open-dsi
/
clamav
mirror of https://github.com/Cisco-Talos/clamav
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

bb#11187 - corrections to prevent evasion and add clarity

Browse Source 
ooxml: added clarity on various parsing errors in json output
ooxml: changed behavior to continue parsing other propfiles if one is malformed
pull/18/head
Kevin Lin 11 years ago
parent b6768907aa
commit 3e8eed1823
1 changed files with 124 additions and 66 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 190
      libclamav/ooxml.c

190
libclamav/ooxml.c
Unescape View File

@ -78,11 +78,29 @@ static int ooxml_is_int(const char *value, size_t len, int32_t *val)
return 1;
}
static int ooxml_add_parse_error(json_object *wrkptr, const xmlChar *errstr)
{
json_object *perr;
if (!wrkptr)
return CL_ENULLARG;
perr = cli_jsonarray(wrkptr, "ParseErrors");
if (perr == NULL) {
return CL_EMEM;
}
return cli_jsonstr(perr, NULL, errstr);
}
static int ooxml_parse_value(json_object *wrkptr, const char *arrname, const xmlChar *node_value)
{
json_object *newobj, *arrobj;
int val;
if (!wrkptr)
return CL_ENULLARG;
arrobj = cli_jsonarray(wrkptr, arrname);
if (arrobj == NULL) {
return CL_EMEM;
@ -247,7 +265,7 @@ static int ooxml_parse_element(cli_ctx *ctx, xmlTextReaderPtr reader, json_objec
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 */
return CL_EFORMAT; /* first type is not an element */
}
node_name = xmlTextReaderConstLocalName(reader);
@ -267,7 +285,7 @@ static int ooxml_parse_element(cli_ctx *ctx, xmlTextReaderPtr reader, json_objec
/* generate json object */
thisjobj = cli_jsonobj(wrkptr, element_tag);
if (!thisjobj) {
return CL_EPARSE;
return CL_EMEM;
}
cli_dbgmsg("ooxml_parse_element: generated json object [%s]\n", element_tag);
@ -406,10 +424,8 @@ static int ooxml_parse_document(int fd, cli_ctx *ctx)
ret = ooxml_parse_element(ctx, reader, ctx->wrkproperty, 0, NULL);
if (ret != CL_SUCCESS && ret != CL_ETIMEOUT && ret != CL_BREAK) {
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);
@ -418,21 +434,35 @@ static int ooxml_parse_document(int fd, cli_ctx *ctx)
static int ooxml_core_cb(int fd, cli_ctx *ctx)
{
int ret;
cli_dbgmsg("in ooxml_core_cb\n");
return ooxml_parse_document(fd, ctx);
//return ooxml_basic_json(fd, ctx, "CoreProperties");
ret = ooxml_parse_document(fd, ctx);
if (ret == CL_EPARSE)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_CORE_XMLPARSER");
else if (ret == CL_EFORMAT)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_CORE_MALFORMED");
return ret;
}
static int ooxml_extn_cb(int fd, cli_ctx *ctx)
{
int ret;
cli_dbgmsg("in ooxml_extn_cb\n");
return ooxml_parse_document(fd, ctx);
//return ooxml_basic_json(fd, ctx, "ExtendedProperties");
ret = ooxml_parse_document(fd, ctx);
if (ret == CL_EPARSE)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_EXTN_XMLPARSER");
else if (ret == CL_EFORMAT)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_EXTN_MALFORMED");
return ret;
}
static int ooxml_content_cb(int fd, cli_ctx *ctx)
{
int ret = CL_SUCCESS, tmp, toval = 0;
int ret = CL_SUCCESS, tmp, toval = 0, state;
int core=0, extn=0, cust=0, dsig=0;
int mcore=0, mextn=0, mcust=0;
const xmlChar *name, *value, *CT, *PN;
@ -444,11 +474,12 @@ static int ooxml_content_cb(int fd, cli_ctx *ctx)
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");
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_XML_READER_FD");
return CL_SUCCESS; // libxml2 failed!
}
/* locate core-properties, extended-properties, and custom-properties (optional) */
