/*
* Extract component parts of OLE2 files (e.g. MS Office Documents)
*
* Copyright (C) 2007-2008 Sourcefire, Inc.
*
* Authors: Trog
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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 to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ctype.h>
#include <stdlib.h>
#include "clamav.h"
#if HAVE_MMAP
#if HAVE_SYS_MMAN_H
#include <sys/mman.h>
#else /* HAVE_SYS_MMAN_H */
#undef HAVE_MMAP
#endif
#endif
#include "cltypes.h"
#include "others.h"
#include "ole2_extract.h"
#include "scanners.h"
#include "hashtab.h"
#include "mbox.h"
#define ole2_endian_convert_16(v) le16_to_host((uint16_t)(v))
#define ole2_endian_convert_32(v) le32_to_host((uint32_t)(v))
#ifndef HAVE_ATTRIB_PACKED
#define __attribute__(x)
#endif
#ifdef HAVE_PRAGMA_PACK
#pragma pack(1)
#endif
#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack 1
#endif
#ifndef O_BINARY
#define O_BINARY 0
#endif
typedef struct ole2_header_tag
{
unsigned char magic[8]; /* should be: 0xd0cf11e0a1b11ae1 */
unsigned char clsid[16];
uint16_t minor_version __attribute__ ((packed));
uint16_t dll_version __attribute__ ((packed));
int16_t byte_order __attribute__ ((packed)); /* -2=intel */
uint16_t log2_big_block_size __attribute__ ((packed)); /* usually 9 (2^9 = 512) */
uint32_t log2_small_block_size __attribute__ ((packed)); /* usually 6 (2^6 = 64) */
int32_t reserved[2] __attribute__ ((packed));
int32_t bat_count __attribute__ ((packed));
int32_t prop_start __attribute__ ((packed));
uint32_t signature __attribute__ ((packed));
uint32_t sbat_cutoff __attribute__ ((packed)); /* cutoff for files held in small blocks (4096) */
int32_t sbat_start __attribute__ ((packed));
int32_t sbat_block_count __attribute__ ((packed));
int32_t xbat_start __attribute__ ((packed));
int32_t xbat_count __attribute__ ((packed));
int32_t bat_array[109] __attribute__ ((packed));
/* not part of the ole2 header, but stuff we need in order to decode */
/* must take account of the size of variables below here when
reading the header */
int32_t sbat_root_start __attribute__ ((packed));
uint32_t max_block_no;
unsigned char *m_area;
off_t m_length;
bitset_t *bitset;
struct uniq *U;
int has_vba;
} ole2_header_t;
typedef struct property_tag
{
char name[64]; /* in unicode */
uint16_t name_size __attribute__ ((packed));
unsigned char type; /* 1=dir 2=file 5=root */
unsigned char color; /* black or red */
uint32_t prev __attribute__ ((packed));
uint32_t next __attribute__ ((packed));
uint32_t child __attribute__ ((packed));
unsigned char clsid[16];
uint32_t user_flags __attribute__ ((packed));
uint32_t create_lowdate __attribute__ ((packed));
uint32_t create_highdate __attribute__ ((packed));
uint32_t mod_lowdate __attribute__ ((packed));
uint32_t mod_highdate __attribute__ ((packed));
uint32_t start_block __attribute__ ((packed));
uint32_t size __attribute__ ((packed));
unsigned char reserved[4];
} property_t;
#ifdef HAVE_PRAGMA_PACK
#pragma pack()
#endif
#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack
#endif
static unsigned char magic_id[] = { 0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1};
static char *get_property_name2(char *name, int size)
{
int i, j;
char *newname;
if (*name == 0 || size <= 0 || size > 64) {
return NULL;
}
newname = (char *) cli_malloc(size*7);
if (!newname) {
return NULL;
}
j=0;
/* size-2 to ignore trailing NULL */
for (i=0 ; i < size-2; i+=2) {
