/*
* OOXML JSON Internals
*
* Copyright (C) 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*
* Authors: Kevin Lin
*
* 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 "clamav.h"
#include "cltypes.h"
#include "others.h"
#include "unzip.h"
#if HAVE_JSON
#include "json.h"
#endif
#include "json_api.h"
#include "ooxml.h"
#if HAVE_LIBXML2
#ifdef _WIN32
#ifndef LIBXML_WRITER_ENABLED
#define LIBXML_WRITER_ENABLED 1
#endif
#endif
#include <libxml/xmlreader.h>
#endif
#define OOXML_DEBUG 0
#if HAVE_LIBXML2 && HAVE_JSON
#define OOXML_JSON_RECLEVEL 16
#define OOXML_JSON_RECLEVEL_MAX 5
#define OOXML_JSON_STRLEN_MAX 100
#define check_state(state) \
do { \
if (state == -1) { \
cli_warnmsg("check_state: CL_EPARSE @ ln%d\n", __LINE__); \
return CL_EPARSE; \
} \
else if (state == 0) { \
cli_dbgmsg("check_state: CL_BREAK @ ln%d\n", __LINE__); \
return CL_BREAK; \
} \
} while(0)
static int ooxml_is_int(const char *value, size_t len, int32_t *val)
{
long val2;
char *endptr = NULL;
val2 = strtol(value, &endptr, 10);
if (endptr != value+len) {
return 0;
}
*val = (int32_t)(val2 & 0x0000ffff);
return 1;
}
static int ooxml_parse_value(json_object *wrkptr, const char *arrname, const xmlChar *node_value)
{
json_object *newobj, *arrobj;
int val;
arrobj = cli_jsonarray(wrkptr, arrname);
if (arrobj == NULL) {
return CL_EMEM;
}
if (ooxml_is_int((const char *)node_value, xmlStrlen(node_value), &val)) {
newobj = json_object_new_int(val);
}
else if (!xmlStrcmp(node_value, (const xmlChar *)"true")) {
newobj = json_object_new_boolean(1);
}
else if (!xmlStrcmp(node_value, (const xmlChar *)"false")) {
newobj = json_object_new_boolean(0);
}
else {
newobj = json_object_new_string((const char *)node_value);
}
if (NULL == newobj) {
cli_errmsg("ooxml_parse_value: no memory for json value for [%s]\n", arrname);
return CL_EMEM;
}
json_object_array_add(arrobj, newobj);
return CL_SUCCESS;
}
static const char *ooxml_keys[] = {
"coreproperties",
"title",
"subject",
"creator",
"keywords",
"comments",
"description",
"lastmodifiedby",
"revision",
"created",
"modified",
"category",
"contentstatus",
"properties",
"application",
"appversion",
"characters",
"characterswithspaces",
"company",
"digsig",
"docsecurity",
//"headingpairs",
"hiddenslides",
"hlinks",
"hyperlinkbase",
"hyperlinkschanged",
"lines",
"linksuptodate",
"manager",
"mmclips",
"notes",
"pages",
"paragraphs",
"presentationformat",
"properties",
"scalecrop",
"shareddoc",
"slides",
"template",
//"titlesofparts",
"totaltime",
"words"
};
static const char *ooxml_json_keys[] = {
"CoreProperties",
"Title",
"Subject",
"Author",
"Keywords",
"Comments",
"Description",
"LastAuthor",
"Revision",
"Created",
"Modified",
"Category",
"ContentStatus",
"ExtendedProperties",
"Application",
"AppVersion",
"Characters",
"CharactersWithSpaces",
"Company",
"DigSig",
"DocSecurity",
//"HeadingPairs",
"HiddenSlides",
"HLinks",
"HyperlinkBase",
"HyperlinksChanged",
"Lines",
"LinksUpToDate",
"Manager",
"MultimediaClips",
"Notes",
"Pages",
"Paragraphs",
"PresentationFormat",
"Properties",
"ScaleCrop",
"SharedDoc",
"Slides",
"Template",
//"TitlesOfParts",
"TotalTime",
"Words"
};
static size_t num_ooxml_keys = 40; //42
static const char *ooxml_check_key(const char* key, size_t keylen)
