Files
sudo/lib/util/mktemp.c
2018-05-24 21:04:23 -06:00

125 lines
2.9 KiB
C

/*
* Copyright (c) 2001, 2003, 2004, 2008-2011, 2013, 2015, 2017, 2018
* Todd C. Miller <Todd.Miller@sudo.ws>
*
* 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.
*/
#include <config.h>
#if !defined(HAVE_MKSTEMPS) || !defined(HAVE_MKDTEMP)
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif /* HAVE_STDLIB_H */
#if defined(HAVE_STDINT_H)
# include <stdint.h>
#elif defined(HAVE_INTTYPES_H)
# include <inttypes.h>
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <ctype.h>
#include <unistd.h>
#include <time.h>
#include "sudo_compat.h"
#include "sudo_rand.h"
#include "pathnames.h"
#define MKTEMP_FILE 1
#define MKTEMP_DIR 2
#define TEMPCHARS "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
#define NUM_CHARS (sizeof(TEMPCHARS) - 1)
#define MIN_X 6
static int
mktemp_internal(char *path, int slen, int mode)
{
char *start, *cp, *ep;
const char tempchars[] = TEMPCHARS;
unsigned int r, tries;
size_t len;
int fd;
len = strlen(path);
if (len < MIN_X || slen < 0 || (size_t)slen > len - MIN_X) {
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;
if (ep - start < MIN_X) {
errno = EINVAL;
return -1;
}
do {
for (cp = start; cp != ep; cp++) {
r = arc4random_uniform(NUM_CHARS);
*cp = tempchars[r];
}
switch (mode) {
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_IRWXU) == 0)
return 0;
if (errno != EEXIST)
return -1;
break;
}
} while (--tries);
errno = EEXIST;
return -1;
}
int
sudo_mkstemps(char *path, int slen)
{
return mktemp_internal(path, slen, MKTEMP_FILE);
}
char *
sudo_mkdtemp(char *path)
{
if (mktemp_internal(path, 0, MKTEMP_DIR) == -1)
return NULL;
return path;
}
#endif /* !HAVE_MKSTEMPS || !HAVE_MKDTEMP */