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freebsd/usr.sbin/pwd_mkdb/pwd_mkdb.c
Garrett Wollman ab5f8d28a4 Fix security hole in YP password support, which wouldmake +user entries
act like + entries in some cases.  Requires support in libc from next
commit.
1994-09-20 21:40:12 +00:00

428 lines
11 KiB
C

/*-
* Copyright (c) 1991, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1991, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)pwd_mkdb.c 8.5 (Berkeley) 4/20/94";
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "pw_scan.h"
#define INSECURE 1
#define SECURE 2
#define PERM_INSECURE (S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)
#define PERM_SECURE (S_IRUSR|S_IWUSR)
HASHINFO openinfo = {
4096, /* bsize */
32, /* ffactor */
256, /* nelem */
2048 * 1024, /* cachesize */
NULL, /* hash() */
0 /* lorder */
};
static enum state { FILE_INSECURE, FILE_SECURE, FILE_ORIG } clean;
static struct passwd pwd; /* password structure */
static char *pname; /* password file name */
static char prefix[MAXPATHLEN];
void cleanup __P((void));
void error __P((char *));
void mv __P((char *, char *));
int scan __P((FILE *, struct passwd *));
void usage __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
DB *dp, *edp;
DBT data, key;
FILE *fp, *oldfp;
sigset_t set;
int ch, cnt, len, makeold, tfd, yp_enabled = 0;
char *p, *t;
char buf[MAX(MAXPATHLEN, LINE_MAX * 2)], tbuf[1024];
char buf2[MAXPATHLEN];
strcpy(prefix, _PATH_PWD);
makeold = 0;
while ((ch = getopt(argc, argv, "d:pv")) != EOF)
switch(ch) {
case 'd':
strcpy(prefix, optarg);
break;
case 'p': /* create V7 "file.orig" */
makeold = 1;
break;
case 'v': /* backward compatible */
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc != 1)
usage();
/*
* This could be changed to allow the user to interrupt.
* Probably not worth the effort.
*/
sigemptyset(&set);
sigaddset(&set, SIGTSTP);
sigaddset(&set, SIGHUP);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGQUIT);
sigaddset(&set, SIGTERM);
(void)sigprocmask(SIG_BLOCK, &set, (sigset_t *)NULL);
/* We don't care what the user wants. */
(void)umask(0);
pname = *argv;
/* Open the original password file */
if (!(fp = fopen(pname, "r")))
error(pname);
/* Open the temporary insecure password database. */
(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _MP_DB);
dp = dbopen(buf,
O_RDWR|O_CREAT|O_EXCL, PERM_INSECURE, DB_HASH, &openinfo);
if (dp == NULL)
error(buf);
clean = FILE_INSECURE;
/*
* Open file for old password file. Minor trickiness -- don't want to
* chance the file already existing, since someone (stupidly) might
* still be using this for permission checking. So, open it first and
* fdopen the resulting fd. The resulting file should be readable by
* everyone.
*/
if (makeold) {
(void)snprintf(buf, sizeof(buf), "%s.orig", pname);
if ((tfd = open(buf,
O_WRONLY|O_CREAT|O_EXCL, PERM_INSECURE)) < 0)
error(buf);
if ((oldfp = fdopen(tfd, "w")) == NULL)
error(buf);
clean = FILE_ORIG;
}
/*
* The databases actually contain three copies of the original data.
* Each password file entry is converted into a rough approximation
* of a ``struct passwd'', with the strings placed inline. This
* object is then stored as the data for three separate keys. The
* first key * is the pw_name field prepended by the _PW_KEYBYNAME
* character. The second key is the pw_uid field prepended by the
* _PW_KEYBYUID character. The third key is the line number in the
* original file prepended by the _PW_KEYBYNUM character. (The special
* characters are prepended to ensure that the keys do not collide.)
*/
data.data = (u_char *)buf;
key.data = (u_char *)tbuf;
for (cnt = 1; scan(fp, &pwd); ++cnt) {
if(pwd.pw_name[0] == '+') {
if(pwd.pw_name[1] && !yp_enabled) {
yp_enabled = 1;
} else if(!pwd.pw_name[1]) {
yp_enabled = -1;
}
}
#define COMPACT(e) t = e; while (*p++ = *t++);
/* Create insecure data. */
p = buf;
COMPACT(pwd.pw_name);
COMPACT("*");
memmove(p, &pwd.pw_uid, sizeof(int));
p += sizeof(int);
memmove(p, &pwd.pw_gid, sizeof(int));
p += sizeof(int);
memmove(p, &pwd.pw_change, sizeof(time_t));
p += sizeof(time_t);
COMPACT(pwd.pw_class);
COMPACT(pwd.pw_gecos);
COMPACT(pwd.pw_dir);
COMPACT(pwd.pw_shell);
memmove(p, &pwd.pw_expire, sizeof(time_t));
p += sizeof(time_t);
memmove(p, &pwd.pw_fields, sizeof pwd.pw_fields);
p += sizeof pwd.pw_fields;
data.size = p - buf;
/* Store insecure by name. */
tbuf[0] = _PW_KEYBYNAME;
len = strlen(pwd.pw_name);
memmove(tbuf + 1, pwd.pw_name, len);
key.size = len + 1;
if ((dp->put)(dp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
/* Store insecure by number. */
