chpass.c revision 1591 
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
35static 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
41static char sccsid[] = "@(#)chpass.c	8.4 (Berkeley) 4/2/94";
42#endif /* not lint */
43
44#include <sys/param.h>
45#include <sys/stat.h>
46#include <sys/signal.h>
47#include <sys/time.h>
48#include <sys/resource.h>
49
50#include <ctype.h>
51#include <err.h>
52#include <errno.h>
53#include <fcntl.h>
54#include <pwd.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#include <pw_scan.h>
61#include <pw_util.h>
62#include "pw_copy.h"
63
64#include "chpass.h"
65#include "pathnames.h"
66
67char *progname = "chpass";
68char *tempname;
69uid_t uid;
70
71void	baduser __P((void));
72void	usage __P((void));
73
74int
75main(argc, argv)
76	int argc;
77	char **argv;
78{
79	enum { NEWSH, LOADENTRY, EDITENTRY } op;
80	struct passwd *pw, lpw;
81	int ch, pfd, tfd;
82	char *arg;
83
84	op = EDITENTRY;
85	while ((ch = getopt(argc, argv, "a:s:")) != EOF)
86		switch(ch) {
87		case 'a':
88			op = LOADENTRY;
89			arg = optarg;
90			break;
91		case 's':
92			op = NEWSH;
93			arg = optarg;
94			break;
95		case '?':
96		default:
97			usage();
98		}
99	argc -= optind;
100	argv += optind;
101
102	uid = getuid();
103
104	if (op == EDITENTRY || op == NEWSH)
105		switch(argc) {
106		case 0:
107			if (!(pw = getpwuid(uid)))
108				errx(1, "unknown user: uid %u", uid);
109			break;
110		case 1:
111			if (!(pw = getpwnam(*argv)))
112				errx(1, "unknown user: %s", *argv);
113			if (uid && uid != pw->pw_uid)
114				baduser();
115			break;
116		default:
117			usage();
118		}
119
120	if (op == NEWSH) {
121		/* protect p_shell -- it thinks NULL is /bin/sh */
122		if (!arg[0])
123			usage();
124		if (p_shell(arg, pw, (ENTRY *)NULL))
125			pw_error((char *)NULL, 0, 1);
126	}
127
128	if (op == LOADENTRY) {
129		if (uid)
130			baduser();
131		pw = &lpw;
132		if (!pw_scan(arg, pw))
133			exit(1);
134	}
135
136	/*
137	 * The temporary file/file descriptor usage is a little tricky here.
138	 * 1:	We start off with two fd's, one for the master password
139	 *	file (used to lock everything), and one for a temporary file.
140	 * 2:	Display() gets an fp for the temporary file, and copies the
141	 *	user's information into it.  It then gives the temporary file
142	 *	to the user and closes the fp, closing the underlying fd.
143	 * 3:	The user edits the temporary file some number of times.
144	 * 4:	Verify() gets an fp for the temporary file, and verifies the
145	 *	contents.  It can't use an fp derived from the step #2 fd,
146	 *	because the user's editor may have created a new instance of
147	 *	the file.  Once the file is verified, its contents are stored
148	 *	in a password structure.  The verify routine closes the fp,
149	 *	closing the underlying fd.
150	 * 5:	Delete the temporary file.
151	 * 6:	Get a new temporary file/fd.  Pw_copy() gets an fp for it
152	 *	file and copies the master password file into it, replacing
153	 *	the user record with a new one.  We can't use the first
154	 *	temporary file for this because it was owned by the user.
155	 *	Pw_copy() closes its fp, flushing the data and closing the
156	 *	underlying file descriptor.  We can't close the master
157	 *	password fp, or we'd lose the lock.
158	 * 7:	Call pw_mkdb() (which renames the temporary file) and exit.
159	 *	The exit closes the master passwd fp/fd.
160	 */
161	pw_init();
162	pfd = pw_lock();
163	tfd = pw_tmp();
164
165	if (op == EDITENTRY) {
166		display(tfd, pw);
167		edit(pw);
168		(void)unlink(tempname);
169		tfd = pw_tmp();
170	}
171
172	pw_copy(pfd, tfd, pw);
173
174	if (!pw_mkdb())
175		pw_error((char *)NULL, 0, 1);
176	exit(0);
177}
178
179void
180baduser()
181{
182
183	errx(1, "%s", strerror(EACCES));
184}
185
186void
187usage()
188{
189
190	(void)fprintf(stderr, "usage: chpass [-a list] [-s shell] [user]\n");
191	exit(1);
192}
193