{
unsigned i;
if (keylen > OOXML_JSON_STRLEN_MAX-1) {
cli_dbgmsg("ooxml_check_key: key name too long\n");
return NULL;
}
for (i = 0; i < num_ooxml_keys; ++i) {
//cli_dbgmsg("%d %d %s %s %s %s\n", keylen, strlen(ooxml_keys[i]), key, keycmp, ooxml_keys[i], ooxml_json_keys[i]);
if (keylen == strlen(ooxml_keys[i]) && !strncasecmp(key, ooxml_keys[i], keylen)) {
return ooxml_json_keys[i];
}
}
return NULL;
}
static int ooxml_parse_element(cli_ctx *ctx, xmlTextReaderPtr reader, json_object *wrkptr, int rlvl, json_object *root)
{
const char *element_tag = NULL, *end_tag = NULL;
const xmlChar *node_name = NULL, *node_value = NULL;
json_object *thisjobj = NULL;
int node_type, ret = CL_SUCCESS, endtag = 0, toval = 0, state = 1;
cli_dbgmsg("in ooxml_parse_element @ layer %d\n", rlvl);
/* check recursion level */
if (rlvl >= OOXML_JSON_RECLEVEL_MAX) {
cli_dbgmsg("ooxml_parse_element: reached ooxml json recursion limit\n");
cli_jsonbool(root, "HitRecursiveLimit", 1);
/* skip it */
state = xmlTextReaderNext(reader);
check_state(state);
return CL_SUCCESS;
}
/* acquire element type */
node_type = xmlTextReaderNodeType(reader);
if (node_type == -1)
return CL_EPARSE;
if (node_type != XML_READER_TYPE_ELEMENT) {
cli_dbgmsg("ooxml_parse_element: first node typed %d, not %d\n", node_type, XML_READER_TYPE_ELEMENT);
return CL_EPARSE; /* first type is not an element */
}
node_name = xmlTextReaderConstLocalName(reader);
if (!node_name) {
cli_dbgmsg("ooxml_parse_element: element tag node nameless\n");
return CL_EPARSE; /* no name, nameless */
}
element_tag = ooxml_check_key((const char *)node_name, xmlStrlen(node_name));
if (!element_tag) {
cli_dbgmsg("ooxml_parse_element: invalid element tag [%s]\n", node_name);
/* skip it */
state = xmlTextReaderNext(reader);
check_state(state);
return CL_SUCCESS;
}
/* generate json object */
thisjobj = cli_jsonobj(wrkptr, element_tag);
if (!thisjobj) {
return CL_EPARSE;
}
cli_dbgmsg("ooxml_parse_element: generated json object [%s]\n", element_tag);
if (rlvl == 0)
root = thisjobj;
/* handle attributes */
state = xmlTextReaderHasAttributes(reader);
if (state == 1) {
json_object *attributes;
attributes = cli_jsonobj(thisjobj, "Attributes");
if (!attributes) {
return CL_EPARSE;
}
cli_dbgmsg("ooxml_parse_element: retrieved json object [Attributes]\n");
while (xmlTextReaderMoveToNextAttribute(reader) == 1) {
const xmlChar *name, *value;
name = xmlTextReaderConstLocalName(reader);
value = xmlTextReaderConstValue(reader);
if (name == NULL || value == NULL) continue;
cli_dbgmsg("%s: %s\n", name, value);
cli_jsonstr(attributes, name, (const char *)value);
}
}
else if (state == -1)
return CL_EPARSE;
state = xmlTextReaderIsEmptyElement(reader);
if (state == 1) {
state = xmlTextReaderNext(reader);
check_state(state);
return CL_SUCCESS;
}
else if (state == -1)
return CL_EPARSE;
/* advance to first content node */
state = xmlTextReaderRead(reader);
check_state(state);
/* parse until the end element tag */
while (!endtag) {
if (cli_json_timeout_cycle_check(ctx, &toval) != CL_SUCCESS) {
return CL_ETIMEOUT;
}
node_type = xmlTextReaderNodeType(reader);
if (node_type == -1)
return CL_EPARSE;
switch (node_type) {
case XML_READER_TYPE_ELEMENT:
