testdisk/src/file_clip.c

115 lines
3.9 KiB
C

/*
File: file_clip.c
Copyright (C) 2021 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.
*/
#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_clip)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"
#include "common.h"
/*@ requires valid_register_header_check(file_stat); */
static void register_header_check_clip(file_stat_t *file_stat);
const file_hint_t file_hint_clip= {
.extension="clip",
.description="Clip Studio Paint",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=&register_header_check_clip
};
struct clip_header
{
char header[8];
uint64_t size;
} __attribute__ ((gcc_struct, __packed__));
struct clip_chunk
{
char chunk[4]; /* CHNK */
char type[4];
uint64_t length;
} __attribute__ ((gcc_struct, __packed__));
/*@
@ requires file_recovery->data_check==&data_check_clip;
@ requires valid_data_check_param(buffer, buffer_size, file_recovery);
@ ensures valid_data_check_result(\result, file_recovery);
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_clip(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
/*@ assert file_recovery->calculated_file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@ assert file_recovery->file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@
@ loop assigns file_recovery->calculated_file_size;
@*/
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 16 <= file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
/*@ assert 0 <= i <= buffer_size - 16; */
const struct clip_chunk *chunk=(const struct clip_chunk *)&buffer[i];
const uint64_t length=be64(chunk->length);
if(length >= 0x100000000 ||
memcmp(&buffer[i], "CHNK", 4)!=0)
return DC_ERROR;
file_recovery->calculated_file_size+=(uint64_t)0x10 + length;
if(length==0)
return DC_STOP;
}
return DC_CONTINUE;
}
/*@
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ ensures valid_header_check_result(\result, file_recovery_new);
@ assigns *file_recovery_new;
@*/
static int header_check_clip(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)
{
const struct clip_header *hdr=(const struct clip_header *)buffer;
const uint64_t size=be64(hdr->size);
if(size <= 0x18 || size > 0x100000000)
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_clip.extension;
file_recovery_new->data_check=&data_check_clip;
file_recovery_new->file_check=&file_check_size;
file_recovery_new->calculated_file_size=0x18;
file_recovery_new->min_filesize=size;
return 1;
}
static void register_header_check_clip(file_stat_t *file_stat)
{
register_header_check(0, "CSFCHUNK", 8, &header_check_clip, file_stat);
}
#endif