if((!(name[i]&0x80)) && isprint(name[i])) {
newname[j++] = tolower(name[i]);
} else {
if (name[i] < 10 && name[i] >= 0) {
newname[j++] = '_';
newname[j++] = name[i] + '0';
}
else {
const uint16_t x = (((uint16_t)name[i]) << 8) | name[i+1];
newname[j++] = '_';
newname[j++] = 'a'+((x&0xF));
newname[j++] = 'a'+((x>>4)&0xF);
newname[j++] = 'a'+((x>>8)&0xF);
newname[j++] = 'a'+((x>>16)&0xF);
newname[j++] = 'a'+((x>>24)&0xF);
}
newname[j++] = '_';
}
}
newname[j] = '\0';
if (strlen(newname) == 0) {
free(newname);
return NULL;
}
return newname;
}
static char *get_property_name(char *name, int size) {
const char *carray = "0123456789abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz._";
int csize = size>>1;
char *newname, *cname;
char *oname = name;
if (csize<=0) return NULL;
newname = cname = (char *)cli_malloc(size);
if (!newname) return NULL;
while(--csize) {
uint16_t lo, hi, u=cli_readint16(oname)-0x3800;
oname+=2;
if (u > 0x1040) {
free(newname);
return get_property_name2(name, size);
}
lo = u % 64;
u >>= 6;
hi = u % 64;
*cname++=carray[lo];
if(csize!=1 || u!= 64) *cname++=carray[hi];
}
*cname='\0';
return newname;
}
static void print_ole2_property(property_t *property)
{
char spam[128], *buf;
if (property->name_size > 64) {
cli_dbgmsg("[err name len: %d]\n", property->name_size);
return;
}
buf = get_property_name(property->name, property->name_size);
snprintf(spam, sizeof(spam), "OLE2: %s ", buf ? buf : "<noname>");
spam[sizeof(spam)-1]='\0';
if (buf) free(buf);
switch (property->type) {
case 2:
strncat(spam, " [file] ", sizeof(spam) - 1 - strlen(spam));
break;
case 1:
strncat(spam, " [dir ] ", sizeof(spam) - 1 - strlen(spam));
break;
case 5:
strncat(spam, " [root] ", sizeof(spam) - 1 - strlen(spam));
break;
default:
strncat(spam, " [unkn] ", sizeof(spam) - 1 - strlen(spam));
}
spam[sizeof(spam)-1]='\0';
switch (property->color) {
case 0:
strncat(spam, " r ", sizeof(spam) - 1 - strlen(spam));
break;
case 1:
strncat(spam, " b ", sizeof(spam) - 1 - strlen(spam));
break;
default:
strncat(spam, " u ", sizeof(spam) - 1 - strlen(spam));
}
spam[sizeof(spam)-1]='\0';
cli_dbgmsg("%s size:0x%.8x flags:0x%.8x\n", spam, property->size, property->user_flags);
}
static void print_ole2_header(ole2_header_t *hdr)
{
int i;
if (!hdr) {
return;
}
cli_dbgmsg("\nMagic:\t\t\t0x");
for (i=0 ; i<8; i++) {
cli_dbgmsg("%x", hdr->magic[i]);
}
cli_dbgmsg("\n");
cli_dbgmsg("CLSID:\t\t\t{");
for (i=0 ; i<16; i++) {
cli_dbgmsg("%x ", hdr->clsid[i]);
}
cli_dbgmsg("}\n");
cli_dbgmsg("Minor version:\t\t0x%x\n", hdr->minor_version);
cli_dbgmsg("DLL version:\t\t0x%x\n", hdr->dll_version);
cli_dbgmsg("Byte Order:\t\t%d\n", hdr->byte_order);
cli_dbgmsg("Big Block Size:\t\t%i\n", hdr->log2_big_block_size);
cli_dbgmsg("Small Block Size:\t%i\n", hdr->log2_small_block_size);
cli_dbgmsg("BAT count:\t\t%d\n", hdr->bat_count);
cli_dbgmsg("Prop start:\t\t%d\n", hdr->prop_start);
cli_dbgmsg("SBAT cutoff:\t\t%d\n", hdr->sbat_cutoff);
cli_dbgmsg("SBat start:\t\t%d\n", hdr->sbat_start);
cli_dbgmsg("SBat block count:\t%d\n", hdr->sbat_block_count);
cli_dbgmsg("XBat start:\t\t%d\n", hdr->xbat_start);
cli_dbgmsg("XBat block count:\t%d\n\n", hdr->xbat_count);
return;
}
static int ole2_read_block(int fd, ole2_header_t *hdr, void *buff, unsigned int size, int32_t blockno)
{
off_t offset, offend;
if (blockno < 0) {
return FALSE;
}
/* other methods: (blockno+1) * 512 or (blockno * block_size) + 512; */