tbuf[0] = _PW_KEYBYNUM;
memmove(tbuf + 1, &cnt, sizeof(cnt));
key.size = sizeof(cnt) + 1;
if ((dp->put)(dp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
/* Store insecure by uid. */
tbuf[0] = _PW_KEYBYUID;
memmove(tbuf + 1, &pwd.pw_uid, sizeof(pwd.pw_uid));
key.size = sizeof(pwd.pw_uid) + 1;
if ((dp->put)(dp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
/* Create original format password file entry */
if (makeold)
(void)fprintf(oldfp, "%s:*:%d:%d:%s:%s:%s\n",
pwd.pw_name, pwd.pw_uid, pwd.pw_gid, pwd.pw_gecos,
pwd.pw_dir, pwd.pw_shell);
}
/* If YP enabled, set flag. */
if(yp_enabled) {
buf[0] = yp_enabled + 2;
data.size = 1;
tbuf[0] = _PW_KEYYPENABLED;
key.size = 1;
if ((dp->put)(dp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
}
(void)(dp->close)(dp);
if (makeold) {
(void)fflush(oldfp);
(void)fclose(oldfp);
}
/* Open the temporary encrypted password database. */
(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _SMP_DB);
edp = dbopen(buf,
O_RDWR|O_CREAT|O_EXCL, PERM_SECURE, DB_HASH, &openinfo);
if (!edp)
error(buf);
clean = FILE_SECURE;
rewind(fp);
for (cnt = 1; scan(fp, &pwd); ++cnt) {
/* Create secure data. */
p = buf;
COMPACT(pwd.pw_name);
COMPACT(pwd.pw_passwd);
memmove(p, &pwd.pw_uid, sizeof(int));
p += sizeof(int);
memmove(p, &pwd.pw_gid, sizeof(int));
p += sizeof(int);
memmove(p, &pwd.pw_change, sizeof(time_t));
p += sizeof(time_t);
COMPACT(pwd.pw_class);
COMPACT(pwd.pw_gecos);
COMPACT(pwd.pw_dir);
COMPACT(pwd.pw_shell);
memmove(p, &pwd.pw_expire, sizeof(time_t));
p += sizeof(time_t);
memmove(p, &pwd.pw_fields, sizeof pwd.pw_fields);
p += sizeof pwd.pw_fields;
data.size = p - buf;
/* Store secure by name. */
tbuf[0] = _PW_KEYBYNAME;
len = strlen(pwd.pw_name);
memmove(tbuf + 1, pwd.pw_name, len);
key.size = len + 1;
if ((dp->put)(edp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
/* Store secure by number. */
tbuf[0] = _PW_KEYBYNUM;
memmove(tbuf + 1, &cnt, sizeof(cnt));
key.size = sizeof(cnt) + 1;
if ((dp->put)(edp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
/* Store secure by uid. */
tbuf[0] = _PW_KEYBYUID;
memmove(tbuf + 1, &pwd.pw_uid, sizeof(pwd.pw_uid));
key.size = sizeof(pwd.pw_uid) + 1;
if ((dp->put)(edp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
}
/* If YP enabled, set flag. */
if(yp_enabled) {
buf[0] = yp_enabled + 2;
data.size = 1;
tbuf[0] = _PW_KEYYPENABLED;
key.size = 1;
if ((dp->put)(dp, &key, &data, R_NOOVERWRITE) == -1)
error("put");
}
(void)(edp->close)(edp);
/* Set master.passwd permissions, in case caller forgot. */
(void)fchmod(fileno(fp), S_IRUSR|S_IWUSR);
(void)fclose(fp);
/* Install as the real password files. */
(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _MP_DB);
(void)snprintf(buf2, sizeof(buf2), "%s/%s", prefix, _MP_DB);
mv(buf, buf2);
(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _SMP_DB);
(void)snprintf(buf2, sizeof(buf2), "%s/%s", prefix, _SMP_DB);
mv(buf, buf2);
if (makeold) {
(void)snprintf(buf2, sizeof(buf2), "%s/%s", prefix, _PASSWD);
(void)snprintf(buf, sizeof(buf), "%s.orig", pname);
mv(buf, buf2);
}
/*
* Move the master password LAST -- chpass(1), passwd(1) and vipw(8)
* all use flock(2) on it to block other incarnations of themselves.
* The rename means that everything is unlocked, as the original file
* can no longer be accessed.
*/
(void)snprintf(buf, sizeof(buf), "%s/%s", prefix, _MASTERPASSWD);
mv(pname, buf);
exit(0);
}
int
scan(fp, pw)
FILE *fp;
struct passwd *pw;
{
static int lcnt;
static char line[LINE_MAX];
char *p;
if (!fgets(line, sizeof(line), fp))
return (0);
++lcnt;
/*
* ``... if I swallow anything evil, put your fingers down my
* throat...''
* -- The Who
*/
if (!(p = strchr(line, '\n'))) {
warnx("line too long");
goto fmt;
}
*p = '\0';
if (!pw_scan(line, pw)) {
warnx("at line #%d", lcnt);
fmt: errno = EFTYPE; /* XXX */
error(pname);
}
return (1);
}
void
mv(from, to)
char *from, *to;
{
char buf[MAXPATHLEN];
if (rename(from, to)) {
int sverrno = errno;
(void)snprintf(buf, sizeof(buf), "%s to %s", from, to);
errno = sverrno;
error(buf);
}
}
void
error(name)
char *name;
{
warn(name);
cleanup();
exit(1);
}
void
cleanup()
{
char buf[MAXPATHLEN];
switch(clean) {
case FILE_ORIG:
(void)snprintf(buf, sizeof(buf), "%s.orig", pname);
(void)unlink(buf);
/* FALLTHROUGH */
case FILE_SECURE:
(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _SMP_DB);
(void)unlink(buf);
/* FALLTHROUGH */
case FILE_INSECURE:
(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _MP_DB);
(void)unlink(buf);
}
}
void
usage()
{
(void)fprintf(stderr, "usage: pwd_mkdb [-p] [-d <dest dir>] file\n");
exit(1);
}