login_chpass.c revision 1.18 
1/*	$OpenBSD: login_chpass.c,v 1.18 2015/10/22 12:32:33 tedu Exp $	*/
2
3/*-
4 * Copyright (c) 1995,1996 Berkeley Software Design, Inc. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *      This product includes software developed by Berkeley Software Design,
17 *      Inc.
18 * 4. The name of Berkeley Software Design, Inc.  may not be used to endorse
19 *    or promote products derived from this software without specific prior
20 *    written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``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 BERKELEY SOFTWARE DESIGN, INC. 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 *	BSDI $From: login_chpass.c,v 1.3 1996/08/21 21:01:48 prb Exp $
35 */
36#include <sys/stat.h>
37#include <sys/time.h>
38#include <sys/resource.h>
39#include <sys/file.h>
40#include <sys/uio.h>
41#include <sys/wait.h>
42
43#include <err.h>
44#include <errno.h>
45#include <pwd.h>
46#include <signal.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <string.h>
50#include <syslog.h>
51#include <unistd.h>
52#include <login_cap.h>
53
54#ifdef YP
55# include <netdb.h>
56# include <rpc/rpc.h>
57# include <rpcsvc/yp_prot.h>
58# include <rpcsvc/ypclnt.h>
59# define passwd yp_passwd_rec
60# include <rpcsvc/yppasswd.h>
61# undef passwd
62#endif
63
64#define	_PATH_LOGIN_LCHPASS	"/usr/libexec/auth/login_lchpass"
65
66#define BACK_CHANNEL	3
67
68#ifdef  YP
69struct iovec iov[2] = { { BI_SILENT, sizeof(BI_SILENT) - 1 }, { "\n", 1 } };
70
71int	_yp_check(char **);
72char	*ypgetnewpasswd(struct passwd *, char **);
73struct passwd *ypgetpwnam(char *);
74void	kbintr(int);
75int	pwd_gensalt(char *, int, login_cap_t *, char);
76#endif
77
78void	local_chpass(char **);
79void	yp_chpass(char *);
80
81int
82main(int argc, char *argv[])
83{
84#ifdef YP
85	char *username;
86#endif
87	struct rlimit rl;
88	int c;
89
90	rl.rlim_cur = 0;
91	rl.rlim_max = 0;
92	(void)setrlimit(RLIMIT_CORE, &rl);
93
94	(void)setpriority(PRIO_PROCESS, 0, 0);
95
96	openlog("login", LOG_ODELAY, LOG_AUTH);
97
98	while ((c = getopt(argc, argv, "s:v:")) != -1)
99		switch (c) {
100		case 'v':
101			break;
102		case 's':	/* service */
103			if (strcmp(optarg, "login") != 0) {
104				syslog(LOG_ERR, "%s: invalid service", optarg);
105				exit(1);
106			}
107			break;
108		default:
109			syslog(LOG_ERR, "usage error");
110			exit(1);
111		}
112
113	switch (argc - optind) {
114	case 2:
115		/* class is not used */
116	case 1:
117#ifdef YP
118		username = argv[optind];
119#endif
120		break;
121	default:
122		syslog(LOG_ERR, "usage error");
123		exit(1);
124	}
125
126#ifdef  YP
127	if (_yp_check(NULL))
128		yp_chpass(username);
129#endif
130	local_chpass(argv);
131	/* NOTREACHED */
132	exit(0);
133}
134
135void
136local_chpass(char *argv[])
137{
138
139	/* login_lchpass doesn't check instance so don't bother restoring it */
140	argv[0] = strrchr(_PATH_LOGIN_LCHPASS, '/') + 1;
141	execv(_PATH_LOGIN_LCHPASS, argv);
142	syslog(LOG_ERR, "%s: %m", _PATH_LOGIN_LCHPASS);
143	exit(1);
144}
145
146#ifdef YP
147void
148yp_chpass(char *username)
149{
150	char *master;
151	int r, rpcport, status;
152	struct yppasswd yppasswd;
153	struct passwd *pw;
154	struct timeval tv;
155	CLIENT *client;
156	extern char *domain;
157
158	(void)signal(SIGINT, kbintr);
159	(void)signal(SIGQUIT, kbintr);
160
161	if ((r = yp_get_default_domain(&domain)) != 0) {
162		warnx("can't get local YP domain. Reason: %s", yperr_string(r));
163		exit(1);
164	}
165
166	/*
167	 * Find the host for the passwd map; it should be running
168	 * the daemon.