offset = (blockno << hdr->log2_big_block_size) + MAX(512, 1 << hdr->log2_big_block_size); /* 512 is header size */
if (hdr->m_area == NULL) {
if (lseek(fd, offset, SEEK_SET) != offset) {
return FALSE;
}
if (cli_readn(fd, buff, size) != size) {
return FALSE;
}
} else {
offend = offset + size;
if ((offend <= 0) || (offend > hdr->m_length)) {
return FALSE;
}
memcpy(buff, hdr->m_area+offset, size);
}
return TRUE;
}
static int32_t ole2_get_next_bat_block(int fd, ole2_header_t *hdr, int32_t current_block)
{
int32_t bat_array_index;
uint32_t bat[128];
if (current_block < 0) {
return -1;
}
bat_array_index = current_block / 128;
if (bat_array_index > hdr->bat_count) {
cli_dbgmsg("bat_array index error\n");
return -10;
}
if (!ole2_read_block(fd, hdr, &bat, 512,
ole2_endian_convert_32(hdr->bat_array[bat_array_index]))) {
return -1;
}
return ole2_endian_convert_32(bat[current_block-(bat_array_index * 128)]);
}
static int32_t ole2_get_next_xbat_block(int fd, ole2_header_t *hdr, int32_t current_block)
{
int32_t xbat_index, xbat_block_index, bat_index, bat_blockno;
uint32_t xbat[128], bat[128];
if (current_block < 0) {
return -1;
}
xbat_index = current_block / 128;
/* NB: The last entry in each XBAT points to the next XBAT block.
This reduces the number of entries in each block by 1.
*/
xbat_block_index = (xbat_index - 109) / 127;
bat_blockno = (xbat_index - 109) % 127;
bat_index = current_block % 128;
if (!ole2_read_block(fd, hdr, &xbat, 512, hdr->xbat_start)) {
return -1;
}
/* Follow the chain of XBAT blocks */
while (xbat_block_index > 0) {
if (!ole2_read_block(fd, hdr, &xbat, 512,
ole2_endian_convert_32(xbat[127]))) {
return -1;
}
xbat_block_index--;
}
if (!ole2_read_block(fd, hdr, &bat, 512, ole2_endian_convert_32(xbat[bat_blockno]))) {
return -1;
}
return ole2_endian_convert_32(bat[bat_index]);
}
static int32_t ole2_get_next_block_number(int fd, ole2_header_t *hdr, int32_t current_block)
{
if (current_block < 0) {
return -1;
}
if ((current_block / 128) > 108) {
return ole2_get_next_xbat_block(fd, hdr, current_block);
} else {
return ole2_get_next_bat_block(fd, hdr, current_block);
}
}
static int32_t ole2_get_next_sbat_block(int fd, ole2_header_t *hdr, int32_t current_block)
{
int32_t iter, current_bat_block;
uint32_t sbat[128];
if (current_block < 0) {
return -1;
}
current_bat_block = hdr->sbat_start;
iter = current_block / 128;
while (iter > 0) {
current_bat_block = ole2_get_next_block_number(fd, hdr, current_bat_block);
iter--;
}
if (!ole2_read_block(fd, hdr, &sbat, 512, current_bat_block)) {
return -1;
}
return ole2_endian_convert_32(sbat[current_block % 128]);
}
/* Retrieve the block containing the data for the given sbat index */
static int32_t ole2_get_sbat_data_block(int fd, ole2_header_t *hdr, void *buff, int32_t sbat_index)
{
int32_t block_count, current_block;
if (sbat_index < 0) {
return FALSE;
}
if (hdr->sbat_root_start < 0) {
cli_dbgmsg("No root start block\n");
return FALSE;
}
block_count = sbat_index / (1 << (hdr->log2_big_block_size - hdr->log2_small_block_size));
current_block = hdr->sbat_root_start;
while (block_count > 0) {
current_block = ole2_get_next_block_number(fd, hdr, current_block);
block_count--;
}
/* current_block now contains the block number of the sbat array
containing the entry for the required small block */
return(ole2_read_block(fd, hdr, buff, 1 << hdr->log2_big_block_size, current_block));
}