ret = ooxml_parse_element(ctx, reader, thisjobj, rlvl+1, root);
if (ret != CL_SUCCESS) {
return ret;
}
break;
case XML_READER_TYPE_END_ELEMENT:
cli_dbgmsg("in ooxml_parse_element @ layer %d closed\n", rlvl);
node_name = xmlTextReaderConstLocalName(reader);
if (!node_name) {
cli_dbgmsg("ooxml_parse_element: element end tag node nameless\n");
return CL_EPARSE; /* no name, nameless */
}
end_tag = ooxml_check_key((const char *)node_name, xmlStrlen(node_name));
if (!end_tag) {
cli_dbgmsg("ooxml_parse_element: invalid element end tag [%s]\n", node_name);
return CL_EFORMAT; /* unrecognized element tag */
}
if (strncmp(element_tag, end_tag, strlen(element_tag))) {
cli_dbgmsg("ooxml_parse_element: element tag does not match end tag\n");
return CL_EFORMAT;
}
/* advance to next element tag */
state = xmlTextReaderRead(reader);
check_state(state);
endtag = 1;
break;
case XML_READER_TYPE_TEXT:
node_value = xmlTextReaderConstValue(reader);
ret = ooxml_parse_value(thisjobj, "Value", node_value);
if (ret != CL_SUCCESS)
return ret;
cli_dbgmsg("ooxml_parse_element: added json value [%s: %s]\n", element_tag, node_value);
/* advance to next element tag */
state = xmlTextReaderRead(reader);
check_state(state);
break;
default:
#if OOXML_DEBUG
node_name = xmlTextReaderConstLocalName(reader);
node_value = xmlTextReaderConstValue(reader);
cli_dbgmsg("ooxml_parse_element: unhandled xml node %s [%d]: %s\n", node_name, node_type, node_value);
#endif
state = xmlTextReaderNext(reader);
check_state(state);
return CL_SUCCESS;
}
}
return CL_SUCCESS;
}
static int ooxml_parse_document(int fd, cli_ctx *ctx)
{
int ret = CL_SUCCESS;
xmlTextReaderPtr reader = NULL;
cli_dbgmsg("in ooxml_parse_document\n");
reader = xmlReaderForFd(fd, "properties.xml", NULL, CLAMAV_MIN_XMLREADER_FLAGS);
if (reader == NULL) {
cli_dbgmsg("ooxml_parse_document: xmlReaderForFd error\n");
return CL_SUCCESS; // internal error from libxml2
}
/* move reader to first element */
if (xmlTextReaderRead(reader) != 1) {
return CL_SUCCESS; /* libxml2 failed */
}
ret = ooxml_parse_element(ctx, reader, ctx->wrkproperty, 0, NULL);
if (ret != CL_SUCCESS && ret != CL_ETIMEOUT && ret != CL_BREAK) {
cli_warnmsg("ooxml_parse_document: encountered issue in parsing properties document\n");
cli_jsonbool(ctx->wrkproperty, "ParseError", 1);
}
xmlTextReaderClose(reader);
xmlFreeTextReader(reader);
return ret;
}
static int ooxml_core_cb(int fd, cli_ctx *ctx)
{
cli_dbgmsg("in ooxml_core_cb\n");
return ooxml_parse_document(fd, ctx);
//return ooxml_basic_json(fd, ctx, "CoreProperties");
}
static int ooxml_extn_cb(int fd, cli_ctx *ctx)
{
cli_dbgmsg("in ooxml_extn_cb\n");
return ooxml_parse_document(fd, ctx);
//return ooxml_basic_json(fd, ctx, "ExtendedProperties");
}
static int ooxml_content_cb(int fd, cli_ctx *ctx)
{
int ret = CL_SUCCESS, tmp, toval = 0;
int core=0, extn=0, cust=0, dsig=0;
int mcore=0, mextn=0, mcust=0;
const xmlChar *name, *value, *CT, *PN;
xmlTextReaderPtr reader = NULL;
uint32_t loff;
cli_dbgmsg("in ooxml_content_cb\n");
reader = xmlReaderForFd(fd, "[Content_Types].xml", NULL, CLAMAV_MIN_XMLREADER_FLAGS);
if (reader == NULL) {
cli_dbgmsg("ooxml_content_cb: xmlReaderForFd error for ""[Content_Types].xml""\n");
return CL_SUCCESS; // libxml2 failed!
