xref: /freebsd/usr.bin/chpass/chpass.c (revision 42c159fe388a3765f69860c84183700af37aca8a)
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 #endif /* not lint */
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/param.h>
48 #include <sys/stat.h>
49 #include <sys/signal.h>
50 #include <sys/time.h>
51 #include <sys/resource.h>
52 
53 #include <ctype.h>
54 #include <err.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <pwd.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <unistd.h>
62 
63 #include <pw_scan.h>
64 #include <pw_util.h>
65 #include "pw_copy.h"
66 #ifdef YP
67 #include <rpcsvc/yp.h>
68 int yp_errno = YP_TRUE;
69 #include "pw_yp.h"
70 #endif
71 
72 #include "chpass.h"
73 #include "pathnames.h"
74 
75 char *tempname;
76 uid_t uid;
77 
78 void	baduser(void);
79 void	usage(void);
80 
81 char localhost[] = "localhost";
82 
83 int
84 main(int argc, char *argv[])
85 {
86 	enum { NEWSH, LOADENTRY, EDITENTRY, NEWPW, NEWEXP } op;
87 	struct passwd *pw = NULL, lpw, old_pw;
88 	char *username = NULL;
89 	int ch, pfd, tfd;
90 	char *arg = NULL;
91 #ifdef YP
92 	int force_local = 0;
93 	int force_yp = 0;
94 #endif
95 
96 	op = EDITENTRY;
97 #ifdef YP
98 	while ((ch = getopt(argc, argv, "a:p:s:e:d:h:oly")) != -1)
99 #else
100 	while ((ch = getopt(argc, argv, "a:p:s:e:")) != -1)
101 #endif
102 		switch(ch) {
103 		case 'a':
104 			op = LOADENTRY;
105 			arg = optarg;
106 			break;
107 		case 's':
108 			op = NEWSH;
109 			arg = optarg;
110 			break;
111 		case 'p':
112 			op = NEWPW;
113 			arg = optarg;
114 			break;
115 		case 'e':
116 			op = NEWEXP;
117 			arg = optarg;
118 			break;
119 #ifdef YP
120 		case 'h':
121 #ifdef PARANOID
122 			if (getuid()) {
123 				warnx("Only the superuser can use the -h flag");
124 			} else {
125 #endif
126 				yp_server = optarg;
127 #ifdef PARANOID
128 			}
129 #endif
130 			break;
131 		case 'd':
132 #ifdef PARANOID
133 			if (getuid()) {
134 				warnx("Only the superuser can use the -d flag");
135 			} else {
136 #endif
137 				yp_domain = optarg;
138 				if (yp_server == NULL)
139 					yp_server = localhost;
140 #ifdef PARANOID
141 			}
142 #endif
143 			break;
144 		case 'l':
145 			_use_yp = 0;
146 			force_local = 1;
147 			break;
148 		case 'y':
149 			_use_yp = force_yp = 1;
150 			break;
151 		case 'o':
152 			force_old++;
153 			break;
154 #endif
155 		case '?':
156 		default:
157 			usage();
158 		}
159 	argc -= optind;
160 	argv += optind;
161 
162 	uid = getuid();
163 
164 	if (op == EDITENTRY || op == NEWSH || op == NEWPW || op == NEWEXP) {
165 		switch(argc) {
166 #ifdef YP
167 		case 0:
168 			GETPWUID(uid)
169 			get_yp_master(1); /* XXX just to set the suser flag */
170 			break;
171 		case 1:
172 			GETPWNAM(*argv)
173 			get_yp_master(1); /* XXX just to set the suser flag */
174 #else
175 		case 0:
176 			if (!(pw = getpwuid(uid)))
177 				errx(1, "unknown user: uid %lu",
178 				    (unsigned long)uid);
179 			break;
180 		case 1:
181 			if (!(pw = getpwnam(*argv)))
182 				errx(1, "unknown user: %s", *argv);
183 #endif
184 			if (uid && uid != pw->pw_uid)
185 				baduser();
186 			break;
187 		default:
188 			usage();
189 		}
190 
191 		/* Make a copy for later verification */
192 		old_pw = *pw;
