OpenBSD-4.6/libexec/login_token/tokendb.c
/* $OpenBSD: tokendb.c,v 1.8 2005/09/16 23:47:00 deraadt Exp $ */
/*-
* Copyright (c) 1995 Migration Associates Corp. 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 Berkeley Software Design,
* Inc.
* 4. The name of Berkeley Software Design, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``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 BERKELEY SOFTWARE DESIGN, INC. 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.
*
* BSDI $From: tokendb.c,v 1.1 1996/08/26 20:13:10 prb Exp $
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <ctype.h>
#include <db.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
#include <stdio.h>
#include <syslog.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "token.h"
#include "tokendb.h"
static DB *tokendb;
/*
* Static function prototypes
*/
static int tokendb_open(void);
static void tokendb_close(void);
/*
* Retrieve a user record from the token database file
*/
int
tokendb_getrec(char *username, TOKENDB_Rec *tokenrec)
{
DBT key;
DBT data;
int status = 0;
key.data = username;
key.size = strlen(username) + 1;
memset(&data, 0, sizeof(data));
if (tokendb_open())
return(-1);
status = (tokendb->get)(tokendb, &key, &data, 0);
switch (status) {
case 1:
tokendb_close();
return(ENOENT);
case -1:
tokendb_close();
return(-1);
}
memcpy(tokenrec, data.data, sizeof(TOKENDB_Rec));
if ((tokenrec->flags & TOKEN_USEMODES) == 0)
tokenrec->mode = tt->modes & ~TOKEN_RIM;
tokendb_close();
return (0);
}
/*
* Put a user record to the token database file.
*/
int
tokendb_putrec(char *username, TOKENDB_Rec *tokenrec)
{
DBT key;
DBT data;
int status = 0;
key.data = username;
key.size = strlen(username) + 1;
if (tokenrec->mode)
tokenrec->flags |= TOKEN_USEMODES;
data.data = tokenrec;
data.size = sizeof(TOKENDB_Rec);
if (!tokendb_open()) {
if (flock((tokendb->fd)(tokendb), LOCK_EX)) {
tokendb_close();
return (-1);
}
status = (tokendb->put)(tokendb, &key, &data, 0);
}
tokendb_close();
return (status);
}
/*
* Remove a user record from the token database file.
*/
int
tokendb_delrec(char *username)
{
DBT key;
DBT data;
int status = 0;
key.data = username;
key.size = strlen(username) + 1;
memset(&data, 0, sizeof(data));
if (!tokendb_open()) {
if (flock((tokendb->fd)(tokendb), LOCK_EX)) {
tokendb_close();
return (-1);
}
status = (tokendb->del)(tokendb, &key, 0);
}
tokendb_close();
return (status);
}
/*
* Open the token database. In order to expedite access in
* heavily loaded conditions, we employ a N1 lock method.
* Updates should be brief, so all locks wait infinitely.
* Wait for a read (shared) lock as all updates read first.
*/
static int
tokendb_open(void)
{
int must_set_perms = 0;
int must_set_mode = 0;
struct group *grp;
struct stat statb;
if ((grp = getgrnam(TOKEN_GROUP)) == NULL) {
printf("Missing %s group, authentication disabled\n",
TOKEN_GROUP);
fflush(stdout);
syslog(LOG_ALERT,
"the %s group is missing, token authentication disabled",
TOKEN_GROUP);
return (-1);
}
if (stat(tt->db, &statb) < 0) {
if (errno != ENOENT)
return (-1);
must_set_perms++;
} else {
if (statb.st_uid != 0 || statb.st_gid != grp->gr_gid) {
#ifdef PARANOID
printf("Authentication disabled\n");
fflush(stdout);
syslog(LOG_ALERT,
"POTENTIAL COMPROMISE of %s. Owner was %u, "
"Group was %u", tt->db, statb.st_uid, statb.st_gid);
return (-1);
#else
must_set_perms++;
#endif
}
if ((statb.st_mode & 0777) != 0640) {
#ifdef PARANOID
printf("Authentication disabled\n");
fflush(stdout);
syslog(LOG_ALERT,
"POTENTIAL COMPROMISE of %s. Mode was %o",
tt->db, statb.st_mode);
return (-1);
#else
must_set_mode++;
#endif
}
}
if (!(tokendb =
dbopen(tt->db, O_CREAT | O_RDWR, 0640, DB_BTREE, 0)) )
return (-1);
if (flock((tokendb->fd)(tokendb), LOCK_SH)) {
(tokendb->close)(tokendb);
return (-1);
}
if (must_set_perms && fchown((tokendb->fd)(tokendb), 0, grp->gr_gid))
syslog(LOG_INFO,
"Can't set owner/group of %s errno=%m", tt->db);
if (must_set_mode && fchmod((tokendb->fd)(tokendb), 0640))
syslog(LOG_INFO,
"Can't set mode of %s errno=%m", tt->db);
return (0);
}
/*
* Close the token database. We are holding an unknown lock.
