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denyhosts/clamscan/libclamav/ole2_extract.c

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添加病毒扫描
2022-10-22 18:41:00 +08:00
/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2007-2013 Sourcefire, Inc.
*
* Authors: Trog
*
* Summary: Extract component parts of OLE2 files (e.g. MS Office Documents).
*
* Acknowledgements: Some ideas and algorithms were based upon OpenOffice and libgsf.
*
* 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>
#include <ctype.h>
#include <stdlib.h>
#include <errno.h>
#include <conv.h>
#include <zlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdbool.h>
#include "clamav.h"
#include "others.h"
#include "hwp.h"
#include "ole2_extract.h"
#include "scanners.h"
#include "fmap.h"
#include "json_api.h"
#if HAVE_JSON
#include "msdoc.h"
#endif
#ifdef DEBUG_OLE2_LIST
#define ole2_listmsg(...) cli_dbgmsg(__VA_ARGS__)
#else
#define ole2_listmsg(...) ;
#endif
#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
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;
off_t m_length;
bitset_t *bitset;
struct uniq *U;
fmap_t *map;
int has_vba;
int has_xlm;
hwp5_header_t *is_hwp;
} 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;
struct ole2_list_node;
typedef struct ole2_list_node {
uint32_t Val;
struct ole2_list_node *Next;
} ole2_list_node_t;
typedef struct ole2_list {
uint32_t Size;
ole2_list_node_t *Head;
} ole2_list_t;
int ole2_list_init(ole2_list_t *list);
int ole2_list_is_empty(ole2_list_t *list);
uint32_t ole2_list_size(ole2_list_t *list);
int ole2_list_push(ole2_list_t *list, uint32_t val);
uint32_t ole2_list_pop(ole2_list_t *list);
int ole2_list_delete(ole2_list_t *list);
int ole2_list_init(ole2_list_t *list)
{
list->Head = NULL;
list->Size = 0;
return CL_SUCCESS;
}
int ole2_list_is_empty(ole2_list_t *list)
{
return (list->Head == NULL);
}
uint32_t
ole2_list_size(ole2_list_t *list)
{
return (list->Size);
}
int ole2_list_push(ole2_list_t *list, uint32_t val)
{
//check the cli - malloc ?
ole2_list_node_t *new_node;
new_node = (ole2_list_node_t *)cli_malloc(sizeof(ole2_list_node_t));
if (!new_node) {
cli_dbgmsg("OLE2: could not allocate new node for worklist!\n");
return CL_EMEM;
}
new_node->Val = val;
new_node->Next = list->Head;
list->Head = new_node;
(list->Size)++;
return CL_SUCCESS;
}
uint32_t
ole2_list_pop(ole2_list_t *list)
{
uint32_t val;
ole2_list_node_t *next;
if (ole2_list_is_empty(list)) {
cli_dbgmsg("OLE2: work list is empty and ole2_list_pop() called!\n");
return -1;
}
val = list->Head->Val;
next = list->Head->Next;
free(list->Head);
list->Head = next;
(list->Size)--;
return val;
}
int ole2_list_delete(ole2_list_t *list)
{
while (!ole2_list_is_empty(list))
ole2_list_pop(list);
return CL_SUCCESS;
}
#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};
char *
cli_ole2_get_property_name2(const char *name, int size)
{
int i, j;
char *newname;
if ((name[0] == 0 && name[1] == 0) || size <= 0 || size > 128) {
return NULL;
}
newname = (char *)cli_malloc(size * 7);
if (!newname) {
cli_errmsg("OLE2 [cli_ole2_get_property_name2]: Unable to allocate memory for newname: %u\n", size * 7);
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]) && name[i + 1] == 0) {
newname[j++] = tolower(name[i]);
} else {
if (name[i] < 10 && name[i] >= 0 && name[i + 1] == 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) {
cli_errmsg("OLE2 [get_property_name]: Unable to allocate memory for newname %u\n", size);
return NULL;
}
while (--csize) {
uint16_t lo, hi, u = cli_readint16(oname) - 0x3800;
oname += 2;
if (u > 0x1040) {
free(newname);
return cli_ole2_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)
{
if (!hdr || !cli_debug_flag) {
return;
}
cli_dbgmsg("\n");
cli_dbgmsg("Magic:\t\t\t0x%x%x%x%x%x%x%x%x\n",
hdr->magic[0], hdr->magic[1], hdr->magic[2], hdr->magic[3],
hdr->magic[4], hdr->magic[5], hdr->magic[6], hdr->magic[7]);
cli_dbgmsg("CLSID:\t\t\t{%x%x%x%x-%x%x-%x%x-%x%x-%x%x%x%x%x%x}\n",
hdr->clsid[0], hdr->clsid[1], hdr->clsid[2], hdr->clsid[3],
hdr->clsid[4], hdr->clsid[5], hdr->clsid[6], hdr->clsid[7],
hdr->clsid[8], hdr->clsid[9], hdr->clsid[10], hdr->clsid[11],
hdr->clsid[12], hdr->clsid[13], hdr->clsid[14], hdr->clsid[15]);
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%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", hdr->xbat_count);
cli_dbgmsg("\n");
return;
}
static int
ole2_read_block(ole2_header_t *hdr, void *buff, unsigned int size, int32_t blockno)
{
off_t offset, offend;
const void *pblock;
if (blockno < 0) {
return FALSE;
}
/* other methods: (blockno+1) * 512 or (blockno * block_size) + 512; */
if (((uint64_t)blockno << hdr->log2_big_block_size) < (INT32_MAX - MAX(512, (uint64_t)1 << hdr->log2_big_block_size))) {