static int ole2_walk_property_tree(int fd, ole2_header_t *hdr, const char *dir, int32_t prop_index,
int (*handler)(int fd, ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx),
unsigned int rec_level, unsigned int *file_count, cli_ctx *ctx, unsigned long *scansize)
{
property_t prop_block[4];
int32_t idx, current_block, i;
char *dirname;
int ret;
current_block = hdr->prop_start;
if ((prop_index < 0) || (prop_index > (int32_t) hdr->max_block_no) || (rec_level > 100) || (*file_count > 100000)) {
return CL_SUCCESS;
}
if (ctx && ctx->engine->maxfiles && (*file_count > ctx->engine->maxfiles)) {
cli_dbgmsg("OLE2: File limit reached (max: %d)\n", ctx->engine->maxfiles);
return CL_SUCCESS;
}
if (ctx && ctx->engine->maxreclevel && (rec_level > ctx->engine->maxreclevel)) {
cli_dbgmsg("OLE2: Recursion limit reached (max: %d)\n", ctx->engine->maxreclevel);
return CL_SUCCESS;
}
idx = prop_index / 4;
for (i=0 ; i < idx ; i++) {
current_block = ole2_get_next_block_number(fd, hdr, current_block);
if (current_block < 0) {
return CL_SUCCESS;
}
}
idx = prop_index % 4;
if (!ole2_read_block(fd, hdr, prop_block, 512,
current_block)) {
return CL_SUCCESS;
}
if (prop_block[idx].type <= 0) {
return CL_SUCCESS;
}
prop_block[idx].name_size = ole2_endian_convert_16(prop_block[idx].name_size);
prop_block[idx].prev = ole2_endian_convert_32(prop_block[idx].prev);
prop_block[idx].next = ole2_endian_convert_32(prop_block[idx].next);
prop_block[idx].child = ole2_endian_convert_32(prop_block[idx].child);
prop_block[idx].user_flags = ole2_endian_convert_32(prop_block[idx].user_flags);
prop_block[idx].create_lowdate = ole2_endian_convert_32(prop_block[idx].create_lowdate);
prop_block[idx].create_highdate = ole2_endian_convert_32(prop_block[idx].create_highdate);
prop_block[idx].mod_lowdate = ole2_endian_convert_32(prop_block[idx].mod_lowdate);
prop_block[idx].mod_highdate = ole2_endian_convert_32(prop_block[idx].mod_highdate);
prop_block[idx].start_block = ole2_endian_convert_32(prop_block[idx].start_block);
prop_block[idx].size = ole2_endian_convert_32(prop_block[idx].size);
if (dir) print_ole2_property(&prop_block[idx]);
/* Check we aren't in a loop */
if (cli_bitset_test(hdr->bitset, (unsigned long) prop_index)) {
/* Loop in property tree detected */
cli_dbgmsg("OLE2: Property tree loop detected at index %d\n", prop_index);
return CL_BREAK;
}
if (!cli_bitset_set(hdr->bitset, (unsigned long) prop_index)) {
return CL_SUCCESS;
}
switch (prop_block[idx].type) {
case 5: /* Root Entry */
if ((prop_index != 0) || (rec_level !=0) ||
(*file_count != 0)) {
/* Can only have RootEntry as the top */
cli_dbgmsg("ERROR: illegal Root Entry\n");
return CL_SUCCESS;
}
hdr->sbat_root_start = prop_block[idx].start_block;
if (
(ret=ole2_walk_property_tree(fd, hdr, dir, prop_block[idx].prev, handler, rec_level+1, file_count, ctx, scansize))!=CL_SUCCESS
||
(ret=ole2_walk_property_tree(fd, hdr, dir, prop_block[idx].next, handler, rec_level+1, file_count, ctx, scansize))!=CL_SUCCESS
||
(ret=ole2_walk_property_tree(fd, hdr, dir,prop_block[idx].child, handler, rec_level+1, file_count, ctx, scansize))!=CL_SUCCESS
) return ret;
break;
case 2: /* File */
if (ctx && ctx->engine->maxfiles && ctx->scannedfiles + *file_count > ctx->engine->maxfiles) {
cli_dbgmsg("OLE2: files limit reached (max: %u)\n", ctx->engine->maxfiles);
return CL_BREAK;
}
if (!ctx || !ctx->engine->maxfilesize || prop_block[idx].size <= ctx->engine->maxfilesize || prop_block[idx].size <= *scansize) {
