xref: /freebsd/usr.bin/chpass/chpass.c (revision c17d43407fe04133a94055b0dbc7ea8965654a9f)
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 #ifndef lint
41 static const char sccsid[] = "From: @(#)chpass.c	8.4 (Berkeley) 4/2/94";
42 static const char rcsid[] =
43   "$FreeBSD$";
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/stat.h>
48 #include <sys/signal.h>
49 #include <sys/time.h>
50 #include <sys/resource.h>
51 
52 #include <ctype.h>
53 #include <err.h>
54 #include <errno.h>
55 #include <fcntl.h>
56 #include <pwd.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #include <pw_scan.h>
63 #include <pw_util.h>
64 #include "pw_copy.h"
65 #ifdef YP
66 #include <rpcsvc/yp.h>
67 int yp_errno = YP_TRUE;
68 #include "pw_yp.h"
69 #endif
70 
71 #include "chpass.h"
72 #include "pathnames.h"
73 
74 char *tempname;
75 uid_t uid;
76 
77 void	baduser(void);
78 void	usage(void);
79 
80 int
81 main(argc, argv)
82 	int argc;
83 	char **argv;
84 {
85 	enum { NEWSH, LOADENTRY, EDITENTRY, NEWPW, NEWEXP } op;
86 	struct passwd *pw = NULL, lpw, old_pw;
87 	char *username = NULL;
88 	int ch, pfd, tfd;
89 	char *arg = NULL;
90 #ifdef YP
91 	int force_local = 0;
92 	int force_yp = 0;
93 #endif
94 
95 	op = EDITENTRY;
96 #ifdef YP
97 	while ((ch = getopt(argc, argv, "a:p:s:e:d:h:oly")) != -1)
98 #else
99 	while ((ch = getopt(argc, argv, "a:p:s:e:")) != -1)
100 #endif
101 		switch(ch) {
102 		case 'a':
103 			op = LOADENTRY;
104 			arg = optarg;
105 			break;
106 		case 's':
107 			op = NEWSH;
108 			arg = optarg;
109 			break;
110 		case 'p':
111 			op = NEWPW;
112 			arg = optarg;
113 			break;
114 		case 'e':
115 			op = NEWEXP;
116 			arg = optarg;
117 			break;
118 #ifdef YP
119 		case 'h':
120 #ifdef PARANOID
121 			if (getuid()) {
122 				warnx("Only the superuser can use the -h flag");
123 			} else {
124 #endif
125 				yp_server = optarg;
126 #ifdef PARANOID
127 			}
128 #endif
129 			break;
130 		case 'd':
131 #ifdef PARANOID
132 			if (getuid()) {
133 				warnx("Only the superuser can use the -d flag");
134 			} else {
135 #endif
136 				yp_domain = optarg;
137 				if (yp_server == NULL)
138 					yp_server = "localhost";
139 #ifdef PARANOID
140 			}
141 #endif
142 			break;
143 		case 'l':
144 			_use_yp = 0;
145 			force_local = 1;
146 			break;
147 		case 'y':
148 			_use_yp = force_yp = 1;
149 			break;
150 		case 'o':
151 			force_old++;
152 			break;
153 #endif
154 		case '?':
155 		default:
156 			usage();
157 		}
158 	argc -= optind;
159 	argv += optind;
160 
161 	uid = getuid();
162 
163 	if (op == EDITENTRY || op == NEWSH || op == NEWPW || op == NEWEXP) {
164 		switch(argc) {
165 #ifdef YP
166 		case 0:
167 			GETPWUID(uid)
168 			get_yp_master(1); /* XXX just to set the suser flag */
169 			break;
170 		case 1:
171 			GETPWNAM(*argv)
172 			get_yp_master(1); /* XXX just to set the suser flag */
173 #else
174 		case 0:
175 			if (!(pw = getpwuid(uid)))
176 				errx(1, "unknown user: uid %lu",
177 				    (unsigned long)uid);
178 			break;
179 		case 1:
180 			if (!(pw = getpwnam(*argv)))
181 				errx(1, "unknown user: %s", *argv);
182 #endif
183 			if (uid && uid != pw->pw_uid)
184 				baduser();
185 			break;
186 		default:
187 			usage();
188 		}
189 
190 		/* Make a copy for later verification */