/* 512 is header size */
offset = (blockno << hdr->log2_big_block_size) + MAX(512, 1 << hdr->log2_big_block_size);
offend = offset + size;
} else {
offset = INT32_MAX - size;
offend = INT32_MAX;
}
if ((offend <= 0) || (offset < 0) || (offset >= hdr->m_length)) {
return FALSE;
} else if (offend > hdr->m_length) {
/* bb#11369 - ole2 files may not be a block multiple in size */
memset(buff, 0, size);
size = hdr->m_length - offset;
}
if (!(pblock = fmap_need_off_once(hdr->map, offset, size))) {
return FALSE;
}
memcpy(buff, pblock, size);
return TRUE;
}
static int32_t
ole2_get_next_bat_block(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(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(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(hdr, &xbat, 512, hdr->xbat_start)) {
return -1;
}
/* Follow the chain of XBAT blocks */
while (xbat_block_index > 0) {
if (!ole2_read_block(hdr, &xbat, 512,
ole2_endian_convert_32(xbat[127]))) {
return -1;
}
xbat_block_index--;
}
if (!ole2_read_block(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(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(hdr, current_block);
} else {
return ole2_get_next_bat_block(hdr, current_block);
}
}
static int32_t
ole2_get_next_sbat_block(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(hdr, current_bat_block);
iter--;
}
if (!ole2_read_block(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(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(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(hdr, buff, 1 << hdr->log2_big_block_size, current_block));
}
static int
ole2_walk_property_tree(ole2_header_t *hdr, const char *dir, int32_t prop_index,
int (*handler)(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, curindex;
char *dirname;
ole2_list_t node_list;
int ret, func_ret;
#if HAVE_JSON
char *name;
int toval = 0;
#endif
ole2_listmsg("ole2_walk_property_tree() called\n");
func_ret = CL_SUCCESS;
ole2_list_init(&node_list);
ole2_listmsg("rec_level: %d\n", rec_level);
ole2_listmsg("file_count: %d\n", *file_count);
if ((rec_level > 100) || (*file_count > 100000)) {
return CL_SUCCESS;
}
if (ctx && ctx->engine->max_recursion_level && (rec_level > ctx->engine->max_recursion_level)) {
// Note: engine->max_recursion_level is re-purposed here out of convenience.
// ole2 recursion does not leverage the ctx->recursion_stack stack.
cli_dbgmsg("OLE2: Recursion limit reached (max: %d)\n", ctx->engine->max_recursion_level);
cli_append_virus_if_heur_exceedsmax(ctx, "Heuristics.Limits.Exceeded.MaxRecursion");
return CL_EMAXREC;
}
//push the 'root' node for the level onto the local list
if ((ret = ole2_list_push(&node_list, prop_index)) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return ret;
}
while (!ole2_list_is_empty(&node_list)) {
ole2_listmsg("within working loop, worklist size: %d\n", ole2_list_size(&node_list));
#if HAVE_JSON
if (cli_json_timeout_cycle_check(ctx, &toval) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return CL_ETIMEOUT;
}
#endif
current_block = hdr->prop_start;
//pop off a node to work on
curindex = ole2_list_pop(&node_list);
ole2_listmsg("current index: %d\n", curindex);
if ((curindex < 0) || (curindex > (int32_t)hdr->max_block_no)) {
continue;
}
//read in the sector referenced by the current index
idx = curindex / 4;
for (i = 0; i < idx; i++) {
current_block = ole2_get_next_block_number(hdr, current_block);
if (current_block < 0) {
continue;
}
}
idx = curindex % 4;
if (!ole2_read_block(hdr, prop_block, 512, current_block)) {
continue;
}
if (prop_block[idx].type <= 0) {
continue;
}
ole2_listmsg("reading prop block\n");
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);
ole2_listmsg("printing ole2 property\n");
if (dir)
print_ole2_property(&prop_block[idx]);
ole2_listmsg("checking bitset\n");
/* Check we aren't in a loop */
if (cli_bitset_test(hdr->bitset, (unsigned long)curindex)) {
/* Loop in property tree detected */
cli_dbgmsg("OLE2: Property tree loop detected at index %d\n", curindex);
ole2_list_delete(&node_list);
return CL_BREAK;
}
ole2_listmsg("setting bitset\n");
if (!cli_bitset_set(hdr->bitset, (unsigned long)curindex)) {
continue;
}
ole2_listmsg("prev: %d next %d child %d\n", prop_block[idx].prev, prop_block[idx].next, prop_block[idx].child);
ole2_listmsg("node type: %d\n", prop_block[idx].type);
switch (prop_block[idx].type) {
case 5: /* Root Entry */
ole2_listmsg("root node\n");
if ((curindex != 0) || (rec_level != 0) ||
(*file_count != 0)) {
/* Can only have RootEntry as the top */
cli_dbgmsg("ERROR: illegal Root Entry\n");
continue;
}
hdr->sbat_root_start = prop_block[idx].start_block;
if ((int)(prop_block[idx].child) != -1) {