193 		old_pw.pw_gecos = strdup(old_pw.pw_gecos);
194 	}
195 
196 	if (op == NEWSH) {
197 		/* protect p_shell -- it thinks NULL is /bin/sh */
198 		if (!arg[0])
199 			usage();
200 		if (p_shell(arg, pw, (ENTRY *)NULL))
201 			pw_error((char *)NULL, 0, 1);
202 	}
203 
204 	if (op == NEWEXP) {
205 		if (uid)	/* only root can change expire */
206 			baduser();
207 		if (p_expire(arg, pw, (ENTRY *)NULL))
208 			pw_error((char *)NULL, 0, 1);
209 	}
210 
211 	if (op == LOADENTRY) {
212 		if (uid)
213 			baduser();
214 		pw = &lpw;
215 		if (!__pw_scan(arg, pw, _PWSCAN_WARN|_PWSCAN_MASTER))
216 			exit(1);
217 	}
218 	username = pw->pw_name;
219 
220 	if (op == NEWPW) {
221 		if (uid)
222 			baduser();
223 
224 		if(strchr(arg, ':')) {
225 			errx(1, "invalid format for password");
226 		}
227 		pw->pw_passwd = arg;
228 	}
229 
230 	/*
231 	 * The temporary file/file descriptor usage is a little tricky here.
232 	 * 1:	Create a temporary file called tempname, get descriptor tfd.
233 	 * 2:	Display() gets an fp for the temporary file, and copies the
234 	 *	user's information into it.  It then gives the temporary file
235 	 *	to the user and closes the fp, closing the underlying fd.
236 	 * 3:	The user edits the temporary file some number of times.
237 	 *	The results are stored in pw by edit().
238 	 * 4:	Delete the temporary file.
239 	 * 5:	Make a new temporary file, descriptor tfd.
240 	 * 6:	Get a descriptor for the master.passwd file, pfd, and
241 	 *	lock master.passwd.
242 	 * 7:	Pw_copy() gets descriptors for master.passwd and the
243 	 *	temporary file and copies the master password file into it,
244 	 *	replacing the modified user's record with a new one.  We can't
245 	 *	use the first temporary file for this because it was owned
246 	 *	by the user.  Pass the new and old user info.  Check the
247 	 *	entry for our user has not been changed by someone else by
248 	 *	while the user was editing by comparing the old info to
249 	 *	the entry freshly read from master.passwd. Pw_copy() closes
250 	 *	its fp, flushing the data and closing the underlying file
251 	 *	descriptor.  We can't close the master password fp, or we'd
252 	 *	lose the lock.
253 	 * 8:	Call pw_mkdb() (which renames the temporary file) and exit.
254 	 *	The exit closes the master passwd fp/fd.
255 	 */
256 	pw_init();
257 	tfd = pw_tmp();
258 
259 	if (op == EDITENTRY) {
260 		display(tfd, pw);
261 		edit(pw);
262 		(void)unlink(tempname);
263 		tfd = pw_tmp();
264 	}
265 
266 #ifdef YP
267 	if (_use_yp) {
268 		yp_submit(pw);
269 		(void)unlink(tempname);
270 	} else {
271 #endif /* YP */
272 	pfd = pw_lock();
273 	pw_copy(pfd, tfd, pw, (op == LOADENTRY) ? NULL : &old_pw);
274 
275 	if (!pw_mkdb(username))
276 		pw_error((char *)NULL, 0, 1);
277 #ifdef YP
278 	}
279 #endif /* YP */
280 	exit(0);
281 }
282 
283 void
284 baduser(void)
285 {
286 	errx(1, "%s", strerror(EACCES));
287 }
288 
289 void
290 usage(void)
291 {
292 
293 	(void)fprintf(stderr,
294 #ifdef YP
295 		"usage: chpass [-l] [-y] [-d domain [-h host]] [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
296 #else
297 		"usage: chpass [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
298 #endif
299 	exit(1);
300 }
301