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/*
File: file_doc.c
Copyright (C) 1998-2006 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_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "common.h"
#include "photorec.h"
#include "ole.h"
static void file_check_doc(t_file_recovery *file_recovery);
static const char* header_check_doc(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, t_file_recovery *file_recovery);
static const unsigned char * find_in_mem(const unsigned char *haystack, const unsigned char *needle, const unsigned int haystack_size);
static uint64_t test_OLE(FILE *file);
const t_file_hint file_hint_doc= {
.extension="doc",
.description="Microsoft Office Document (doc/xls/ppt/vis/...)",
.min_header_distance=0,
.min_filesize=0,
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.header_check=&header_check_doc,
.data_check=NULL,
.file_check=&file_check_doc
};
static const unsigned char * find_in_mem(const unsigned char *haystack, const unsigned char *needle, const unsigned int haystack_size)
{
unsigned int i;
unsigned int needle_size=strlen(needle);
for(i=0;i<haystack_size-needle_size;i++)
if(memcmp(&haystack[i],needle,needle_size)==0)
return &haystack[i];
return NULL;
}
static void file_check_doc(t_file_recovery *file_recovery)
{
uint64_t doc_file_size=test_OLE(file_recovery->handle);
file_recovery->file_size=(doc_file_size>0?((doc_file_size<=(file_recovery->file_size))?doc_file_size:0):0);
#ifdef DEBUG_OLE
ecrit_rapport("size found : %llu\n",(long long unsigned)doc_file_size);
ecrit_rapport("==> size : %llu\n",(long long unsigned)file_recovery->file_size);
#endif
}
static const char* header_check_doc(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, t_file_recovery *file_recovery)
{
const unsigned char doc_header[]= { 0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1};
if(memcmp(buffer,doc_header,sizeof(doc_header))==0)
{
const struct OLE_HDR *header=(const struct OLE_HDR *)buffer;
if(le16(header->reserved)!=0 || le32(header->reserved1)!=0 || le32(header->reserved2)!=0)
return NULL;
if(le16(header->uMiniSectorShift)!=6 || le16(header->uSectorShift)!=9)
return NULL;
if(le32(header->num_FAT_blocks)==0 || le32(header->num_FAT_blocks)>100)
return NULL;
if(le32(header->num_FAT_blocks)==0 ||
le32(header->num_extra_FAT_blocks)>50 ||
le32(header->num_FAT_blocks)>109+le32(header->num_extra_FAT_blocks)*((1<<le16(header->uSectorShift))-1))
return NULL;
/* TODO read the Root Directory */
if(find_in_mem(buffer,"WordDocument",buffer_size)!=NULL)
{
return "doc";
}
else if(find_in_mem(buffer,"StarDraw",buffer_size)!=NULL)
{
return "sda";
}
else if(find_in_mem(buffer,"StarCalc",buffer_size)!=NULL)
{
return "sdc";
}
else if(find_in_mem(buffer,"StarImpress",buffer_size)!=NULL)
{
return "sdd";
}
else if(find_in_mem(buffer,"Worksheet",buffer_size)!=NULL || find_in_mem(buffer,"Book",buffer_size)!=NULL || find_in_mem(buffer,"Workbook",buffer_size)!=NULL || find_in_mem(buffer,"Calc",buffer_size)!=NULL)
{
return "xls";
}
else if(find_in_mem(buffer,"Power",buffer_size)!=NULL)
{
return "ppt";
}
else if(find_in_mem(buffer,"AccessObjSiteData",buffer_size)!=NULL)
{
return "mdb";
}
else if(find_in_mem(buffer,"Visio",buffer_size)!=NULL)
{
return "vis";
}
else if(find_in_mem(buffer,"Sfx",buffer_size)!=NULL)
{
return "sdw";
}
else if(find_in_mem(buffer,"CPicPage",buffer_size)!=NULL)
{ /* Flash */
return "fla";
}
else if(find_in_mem(buffer,"Microsoft Publisher",buffer_size)!=NULL)
{
return "pub";
}
return file_hint_doc.extension;
}
return NULL;
}
static uint64_t test_OLE(FILE *IN)
{
unsigned char buffer_header[512];
uint64_t totalsize;
uint32_t *dif;
uint32_t *fat;
unsigned int freesect_count=0;
struct OLE_HDR *header=(struct OLE_HDR*)&buffer_header;
if(!IN)
return 0;
fseek(IN,SEEK_SET,0);
fread(&buffer_header,sizeof(buffer_header),1,IN); /*reads first sector including OLE header */
/*
ecrit_rapport("num_FAT_blocks %u\n",le32(header->num_FAT_blocks));
ecrit_rapport("num_extra_FAT_blocks %u\n",le32(header->num_extra_FAT_blocks));
*/
/* Sanity check */
if(le32(header->num_FAT_blocks)==0 ||
le32(header->num_extra_FAT_blocks)>50 ||
le32(header->num_FAT_blocks)>109+le32(header->num_extra_FAT_blocks)*((1<<le16(header->uSectorShift))-1))
return 0;
dif=(uint32_t*)MALLOC(109*4+(le32(header->num_extra_FAT_blocks)<<le16(header->uSectorShift)));
memcpy(dif,(header+1),109*4);
if(le32(header->num_extra_FAT_blocks)>0)
{ /* Load DIF*/
uint32_t *dif_pos=dif+109;
unsigned long int i;
unsigned long int block=le32(header->FAT_next_block);
for(i=0;i<le32(header->num_extra_FAT_blocks) && block!=0xFFFFFFFF && block!=0xFFFFFFFE;i++)
{
// ecrit_rapport("pointeur:0x%x\n",block);
if(fseek(IN,512+(block<<le16(header->uSectorShift)),SEEK_SET)<0)
{
free(dif);
return 0;
}
fread(dif_pos, (i<le32(header->num_extra_FAT_blocks)?128:(le32(header->num_FAT_blocks)-109)%127),4,IN);
dif_pos+=(((1<<le16(header->uSectorShift))/4)-1);
block=le32(dif[109+i*(((1<<le16(header->uSectorShift))/4)-1)+127]);
}
}
fat=(uint32_t*)MALLOC(le32(header->num_FAT_blocks)<<le16(header->uSectorShift));
{ /* Load FAT */
unsigned long int j;
for(j=0;j<le32(header->num_FAT_blocks);j++)
{
if(fseek(IN,512+(le32(dif[j])<<le16(header->uSectorShift)),SEEK_SET)<0)
{
free(dif);
free(fat);
return 0;
}
fread(fat+((j<<le16(header->uSectorShift))/4),(1<<le16(header->uSectorShift)),1,IN);
}
}
{ /* Search how many entries are not used at the end of the FAT */
unsigned long int i;
for(i=(le32(header->num_FAT_blocks)<<le16(header->uSectorShift))/4-1;
i>((le32(header->num_FAT_blocks)-1)<<le16(header->uSectorShift))/4 && le32(fat[i])==0xFFFFFFFF; i--)
freesect_count++;
}
totalsize=512+((le32(header->num_FAT_blocks)*128-freesect_count)<<le16(header->uSectorShift));
free(dif);
free(fat);
return totalsize;
}
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