(*file_count)++;
*scansize-=prop_block[idx].size;
if ((ret=handler(fd, hdr, &prop_block[idx], dir, ctx)) != CL_SUCCESS)
return ret;
} else {
cli_dbgmsg("OLE2: filesize exceeded\n");
}
if (
(ret=ole2_walk_property_tree(fd, hdr, dir, prop_block[idx].prev, handler, rec_level, file_count, ctx, scansize))!=CL_SUCCESS
||
(ret=ole2_walk_property_tree(fd, hdr, dir, prop_block[idx].next, handler, rec_level, file_count, ctx, scansize))!=CL_SUCCESS
||
(ret=ole2_walk_property_tree(fd, hdr, dir, prop_block[idx].child, handler, rec_level, file_count, ctx, scansize))!=CL_SUCCESS
) return ret;
break;
case 1: /* Directory */
if (dir) {
dirname = (char *) cli_malloc(strlen(dir)+8);
if (!dirname) return CL_BREAK;
snprintf(dirname, strlen(dir)+8, "%s/%.6d", dir, prop_index);
if (mkdir(dirname, 0700) != 0) {
free(dirname);
return CL_BREAK;
}
cli_dbgmsg("OLE2 dir entry: %s\n",dirname);
} else dirname = NULL;
if (
(ret=ole2_walk_property_tree(fd, hdr, dir, prop_block[idx].prev, handler, rec_level+1, file_count, ctx, scansize))!=CL_SUCCESS
||
(ret=ole2_walk_property_tree(fd, hdr, dir,prop_block[idx].next, handler, rec_level+1, file_count, ctx, scansize))!=CL_SUCCESS
||
(ret=ole2_walk_property_tree(fd, hdr, dirname, prop_block[idx].child, handler, rec_level+1, file_count, ctx, scansize))!=CL_SUCCESS
) {}
if (dirname) free(dirname);
return ret;
break;
default:
cli_dbgmsg("ERROR: unknown OLE2 entry type: %d\n", prop_block[idx].type);
break;
}
return CL_SUCCESS;
}
/* Write file Handler - write the contents of the entry to a file */
static int handler_writefile(int fd, ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx)
{
unsigned char *buff;
int32_t current_block, ofd, len, offset;
char *name, newname[1024];
bitset_t *blk_bitset;
char *hash;
uint32_t cnt;
if (prop->type != 2) {
/* Not a file */
return CL_SUCCESS;
}
if (prop->name_size > 64) {
cli_dbgmsg("OLE2 [handler_writefile]: property name too long: %d\n", prop->name_size);
return CL_SUCCESS;
}
name = get_property_name2(prop->name, prop->name_size);
if (name) cnt = uniq_add(hdr->U, name, strlen(name), &hash);
else cnt = uniq_add(hdr->U, NULL, 0, &hash);
snprintf(newname, sizeof(newname), "%s/%s_%u", dir, hash, cnt);
newname[sizeof(newname)-1]='\0';
cli_dbgmsg("OLE2 [handler_writefile]: Dumping '%s' to '%s'\n", name ? name : "<empty>", newname);
if (name) free(name);
ofd = open(newname, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, S_IRWXU);
if (ofd < 0) {
cli_errmsg("OLE2 [handler_writefile]: failed to create file: %s\n", newname);
return CL_SUCCESS;
}
current_block = prop->start_block;
len = prop->size;
buff = (unsigned char *) cli_malloc(1 << hdr->log2_big_block_size);
if (!buff) {
close(ofd);
return CL_BREAK;
}
blk_bitset = cli_bitset_init();
if (!blk_bitset) {
cli_errmsg("OLE2 [handler_writefile]: init bitset failed\n");
close(ofd);
free(buff);
return CL_BREAK;
}
while((current_block >= 0) && (len > 0)) {
if (current_block > (int32_t) hdr->max_block_no) {
cli_dbgmsg("OLE2 [handler_writefile]: Max block number for file size exceeded: %d\n", current_block);
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_SUCCESS;
}
/* Check we aren't in a loop */
if (cli_bitset_test(blk_bitset, (unsigned long) current_block)) {
/* Loop in block list */
cli_dbgmsg("OLE2 [handler_writefile]: Block list loop detected\n");
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_BREAK;
}
