/*      $NetBSD: safefile.c,v 1.5 2025/03/07 15:55:29 christos Exp $    */

/*      $KAME: safefile.c,v 1.5 2001/03/05 19:54:06 thorpej Exp $       */

/*
 * Copyright (C) 2000 WIDE Project.
 * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#include "plog.h"
#include "debug.h"
#include "misc.h"
#include "safefile.h"

int
safefile(const char *path, int secret)
{
        struct stat s;
        uid_t me;

        /* no setuid */
        if (getuid() != geteuid()) {
                plog(LLV_ERROR, LOCATION, NULL,
                    "setuid'ed execution not allowed\n");
                return -1;
        }

        if (stat(path, &s) != 0)
                return -1;

        /* the file must be owned by the running uid */
        me = getuid();
        if (s.st_uid != me) {
                plog(LLV_ERROR, LOCATION, NULL,
                    "%s has invalid owner uid\n", path);
                return -1;
        }

        switch (s.st_mode & S_IFMT) {
        case S_IFREG:
                break;
        default:
                plog(LLV_ERROR, LOCATION, NULL,
                    "%s is an invalid file type 0x%x\n", path,
                    (s.st_mode & S_IFMT));
                return -1;
        }

        /* secret file should not be read by others */
        if (secret) {
                if ((s.st_mode & S_IRWXG) != 0 || (s.st_mode & S_IRWXO) != 0) {
                        plog(LLV_ERROR, LOCATION, NULL,
                            "%s has weak file permission\n", path);
                        return -1;
                }
        }

        return 0;
}