xref: /freebsd/usr.bin/chpass/chpass.c (revision 8e6b01171e30297084bb0b4457c4183c2746aacc)
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 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 char sccsid[] = "From: @(#)chpass.c	8.4 (Berkeley) 4/2/94";
42 static char rcsid[] =
43 	"$Id: chpass.c,v 1.4 1995/08/13 16:12:24 wpaul Exp $";
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 "pw_yp.h"
67 #endif
68 
69 #include "chpass.h"
70 #include "pathnames.h"
71 
72 char *progname = "chpass";
73 char *tempname;
74 uid_t uid;
75 
76 void	baduser __P((void));
77 void	usage __P((void));
78 
79 int
80 main(argc, argv)
81 	int argc;
82 	char **argv;
83 {
84 	enum { NEWSH, LOADENTRY, EDITENTRY, NEWPW } op;
85 	struct passwd *pw, lpw;
86 	int ch, pfd, tfd;
87 	char *arg;
88 #ifdef YP
89 	int force_local = 0;
90 	int force_yp = 0;
91 #endif
92 
93 	op = EDITENTRY;
94 #ifdef YP
95 	while ((ch = getopt(argc, argv, "a:p:s:ly")) != EOF)
96 #else
97 	while ((ch = getopt(argc, argv, "a:p:s:")) != EOF)
98 #endif
99 		switch(ch) {
100 		case 'a':
101 			op = LOADENTRY;
102 			arg = optarg;
103 			break;
104 		case 's':
105 			op = NEWSH;
106 			arg = optarg;
107 			break;
108 		case 'p':
109 			op = NEWPW;
110 			arg = optarg;
111 			break;
112 #ifdef YP
113 		case 'l':
114 			force_local = 1;
115 			break;
116 		case 'y':
117 			force_yp = 1;
118 			break;
119 #endif
120 		case '?':
121 		default:
122 			usage();
123 		}
124 	argc -= optind;
125 	argv += optind;
126 
127 	uid = getuid();
128 
129 	if (op == EDITENTRY || op == NEWSH || op == NEWPW)
130 		switch(argc) {
131 		case 0:
132 			if (!(pw = getpwuid(uid)))
133 				errx(1, "unknown user: uid %u", uid);
134 			break;
135 		case 1:
136 			if (!(pw = getpwnam(*argv)))
137 				errx(1, "unknown user: %s", *argv);
138 			if (uid && uid != pw->pw_uid)
139 				baduser();
140 			break;
141 		default:
142 			usage();
143 		}
144 	if (op == NEWSH) {
145 		/* protect p_shell -- it thinks NULL is /bin/sh */
146 		if (!arg[0])
147 			usage();
148 		if (p_shell(arg, pw, (ENTRY *)NULL))
149 			pw_error((char *)NULL, 0, 1);
150 	}
151 
152 	if (op == LOADENTRY) {
153 		if (uid)
154 			baduser();
155 		pw = &lpw;
156 		if (!pw_scan(arg, pw))
157 			exit(1);
158 	}
159 
160 	if (op == NEWPW) {
161 		if (uid)
162 			baduser();
163 
164 		if(strchr(arg, ':')) {
165 			errx(1, "invalid format for password");
166 		}
167 		pw->pw_passwd = arg;
168 	}
169 
170 #ifdef YP
171 	pw->pw_name = strdup(pw->pw_name);
172 	_use_yp = use_yp(pw->pw_name);
173 	if (_use_yp == USER_YP_ONLY) {
174 		if (!force_local) {
175 			_use_yp = 1;
176 			pw = (struct passwd *)&yp_password;
177 		} else
178 			errx(1, "unknown local user: %s.", pw->pw_name);
179 	} else if (_use_yp == USER_LOCAL_ONLY) {
180 		if (!force_yp) {
181 			_use_yp = 0;
182 			pw = (struct passwd *)&local_password;
183 		} else
184 			errx(1, "unknown NIS user: %s.", pw->pw_name);
185 	} else if (_use_yp == USER_YP_AND_LOCAL) {
186 		if (!force_local) {
187 			_use_yp = 1;
188 			pw = (struct passwd *)&yp_password;
189 		} else {
190 			_use_yp = 0;
191 			pw = (struct passwd *)&local_password;
192 		}
193 	}
194 #endif /* YP */
195 
196 	/*
197 	 * The temporary file/file descriptor usage is a little tricky here.
198 	 * 1:	We start off with two fd's, one for the master password
199 	 *	file (used to lock everything), and one for a temporary file.
200 	 * 2:	Display() gets an fp for the temporary file, and copies the
201 	 *	user's information into it.  It then gives the temporary file
202 	 *	to the user and closes the fp, closing the underlying fd.
203 	 * 3:	The user edits the temporary file some number of times.
204 	 * 4:	Verify() gets an fp for the temporary file, and verifies the
205 	 *	contents.  It can't use an fp derived from the step #2 fd,
206 	 *	because the user's editor may have created a new instance of
207 	 *	the file.  Once the file is verified, its contents are stored
208 	 *	in a password structure.  The verify routine closes the fp,
209 	 *	closing the underlying fd.
210 	 * 5:	Delete the temporary file.
211 	 * 6:	Get a new temporary file/fd.  Pw_copy() gets an fp for it
212 	 *	file and copies the master password file into it, replacing
213 	 *	the user record with a new one.  We can't use the first
214 	 *	temporary file for this because it was owned by the user.
215 	 *	Pw_copy() closes its fp, flushing the data and closing the
216 	 *	underlying file descriptor.  We can't close the master
217 	 *	password fp, or we'd lose the lock.
218 	 * 7:	Call pw_mkdb() (which renames the temporary file) and exit.
219 	 *	The exit closes the master passwd fp/fd.
220 	 */
221 	pw_init();
222 	pfd = pw_lock();
223 	tfd = pw_tmp();
224 
225 	if (op == EDITENTRY) {
226 		display(tfd, pw);
227 		edit(pw);
228 		(void)unlink(tempname);
229 		tfd = pw_tmp();
230 	}
231 
232 #ifdef YP
233 	if (_use_yp) {
234 		yp_submit(pw);
235 		(void)unlink(tempname);
236 	} else {
237 #endif /* YP */
238 	pw_copy(pfd, tfd, pw);
239 
240 	if (!pw_mkdb())
241 		pw_error((char *)NULL, 0, 1);
242 #ifdef YP
243 	}
244 #endif /* YP */
245 	exit(0);
246 }
247 
248 void
249 baduser()
250 {
251 	errx(1, "%s", strerror(EACCES));
252 }
253 
254 void
255 usage()
256 {
257 
258 	(void)fprintf(stderr,
259 #ifdef YP
260 		"usage: chpass [-l] [-y] [-a list] [-p encpass] [-s shell] [user]\n");
261 #else
262 		"usage: chpass [-a list] [-p encpass] [-s shell] [user]\n");
263 #endif
264 	exit(1);
265 }
266