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chpass.c revision 1.4.2.2
      1 /*-
      2  * Copyright (c) 1988 The Regents of the University of California.
      3  * 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 char copyright[] =
     36 "@(#) Copyright (c) 1988 The Regents of the University of California.\n\
     37  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 /*static char sccsid[] = "from: @(#)chpass.c	5.17 (Berkeley) 3/3/91";*/
     42 static char rcsid[] = "$Id: chpass.c,v 1.4.2.2 1994/08/17 19:54:40 deraadt Exp $";
     43 #endif /* not lint */
     44 
     45 #include <sys/param.h>
     46 #include <sys/stat.h>
     47 #include <sys/signal.h>
     48 #include <sys/time.h>
     49 #include <sys/resource.h>
     50 #include <fcntl.h>
     51 #include <pwd.h>
     52 #include <errno.h>
     53 #include <stdio.h>
     54 #include <ctype.h>
     55 #include <string.h>
     56 #include "chpass.h"
     57 #include "pathnames.h"
     58 
     59 char *progname = "chpass";
     60 char *tempname;
     61 uid_t uid;
     62 
     63 #ifdef	YP
     64 int use_yp;
     65 int force_yp = 0;
     66 extern struct passwd *ypgetpwnam(), *ypgetpwuid();
     67 #endif
     68 
     69 main(argc, argv)
     70 	int argc;
     71 	char **argv;
     72 {
     73 	extern int optind;
     74 	extern char *optarg;
     75 	register enum { NEWSH, LOADENTRY, EDITENTRY } op;
     76 	register struct passwd *pw;
     77 	struct passwd lpw;
     78 	int ch, pfd, tfd;
     79 	char *arg;
     80 
     81 #ifdef	YP
     82 	use_yp = _yp_check(NULL);
     83 #endif
     84 
     85 	op = EDITENTRY;
     86 	while ((ch = getopt(argc, argv, "a:s:ly")) != EOF)
     87 		switch(ch) {
     88 		case 'a':
     89 			op = LOADENTRY;
     90 			arg = optarg;
     91 			break;
     92 		case 's':
     93 			op = NEWSH;
     94 			arg = optarg;
     95 			break;
     96 #ifdef	YP
     97 		case 'l':
     98 			use_yp = 0;
     99 			break;
    100 		case 'y':
    101 			if (!use_yp) {
    102 				fprintf(stderr, "chpass: YP not in use.\n");
    103 				usage();
    104 				exit(1);
    105 			}
    106 			force_yp = 1;
    107 			break;
    108 #endif
    109 		case '?':
    110 		default:
    111 			usage();
    112 		}
    113 	argc -= optind;
    114 	argv += optind;
    115 
    116 #ifdef	YP
    117 	if (op == LOADENTRY && use_yp) {
    118 		(void)fprintf(stderr, "chpass: cannot load entry using NIS.\n\tUse the -l flag to load local.\n");
    119 		exit(1);
    120 	}
    121 #endif
    122 	uid = getuid();
    123 
    124 	if (op == EDITENTRY || op == NEWSH)
    125 		switch(argc) {
    126 		case 0:
    127 			pw = getpwuid(uid);
    128 #ifdef	YP
    129 			if (pw && !force_yp)
    130 				use_yp = 0;
    131 			else if (use_yp)
    132 				pw = ypgetpwuid(uid);
    133 #endif	/* YP */
    134 			if (!pw) {
    135 				(void)fprintf(stderr,
    136 				    "chpass: unknown user: uid %u\n", uid);
    137 				exit(1);
    138 			}
    139 			break;
    140 		case 1:
    141 			pw = getpwnam(*argv);
    142 #ifdef	YP
    143 			if (pw && !force_yp)
    144 				use_yp = 0;
    145 			else if (use_yp)
    146 				pw = ypgetpwnam(*argv);
    147 #endif	/* YP */
    148 			if (!pw) {
    149 				(void)fprintf(stderr,
    150 				    "chpass: unknown user %s.\n", *argv);
    151 				exit(1);
    152 			}
    153 			if (uid && uid != pw->pw_uid)
    154 				baduser();
    155 			break;
    156 		default:
    157 			usage();
    158 		}
    159 
    160 	if (op == NEWSH) {
    161 		/* protect p_shell -- it thinks NULL is /bin/sh */
    162 		if (!arg[0])
    163 			usage();
    164 		if (p_shell(arg, pw, (ENTRY *)NULL))
    165 			pw_error((char *)NULL, 0, 1);
    166 	}
    167 
    168 	if (op == LOADENTRY) {
    169 		if (uid)
    170 			baduser();
    171 		pw = &lpw;
    172 		if (!pw_scan(arg, pw))
    173 			exit(1);
    174 	}
    175 
    176 	/*
    177 	 * The temporary file/file descriptor usage is a little tricky here.
    178 	 * 1:	We start off with two fd's, one for the master password
    179 	 *	file (used to lock everything), and one for a temporary file.
    180 	 * 2:	Display() gets an fp for the temporary file, and copies the
    181 	 *	user's information into it.  It then gives the temporary file
    182 	 *	to the user and closes the fp, closing the underlying fd.
    183 	 * 3:	The user edits the temporary file some number of times.
    184 	 * 4:	Verify() gets an fp for the temporary file, and verifies the
    185 	 *	contents.  It can't use an fp derived from the step #2 fd,
    186 	 *	because the user's editor may have created a new instance of
    187 	 *	the file.  Once the file is verified, its contents are stored
    188 	 *	in a password structure.  The verify routine closes the fp,
    189 	 *	closing the underlying fd.
    190 	 * 5:	Delete the temporary file.
    191 	 * 6:	Get a new temporary file/fd.  Pw_copy() gets an fp for it
    192 	 *	file and copies the master password file into it, replacing
    193 	 *	the user record with a new one.  We can't use the first
    194 	 *	temporary file for this because it was owned by the user.
    195 	 *	Pw_copy() closes its fp, flushing the data and closing the
    196 	 *	underlying file descriptor.  We can't close the master
    197 	 *	password fp, or we'd lose the lock.
    198 	 * 7:	Call pw_mkdb() (which renames the temporary file) and exit.
    199 	 *	The exit closes the master passwd fp/fd.
    200 	 */
    201 	pw_init();
    202 	pfd = pw_lock();
    203 	tfd = pw_tmp();
    204 
    205 	if (op == EDITENTRY) {
    206 		display(tfd, pw);
    207 		edit(pw);
    208 		(void)unlink(tempname);
    209 		tfd = pw_tmp();
    210 	}
    211 
    212 #ifdef	YP
    213 	if (use_yp) {
    214 		(void)unlink(tempname);
    215 		if (pw_yp(pw, uid))
    216 			pw_error((char *)NULL, 0, 1);
    217 		else
    218 			exit(0);
    219 	}
    220 	else
    221 #endif	/* YP */
    222 	pw_copy(pfd, tfd, pw);
    223 
    224 	if (!pw_mkdb())
    225 		pw_error((char *)NULL, 0, 1);
    226 
    227 	exit(0);
    228 }
    229 
    230 baduser()
    231 {
    232 	(void)fprintf(stderr, "chpass: %s\n", strerror(EACCES));
    233 	exit(1);
    234 }
    235 
    236 usage()
    237 {
    238 #ifdef	YP
    239 	(void)fprintf(stderr, "usage: chpass [-a list] [-s shell] [-l]%s [user]\n", use_yp?" [-y]":"");
    240 #else
    241 	(void)fprintf(stderr, "usage: chpass [-a list] [-s shell] [user]\n");
    242 #endif
    243 	exit(1);
    244 }
    245