Handle Zip CRC validation for uncompressed Zip archives even on

platforms that lack zlib.
This commit is contained in:
Tim Kientzle 2009-12-28 03:11:36 +00:00
parent 10f117ebc2
commit 966062dd11
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=201102
2 changed files with 71 additions and 6 deletions

View file

@ -0,0 +1,66 @@
/*-
* Copyright (c) 2009 Joerg Sonnenberger
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
*
* $FreeBSD$
*/
#ifndef __LIBARCHIVE_BUILD
#error This header is only to be used internally to libarchive.
#endif
/*
* When zlib is unavailable, we should still be able to validate
* uncompressed zip archives. That requires us to be able to compute
* the CRC32 check value. This is a drop-in compatible replacement
* for crc32() from zlib. It's slower than the zlib implementation,
* but still pretty fast: This runs about 300MB/s on my 3GHz P4
* compared to about 800MB/s for the zlib implementation.
*/
static unsigned long
crc32(unsigned long crc, const void *_p, size_t len)
{
unsigned long crc2, b, i;
const unsigned char *p = _p;
static volatile int crc_tbl_inited = 0;
static unsigned long crc_tbl[256];
if (!crc_tbl_inited) {
for (b = 0; b < 256; ++b) {
crc2 = b;
for (i = 8; i > 0; --i) {
if (crc2 & 1)
crc2 = (crc2 >> 1) ^ 0xedb88320UL;
else
crc2 = (crc2 >> 1);
}
crc_tbl[b] = crc2;
}
crc_tbl_inited = 1;
}
crc = crc ^ 0xffffffffUL;
while (len--)
crc = crc_tbl[(crc ^ *p++) & 0xff] ^ (crc >> 8);
return (crc ^ 0xffffffffUL);
}

View file

@ -36,10 +36,6 @@ __FBSDID("$FreeBSD$");
#include <time.h>
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#else
/* Hmmm... This is necessary, but means that we can't correctly extract
* even uncompressed entries on platforms that lack zlib. */
#define crc32(crc, buf, len) (unsigned long)0
#endif
#include "archive.h"
@ -48,6 +44,10 @@ __FBSDID("$FreeBSD$");
#include "archive_read_private.h"
#include "archive_endian.h"
#ifndef HAVE_ZLIB_H
#include "archive_crc32.h"
#endif
struct zip {
/* entry_bytes_remaining is the number of bytes we expect. */
int64_t entry_bytes_remaining;
@ -540,8 +540,7 @@ archive_read_format_zip_read_data(struct archive_read *a,
return (r);
/* Update checksum */
if (*size)
zip->entry_crc32 =
crc32(zip->entry_crc32, *buff, *size);
zip->entry_crc32 = crc32(zip->entry_crc32, *buff, *size);
/* If we hit the end, swallow any end-of-data marker. */
if (zip->end_of_entry) {
if (zip->flags & ZIP_LENGTH_AT_END) {