if (!cli_bitset_set(blk_bitset, (unsigned long) current_block)) {
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_BREAK;
}
if (prop->size < (int64_t)hdr->sbat_cutoff) {
/* Small block file */
if (!ole2_get_sbat_data_block(fd, hdr, buff, current_block)) {
cli_dbgmsg("OLE2 [handler_writefile]: ole2_get_sbat_data_block failed\n");
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_SUCCESS;
}
/* buff now contains the block with N small blocks in it */
offset = (1 << hdr->log2_small_block_size) * (current_block % (1 << (hdr->log2_big_block_size - hdr->log2_small_block_size)));
if (cli_writen(ofd, &buff[offset], MIN(len,1 << hdr->log2_small_block_size)) != MIN(len,1 << hdr->log2_small_block_size)) {
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_BREAK;
}
len -= MIN(len,1 << hdr->log2_small_block_size);
current_block = ole2_get_next_sbat_block(fd, hdr, current_block);
} else {
/* Big block file */
if (!ole2_read_block(fd, hdr, buff, 1 << hdr->log2_big_block_size, current_block)) {
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_SUCCESS;
}
if (cli_writen(ofd, buff, MIN(len,(1 << hdr->log2_big_block_size))) !=
MIN(len,(1 << hdr->log2_big_block_size))) {
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_BREAK;
}
current_block = ole2_get_next_block_number(fd, hdr, current_block);
len -= MIN(len,(1 << hdr->log2_big_block_size));
}
}
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
return CL_SUCCESS;
}
/* enum file Handler - checks for VBA presence */
static int handler_enum(int fd, ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx)
{
char *name;
if (!hdr->has_vba) {
name = get_property_name2(prop->name, prop->name_size);
if (name) {
if (!strcmp(name, "_vba_project") || !strcmp(name, "powerpoint document") || !strcmp(name, "worddocument") || !strcmp(name, "_1_ole10native"))
hdr->has_vba = 1;
free(name);
}
}
return CL_SUCCESS;
}
static int handler_otf(int fd, ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx)
{
char *tempfile;
unsigned char *buff;
int32_t current_block, len, offset;
int ofd, ret;
bitset_t *blk_bitset;
if (prop->type != 2) {
/* Not a file */
return CL_SUCCESS;
}
print_ole2_property(prop);
if(!(tempfile = cli_gentemp(ctx ? ctx->engine->tmpdir : NULL)))
return CL_EMEM;
if((ofd = open(tempfile, O_RDWR|O_CREAT|O_TRUNC|O_BINARY, S_IRWXU)) < 0) {
cli_dbgmsg("OLE2: Can't create file %s\n", tempfile);
free(tempfile);
return CL_ECREAT;
}
current_block = prop->start_block;
len = prop->size;
buff = (unsigned char *) cli_malloc(1 << hdr->log2_big_block_size);
if (!buff) {
close(ofd);
cli_unlink(tempfile);
free(tempfile);
return CL_EMEM;
}
blk_bitset = cli_bitset_init();
if (!blk_bitset) {
cli_errmsg("OLE2: OTF handler init bitset failed\n");
free(buff);
close(ofd);
if (cli_unlink(tempfile)) {
free(tempfile);
return CL_EUNLINK;
}
free(tempfile);
return CL_BREAK;
}
while((current_block >= 0) && (len > 0)) {
if (current_block > (int32_t) hdr->max_block_no) {
cli_dbgmsg("OLE2: Max block number for file size exceeded: %d\n", current_block);
break;
}
/* Check we aren't in a loop */
if (cli_bitset_test(blk_bitset, (unsigned long) current_block)) {
/* Loop in block list */
cli_dbgmsg("OLE2: Block list loop detected\n");
break;
}
if (!cli_bitset_set(blk_bitset, (unsigned long) current_block)) {
break;
}
if (prop->size < (int64_t)hdr->sbat_cutoff) {
/* Small block file */
if (!ole2_get_sbat_data_block(fd, hdr, buff, current_block)) {
