xref: /freebsd/usr.bin/passwd/passwd.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*-
2  * Copyright (c) 2002 Networks Associates Technologies, Inc.
3  * All rights reserved.
4  *
5  * This software was developed for the FreeBSD Project by ThinkSec AS and
6  * NAI Labs, the Security Research Division of Network Associates, Inc.
7  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
8  * DARPA CHATS research program.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote
19  *    products derived from this software without specific prior written
20  *    permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 
40 #include <err.h>
41 #include <pwd.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <syslog.h>
45 #include <unistd.h>
46 
47 #include <security/pam_appl.h>
48 #include <security/openpam.h>
49 
50 static pam_handle_t *pamh;
51 static struct pam_conv pamc = {
52 	openpam_ttyconv,
53 	NULL
54 };
55 
56 static char	*yp_domain;
57 static char	*yp_host;
58 
59 static void
60 usage(void)
61 {
62 	fprintf(stderr, "usage: passwd [-ly] [-d domain] [-h host] [user]\n");
63 	exit(1);
64 }
65 
66 int
67 main(int argc, char *argv[])
68 {
69 	char hostname[MAXHOSTNAMELEN];
70 	struct passwd *pwd;
71 	int o, pam_err;
72 	uid_t uid;
73 
74 	while ((o = getopt(argc, argv, "d:h:loy")) != -1)
75 		switch (o) {
76 		case 'd':
77 			yp_domain = optarg;
78 			break;
79 		case 'h':
80 			yp_host = optarg;
81 			break;
82 		case 'l':
83 		case 'o':
84 		case 'y':
85 			/* compatibility */
86 			break;
87 		default:
88 			usage();
89 		}
90 
91 	argc -= optind;
92 	argv += optind;
93 
94 	uid = getuid();
95 
96 	switch (argc) {
97 	case 0:
98 		if ((pwd = getpwuid(uid)) == NULL)
99 			errx(1, "who are you?");
100 		break;
101 	case 1:
102 		if ((pwd = getpwnam(*argv)) == NULL)
103 			errx(1, "%s: no such user", *argv);
104 		break;
105 	default:
106 		usage();
107 	}
108 
109 	if (uid != 0 && uid != pwd->pw_uid)
110 		errx(1, "permission denied");
111 
112 	/* check where the user's from */
113 	switch (pwd->pw_fields & _PWF_SOURCE) {
114 	case _PWF_FILES:
115 		fprintf(stderr, "Changing local password for %s\n",
116 		    pwd->pw_name);
117 		break;
118 	case _PWF_NIS:
119 		fprintf(stderr, "Changing NIS password for %s\n",
120 		    pwd->pw_name);
121 		break;
122 	default:
123 		/* XXX: Green men ought to be supported via PAM. */
124 		errx(1,
125 	  "Sorry, `passwd' can only change passwords for local or NIS users.");
126 	}
127 
128 #define pam_check(func) do { \
129 	if (pam_err != PAM_SUCCESS) { \
130 		if (pam_err == PAM_AUTH_ERR || pam_err == PAM_PERM_DENIED || \
131 		    pam_err == PAM_AUTHTOK_RECOVERY_ERR) \
132 			warnx("sorry"); \
133 		else \
134 			warnx("%s(): %s", func, pam_strerror(pamh, pam_err)); \
135 		goto end; \
136 	} \
137 } while (0)
138 
139 	/* initialize PAM */
140 	pam_err = pam_start("passwd", pwd->pw_name, &pamc, &pamh);
141 	pam_check("pam_start");
142 
143 	pam_err = pam_set_item(pamh, PAM_TTY, ttyname(STDERR_FILENO));
144 	pam_check("pam_set_item");
145 	gethostname(hostname, sizeof hostname);
146 	pam_err = pam_set_item(pamh, PAM_RHOST, hostname);
147 	pam_check("pam_set_item");
148 	pam_err = pam_set_item(pamh, PAM_RUSER, getlogin());
149 	pam_check("pam_set_item");
150 
151 	/* set YP domain and host */
152 	pam_err = pam_set_data(pamh, "yp_domain", yp_domain, NULL);
153 	pam_check("pam_set_data");
154 	pam_err = pam_set_data(pamh, "yp_server", yp_host, NULL);
155 	pam_check("pam_set_data");
156 
157 	/* set new password */
158 	pam_err = pam_chauthtok(pamh, 0);
159 	pam_check("pam_chauthtok");
160 
161  end:
162 	pam_end(pamh, pam_err);
163 	exit(pam_err == PAM_SUCCESS ? 0 : 1);
164 }
165