	*yp_domain;
59 static char	*yp_host;
60 
61 static void
62 usage(void)
63 {
64 	fprintf(stderr, "usage: passwd [-ly] [-d domain] [-h host] [user]\n");
65 	exit(1);
66 }
67 
68 int
69 main(int argc, char *argv[])
70 {
71 	char hostname[MAXHOSTNAMELEN];
72 	struct passwd *pwd = NULL; /* Keep compiler happy. */
73 	int o, pam_err;
74 	uid_t uid;
75 
76 	while ((o = getopt(argc, argv, "d:h:loy")) != -1)
77 		switch (o) {
78 		case 'd':
79 			yp_domain = optarg;
80 			break;
81 		case 'h':
82 			yp_host = optarg;
83 			break;
84 		case 'l':
85 		case 'o':
86 		case 'y':
87 			/* compatibility */
88 			break;
89 		default:
90 			usage();
91 		}
92 
93 	argc -= optind;
94 	argv += optind;
95 
96 	uid = getuid();
97 
98 	switch (argc) {
99 	case 0:
100 		if ((pwd = getpwuid(uid)) == NULL)
101 			errx(1, "who are you?");
102 		break;
103 	case 1:
104 		if ((pwd = getpwnam(*argv)) == NULL)
105 			errx(1, "%s: no such user", *argv);
106 		break;
107 	default:
108 		usage();
109 	}
110 
111 	if (uid != 0 && uid != pwd->pw_uid)
112 		errx(1, "permission denied");
113 
114 	/* check where the user's from */
115 	switch (pwd->pw_fields & _PWF_SOURCE) {
116 	case _PWF_FILES:
117 		fprintf(stderr, "Changing local password for %s\n",
118 		    pwd->pw_name);
119 		break;
120 	case _PWF_NIS:
121 		fprintf(stderr, "Changing NIS password for %s\n",
122 		    pwd->pw_name);
123 		break;
124 	default:
125 		/* XXX: Green men ought to be supported via PAM. */
126 		errx(1,
127 	  "Sorry, `passwd' can only change passwords for local or NIS users.");
128 	}
129 
130 #define pam_check(func) do { \
131 	if (pam_err != PAM_SUCCESS) { \
132 		if (pam_err == PAM_AUTH_ERR || pam_err == PAM_PERM_DENIED || \
133 		    pam_err == PAM_AUTHTOK_RECOVERY_ERR) \
134 			warnx("sorry"); \
135 		else \
136 			warnx("%s(): %s", func, pam_strerror(pamh, pam_err)); \
137 		goto end; \
138 	} \
139 } while (0)
140 
141 	/* initialize PAM */
142 	pam_err = pam_start("passwd", pwd->pw_name, &pamc, &pamh);
143 	pam_check("pam_start");
144 
145 	pam_err = pam_set_item(pamh, PAM_TTY, ttyname(STDERR_FILENO));
146 	pam_check("pam_set_item");
147 	gethostname(hostname, sizeof hostname);
148 	pam_err = pam_set_item(pamh, PAM_RHOST, hostname);
149 	pam_check("pam_set_item");
150 	pam_err = pam_set_item(pamh, PAM_RUSER, getlogin());
151 	pam_check("pam_set_item");
152 
153 	/* set YP domain and host */
154 	pam_err = pam_set_data(pamh, "yp_domain", yp_domain, NULL);
155 	pam_check("pam_set_data");
156 	pam_err = pam_set_data(pamh, "yp_server", yp_host, NULL);
157 	pam_check("pam_set_data");
158 
159 	/* set new password */
160 	pam_err = pam_chauthtok(pamh, 0);
161 	pam_check("pam_chauthtok");
162 
163  end:
164 	pam_end(pamh, pam_err);
165 	exit(pam_err == PAM_SUCCESS ? 0 : 1);
166 }
167