xref: /freebsd/usr.bin/chpass/chpass.c (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
1 /*-
2  * Copyright (c) 1988, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1988, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #if 0
41 #ifndef lint
42 static char sccsid[] = "@(#)chpass.c	8.4 (Berkeley) 4/2/94";
43 #endif /* not lint */
44 #endif
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/param.h>
50 #include <sys/stat.h>
51 #include <sys/signal.h>
52 #include <sys/time.h>
53 #include <sys/resource.h>
54 
55 #include <ctype.h>
56 #include <err.h>
57 #include <errno.h>
58 #include <fcntl.h>
59 #include <pwd.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <unistd.h>
64 
65 #include <pw_scan.h>
66 #include <pw_util.h>
67 #include "pw_copy.h"
68 #ifdef YP
69 #include <rpcsvc/yp.h>
70 int yp_errno = YP_TRUE;
71 #include "pw_yp.h"
72 #endif
73 
74 #include "chpass.h"
75 #include "pathnames.h"
76 
77 char *tempname;
78 uid_t uid;
79 
80 void	baduser(void);
81 void	usage(void);
82 
83 char localhost[] = "localhost";
84 
85 int
86 main(int argc, char *argv[])
87 {
88 	enum { NEWSH, LOADENTRY, EDITENTRY, NEWPW, NEWEXP } op;
89 	struct passwd *pw = NULL, lpw, old_pw;
90 	char *username = NULL;
91 	int ch, pfd, tfd;
92 	char *arg = NULL;
93 #ifdef YP
94 	int force_local = 0;
95 	int force_yp = 0;
96 #endif
97 
98 	op = EDITENTRY;
99 #ifdef YP
100 	while ((ch = getopt(argc, argv, "a:p:s:e:d:h:oly")) != -1)
101 #else
102 	while ((ch = getopt(argc, argv, "a:p:s:e:")) != -1)
103 #endif
104 		switch(ch) {
105 		case 'a':
106 			op = LOADENTRY;
107 			arg = optarg;
108 			break;
109 		case 's':
110 			op = NEWSH;
111 			arg = optarg;
112 			break;
113 		case 'p':
114 			op = NEWPW;
115 			arg = optarg;
116 			break;
117 		case 'e':
118 			op = NEWEXP;
119 			arg = optarg;
120 			break;
121 #ifdef YP
122 		case 'h':
123 #ifdef PARANOID
124 			if (getuid()) {
125 				warnx("Only the superuser can use the -h flag");
126 			} else {
127 #endif
128 				yp_server = optarg;
129 #ifdef PARANOID
130 			}
131 #endif
132 			break;
133 		case 'd':
134 #ifdef PARANOID
135 			if (getuid()) {
136 				warnx("Only the superuser can use the -d flag");
137 			} else {
138 #endif
139 				yp_domain = optarg;
140 				if (yp_server == NULL)
141 					yp_server = localhost;
142 #ifdef PARANOID
143 			}
144 #endif
145 			break;
146 		case 'l':
147 			_use_yp = 0;
148 			force_local = 1;
149 			break;
150 		case 'y':
151 			_use_yp = force_yp = 1;
152 			break;
153 		case 'o':
154 			force_old++;
155 			break;
156 #endif
157 		case '?':
158 		default:
159 			usage();
160 		}
161 	argc -= optind;
162 	argv += optind;
163 
164 	uid = getuid();
165 
166 	if (op == EDITENTRY || op == NEWSH || op == NEWPW || op == NEWEXP) {
167 		switch(argc) {
168 #ifdef YP
169 		case 0:
170 			GETPWUID(uid)
171 			get_yp_master(1); /* XXX just to set the suser flag */
172 			break;
173 		case 1:
174 			GETPWNAM(*argv)
175 			get_yp_master(1); /* XXX just to set the suser flag */
176 #else
177 		case 0:
178 			if (!(pw = getpwuid(uid)))
179 				errx(1, "unknown user: uid %lu",
180 				    (unsigned long)uid);
181 			break;
182 		case 1:
183 			if (!(pw = getpwnam(*argv)))
184 				errx(1, "unknown user: %s", *argv);
185 #endif
186 			if (uid && uid != pw->pw_uid)
187 				baduser();
188 			break;
189 		default:
190 			usage();
191 		}
192 
193 		/* Make a copy for later verification */
194 		old_pw = *pw;
195 		old_pw.pw_gecos = strdup(old_pw.pw_gecos);
196 	}
197 
198 	if (op == NEWSH) {
199 		/* protect p_shell -- it thinks NULL is /bin/sh */
200 		if (!arg[0])
201 			usage();
202 		if (p_shell(arg, pw, (ENTRY *)NULL))
203 			pw_error((char *)NULL, 0, 1);
204 	}
205 
206 	if (op == NEWEXP) {
207 		if (uid)	/* only root can change expire */
208 			baduser();
209 		if (p_expire(arg, pw, (ENTRY *)NULL))
210 			pw_error((char *)NULL, 0, 1);
211 	}
212 
213 	if (op == LOADENTRY) {
214 		if (uid)
215 			baduser();
216 		pw = &lpw;
217 		if (!__pw_scan(arg, pw, _PWSCAN_WARN|_PWSCAN_MASTER))
218 			exit(1);
219 	}
220 	username = pw->pw_name;
221 
222 	if (op == NEWPW) {
223 		if (uid)
224 			baduser();
225 
226 		if(strchr(arg, ':')) {
227 			errx(1, "invalid format for password");
228 		}
229 		pw->pw_passwd = arg;
230 	}
231 
232 	/*
233 	 * The temporary file/file descriptor usage is a little tricky here.
234 	 * 1:	Create a temporary file called tempname, get descriptor tfd.
235 	 * 2:	Display() gets an fp for the temporary file, and copies the
236 	 *	user's information into it.  It then gives the temporary file
237 	 *	to the user and closes the fp, closing the underlying fd.
238 	 * 3:	The user edits the temporary file some number of times.
239 	 *	The results are stored in pw by edit().
240 	 * 4:	Delete the temporary file.
241 	 * 5:	Make a new temporary file, descriptor tfd.
242 	 * 6:	Get a descriptor for the master.passwd file, pfd, and
243 	 *	lock master.passwd.
244 	 * 7:	Pw_copy() gets descriptors for master.passwd and the
245 	 *	temporary file and copies the master password file into it,
246 	 *	replacing the modified user's record with a new one.  We can't
247 	 *	use the first temporary file for this because it was owned
248 	 *	by the user.  Pass the new and old user info.  Check the
249 	 *	entry for our user has not been changed by someone else by
250 	 *	while the user was editing by comparing the old info to
251 	 *	the entry freshly read from master.passwd. Pw_copy() closes
252 	 *	its fp, flushing the data and closing the underlying file
253 	 *	descriptor.  We can't close the master password fp, or we'd
254 	 *	lose the lock.
255 	 * 8:	Call pw_mkdb() (which renames the temporary file) and exit.
256 	 *	The exit closes the master passwd fp/fd.
257 	 */
258 	pw_init();
259 	tfd = pw_tmp();
260 
261 	if (op == EDITENTRY) {
262 		display(tfd, pw);
263 		edit(pw);
264 		(void)unlink(tempname);
265 		tfd = pw_tmp();
266 	}
267 
268 #ifdef YP
269 	if (_use_yp) {
270 		yp_submit(pw);
271 		(void)unlink(tempname);
272 	} else {
273 #endif /* YP */
274 	pfd = pw_lock();
275 	pw_copy(pfd, tfd, pw, (op == LOADENTRY) ? NULL : &old_pw);
276 
277 	if (!pw_mkdb(username))
278 		pw_error((char *)NULL, 0, 1);
279 #ifdef YP
280 	}
281 #endif /* YP */
282 	exit(0);
283 }
284 
285 void
286 baduser(void)
287 {
288 	errx(1, "%s", strerror(EACCES));
289 }
290 
291 void
292 usage(void)
293 {
294 
295 	(void)fprintf(stderr,
296 #ifdef YP
297 		"usage: chpass [-o] [-l] [-y] [-d domain] [-h host] [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
298 #else
299 		"usage: chpass [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
300 #endif
301 	exit(1);
302 }
303