ret = ole2_walk_property_tree(hdr, dir, prop_block[idx].child, handler, rec_level + 1, file_count, ctx, scansize);
if (ret != CL_SUCCESS) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS)) {
func_ret = ret;
} else {
ole2_list_delete(&node_list);
return ret;
}
}
}
if ((int)(prop_block[idx].prev) != -1) {
if ((ret = ole2_list_push(&node_list, prop_block[idx].prev)) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return ret;
}
}
if ((int)(prop_block[idx].next) != -1) {
if ((ret = ole2_list_push(&node_list, prop_block[idx].next)) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return ret;
}
}
break;
case 2: /* File */
ole2_listmsg("file node\n");
if (ctx && ctx->engine->maxfiles && ((*file_count > ctx->engine->maxfiles) || (ctx->scannedfiles > ctx->engine->maxfiles - *file_count))) {
cli_dbgmsg("OLE2: files limit reached (max: %u)\n", ctx->engine->maxfiles);
cli_append_virus_if_heur_exceedsmax(ctx, "Heuristics.Limits.Exceeded.MaxFiles");
ole2_list_delete(&node_list);
return CL_EMAXFILES;
}
if (!ctx || !(ctx->engine->maxfilesize) || prop_block[idx].size <= ctx->engine->maxfilesize || prop_block[idx].size <= *scansize) {
(*file_count)++;
*scansize -= prop_block[idx].size;
ole2_listmsg("running file handler\n");
ret = handler(hdr, &prop_block[idx], dir, ctx);
if (ret != CL_SUCCESS) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS)) {
func_ret = ret;
} else {
ole2_listmsg("file handler returned %d\n", ret);
ole2_list_delete(&node_list);
return ret;
}
}
} else {
cli_dbgmsg("OLE2: filesize exceeded\n");
}
if ((int)(prop_block[idx].child) != -1) {
ret = ole2_walk_property_tree(hdr, dir, prop_block[idx].child, handler, rec_level, file_count, ctx, scansize);
if (ret != CL_SUCCESS) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS)) {
func_ret = ret;
} else {
ole2_list_delete(&node_list);
return ret;
}
}
}
if ((int)(prop_block[idx].prev) != -1) {
if ((ret = ole2_list_push(&node_list, prop_block[idx].prev)) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return ret;
}
}
if ((int)(prop_block[idx].next) != -1) {
if ((ret = ole2_list_push(&node_list, prop_block[idx].next)) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return ret;
}
}
break;
case 1: /* Directory */
ole2_listmsg("directory node\n");
if (dir) {
#if HAVE_JSON
if (SCAN_COLLECT_METADATA && (ctx->wrkproperty != NULL)) {
if (!json_object_object_get_ex(ctx->wrkproperty, "DigitalSignatures", NULL)) {
name = cli_ole2_get_property_name2(prop_block[idx].name, prop_block[idx].name_size);
if (name) {
if (!strcmp(name, "_xmlsignatures") || !strcmp(name, "_signatures")) {
cli_jsonbool(ctx->wrkproperty, "HasDigitalSignatures", 1);
}
free(name);
}
}
}
#endif
dirname = (char *)cli_malloc(strlen(dir) + 8);
if (!dirname) {
ole2_listmsg("OLE2: malloc failed for dirname\n");
ole2_list_delete(&node_list);
return CL_EMEM;
}
snprintf(dirname, strlen(dir) + 8, "%s" PATHSEP "%.6d", dir, curindex);
if (mkdir(dirname, 0700) != 0) {
ole2_listmsg("OLE2: mkdir failed for directory %s\n", dirname);
free(dirname);
ole2_list_delete(&node_list);
return CL_BREAK;
}
cli_dbgmsg("OLE2 dir entry: %s\n", dirname);
} else
dirname = NULL;
if ((int)(prop_block[idx].child) != -1) {
ret = ole2_walk_property_tree(hdr, dirname, prop_block[idx].child, handler, rec_level + 1, file_count, ctx, scansize);
if (ret != CL_SUCCESS) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS)) {
func_ret = ret;
} else {
ole2_list_delete(&node_list);
if (dirname)
free(dirname);
return ret;
}
}
}
if (dirname) {
free(dirname);
dirname = NULL;
}
if ((int)(prop_block[idx].prev) != -1) {
if ((ret = ole2_list_push(&node_list, prop_block[idx].prev)) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return ret;
}
}
if ((int)(prop_block[idx].next) != -1) {
if ((ret = ole2_list_push(&node_list, prop_block[idx].next)) != CL_SUCCESS) {
ole2_list_delete(&node_list);
return ret;
}
}
break;
default:
cli_dbgmsg("ERROR: unknown OLE2 entry type: %d\n", prop_block[idx].type);
break;
}
ole2_listmsg("loop ended: %d %d\n", ole2_list_size(&node_list), ole2_list_is_empty(&node_list));
}
ole2_list_delete(&node_list);
return func_ret;
}
/* Write file Handler - write the contents of the entry to a file */
static int
handler_writefile(ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx)
{
unsigned char *buff;
int32_t current_block, ofd;
size_t len, offset;
char *name, newname[1024];
bitset_t *blk_bitset;
char *hash;
uint32_t cnt;
UNUSEDPARAM(ctx);
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 = cli_ole2_get_property_name2(prop->name, prop->name_size);
if (name) {
cli_dbgmsg("Storing %s in uniq\n", name);
if (CL_SUCCESS != uniq_add(hdr->U, name, strlen(name), &hash, &cnt)) {
free(name);
cli_dbgmsg("OLE2 [handler_writefile]: too many property names added to uniq store.\n");