* Release it, then close the db. Since little can be done
* about errors, we ignore them.
*/
static void
tokendb_close(void)
{
if (tokendb) {
(void)flock((tokendb->fd)(tokendb), LOCK_UN);
(tokendb->close)(tokendb);
tokendb = NULL;
}
}
/*
* Retrieve the first user record from the database, leaving the
* database open for the next retrieval. If the march thru the
* the database is aborted before end-of-file, the caller should
* call tokendb_close to release the read lock.
*/
int
tokendb_firstrec(int reverse_flag, TOKENDB_Rec *tokenrec)
{
DBT key;
DBT data;
int status = 0;
memset(&data, 0, sizeof(data));
if (!tokendb_open()) {
status = (tokendb->seq)(tokendb, &key, &data,
reverse_flag ? R_LAST : R_FIRST);
}
if (status) {
tokendb_close();
return (status);
}
if (!data.data) {
tokendb_close();
return (ENOENT);
}
memcpy(tokenrec, data.data, sizeof(TOKENDB_Rec));
if ((tokenrec->flags & TOKEN_USEMODES) == 0)
tokenrec->mode = tt->modes & ~TOKEN_RIM;
return (0);
}
/*
* Retrieve the next sequential user record from the database. Close
* the database only on end-of-file or error.
*/
int
tokendb_nextrec(int reverse_flag, TOKENDB_Rec *tokenrec)
{
DBT key;
DBT data;
int status;
memset(&data, 0, sizeof(data));
status = (tokendb->seq)(tokendb, &key, &data,
reverse_flag ? R_PREV : R_NEXT);
if (status) {
tokendb_close();
return (status);
}
if (!data.data) {
tokendb_close();
return (ENOENT);
}
memcpy(tokenrec, data.data, sizeof(TOKENDB_Rec));
if ((tokenrec->flags & TOKEN_USEMODES) == 0)
tokenrec->mode = tt->modes & ~TOKEN_RIM;
return (0);
}
/*
* Retrieve and lock a user record. Since there are no facilities in
* BSD for record locking, we hack a bit lock into the user record.
*/
int
tokendb_lockrec(char *username, TOKENDB_Rec *tokenrec, unsigned recflags)
{
DBT key;
DBT data;
int status;
key.data = username;
key.size = strlen(username) + 1;
memset(&data, 0, sizeof(data));
if (tokendb_open())
return(-1);
if (flock((tokendb->fd)(tokendb), LOCK_EX)) {
tokendb_close();
return(-1);
}
switch ((tokendb->get)(tokendb, &key, &data, 0)) {
case 1:
tokendb_close();
return (ENOENT);
case -1:
tokendb_close();
return(-1);
}
memcpy(tokenrec, data.data, sizeof(TOKENDB_Rec));
if ((tokenrec->flags & TOKEN_LOCKED)||(tokenrec->flags & recflags)) {
tokendb_close();
return(1);
}
data.data = tokenrec;
data.size = sizeof(TOKENDB_Rec);
time(&tokenrec->lock_time);
tokenrec->flags |= recflags;
status = (tokendb->put)(tokendb, &key, &data, 0);
tokendb_close();
if (status)
return(-1);
if ((tokenrec->flags & TOKEN_USEMODES) == 0)
tokenrec->mode = tt->modes & ~TOKEN_RIM;
return(0);
}