191 		old_pw = *pw;
192 		old_pw.pw_gecos = strdup(old_pw.pw_gecos);
193 	}
194 
195 	if (op == NEWSH) {
196 		/* protect p_shell -- it thinks NULL is /bin/sh */
197 		if (!arg[0])
198 			usage();
199 		if (p_shell(arg, pw, (ENTRY *)NULL))
200 			pw_error((char *)NULL, 0, 1);
201 	}
202 
203 	if (op == NEWEXP) {
204 		if (uid)	/* only root can change expire */
205 			baduser();
206 		if (p_expire(arg, pw, (ENTRY *)NULL))
207 			pw_error((char *)NULL, 0, 1);
208 	}
209 
210 	if (op == LOADENTRY) {
211 		if (uid)
212 			baduser();
213 		pw = &lpw;
214 		if (!__pw_scan(arg, pw, _PWSCAN_WARN|_PWSCAN_MASTER))
215 			exit(1);
216 	}
217 	username = pw->pw_name;
218 
219 	if (op == NEWPW) {
220 		if (uid)
221 			baduser();
222 
223 		if(strchr(arg, ':')) {
224 			errx(1, "invalid format for password");
225 		}
226 		pw->pw_passwd = arg;
227 	}
228 
229 	/*
230 	 * The temporary file/file descriptor usage is a little tricky here.
231 	 * 1:	Create a temporary file called tempname, get descriptor tfd.
232 	 * 2:	Display() gets an fp for the temporary file, and copies the
233 	 *	user's information into it.  It then gives the temporary file
234 	 *	to the user and closes the fp, closing the underlying fd.
235 	 * 3:	The user edits the temporary file some number of times.
236 	 *	The results are stored in pw by edit().
237 	 * 4:	Delete the temporary file.
238 	 * 5:	Make a new temporary file, descriptor tfd.
239 	 * 6:	Get a descriptor for the master.passwd file, pfd, and
240 	 *	lock master.passwd.
241 	 * 7:	Pw_copy() gets descriptors for master.passwd and the
242 	 *	temporary file and copies the master password file into it,
243 	 *	replacing the modified user's record with a new one.  We can't
244 	 *	use the first temporary file for this because it was owned
245 	 *	by the user.  Pass the new and old user info.  Check the
246 	 *	entry for our user has not been changed by someone else by
247 	 *	while the user was editing by comparing the old info to
248 	 *	the entry freshly read from master.passwd. Pw_copy() closes
249 	 *	its fp, flushing the data and closing the underlying file
250 	 *	descriptor.  We can't close the master password fp, or we'd
251 	 *	lose the lock.
252 	 * 8:	Call pw_mkdb() (which renames the temporary file) and exit.
253 	 *	The exit closes the master passwd fp/fd.
254 	 */
255 	pw_init();
256 	tfd = pw_tmp();
257 
258 	if (op == EDITENTRY) {
259 		display(tfd, pw);
260 		edit(pw);
261 		(void)unlink(tempname);
262 		tfd = pw_tmp();
263 	}
264 
265 #ifdef YP
266 	if (_use_yp) {
267 		yp_submit(pw);
268 		(void)unlink(tempname);
269 	} else {
270 #endif /* YP */
271 	pfd = pw_lock();
272 	pw_copy(pfd, tfd, pw, (op == LOADENTRY) ? NULL : &old_pw);
273 
274 	if (!pw_mkdb(username))
275 		pw_error((char *)NULL, 0, 1);
276 #ifdef YP
277 	}
278 #endif /* YP */
279 	exit(0);
280 }
281 
282 void
283 baduser()
284 {
285 	errx(1, "%s", strerror(EACCES));
286 }
287 
288 void
289 usage()
290 {
291 
292 	(void)fprintf(stderr,
293 #ifdef YP
294 		"usage: chpass [-l] [-y] [-d domain [-h host]] [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
295 #else
296 		"usage: chpass [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
297 #endif
298 	exit(1);
299 }
300