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/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//
// Access to entries in a Zip archive.
//
#include "ZipEntry.h"
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <inttypes.h>
using namespace android;
#define LOG(...) fprintf(stderr, __VA_ARGS__)
/* Jan 01 2008 */
#define STATIC_DATE (28 << 9 | 1 << 5 | 1)
#define STATIC_TIME 0
/*
* Initialize a new ZipEntry structure from a FILE* positioned at a
* CentralDirectoryEntry. Rewrites the headers to remove the dynamic
* timestamps.
*
* On exit, the file pointer will be at the start of the next CDE or
* at the EOCD.
*/
status_t ZipEntry::initAndRewriteFromCDE(FILE* fp)
{
status_t result;
long posn;
/* read the CDE */
result = mCDE.rewrite(fp);
if (result != 0) {
LOG("mCDE.rewrite failed\n");
return result;
}
/* using the info in the CDE, go load up the LFH */
posn = ftell(fp);
if (fseek(fp, mCDE.mLocalHeaderRelOffset, SEEK_SET) != 0) {
LOG("local header seek failed (%" PRIu32 ")\n",
mCDE.mLocalHeaderRelOffset);
return -1;
}
result = mLFH.rewrite(fp);
if (result != 0) {
LOG("mLFH.rewrite failed\n");
return result;
}
if (fseek(fp, posn, SEEK_SET) != 0)
return -1;
return 0;
}
/*
* ===========================================================================
* ZipEntry::LocalFileHeader
* ===========================================================================
*/
/*
* Rewrite a local file header.
*
* On entry, "fp" points to the signature at the start of the header.
*/
status_t ZipEntry::LocalFileHeader::rewrite(FILE* fp)
{
status_t result = 0;
uint8_t buf[kLFHLen];
if (fread(buf, 1, kLFHLen, fp) != kLFHLen)
return -1;
if (ZipEntry::getLongLE(&buf[0x00]) != kSignature) {
LOG("whoops: didn't find expected signature\n");
return -1;
}
ZipEntry::putShortLE(&buf[0x0a], STATIC_TIME);
ZipEntry::putShortLE(&buf[0x0c], STATIC_DATE);
if (fseek(fp, -kLFHLen, SEEK_CUR) != 0)
return -1;
if (fwrite(buf, 1, kLFHLen, fp) != kLFHLen)
return -1;
return 0;
}
/*
* ===========================================================================
* ZipEntry::CentralDirEntry
* ===========================================================================
*/
/*
* Read and rewrite the central dir entry that appears next in the file.
*
* On entry, "fp" should be positioned on the signature bytes for the
* entry. On exit, "fp" will point at the signature word for the next
* entry or for the EOCD.
*/
status_t ZipEntry::CentralDirEntry::rewrite(FILE* fp)
{
status_t result = 0;
uint8_t buf[kCDELen];
uint16_t fileNameLength, extraFieldLength, fileCommentLength;
if (fread(buf, 1, kCDELen, fp) != kCDELen)
return -1;
if (ZipEntry::getLongLE(&buf[0x00]) != kSignature) {
LOG("Whoops: didn't find expected signature\n");
return -1;
}
ZipEntry::putShortLE(&buf[0x0c], STATIC_TIME);
ZipEntry::putShortLE(&buf[0x0e], STATIC_DATE);
fileNameLength = ZipEntry::getShortLE(&buf[0x1c]);
extraFieldLength = ZipEntry::getShortLE(&buf[0x1e]);
fileCommentLength = ZipEntry::getShortLE(&buf[0x20]);
mLocalHeaderRelOffset = ZipEntry::getLongLE(&buf[0x2a]);
if (fseek(fp, -kCDELen, SEEK_CUR) != 0)
return -1;
if (fwrite(buf, 1, kCDELen, fp) != kCDELen)
return -1;
if (fseek(fp, fileNameLength + extraFieldLength + fileCommentLength, SEEK_CUR) != 0)
return -1;
return 0;
}
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