xref: /freebsd/usr.bin/passwd/passwd.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
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/param.h>
38 
39 #include <err.h>
40 #include <pwd.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <syslog.h>
44 #include <unistd.h>
45 
46 #include <security/pam_appl.h>
47 #include <security/openpam.h>
48 
49 static pam_handle_t *pamh;
50 static struct pam_conv pamc = {
51 	openpam_ttyconv,
52 	NULL
53 };
54 
55 static char	*yp_domain;
56 static char	*yp_host;
57 
58 static void
59 usage(void)
60 {
61 	fprintf(stderr, "usage: passwd [-ly] [-d domain] [-h host] [user]\n");
62 	exit(1);
63 }
64 
65 int
66 main(int argc, char *argv[])
67 {
68 	char hostname[MAXHOSTNAMELEN];
69 	struct passwd *pwd = NULL; /* Keep compiler happy. */
70 	int o, pam_err;
71 	uid_t uid;
72 
73 	while ((o = getopt(argc, argv, "d:h:loy")) != -1)
74 		switch (o) {
75 		case 'd':
76 			yp_domain = optarg;
77 			break;
78 		case 'h':
79 			yp_host = optarg;
80 			break;
81 		case 'l':
82 		case 'o':
83 		case 'y':
84 			/* compatibility */
85 			break;
86 		default:
87 			usage();
88 		}
89 
90 	argc -= optind;
91 	argv += optind;
92 
93 	uid = getuid();
94 
95 	switch (argc) {
96 	case 0:
97 		if ((pwd = getpwuid(uid)) == NULL)
98 			errx(1, "who are you?");
99 		break;
100 	case 1:
101 		if ((pwd = getpwnam(*argv)) == NULL)
102 			errx(1, "%s: no such user", *argv);
103 		break;
104 	default:
105 		usage();
106 	}
107 
108 	if (uid != 0 && uid != pwd->pw_uid)
109 		errx(1, "permission denied");
110 
111 	/* check where the user's from */
112 	switch (pwd->pw_fields & _PWF_SOURCE) {
113 	case _PWF_FILES:
114 		fprintf(stderr, "Changing local password for %s\n",
115 		    pwd->pw_name);
116 		break;
117 	case _PWF_NIS:
118 		fprintf(stderr, "Changing NIS password for %s\n",
119 		    pwd->pw_name);
120 		break;
121 	default:
122 		/* XXX: Green men ought to be supported via PAM. */
123 		errx(1,
124 	  "Sorry, `passwd' can only change passwords for local or NIS users.");
125 	}
126 
127 #define pam_check(func) do { \
128 	if (pam_err != PAM_SUCCESS) { \
129 		if (pam_err == PAM_AUTH_ERR || pam_err == PAM_PERM_DENIED || \
130 		    pam_err == PAM_AUTHTOK_RECOVERY_ERR) \
131 			warnx("sorry"); \
132 		else \
133 			warnx("%s(): %s", func, pam_strerror(pamh, pam_err)); \
134 		goto end; \
135 	} \
136 } while (0)
137 
138 	/* initialize PAM */
139 	pam_err = pam_start("passwd", pwd->pw_name, &pamc, &pamh);
140 	pam_check("pam_start");
141 
142 	pam_err = pam_set_item(pamh, PAM_TTY, ttyname(STDERR_FILENO));
143 	pam_check("pam_set_item");
144 	gethostname(hostname, sizeof hostname);
145 	pam_err = pam_set_item(pamh, PAM_RHOST, hostname);
146 	pam_check("pam_set_item");
147 	pam_err = pam_set_item(pamh, PAM_RUSER, getlogin());
148 	pam_check("pam_set_item");
149 
150 	/* set YP domain and host */
151 	pam_err = pam_set_data(pamh, "yp_domain", yp_domain, NULL);
152 	pam_check("pam_set_data");
153 	pam_err = pam_set_data(pamh, "yp_server", yp_host, NULL);
154 	pam_check("pam_set_data");
155 
156 	/* set new password */
157 	pam_err = pam_chauthtok(pamh, 0);
158 	pam_check("pam_chauthtok");
159 
160  end:
161 	pam_end(pamh, pam_err);
162 	exit(pam_err == PAM_SUCCESS ? 0 : 1);
163 }
164