/* THIS FILE HAS BEEN MODIFIED FROM THE ORIGINAL OPENBSD SOURCE */
/* Changes: Removed mktemp */

/*      $OpenBSD: mktemp.c,v 1.30 2010/03/21 23:09:30 schwarze Exp $ */
/*
 * Copyright (c) 1996-1998, 2008 Theo de Raadt
 * Copyright (c) 1997, 2008-2009 Todd C. Miller
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* OPENBSD ORIGINAL: lib/libc/stdio/mktemp.c */

#include "includes.h"

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

#ifdef mkstemp
#undef mkstemp
#endif
int mkstemp(char *);

/*
 * From glibc man page: 'In glibc versions 2.06 and earlier, the file is
 * created with permissions 0666, that is, read and write for all users.'
 * Provide a wrapper to make sure the mask is reasonable (POSIX requires
 * mode 0600, so mask off any other bits).
 */
int
_ssh_mkstemp(char *template)
{
        mode_t mask;
        int ret;

        mask = umask(0177);
        ret = mkstemp(template);
        (void)umask(mask);
        return ret;
}

#if !defined(HAVE_MKDTEMP)

#define MKTEMP_NAME     0
#define MKTEMP_FILE     1
#define MKTEMP_DIR      2

#define TEMPCHARS       "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
#define NUM_CHARS       (sizeof(TEMPCHARS) - 1)

static int
mktemp_internal(char *path, int slen, int mode)
{
        char *start, *cp, *ep;
        const char *tempchars = TEMPCHARS;
        unsigned int r, tries;
        struct stat sb;
        size_t len;
        int fd;

        len = strlen(path);
        if (len == 0 || slen < 0 || (size_t)slen >= len) {
                errno = EINVAL;
                return(-1);
        }
        ep = path + len - slen;

        tries = 1;
        for (start = ep; start > path && start[-1] == 'X'; start--) {
                if (tries < INT_MAX / NUM_CHARS)
                        tries *= NUM_CHARS;
        }
        tries *= 2;

        do {
                for (cp = start; cp != ep; cp++) {
                        r = arc4random_uniform(NUM_CHARS);
                        *cp = tempchars[r];
                }

                switch (mode) {
                case MKTEMP_NAME:
                        if (lstat(path, &sb) != 0)
                                return(errno == ENOENT ? 0 : -1);
                        break;
                case MKTEMP_FILE:
                        fd = open(path, O_CREAT|O_EXCL|O_RDWR, S_IRUSR|S_IWUSR);
                        if (fd != -1 || errno != EEXIST)
                                return(fd);
                        break;
                case MKTEMP_DIR:
                        if (mkdir(path, S_IRUSR|S_IWUSR|S_IXUSR) == 0)
                                return(0);
                        if (errno != EEXIST)
                                return(-1);
                        break;
                }
        } while (--tries);

        errno = EEXIST;
        return(-1);
}

#if 0
char *_mktemp(char *);

char *
_mktemp(char *path)
{
        if (mktemp_internal(path, 0, MKTEMP_NAME) == -1)
                return(NULL);
        return(path);
}

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

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

int
mkstemp(char *path)
{
        return(mktemp_internal(path, 0, MKTEMP_FILE));
}

int
mkstemps(char *path, int slen)
{
        return(mktemp_internal(path, slen, MKTEMP_FILE));
}

char *
mkdtemp(char *path)
{
        int error;

        error = mktemp_internal(path, 0, MKTEMP_DIR);
        return(error ? NULL : path);
}

#endif /* !defined(HAVE_MKDTEMP) */