xref: /freebsd/usr.bin/chpass/chpass.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
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 	"$Id$";
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 
66 #include "chpass.h"
67 #include "pathnames.h"
68 
69 char *progname = "chpass";
70 char *tempname;
71 uid_t uid;
72 
73 void	baduser __P((void));
74 void	usage __P((void));
75 
76 int
77 main(argc, argv)
78 	int argc;
79 	char **argv;
80 {
81 	enum { NEWSH, LOADENTRY, EDITENTRY, NEWPW } op;
82 	struct passwd *pw, lpw;
83 	int ch, pfd, tfd;
84 	char *arg;
85 
86 	op = EDITENTRY;
87 	while ((ch = getopt(argc, argv, "a:p:s:")) != EOF)
88 		switch(ch) {
89 		case 'a':
90 			op = LOADENTRY;
91 			arg = optarg;
92 			break;
93 		case 's':
94 			op = NEWSH;
95 			arg = optarg;
96 			break;
97 		case 'p':
98 			op = NEWPW;
99 			arg = optarg;
100 			break;
101 		case '?':
102 		default:
103 			usage();
104 		}
105 	argc -= optind;
106 	argv += optind;
107 
108 	uid = getuid();
109 
110 	if (op == EDITENTRY || op == NEWSH || op == NEWPW)
111 		switch(argc) {
112 		case 0:
113 			if (!(pw = getpwuid(uid)))
114 				errx(1, "unknown user: uid %u", uid);
115 			break;
116 		case 1:
117 			if (!(pw = getpwnam(*argv)))
118 				errx(1, "unknown user: %s", *argv);
119 			if (uid && uid != pw->pw_uid)
120 				baduser();
121 			break;
122 		default:
123 			usage();
124 		}
125 
126 	if (op == NEWSH) {
127 		/* protect p_shell -- it thinks NULL is /bin/sh */
128 		if (!arg[0])
129 			usage();
130 		if (p_shell(arg, pw, (ENTRY *)NULL))
131 			pw_error((char *)NULL, 0, 1);
132 	}
133 
134 	if (op == LOADENTRY) {
135 		if (uid)
136 			baduser();
137 		pw = &lpw;
138 		if (!pw_scan(arg, pw))
139 			exit(1);
140 	}
141 
142 	if (op == NEWPW) {
143 		if (uid)
144 			baduser();
145 
146 		if(strchr(arg, ':')) {
147 			errx(1, "invalid format for password");
148 		}
149 		pw->pw_passwd = arg;
150 	}
151 
152 	/*
153 	 * The temporary file/file descriptor usage is a little tricky here.
154 	 * 1:	We start off with two fd's, one for the master password
155 	 *	file (used to lock everything), and one for a temporary file.
156 	 * 2:	Display() gets an fp for the temporary file, and copies the
157 	 *	user's information into it.  It then gives the temporary file
158 	 *	to the user and closes the fp, closing the underlying fd.
159 	 * 3:	The user edits the temporary file some number of times.
160 	 * 4:	Verify() gets an fp for the temporary file, and verifies the
161 	 *	contents.  It can't use an fp derived from the step #2 fd,
162 	 *	because the user's editor may have created a new instance of
163 	 *	the file.  Once the file is verified, its contents are stored
164 	 *	in a password structure.  The verify routine closes the fp,
165 	 *	closing the underlying fd.
166 	 * 5:	Delete the temporary file.
167 	 * 6:	Get a new temporary file/fd.  Pw_copy() gets an fp for it
168 	 *	file and copies the master password file into it, replacing
169 	 *	the user record with a new one.  We can't use the first
170 	 *	temporary file for this because it was owned by the user.
171 	 *	Pw_copy() closes its fp, flushing the data and closing the
172 	 *	underlying file descriptor.  We can't close the master
173 	 *	password fp, or we'd lose the lock.
174 	 * 7:	Call pw_mkdb() (which renames the temporary file) and exit.
175 	 *	The exit closes the master passwd fp/fd.
176 	 */
177 	pw_init();
178 	pfd = pw_lock();
179 	tfd = pw_tmp();
180 
181 	if (op == EDITENTRY) {
182 		display(tfd, pw);
183 		edit(pw);
184 		(void)unlink(tempname);
185 		tfd = pw_tmp();
186 	}
187 
188 	pw_copy(pfd, tfd, pw);
189 
190 	if (!pw_mkdb())
191 		pw_error((char *)NULL, 0, 1);
192 	exit(0);
193 }
194 
195 void
196 baduser()
197 {
198 	errx(1, "%s", strerror(EACCES));
199 }
200 
201 void
202 usage()
203 {
204 
205 	(void)fprintf(stderr,
206 		"usage: chpass [-a list] [-p encpass] [-s shell] [user]\n");
207 	exit(1);
208 }
209