cli_dbgmsg("ole2_get_sbat_data_block failed\n");
break;
}
/* buff now contains the block with N small blocks in it */
offset = (1 << hdr->log2_small_block_size) * (current_block % (1 << (hdr->log2_big_block_size - hdr->log2_small_block_size)));
if (cli_writen(ofd, &buff[offset], MIN(len,1 << hdr->log2_small_block_size)) != MIN(len,1 << hdr->log2_small_block_size)) {
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
if (cli_unlink(tempfile)) {
free(tempfile);
return CL_EUNLINK;
}
free(tempfile);
return CL_BREAK;
}
len -= MIN(len,1 << hdr->log2_small_block_size);
current_block = ole2_get_next_sbat_block(fd, hdr, current_block);
} else {
/* Big block file */
if (!ole2_read_block(fd, hdr, buff, 1 << hdr->log2_big_block_size, current_block)) {
break;
}
if (cli_writen(ofd, buff, MIN(len,(1 << hdr->log2_big_block_size))) !=
MIN(len,(1 << hdr->log2_big_block_size))) {
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
if (cli_unlink(tempfile)) {
free(tempfile);
return CL_EUNLINK;
}
free(tempfile);
return CL_EWRITE;
}
current_block = ole2_get_next_block_number(fd, hdr, current_block);
len -= MIN(len,(1 << hdr->log2_big_block_size));
}
}
lseek(ofd, 0, SEEK_SET);
ret=cli_magic_scandesc(ofd, ctx);
close(ofd);
free(buff);
cli_bitset_free(blk_bitset);
if(ctx && !ctx->engine->keeptmp) {
if (cli_unlink(tempfile)) {
free(tempfile);
return CL_EUNLINK;
}
}
free(tempfile);
return ret==CL_VIRUS ? CL_VIRUS : CL_SUCCESS;
}
#if !defined(HAVE_ATTRIB_PACKED) && !defined(HAVE_PRAGMA_PACK) && !defined(HAVE_PRAGMA_PACK_HPPA)
static int ole2_read_header(int fd, ole2_header_t *hdr)
{
int i;
if (cli_readn(fd, &hdr->magic, 8) != 8) {
return FALSE;
}
if (cli_readn(fd, &hdr->clsid, 16) != 16) {
return FALSE;
}
if (cli_readn(fd, &hdr->minor_version, 2) != 2) {
return FALSE;
}
if (cli_readn(fd, &hdr->dll_version, 2) != 2) {
return FALSE;
}
if (cli_readn(fd, &hdr->byte_order, 2) != 2) {
return FALSE;
}
if (cli_readn(fd, &hdr->log2_big_block_size, 2) != 2) {
return FALSE;
}
if (cli_readn(fd, &hdr->log2_small_block_size, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->reserved, 8) != 8) {
return FALSE;
}
if (cli_readn(fd, &hdr->bat_count, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->prop_start, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->signature, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->sbat_cutoff, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->sbat_start, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->sbat_block_count, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->xbat_start, 4) != 4) {
return FALSE;
}
if (cli_readn(fd, &hdr->xbat_count, 4) != 4) {
return FALSE;
}
for (i=0 ; i < 109 ; i++) {
if (cli_readn(fd, &hdr->bat_array[i], 4) != 4) {
return FALSE;
}
}
return TRUE;
}
#endif
int cli_ole2_extract(int fd, const char *dirname, cli_ctx *ctx, struct uniq **vba)
{
ole2_header_t hdr;
int hdr_size, ret=CL_CLEAN;
struct stat statbuf;
unsigned int file_count=0;
unsigned long scansize, scansize2;
cli_dbgmsg("in cli_ole2_extract()\n");
if (ctx && ctx->engine->maxscansize) {
if (ctx->engine->maxscansize > ctx->scansize)
scansize = ctx->engine->maxscansize - ctx->scansize;
else
return CL_EMAXSIZE;
} else scansize = -1;
scansize2 = scansize;
/* size of header - size of other values in struct */
hdr_size = sizeof(struct ole2_header_tag) - sizeof(int32_t) - sizeof(uint32_t) -
sizeof(unsigned char *) - sizeof(off_t) - sizeof(bitset_t *) -