return CL_BREAK;
}
} else {
if (CL_SUCCESS != uniq_add(hdr->U, NULL, 0, &hash, &cnt)) {
cli_dbgmsg("OLE2 [handler_writefile]: too many property names added to uniq store.\n");
return CL_BREAK;
}
}
snprintf(newname, sizeof(newname), "%s" PATHSEP "%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_IRUSR | S_IWUSR);
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) {
cli_errmsg("OLE2 [handler_writefile]: Unable to allocate memory for buff: %u\n", 1 << hdr->log2_big_block_size);
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(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(hdr, current_block);
} else {
/* Big block file */
if (!ole2_read_block(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(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 biff_parser_states {
BIFF_PARSER_INITIAL,
BIFF_PARSER_EXPECTING_2ND_TAG_BYTE,
BIFF_PARSER_EXPECTING_1ST_LENGTH_BYTE,
BIFF_PARSER_EXPECTING_2ND_LENGTH_BYTE,
BIFF_PARSER_NAME_RECORD,
BIFF_PARSER_BOUNDSHEET_RECORD,
BIFF_PARSER_DATA,
};
struct biff_parser_state {
enum biff_parser_states state;
uint16_t opcode;
uint16_t length;
uint16_t data_offset;
uint8_t tmp;
};
/**
* Scan through a buffer of BIFF records and find PARSERNAME, BOUNDSHEET records (Which indicate XLM macros).
* BIFF streams follow the format OOLLDDDDDDDDD..., where OO is the opcode (little endian 16 bit value),
* LL is the data length (little endian 16 bit value), followed by LL bytes of data. Records are defined in
* the MICROSOFT OFFICE EXCEL 97-2007 BINARY FILE FORMAT SPECIFICATION.
*
* \param state The parser state.
* \param buff The buffer.
* \param len The buffer's size in bytes.
* \param ctx The ClamAV context for emitting JSON about the document.
* \returns true if a macro has been found, false otherwise.
*/
static bool
scan_biff_for_xlm_macros(struct biff_parser_state *state, unsigned char *buff, size_t len, cli_ctx *ctx)
{
size_t i;
bool found_macro = false;
for (i = 0; i < len; ++i) {
switch (state->state) {
case BIFF_PARSER_INITIAL:
state->opcode = buff[i];
state->state = BIFF_PARSER_EXPECTING_2ND_TAG_BYTE;
break;
case BIFF_PARSER_EXPECTING_2ND_TAG_BYTE:
state->opcode |= buff[i] << 8;
state->state = BIFF_PARSER_EXPECTING_1ST_LENGTH_BYTE;
break;
case BIFF_PARSER_EXPECTING_1ST_LENGTH_BYTE:
state->length = buff[i];
state->state = BIFF_PARSER_EXPECTING_2ND_LENGTH_BYTE;
break;
case BIFF_PARSER_EXPECTING_2ND_LENGTH_BYTE:
state->length |= buff[i] << 8;
state->data_offset = 0;
switch (state->opcode) {
case 0x85:
state->state = BIFF_PARSER_BOUNDSHEET_RECORD;
break;
case 0x18:
state->state = BIFF_PARSER_NAME_RECORD;
break;
default:
state->state = BIFF_PARSER_DATA;
break;
}
if (state->length == 0) {
state->state = BIFF_PARSER_INITIAL;
}
break;
default:
switch (state->state) {
case BIFF_PARSER_NAME_RECORD:
#if HAVE_JSON
if (state->data_offset == 0) {
state->tmp = buff[i] & 0x20;
} else if ((state->data_offset == 14 || state->data_offset == 15) && state->tmp) {
if (buff[i] == 1 || buff[i] == 2) {
if (SCAN_COLLECT_METADATA && (ctx->wrkproperty != NULL)) {
json_object *indicators = cli_jsonarray(ctx->wrkproperty, "MacroIndicators");
if (indicators) {
cli_jsonstr(indicators, NULL, "autorun");
} else {
cli_dbgmsg("[scan_biff_for_xlm_macros] Failed to add \"autorun\" entry to MacroIndicators JSON array\n");
}
}
}
if (buff[i] != 0) {
state->tmp = 0;
}
}
#endif
break;
case BIFF_PARSER_BOUNDSHEET_RECORD:
if (state->data_offset == 4) {
state->tmp = buff[i];
} else if (state->data_offset == 5 && buff[i] == 1) { //Excel 4.0 macro sheet
cli_dbgmsg("[scan_biff_for_xlm_macros] Found XLM macro sheet\n");
#if HAVE_JSON
if (SCAN_COLLECT_METADATA && (ctx->wrkproperty != NULL)) {
cli_jsonbool(ctx->wrkproperty, "HasMacros", 1);
json_object *macro_languages = cli_jsonarray(ctx->wrkproperty, "MacroLanguages");
if (macro_languages) {
cli_jsonstr(macro_languages, NULL, "XLM");
} else {
cli_dbgmsg("[scan_biff_for_xlm_macros] Failed to add \"XLM\" entry to MacroLanguages JSON array\n");
}
if (state->tmp == 1 || state->tmp == 2) {
json_object *indicators = cli_jsonarray(ctx->wrkproperty, "MacroIndicators");
if (indicators) {
cli_jsonstr(indicators, NULL, "hidden");
} else {
cli_dbgmsg("[scan_biff_for_xlm_macros] Failed to add \"hidden\" entry to MacroIndicators JSON array\n");
}
}
}
#endif
found_macro = true;
}
break;
case BIFF_PARSER_DATA:
break;
default:
//Should never arrive here
cli_dbgmsg("[scan_biff_for_xlm_macros] Unexpected state value %d\n", (int)state->state);
break;
}
state->data_offset += 1;
if (state->data_offset >= state->length) {
state->state = BIFF_PARSER_INITIAL;
}
}
}
return found_macro;
}
/**
* Scan for XLM (Excel 4.0) macro sheets in an OLE2 Workbook stream.
