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/*
File: file_gz.c
Copyright (C) 1998-2006 Christophe GRENIER <grenier@cgsecurity.org>
This software is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write the Free Software Foundation, Inc., 51
Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "photorec.h"
static const char* header_check_gz(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, t_file_recovery *file_recovery);
const t_file_hint file_hint_gz= {
.extension="gz",
.description="gzip compressed data",
.min_header_distance=0,
.min_filesize=22,
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.header_check=&header_check_gz,
.data_check=NULL,
.file_check=NULL
};
static const char* header_check_gz(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, t_file_recovery *file_recovery)
{
/* gzip file format:
* a 10-byte header, containing a magic number, a version number and a timestamp
* optional extra headers, such as the original file name,
* a body, containing a deflate-compressed payload
* a CRC-32 checksum
* the length (32 bits) of the original uncompressed data
*/
/* gzip, deflate */
if(buffer[0]==0x1F && buffer[1]==0x8B && buffer[2]==0x08 && (buffer[3]==0 || buffer[3]==0x08))
return file_hint_gz.extension;
return NULL;
}
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