testdisk/src/file_evt.c
2008-06-10 12:54:11 +02:00

99 lines
3.6 KiB
C

/*
File: file_evt.c
Copyright (C) 2007-2008 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 "common.h"
#include "filegen.h"
#include "log.h"
static void register_header_check_evt(file_stat_t *file_stat);
static int header_check_evt(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new);
static int data_check_evt(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery);
const file_hint_t file_hint_evt= {
.extension="evt",
.description="Windows Event Log",
.min_header_distance=0,
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=&register_header_check_evt
};
static const unsigned char evt_header[8]= {0x30, 0x00, 0x00, 0x00, 'L', 'f', 'L', 'e'};
static void register_header_check_evt(file_stat_t *file_stat)
{
register_header_check(0, evt_header,sizeof(evt_header), &header_check_evt, file_stat);
}
static int header_check_evt(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
if(memcmp(buffer,evt_header,sizeof(evt_header))==0)
{
reset_file_recovery(file_recovery_new);
file_recovery_new->calculated_file_size=buffer[0] + (buffer[1]<<8) + (buffer[2]<<16) + (buffer[3]<<24);
file_recovery_new->data_check=&data_check_evt;
file_recovery_new->file_check=&file_check_size;
file_recovery_new->extension=file_hint_evt.extension;
return 1;
}
return 0;
}
static int data_check_evt(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 8 < file_recovery->file_size + buffer_size/2)
{
unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
if((buffer[i+4]=='L' && buffer[i+5]=='f' && buffer[i+6]=='L' && buffer[i+7]=='e') ||
(buffer[i+4]==0x11 && buffer[i+5]==0x11 && buffer[i+6]==0x11 && buffer[i+7]==0x11) ||
(buffer[i+4]==0x22 && buffer[i+5]==0x22 && buffer[i+6]==0x22 && buffer[i+7]==0x22) ||
(buffer[i+4]==0x33 && buffer[i+5]==0x33 && buffer[i+6]==0x33 && buffer[i+7]==0x33) ||
(buffer[i+4]==0x44 && buffer[i+5]==0x44 && buffer[i+6]==0x44 && buffer[i+7]==0x44))
{
unsigned int length=(buffer[i+0] + (buffer[i+1]<<8) + (buffer[i+2]<<16) + (buffer[i+3]<<24));
if(length<8)
{
return 2;
}
file_recovery->calculated_file_size+=length;
}
else
{
return 2;
}
}
/*
log_trace("data_check_evt record_offset=0x%x\n\n",record_offset);
*/
return 1;
}