sizeof(struct uniq *) - sizeof(int);
hdr.m_area = NULL;
if (fstat(fd, &statbuf) == 0) {
if (statbuf.st_size < hdr_size) {
return CL_CLEAN;
}
#ifdef HAVE_MMAP
hdr.m_length = statbuf.st_size;
hdr.m_area = (unsigned char *) mmap(NULL, hdr.m_length, PROT_READ, MAP_PRIVATE, fd, 0);
if (hdr.m_area == MAP_FAILED) {
hdr.m_area = NULL;
} else {
cli_dbgmsg("mmap'ed file\n");
memcpy(&hdr, hdr.m_area, hdr_size);
}
#endif
}
if (hdr.m_area == NULL) {
hdr.bitset = NULL;
#if defined(HAVE_ATTRIB_PACKED) || defined(HAVE_PRAGMA_PACK) || defined(HAVE_PRAGMA_PACK_HPPA)
if (cli_readn(fd, &hdr, hdr_size) != hdr_size) {
goto abort;
}
#else
if (!ole2_read_header(fd, &hdr)) {
goto abort;
}
#endif
}
hdr.minor_version = ole2_endian_convert_16(hdr.minor_version);
hdr.dll_version = ole2_endian_convert_16(hdr.dll_version);
hdr.byte_order = ole2_endian_convert_16(hdr.byte_order);
hdr.log2_big_block_size = ole2_endian_convert_16(hdr.log2_big_block_size);
hdr.log2_small_block_size = ole2_endian_convert_32(hdr.log2_small_block_size);
hdr.bat_count = ole2_endian_convert_32(hdr.bat_count);
hdr.prop_start = ole2_endian_convert_32(hdr.prop_start);
hdr.sbat_cutoff = ole2_endian_convert_32(hdr.sbat_cutoff);
hdr.sbat_start = ole2_endian_convert_32(hdr.sbat_start);
hdr.sbat_block_count = ole2_endian_convert_32(hdr.sbat_block_count);
hdr.xbat_start = ole2_endian_convert_32(hdr.xbat_start);
hdr.xbat_count = ole2_endian_convert_32(hdr.xbat_count);
hdr.sbat_root_start = -1;
hdr.bitset = cli_bitset_init();
if (!hdr.bitset) {
ret=CL_EMEM;
goto abort;
}
if (memcmp(hdr.magic, magic_id, 8) != 0) {
cli_dbgmsg("OLE2 magic failed!\n");
ret=CL_EFORMAT;
goto abort;
}
if (hdr.log2_big_block_size < 6 || hdr.log2_big_block_size > 30) {
cli_dbgmsg("CAN'T PARSE: Invalid big block size (2^%u)\n", hdr.log2_big_block_size);
goto abort;
}
if (!hdr.log2_small_block_size || hdr.log2_small_block_size > hdr.log2_big_block_size) {
cli_dbgmsg("CAN'T PARSE: Invalid small block size (2^%u)\n", hdr.log2_small_block_size);
goto abort;
}
if (hdr.sbat_cutoff != 4096) {
cli_dbgmsg("WARNING: Untested sbat cutoff (%u); data may not extract correctly\n", hdr.sbat_cutoff);
}
/* 8 SBAT blocks per file block */
hdr.max_block_no = (statbuf.st_size - MAX(512, 1 << hdr.log2_big_block_size)) / (1 << hdr.log2_small_block_size);
print_ole2_header(&hdr);
cli_dbgmsg("Max block number: %lu\n", (unsigned long int) hdr.max_block_no);
/* PASS 1 : Count files and check for VBA */
hdr.has_vba = 0;
ret = ole2_walk_property_tree(fd, &hdr, NULL, 0, handler_enum, 0, &file_count, ctx, &scansize);
cli_bitset_free(hdr.bitset);
hdr.bitset = NULL;
if (!file_count || !(hdr.bitset = cli_bitset_init()))
goto abort;
/* If there's no VBA we scan OTF */
if (hdr.has_vba) {
/* PASS 2/A : VBA scan */
cli_dbgmsg("OLE2: VBA project found\n");
if (!(hdr.U = uniq_init(file_count))) {
cli_dbgmsg("OLE2: uniq_init() failed\n");
ret = CL_EMEM;
goto abort;
}
file_count = 0;
ole2_walk_property_tree(fd, &hdr, dirname, 0, handler_writefile, 0, &file_count, ctx, &scansize2);
ret = CL_CLEAN;
*vba = hdr.U;
} else {
cli_dbgmsg("OLE2: no VBA projects found\n");
/* PASS 2/B : OTF scan */
file_count = 0;
if(ctx)
ret = ole2_walk_property_tree(fd, &hdr, NULL, 0, handler_otf, 0, &file_count, ctx, &scansize2);
}
abort:
#ifdef HAVE_MMAP
if (hdr.m_area != NULL) {
munmap(hdr.m_area, hdr.m_length);
}
#endif
if(hdr.bitset)
cli_bitset_free(hdr.bitset);
return ret == CL_BREAK ? CL_CLEAN : ret;
}