/*	$OpenBSD: mktemp.c,v 1.24 2008/09/15 20:28:44 chl Exp $ */
/*
 * Copyright (c) 1987, 1993
 *	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. 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.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>

static int _gettemp(char *, int *, int, int);

int
mkstemps(char *path, int slen)
{
	int fd;

	return (_gettemp(path, &fd, 0, slen) ? fd : -1);
}

int
mkstemp(char *path)
{
	int fd;

	return (_gettemp(path, &fd, 0, 0) ? fd : -1);
}

char *
mkdtemp(char *path)
{
	return(_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
}

char *_mktemp(char *);

char *
_mktemp(char *path)
{
	return(_gettemp(path, (int *)NULL, 0, 0) ? path : (char *)NULL);
}

__warn_references(mktemp,
    "warning: mktemp() possibly used unsafely; consider using mkstemp()");

char *
mktemp(char *path)
{
	return(_mktemp(path));
}


static int
_gettemp(char *path, int *doopen, int domkdir, int slen)
{
	char *start, *cp, *ep;
	struct stat sbuf;
	size_t len;
	int r;

	if (doopen && domkdir) {
		errno = EINVAL;
		return(0);
	}

	len = strlen(path);
	if (len == 0 || slen >= len) {
		errno = EINVAL;
		return(0);
	}
	ep = path + len - slen;

	for (start = ep; *--start == 'X';)
		;
	start++;

	for (;;) {
		for (cp = start; cp != ep; cp++) {
			r = arc4random_uniform(26 + 26);
			if (r < 26)
				*cp = r + 'A';
			else
				*cp = (r - 26) + 'a';
		}

		if (doopen) {
			if ((*doopen =
			    open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
				return(1);
			if (errno != EEXIST)
				return(0);
		} else if (domkdir) {
			if (mkdir(path, 0700) == 0)
				return(1);
			if (errno != EEXIST)
				return(0);
		} else if (lstat(path, &sbuf))
			return(errno == ENOENT ? 1 : 0);
	}
	/*NOTREACHED*/
}