169	 */
170	if ((r = yp_master(domain, "passwd.byname", &master)) != 0) {
171		warnx("can't find the master YP server. Reason: %s",
172		    yperr_string(r));
173		exit(1);
174	}
175
176	/* Ask the portmapper for the port of the daemon. */
177	if ((rpcport = getrpcport(master, YPPASSWDPROG,
178	    YPPASSWDPROC_UPDATE, IPPROTO_UDP)) == 0) {
179		warnx("master YP server not running yppasswd daemon.");
180		warnx("Can't change password.");
181		exit(1);
182	}
183
184	if (rpcport >= IPPORT_RESERVED) {
185		warnx("yppasswd daemon is on an invalid port.");
186		exit(1);
187	}
188
189	/* If user doesn't exist, just prompt for old password and exit. */
190	pw = ypgetpwnam(username);
191	if (pw) {
192		if (pw->pw_uid == 0) {
193			syslog(LOG_ERR, "attempted root password change");
194			pw = NULL;
195		} else if (*pw->pw_passwd == '\0') {
196			syslog(LOG_ERR, "%s attempting to add password",
197			    username);
198			pw = NULL;
199		}
200	}
201	if (pw == NULL) {
202		char *p;
203		/* no such user, but fake to thwart timing attack */
204		if ((p = getpass("Old password:")) != NULL) {
205			crypt_checkpass(p, NULL);
206			explicit_bzero(p, strlen(p));
207		}
208		warnx("YP passwd database unchanged.");
209		exit(1);
210	}
211
212	/* prompt for new password */
213	yppasswd.newpw.pw_passwd = ypgetnewpasswd(pw, &yppasswd.oldpass);
214
215	/* tell rpc.yppasswdd */
216	yppasswd.newpw.pw_name	= pw->pw_name;
217	yppasswd.newpw.pw_uid	= pw->pw_uid;
218	yppasswd.newpw.pw_gid	= pw->pw_gid;
219	yppasswd.newpw.pw_gecos = pw->pw_gecos;
220	yppasswd.newpw.pw_dir	= pw->pw_dir;
221	yppasswd.newpw.pw_shell	= pw->pw_shell;
222
223	client = clnt_create(master, YPPASSWDPROG, YPPASSWDVERS, "udp");
224	if (client == NULL) {
225		warnx("cannot contact yppasswdd on %s: Reason: %s",
226		    master, yperr_string(YPERR_YPBIND));
227		free(yppasswd.newpw.pw_passwd);
228		exit(1);
229	}
230	client->cl_auth = authunix_create_default();
231	tv.tv_sec = 2;
232	tv.tv_usec = 0;
233	r = clnt_call(client, YPPASSWDPROC_UPDATE,
234	    xdr_yppasswd, &yppasswd, xdr_int, &status, tv);
235	if (r)
236		warnx("rpc to yppasswdd failed.");
237	else if (status) {
238		printf("Couldn't change YP password.\n");
239		free(yppasswd.newpw.pw_passwd);
240		exit(1);
241	}
242	printf("The YP password has been changed on %s, the master YP passwd server.\n",
243	    master);
244	free(yppasswd.newpw.pw_passwd);
245	(void)writev(BACK_CHANNEL, iov, 2);
246	exit(0);
247}
248
249/* ARGSUSED */
250void
251kbintr(int signo)
252{
253	char msg[] = "YP passwd database unchanged.\n";
254	struct iovec iv[3];
255	extern char *__progname;
256
257	iv[0].iov_base = __progname;
258	iv[0].iov_len = strlen(__progname);
259	iv[1].iov_base = ": ";
260	iv[1].iov_len = 2;
261	iv[2].iov_base = msg;
262	iv[2].iov_len = sizeof(msg) - 1;
263	writev(STDERR_FILENO, iv, 3);
264
265	_exit(1);
266}
267#endif
268