* The stream should be encoded with <= BIFF8.
*/
static int
scan_for_xlm_macros(ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx)
{
unsigned char *buff = NULL;
int32_t current_block;
size_t len, offset;
bitset_t *blk_bitset = NULL;
struct biff_parser_state state;
bool found_macro = false;
UNUSEDPARAM(ctx);
UNUSEDPARAM(dir);
if (prop->type != 2) {
/* Not a file */
goto done;
}
state.state = BIFF_PARSER_INITIAL;
state.length = 0;
current_block = prop->start_block;
len = prop->size;
buff = (unsigned char *)cli_malloc(1 << hdr->log2_big_block_size);
if (!buff) {
cli_errmsg("OLE2 [scan_for_xlm_macros]: Unable to allocate memory for buff: %u\n", 1 << hdr->log2_big_block_size);
goto done;
}
blk_bitset = cli_bitset_init();
if (!blk_bitset) {
cli_errmsg("OLE2 [scan_for_xlm_macros]: init bitset failed\n");
goto done;
}
while ((current_block >= 0) && (len > 0)) {
if (current_block > (int32_t)hdr->max_block_no) {
cli_dbgmsg("OLE2 [scan_for_xlm_macros]: Max block number for file size exceeded: %d\n", current_block);
goto done;
}
/* Check we aren't in a loop */
if (cli_bitset_test(blk_bitset, (unsigned long)current_block)) {
/* Loop in block list */
cli_dbgmsg("OLE2 [scan_for_xlm_macros]: Block list loop detected\n");
goto done;
}
if (!cli_bitset_set(blk_bitset, (unsigned long)current_block)) {
goto done;
}
if (prop->size < (int64_t)hdr->sbat_cutoff) {
/* Small block file */
if (!ole2_get_sbat_data_block(hdr, buff, current_block)) {
cli_dbgmsg("OLE2 [scan_for_xlm_macros]: ole2_get_sbat_data_block failed\n");
goto done;
}
/* 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)));
found_macro = scan_biff_for_xlm_macros(&state, &buff[offset], MIN(len, 1 << hdr->log2_small_block_size), ctx) || found_macro;
len -= MIN(len, 1 << hdr->log2_small_block_size);
current_block = ole2_get_next_sbat_block(hdr, current_block);
} else {
/* Big block file */
if (!ole2_read_block(hdr, buff, 1 << hdr->log2_big_block_size, current_block)) {
goto done;
}
found_macro = scan_biff_for_xlm_macros(&state, buff, MIN(len, (1 << hdr->log2_big_block_size)), ctx) || found_macro;
current_block = ole2_get_next_block_number(hdr, current_block);
len -= MIN(len, (1 << hdr->log2_big_block_size));
}
}
done:
if (buff) {
free(buff);
}
if (blk_bitset) {
cli_bitset_free(blk_bitset);
}
return found_macro;
}
/* enum file Handler - checks for VBA presence */
static int
handler_enum(ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx)
{
char *name = NULL;
unsigned char *hwp_check;
int32_t offset;
int ret = CL_SUCCESS;
#if HAVE_JSON
json_object *arrobj, *strmobj;
name = cli_ole2_get_property_name2(prop->name, prop->name_size);
if (name) {
if (SCAN_COLLECT_METADATA && ctx->wrkproperty != NULL) {
arrobj = cli_jsonarray(ctx->wrkproperty, "Streams");
if (NULL == arrobj) {
cli_warnmsg("ole2: no memory for streams list or streams is not an array\n");
} else {
strmobj = json_object_new_string(name);
json_object_array_add(arrobj, strmobj);
}
if (!strcmp(name, "powerpoint document")) {
cli_jsonstr(ctx->wrkproperty, "FileType", "CL_TYPE_MSPPT");
}
if (!strcmp(name, "worddocument")) {
cli_jsonstr(ctx->wrkproperty, "FileType", "CL_TYPE_MSWORD");
}
if (!strcmp(name, "workbook")) {
cli_jsonstr(ctx->wrkproperty, "FileType", "CL_TYPE_MSXL");
}
}
}
#else
UNUSEDPARAM(ctx);
#endif
UNUSEDPARAM(dir);
if (!hdr->has_vba) {
if (!name)
name = cli_ole2_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;
}
}
/*
* if we can find a root entry fileheader, it may be a HWP file
* identify the HWP signature "HWP Document File" at offset 0 stream
*/
if (!hdr->is_hwp) {
if (!name)
name = cli_ole2_get_property_name2(prop->name, prop->name_size);
if (name) {
if (!strcmp(name, "fileheader")) {