}
/* locate core-properties, extended-properties, and custom-properties (optional) */
while (xmlTextReaderRead(reader) == 1) {
if (cli_json_timeout_cycle_check(ctx, &toval) != CL_SUCCESS) {
ret = CL_ETIMEOUT;
goto ooxml_content_exit;
}
name = xmlTextReaderConstLocalName(reader);
if (name == NULL) continue;
if (strcmp((const char *)name, "Override")) continue;
if (xmlTextReaderHasAttributes(reader) != 1) continue;
CT = PN = NULL;
while (xmlTextReaderMoveToNextAttribute(reader) == 1) {
name = xmlTextReaderConstLocalName(reader);
value = xmlTextReaderConstValue(reader);
if (name == NULL || value == NULL) continue;
if (!xmlStrcmp(name, (const xmlChar *)"ContentType")) {
CT = value;
}
else if (!xmlStrcmp(name, (const xmlChar *)"PartName")) {
PN = value;
}
cli_dbgmsg("%s: %s\n", name, value);
}
if (!CT && !PN) continue;
if (!xmlStrcmp(CT, (const xmlChar *)"application/vnd.openxmlformats-package.core-properties+xml")) {
if (!core) {
/* default: /docProps/core.xml*/
tmp = unzip_search_single(ctx, (const char *)(PN+1), xmlStrlen(PN)-1, &loff);
if (tmp == CL_ETIMEOUT) {
ret = tmp;
}
else if (tmp != CL_VIRUS) {
cli_dbgmsg("cli_process_ooxml: failed to find core properties file \"%s\"!\n", PN);
mcore++;
}
else {
cli_dbgmsg("ooxml_content_cb: found core properties file \"%s\" @ %x\n", PN, loff);
ret = unzip_single_internal(ctx, loff, ooxml_core_cb);
core++;
}
}
}
else if (!xmlStrcmp(CT, (const xmlChar *)"application/vnd.openxmlformats-officedocument.extended-properties+xml")) {
if (!extn) {
/* default: /docProps/app.xml */
tmp = unzip_search_single(ctx, (const char *)(PN+1), xmlStrlen(PN)-1, &loff);
if (tmp == CL_ETIMEOUT) {
ret = tmp;
}
else if (tmp != CL_VIRUS) {
cli_dbgmsg("cli_process_ooxml: failed to find extended properties file \"%s\"!\n", PN);
mextn++;
}
else {
cli_dbgmsg("ooxml_content_cb: found extended properties file \"%s\" @ %x\n", PN, loff);
ret = unzip_single_internal(ctx, loff, ooxml_extn_cb);
extn++;
}
}
}
else if (!xmlStrcmp(CT, (const xmlChar *)"application/vnd.openxmlformats-officedocument.custom-properties+xml")) {
if (!cust) {
/* default: /docProps/custom.xml */
tmp = unzip_search_single(ctx, (const char *)(PN+1), xmlStrlen(PN)-1, &loff);
if (tmp == CL_ETIMEOUT) {
ret = tmp;
}
else if (tmp != CL_VIRUS) {
cli_dbgmsg("cli_process_ooxml: failed to find custom properties file \"%s\"!\n", PN);
mcust++;
}
else {
cli_dbgmsg("ooxml_content_cb: found custom properties file \"%s\" @ %x\n", PN, loff);
cust++;
//ret = unzip_single_internal(ctx, loff, ooxml_cust_cb);
}
}
}
else if (!xmlStrcmp(CT, (const xmlChar *)"application/vnd.openxmlformats-package.digital-signature-xmlsignature+xml")) {
