testdisk/src/file_arj.c
2021-06-03 13:49:24 +02:00

181 lines
6.1 KiB
C

/*
File: file_arj.c
Copyright (C) 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.
*/
#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_arj)
#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_arj(file_stat_t *file_stat);
const file_hint_t file_hint_arj= {
.extension="arj",
.description="ARJ archive",
.max_filesize=PHOTOREC_MAX_SIZE_32,
.recover=1,
.enable_by_default=1,
.register_header_check=&register_header_check_arj
};
/*
* 60 ea 24 00 22 0b 01 02 10 00 02 XX XX XX 50 48
* ID HS FH V V OS FL SV FT R DATE/TIME
*
* Extract from "ARJ TECHNICAL INFORMATION April 1993"
http://datacompression.info/ArchiveFormats/arj.txt
Structure of main header (low order byte first):
Bytes Description
-------------------------------------------------------------------
2 header id (main and local file) = 0x60 0xEA
2 basic header size (from 'first_hdr_size' thru 'comment' below)
= first_hdr_size + strlen(filename) + 1 + strlen(comment) + 1
= 0 if end of archive
maximum header size is 2600
1 first_hdr_size (size up to and including 'extra data')
1 archiver version number
1 minimum archiver version to extract
1 host OS (0 = MSDOS, 1 = PRIMOS, 2 = UNIX, 3 = AMIGA, 4 = MAC-OS)
(5 = OS/2, 6 = APPLE GS, 7 = ATARI ST, 8 = NEXT)
(9 = VAX VMS)
1 arj flags
(0x01 = NOT USED)
(0x02 = OLD_SECURED_FLAG)
(0x04 = VOLUME_FLAG) indicates presence of succeeding
volume
(0x08 = NOT USED)
(0x10 = PATHSYM_FLAG) indicates archive name translated
("\" changed to "/")
(0x20 = BACKUP_FLAG) indicates backup type archive
(0x40 = SECURED_FLAG)
1 security version (2 = current)
1 file type (must equal 2)
1 reserved
4 date time when original archive was created
4 date time when archive was last modified
4 archive size (currently used only for secured archives)
4 security envelope file position
2 filespec position in filename
2 length in bytes of security envelope data
2 (currently not used)
? (currently none)
? filename of archive when created (null-terminated string)
? archive comment (null-terminated string)
4 basic header CRC
2 1st extended header size (0 if none)
? 1st extended header (currently not used)
4 1st extended header's CRC (not present when 0 extended header size)
*/
struct arj_main_header {
uint16_t header_id;
uint16_t basic_header_size;
uint8_t first_header_size;
uint8_t archiver_ver;
uint8_t archiver_ver_min;
uint8_t host_os;
uint8_t flags;
uint8_t security_ver;
uint8_t file_type;
uint8_t reserved;
uint32_t ctime;
uint32_t mtime;
uint32_t size;
uint32_t security_env_pos;
uint16_t filespec_pos;
uint16_t security_env_size;
uint16_t unused;
char filename;
} __attribute__ ((gcc_struct, __packed__));
/*@
@ requires file_recovery->file_check == &file_check_arj;
@ 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_arj(file_recovery_t *file_recovery)
{
static const unsigned char arj_footer[4]={0x60, 0xEA, 0x00, 0x00 };
file_search_footer(file_recovery, arj_footer, sizeof(arj_footer), 0);
}
/*@
@ requires buffer_size >= sizeof(struct arj_main_header);
@ requires separation: \separated(&file_hint_arj, 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);
@ assigns *file_recovery_new;
@*/
static int header_check_arj(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 arj_main_header *arj=(const struct arj_main_header*)buffer;
if(le16(arj->basic_header_size) > 0 &&
le16(arj->basic_header_size) <= 2600 &&
arj->archiver_ver_min <= arj->archiver_ver &&
arj->archiver_ver <=12 &&
(arj->flags&0x01)==0 &&
arj->file_type==2)
{
if((arj->flags&0x040)!=0)
{
if(le32(arj->size) < sizeof(struct arj_main_header))
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->calculated_file_size=le32(arj->size);
file_recovery_new->data_check=&data_check_size;
file_recovery_new->file_check=&file_check_size;
}
else
{
// if(le32(arj->size)!=0)
// return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->file_check=&file_check_arj;
}
file_recovery_new->extension=file_hint_arj.extension;
file_recovery_new->time=le32(arj->ctime);
if(file_recovery_new->time < le32(arj->mtime))
file_recovery_new->time=le32(arj->mtime);
return 1;
}
return 0;
}
static void register_header_check_arj(file_stat_t *file_stat)
{
static const unsigned char arj_header[2]={0x60, 0xEA};
register_header_check(0, arj_header,sizeof(arj_header), &header_check_arj, file_stat);
}
#endif