hwp_check = (unsigned char *)cli_calloc(1, 1 << hdr->log2_big_block_size);
if (!hwp_check) {
free(name);
return CL_EMEM;
}
/* reading safety checks; do-while used for breaks */
do {
if (prop->size == 0)
break;
if (prop->start_block > hdr->max_block_no)
break;
/* read the header block (~256 bytes) */
offset = 0;
if (prop->size < (int64_t)hdr->sbat_cutoff) {
if (!ole2_get_sbat_data_block(hdr, hwp_check, prop->start_block)) {
ret = CL_EREAD;
break;
}
offset = (1 << hdr->log2_small_block_size) *
(prop->start_block % (1 << (hdr->log2_big_block_size - hdr->log2_small_block_size)));
/* reading safety */
if (offset + 40 >= 1 << hdr->log2_big_block_size)
break;
} else {
if (!ole2_read_block(hdr, hwp_check, 1 << hdr->log2_big_block_size, prop->start_block)) {
ret = CL_EREAD;
break;
}
}
/* compare against HWP signature; we could add the 15 padding NULLs too */
if (!memcmp(hwp_check + offset, "HWP Document File", 17)) {
hwp5_header_t *hwp_new;
#if HAVE_JSON
cli_jsonstr(ctx->wrkproperty, "FileType", "CL_TYPE_HWP5");
#endif
hwp_new = cli_calloc(1, sizeof(hwp5_header_t));
if (!(hwp_new)) {
ret = CL_EMEM;
break;
}
memcpy(hwp_new, hwp_check + offset, sizeof(hwp5_header_t));
hwp_new->version = ole2_endian_convert_32(hwp_new->version);
hwp_new->flags = ole2_endian_convert_32(hwp_new->flags);
hdr->is_hwp = hwp_new;
}
} while (0);
free(hwp_check);
}
}
}
if (!hdr->has_xlm) {
if (!name) {
name = cli_ole2_get_property_name2(prop->name, prop->name_size);
}
if (name && (strcmp(name, "workbook") == 0 || strcmp(name, "book") == 0)) {
hdr->has_xlm = scan_for_xlm_macros(hdr, prop, dir, ctx);
}
}
if (name)
free(name);
return ret;
}
static int
likely_mso_stream(int fd)
{
off_t fsize;
unsigned char check[2];
fsize = lseek(fd, 0, SEEK_END);
if (fsize == -1) {
cli_dbgmsg("likely_mso_stream: call to lseek() failed\n");
return 0;
} else if (fsize < 6) {
return 0;
}
if (lseek(fd, 4, SEEK_SET) == -1) {
cli_dbgmsg("likely_mso_stream: call to lseek() failed\n");
return 0;
}
if (cli_readn(fd, check, 2) != 2) {
cli_dbgmsg("likely_mso_stream: reading from fd failed\n");
return 0;
}
if (check[0] == 0x78 && check[1] == 0x9C)
return 1;
return 0;
}
static cl_error_t scan_mso_stream(int fd, cli_ctx *ctx)
{
int zret, ofd;
cl_error_t ret = CL_SUCCESS;
fmap_t *input;
off_t off_in = 0;
size_t count, outsize = 0;
z_stream zstrm;
char *tmpname;
uint32_t prefix;
unsigned char inbuf[FILEBUFF], outbuf[FILEBUFF];
/* fmap the input file for easier manipulation */
if (fd < 0) {
cli_dbgmsg("scan_mso_stream: Invalid file descriptor argument\n");
return CL_ENULLARG;
} else {
STATBUF statbuf;
if (FSTAT(fd, &statbuf) == -1) {
cli_dbgmsg("scan_mso_stream: Can't stat file descriptor\n");
return CL_ESTAT;
}
input = fmap(fd, 0, statbuf.st_size, NULL);
if (!input) {
cli_dbgmsg("scan_mso_stream: Failed to get fmap for input stream\n");
return CL_EMAP;
}
}
/* reserve tempfile for output and scanning */
if ((ret = cli_gentempfd(ctx->sub_tmpdir, &tmpname, &ofd)) != CL_SUCCESS) {
cli_errmsg("scan_mso_stream: Can't generate temporary file\n");
funmap(input);
return ret;
}
/* initialize zlib inflation stream */
memset(&zstrm, 0, sizeof(zstrm));
zstrm.zalloc = Z_NULL;
zstrm.zfree = Z_NULL;
zstrm.opaque = Z_NULL;
zstrm.next_in = inbuf;
zstrm.next_out = outbuf;
zstrm.avail_in = 0;
zstrm.avail_out = FILEBUFF;
zret = inflateInit(&zstrm);
if (zret != Z_OK) {
cli_dbgmsg("scan_mso_stream: Can't initialize zlib inflation stream\n");
ret = CL_EUNPACK;
goto mso_end;
}
/* extract 32-bit prefix */
if (fmap_readn(input, &prefix, off_in, sizeof(prefix)) != sizeof(prefix)) {
cli_dbgmsg("scan_mso_stream: Can't extract 4-byte prefix\n");
ret = CL_EREAD;
goto mso_end;
}
/* RFC1952 says numbers are stored with least significant byte first */
