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/*
File: file_bkf.c
Copyright (C) 2006-2007 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_bkf)
#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"
#include "log.h"
/*@
@ requires valid_register_header_check(file_stat);
@*/
static void register_header_check_bkf(file_stat_t *file_stat);
const file_hint_t file_hint_bkf= {
.extension="bkf",
.description="MS Backup file",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_bkf
};
struct mtf_db_hdr
{
uint32_t type; /* DBLK type */
uint32_t attr; /* block attributes */
uint16_t off; /* offset to first event */
uint8_t osId; /* OS ID */
uint8_t osVer; /* OS version */
uint64_t size; /* displayable size */
uint64_t fla; /* format logical address */
uint16_t mbc; /* reserved for MBC */
uint8_t rsv1[6]; /* reserved for future use */
uint32_t cbId; /* control block ID */
uint8_t rsv2[4]; /* reserved for future use */
uint32_t osData; /* OS-specific data */
uint8_t strType; /* string type */
uint8_t rsv3; /* reserved for future use */
uint16_t check; /* header checksum */
} __attribute__ ((gcc_struct, __packed__));
/*@
@ requires file_recovery->file_check == &file_check_bkf;
@ requires valid_file_check_param(file_recovery);
@ ensures valid_file_check_result(file_recovery);
@ assigns *file_recovery->handle, errno, file_recovery->file_size;
@ assigns Frama_C_entropy_source;
@*/
static void file_check_bkf(file_recovery_t *file_recovery)
{
const unsigned char bkf_footer[4]= { 'S', 'F', 'M', 'B'};
file_search_footer(file_recovery, bkf_footer, sizeof(bkf_footer), 0x400-4);
}
/*@
@ requires buffer_size >= sizeof(struct mtf_db_hdr);
@ requires separation: \separated(&file_hint_bkf, buffer+(..), file_recovery, file_recovery_new);
@ 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);
@ ensures (\result == 1) ==> file_recovery_new->file_size == 0;
@ ensures (\result == 1) ==> (file_recovery_new->time == 0);
@ ensures (\result == 1) ==> (file_recovery_new->calculated_file_size == 0);
@ ensures (\result == 1) ==> (file_recovery_new->min_filesize == 52);
@ ensures (\result == 1) ==> (file_recovery_new->extension == file_hint_bkf.extension);
@ ensures (\result == 1) ==> (file_recovery_new->file_check == &file_check_bkf);
@ assigns *file_recovery_new;
@*/
static int header_check_bkf(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 mtf_db_hdr *hdr=(const struct mtf_db_hdr *)buffer;
/* Microsoft Tape Format
* The DBLK Type field is set to ‘TAPE’.
* The Format Logical Address field is set to zero.
* The Control Block ID field is set to zero.
*/
if(le64(hdr->fla)!=0 || le32(hdr->cbId)!=0 || hdr->strType>2 ||
le16(hdr->off)<sizeof(struct mtf_db_hdr))
return 0;
#ifdef DEBUG_BKF
log_info("off=%u\n", le16(hdr->off));
#endif
reset_file_recovery(file_recovery_new);
file_recovery_new->min_filesize=52;
file_recovery_new->extension=file_hint_bkf.extension;
file_recovery_new->file_check=&file_check_bkf;
return 1;
}
static void register_header_check_bkf(file_stat_t *file_stat)
{
static const unsigned char bkf_header[4]= { 'T','A','P','E'};
register_header_check(0, bkf_header,sizeof(bkf_header), &header_check_bkf, file_stat);
}
#endif
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