while (xmlTextReaderRead(reader) == 1) {
/* locate core-properties, extended-properties, and custom-properties (optional) */
while ((state = xmlTextReaderRead(reader)) == 1) {
if (cli_json_timeout_cycle_check(ctx, &toval) != CL_SUCCESS) {
ret = CL_ETIMEOUT;
goto ooxml_content_exit;
@ -480,88 +511,107 @@ static int ooxml_content_cb(int fd, cli_ctx *ctx)
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++;
/* 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);
if (!core) {
tmp = unzip_single_internal(ctx, loff, ooxml_core_cb);
if (tmp == CL_ETIMEOUT || tmp == CL_EMEM) {
ret = tmp;
}
}
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++;
/* 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);
if (!extn) {
tmp = unzip_single_internal(ctx, loff, ooxml_extn_cb);
if (tmp == CL_ETIMEOUT || tmp == CL_EMEM) {
ret = tmp;
}
}
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);
}
/* 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);
/* custom properties are not parsed */
cust++;
}
}
else if (!xmlStrcmp(CT, (const xmlChar *)"application/vnd.openxmlformats-package.digital-signature-xmlsignature+xml")) {
dsig++;
}
if (ret != CL_BREAK && ret != CL_SUCCESS)
if (ret != CL_SUCCESS)
goto ooxml_content_exit;
}
ooxml_content_exit:
if (core)
if (core) {
cli_jsonint(ctx->wrkproperty, "CorePropertiesFileCount", core);
if (core > 1)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_MULTIPLE_CORE_PROPFILES");
}
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 (mcore) {
cli_jsonint(ctx->wrkproperty, "CorePropertiesMissingFileCount", mcore);
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_MISSING_CORE_PROPFILES");
}
if (extn)
if (extn) {
cli_jsonint(ctx->wrkproperty, "ExtendedPropertiesFileCount", extn);
if (extn > 1)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_MULTIPLE_EXTN_PROPFILES");
}
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 (mextn) {
cli_jsonint(ctx->wrkproperty, "ExtendedPropertiesMissingFileCount", mextn);
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_MISSING_EXTN_PROPFILES");
}
if (cust)
if (cust) {
cli_jsonint(ctx->wrkproperty, "CustomPropertiesFileCount", cust);
if (cust > 1)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_MULTIPLE_CUSTOM_PROPFILES");
}
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 (mcust) {
cli_jsonint(ctx->wrkproperty, "CustomPropertiesMissingFileCount", mcust);
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_MISSING_CUST_PROPFILES");
}
if (dsig) {
cli_jsonint(ctx->wrkproperty, "DigitalSignaturesCount", dsig);
@ -620,15 +670,23 @@ int cli_process_ooxml(cli_ctx *ctx)
/* find "[Content Types].xml" */
tmp = unzip_search_single(ctx, "[Content_Types].xml", 18, &loff);
if (tmp == CL_ETIMEOUT) {
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_TIMEOUT");
return CL_ETIMEOUT;
}
else if (tmp != CL_VIRUS) {
cli_dbgmsg("cli_process_ooxml: failed to find ""[Content_Types].xml""!\n");
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_NO_CONTENT_TYPES");
return CL_EFORMAT;
}
cli_dbgmsg("cli_process_ooxml: found ""[Content_Types].xml"" @ %x\n", loff);
return unzip_single_internal(ctx, loff, ooxml_content_cb);
tmp = unzip_single_internal(ctx, loff, ooxml_content_cb);
if (tmp == CL_ETIMEOUT)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_TIMEOUT");
else if (tmp == CL_EMEM)
ooxml_add_parse_error(ctx->wrkproperty, "OOXML_ERROR_OUTOFMEM");
return tmp;
#else
UNUSEDPARAM(ctx);
cli_dbgmsg("in cli_processooxml\n");

Write Preview
Loading…
Cancel
Save