prefix = le32_to_host(prefix);
off_in += sizeof(uint32_t);
cli_dbgmsg("scan_mso_stream: stream prefix = %08x(%d)\n", prefix, prefix);
/* inflation loop */
do {
if (zstrm.avail_in == 0) {
size_t bytes_read;
zstrm.next_in = inbuf;
bytes_read = fmap_readn(input, inbuf, off_in, FILEBUFF);
if (bytes_read == (size_t)-1) {
cli_errmsg("scan_mso_stream: Error reading MSO file\n");
ret = CL_EUNPACK;
goto mso_end;
}
if (bytes_read == 0)
break;
zstrm.avail_in = bytes_read;
off_in += bytes_read;
}
zret = inflate(&zstrm, Z_SYNC_FLUSH);
count = FILEBUFF - zstrm.avail_out;
if (count) {
if (cli_checklimits("MSO", ctx, outsize + count, 0, 0) != CL_SUCCESS)
break;
if (cli_writen(ofd, outbuf, count) != count) {
cli_errmsg("scan_mso_stream: Can't write to file %s\n", tmpname);
ret = CL_EWRITE;
goto mso_end;
}
outsize += count;
}
zstrm.next_out = outbuf;
zstrm.avail_out = FILEBUFF;
} while (zret == Z_OK);
/* post inflation checks */
if (zret != Z_STREAM_END && zret != Z_OK) {
if (outsize == 0) {
cli_infomsg(ctx, "scan_mso_stream: Error decompressing MSO file. No data decompressed.\n");
ret = CL_EUNPACK;
goto mso_end;
}
cli_infomsg(ctx, "scan_mso_stream: Error decompressing MSO file. Scanning what was decompressed.\n");
}
cli_dbgmsg("scan_mso_stream: Decompressed %llu bytes to %s\n", (long long unsigned)outsize, tmpname);
if (outsize != prefix) {
cli_warnmsg("scan_mso_stream: declared prefix != inflated stream size, %llu != %llu\n",
(long long unsigned)prefix, (long long unsigned)outsize);
} else {
cli_dbgmsg("scan_mso_stream: declared prefix == inflated stream size, %llu == %llu\n",
(long long unsigned)prefix, (long long unsigned)outsize);
}
/* scanning inflated stream */
ret = cli_magic_scan_desc(ofd, tmpname, ctx, NULL);
/* clean-up */
mso_end:
zret = inflateEnd(&zstrm);
if (zret != Z_OK)
ret = CL_EUNPACK;
close(ofd);
if (!ctx->engine->keeptmp)
if (cli_unlink(tmpname))
ret = CL_EUNLINK;
free(tmpname);
funmap(input);
return ret;
}
static int
handler_otf(ole2_header_t *hdr, property_t *prop, const char *dir, cli_ctx *ctx)
{
char *tempfile, *name = NULL;
unsigned char *buff;
int32_t current_block;
size_t len, offset;
int ofd, is_mso, ret;
bitset_t *blk_bitset;
UNUSEDPARAM(dir);
if (prop->type != 2) {
/* Not a file */
return CL_SUCCESS;
}
print_ole2_property(prop);
if (!(tempfile = cli_gentemp(ctx ? ctx->sub_tmpdir : NULL)))
return CL_EMEM;
if ((ofd = open(tempfile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) < 0) {
cli_dbgmsg("OLE2: Can't create file %s\n", tempfile);
free(tempfile);
return CL_ECREAT;
}
current_block = prop->start_block;
len = prop->size;
if (cli_debug_flag) {
if (!name)
name = cli_ole2_get_property_name2(prop->name, prop->name_size);
cli_dbgmsg("OLE2 [handler_otf]: Dumping '%s' to '%s'\n", name, tempfile);
}
buff = (unsigned char *)cli_malloc(1 << hdr->log2_big_block_size);
if (!buff) {
close(ofd);
if (name)
free(name);
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 (name)
free(name);
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(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);
if (name)
free(name);
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(hdr, current_block);
} else {
/* Big block file */
if (!ole2_read_block(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);
if (name)
free(name);
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(hdr, current_block);
len -= MIN(len, (1 << hdr->log2_big_block_size));
}
}
/* defragmenting of ole2 stream complete */
is_mso = likely_mso_stream(ofd);
if (lseek(ofd, 0, SEEK_SET) == -1) {
close(ofd);
if (name)
free(name);
if (ctx && !(ctx->engine->keeptmp))
cli_unlink(tempfile);
free(tempfile);
free(buff);
