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/*
File: file_ace.c
Copyright (C) 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.
*/
#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"
#include "crc.h"
/* #define DEBUG_ACE */
static void register_header_check_ace(file_stat_t *file_stat);
const file_hint_t file_hint_ace= {
.extension="ace",
.description="ACE archive",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_ace
};
struct header_ace {
uint16_t crc16; /** Lower 16bits of CRC32 over block up from HEAD_TYPE */
uint16_t size; /** Size of the block from HEAD_TYPE
up to the beginning of the ADDSIZE block */
uint8_t type; /** indicates type of block */
uint16_t flags; /** flags related to the block and its content
for all blocks these flags are valid.
bit 0 indicates if field add size is preset */
uint32_t addsize; /** an optional field which represents the size of
an additional block without specified structure */
} __attribute__ ((gcc_struct, __packed__));
typedef struct header_ace ace_header_t;
static void file_check_ace(file_recovery_t *file_recovery)
{
file_recovery->offset_error = 0;
file_recovery->offset_ok = 0;
file_recovery->file_size = 0;
if(my_fseek(file_recovery->handle, 0, SEEK_SET)<0)
return ;
#ifdef DEBUG_ACE
log_trace("file_check_ace\n");
#endif
while (!feof(file_recovery->handle))
{
ace_header_t h;
size_t res;
memset(&h, 0, sizeof(h));
res=fread(&h, 1, sizeof(h), file_recovery->handle);
if(res==0)
return ;
if(res != sizeof(h))
{
file_recovery->offset_error=file_recovery->file_size;
file_recovery->file_size=0;
return ;
}
if(my_fseek(file_recovery->handle, -sizeof(h)+4, SEEK_CUR)<0)
{
file_recovery->offset_error=file_recovery->file_size;
file_recovery->file_size=0;
return ;
}
#ifdef DEBUG_ACE
log_trace("file_ace: Block header at 0x%08lx: CRC16=0x%04X size=%u type=%u"
" flags=0x%04X addsize=%u\n",
(long unsigned) file_recovery->file_size,
le16(h.crc16), le16(h.size), h.type, le16(h.flags),
(le16(h.flags)&1) ? le32(h.addsize):0);
#endif
/* Type 0=Archive header, 1=File block, 2=Recovery Record, 5 new_recovery ? */
if (h.type==0 && le16(h.size)==0)
{
return ;
}
if (h.type!=0 && h.type!=1 && h.type!=2 && h.type!=5)
{
#ifdef DEBUG_ACE
log_trace("file_ace: Invalid block type %u\n", h.type);
#endif
file_recovery->offset_error=file_recovery->file_size;
file_recovery->file_size=0;
return ;
}
/* Minimal size is type+flags */
if (le16(h.size) < 1U + 2U)
{
#ifdef DEBUG_ACE
log_trace("file_ace: Invalid block size %u\n", le16(h.size));
#endif
file_recovery->offset_error=file_recovery->file_size;
file_recovery->file_size=0;
return ;
}
{
/* Header hardly ever bigger than a filename */
#define BUF_SIZE 4096
unsigned char buffer[BUF_SIZE];
unsigned int len=le16(h.size);
uint32_t crc32=0xFFFFFFFF;
while (len>0)
{
const unsigned int count = ((len>BUF_SIZE) ? BUF_SIZE : len);
if(fread(buffer, 1, count, file_recovery->handle) != count)
{
#ifdef DEBUG_ACE
log_trace("file_ace: truncated file\n");
#endif
file_recovery->offset_error=file_recovery->file_size;
file_recovery->file_size=0;
return ;
}
crc32=get_crc32(buffer, count, crc32);
len -= count;
}
if (le16(h.crc16) != (crc32&0xFFFF))
{
#ifdef DEBUG_ACE
log_trace("file_ace: bad CRC32: %04X vs %04X\n", le16(h.crc16), crc32);
#endif
file_recovery->offset_error=file_recovery->file_size;
file_recovery->file_size=0;
return ;
}
}
/* Add its header size */
file_recovery->file_size += 2U + 2 + le16(h.size); /* +2: CRC16, +2: size */
/* If addsize flag, add complementary size */
if (le16(h.flags)&1)
{
file_recovery->file_size += le32(h.addsize);
if(my_fseek(file_recovery->handle, file_recovery->file_size, SEEK_SET)<0)
{
file_recovery->offset_error=file_recovery->file_size;
file_recovery->file_size=0;
return;
}
}
}
}
static int header_check_ace(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 ace_header_t *h=(const ace_header_t *)buffer;
if(le16(h->size) < 1+2 || h->type!=0)
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_ace.extension;
file_recovery_new->min_filesize=
2 + /* CRC16 */
2 + /* Head size */
1 + /* Head type */
2 + /* Flags */
7 + /* Signature */
16; /* Minimal size for marker header */
file_recovery_new->file_check=&file_check_ace;
return 1;
}
static void register_header_check_ace(file_stat_t *file_stat)
{
static const unsigned char ace_header[7] = { '*','*','A','C','E','*','*'};
register_header_check(7, ace_header,sizeof(ace_header), &header_check_ace, file_stat);
}
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