dsig++;
}
if (ret != CL_BREAK && ret != CL_SUCCESS)
goto ooxml_content_exit;
}
ooxml_content_exit:
if (core)
cli_jsonint(ctx->wrkproperty, "CorePropertiesFileCount", core);
else if (!mcore)
cli_dbgmsg("cli_process_ooxml: file does not contain core properties file\n");
if (mcore)
cli_jsonint(ctx->wrkproperty, "CorePropertiesMissingFileCount", core);
if (extn)
cli_jsonint(ctx->wrkproperty, "ExtendedPropertiesFileCount", extn);
else if (!mextn)
cli_dbgmsg("cli_process_ooxml: file does not contain extended properties file\n");
if (mextn)
cli_jsonint(ctx->wrkproperty, "ExtendedPropertiesMissingFileCount", extn);
if (cust)
cli_jsonint(ctx->wrkproperty, "CustomPropertiesFileCount", cust);
else if (!mcust)
cli_dbgmsg("cli_process_ooxml: file does not contain custom properties file\n");
if (mcust)
cli_jsonint(ctx->wrkproperty, "CustomPropertiesMissingFileCount", cust);
if (dsig) {
cli_jsonint(ctx->wrkproperty, "DigitalSignaturesCount", dsig);
}
xmlTextReaderClose(reader);
xmlFreeTextReader(reader);
return ret;
}
#endif /* HAVE_LIBXML2 && HAVE_JSON */
int cli_ooxml_filetype(cli_ctx *ctx, fmap_t *map)
{
struct zip_requests requests;
int ret;
memset(&requests, 0, sizeof(struct zip_requests));
if ((ret = unzip_search_add(&requests, "xl/", 3)) != CL_SUCCESS) {
return CL_SUCCESS;
}
if ((ret = unzip_search_add(&requests, "ppt/", 4)) != CL_SUCCESS) {
return CL_SUCCESS;
}
if ((ret = unzip_search_add(&requests, "word/", 5)) != CL_SUCCESS) {
return CL_SUCCESS;
}
if ((ret = unzip_search(ctx, map, &requests)) == CL_VIRUS) {
switch (requests.found) {
case 0:
return CL_TYPE_OOXML_XL;
case 1:
return CL_TYPE_OOXML_PPT;
case 2:
return CL_TYPE_OOXML_WORD;
default:
return CL_SUCCESS;
}
}
return CL_SUCCESS;
}
int cli_process_ooxml(cli_ctx *ctx)
{
#if HAVE_LIBXML2 && HAVE_JSON
uint32_t loff = 0;
int tmp = CL_SUCCESS;
cli_dbgmsg("in cli_processooxml\n");
if (!ctx) {
return CL_ENULLARG;
}
/* find "[Content Types].xml" */
tmp = unzip_search_single(ctx, "[Content_Types].xml", 18, &loff);
if (tmp == CL_ETIMEOUT) {
return CL_ETIMEOUT;
}
else if (tmp != CL_VIRUS) {
cli_dbgmsg("cli_process_ooxml: failed to find ""[Content_Types].xml""!\n");
return CL_EFORMAT;
}
cli_dbgmsg("cli_process_ooxml: found ""[Content_Types].xml"" @ %x\n", loff);
return unzip_single_internal(ctx, loff, ooxml_content_cb);
#else
UNUSEDPARAM(ctx);
cli_dbgmsg("in cli_processooxml\n");
#if !HAVE_LIBXML2
cli_dbgmsg("cli_process_ooxml: libxml2 needs to enabled!");
#endif
#if !HAVE_JSON
cli_dbgmsg("cli_process_ooxml: libjson needs to enabled!");
#endif
return CL_SUCCESS;
#endif
}