cli_bitset_free(blk_bitset);
return CL_ESEEK;
}
#if HAVE_JSON
/* JSON Output Summary Information */
if (SCAN_COLLECT_METADATA && (ctx->properties != NULL)) {
if (!name)
name = cli_ole2_get_property_name2(prop->name, prop->name_size);
if (name) {
if (!strncmp(name, "_5_summaryinformation", 21)) {
cli_dbgmsg("OLE2: detected a '_5_summaryinformation' stream\n");
/* JSONOLE2 - what to do if something breaks? */
if (cli_ole2_summary_json(ctx, ofd, 0) == CL_ETIMEOUT) {
free(name);
close(ofd);
if (ctx && !(ctx->engine->keeptmp))
cli_unlink(tempfile);
free(tempfile);
free(buff);
cli_bitset_free(blk_bitset);
return CL_ETIMEOUT;
}
}
if (!strncmp(name, "_5_documentsummaryinformation", 29)) {
cli_dbgmsg("OLE2: detected a '_5_documentsummaryinformation' stream\n");
/* JSONOLE2 - what to do if something breaks? */
if (cli_ole2_summary_json(ctx, ofd, 1) == CL_ETIMEOUT) {
free(name);
close(ofd);
if (ctx && !(ctx->engine->keeptmp))
cli_unlink(tempfile);
free(tempfile);
free(buff);
cli_bitset_free(blk_bitset);
return CL_ETIMEOUT;
}
}
}
}
#endif
if (hdr->is_hwp) {
if (!name)
name = cli_ole2_get_property_name2(prop->name, prop->name_size);
ret = cli_scanhwp5_stream(ctx, hdr->is_hwp, name, ofd, tempfile);
} else if (is_mso < 0) {
ret = CL_ESEEK;
} else if (is_mso) {
/* MSO Stream Scan */
ret = scan_mso_stream(ofd, ctx);
} else {
/* Normal File Scan */
ret = cli_magic_scan_desc(ofd, tempfile, ctx, NULL);
}
if (name)
free(name);
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(const char *dirname, cli_ctx *ctx, struct uniq **files, int *has_vba, int *has_xlm)
{
ole2_header_t hdr;
int ret = CL_CLEAN;
size_t hdr_size;
unsigned int file_count = 0;
unsigned long scansize, scansize2;
const void *phdr;
cli_dbgmsg("in cli_ole2_extract()\n");
if (!ctx)
return CL_ENULLARG;
hdr.is_hwp = NULL;
hdr.bitset = NULL;
if (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(off_t) - sizeof(bitset_t *) -
sizeof(struct uniq *) - sizeof(fmap_t *) - sizeof(int) - sizeof(hwp5_header_t *);
if ((size_t)(ctx->fmap->len) < (size_t)(hdr_size)) {
return CL_CLEAN;
}
hdr.map = ctx->fmap;
hdr.m_length = hdr.map->len;
phdr = fmap_need_off_once(hdr.map, 0, hdr_size);
if (phdr) {
memcpy(&hdr, phdr, hdr_size);
} else {
cli_dbgmsg("cli_ole2_extract: failed to read header\n");
goto abort;
}
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);
}
if (hdr.map->len > INT32_MAX) {
cli_dbgmsg("OLE2 extract: Overflow detected\n");
ret = CL_EFORMAT;
goto abort;
}
/* 8 SBAT blocks per file block */
hdr.max_block_no = (hdr.map->len - 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;
hdr.has_xlm = 0;
ret = ole2_walk_property_tree(&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 (hdr.is_hwp) {
cli_dbgmsg("OLE2: identified HWP document\n");
cli_dbgmsg("OLE2: HWP signature: %.17s\n", hdr.is_hwp->signature);
cli_dbgmsg("OLE2: HWP version: 0x%08x\n", hdr.is_hwp->version);
cli_dbgmsg("OLE2: HWP flags: 0x%08x\n", hdr.is_hwp->flags);
ret = cli_hwp5header(ctx, hdr.is_hwp);
if (ret != CL_SUCCESS)
goto abort;
}
/* If there's no VBA we scan OTF */
if (hdr.has_vba || hdr.has_xlm) {
/* 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(&hdr, dirname, 0, handler_writefile, 0, &file_count, ctx, &scansize2);
ret = CL_CLEAN;
*files = hdr.U;
if (has_vba) {
*has_vba = hdr.has_vba;
}
if (has_xlm) {
*has_xlm = hdr.has_xlm;
}
} else {
cli_dbgmsg("OLE2: no VBA projects found\n");
/* PASS 2/B : OTF scan */
file_count = 0;
ret = ole2_walk_property_tree(&hdr, NULL, 0, handler_otf, 0, &file_count, ctx, &scansize2);
}
abort:
if (hdr.bitset)
cli_bitset_free(hdr.bitset);
if (hdr.is_hwp)
free(hdr.is_hwp);
return ret == CL_BREAK ? CL_CLEAN : ret;
}
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