ModSecurity/src/operators/validate_schema.cc
2021-08-04 13:21:19 -03:00

141 lines
3.9 KiB
C++

/*
* ModSecurity, http://www.modsecurity.org/
* Copyright (c) 2015 - 2021 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* You may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* If any of the files related to licensing are missing or if you have any
* other questions related to licensing please contact Trustwave Holdings, Inc.
* directly using the email address security@modsecurity.org.
*
*/
#include "src/operators/validate_schema.h"
#include <string>
#include "src/operators/operator.h"
#include "src/request_body_processor/xml.h"
#include "src/utils/system.h"
namespace modsecurity {
namespace operators {
#ifdef WITH_LIBXML2
bool ValidateSchema::init(const std::string &file, std::string *error) {
std::string err;
m_resource = utils::find_resource(m_param, file, &err);
if (m_resource == "") {
error->assign("XML: File not found: " + m_param + ". " + err);
return false;
}
return true;
}
bool ValidateSchema::evaluate(Transaction *transaction,
RuleWithActions *rule,
const bpstd::string_view &str,
RuleMessage *ruleMessage) {
int rc;
m_parserCtx = xmlSchemaNewParserCtxt(m_resource.c_str());
if (m_parserCtx == NULL) {
std::stringstream err;
err << "XML: Failed to load Schema from file: ";
err << m_resource;
err << ". ";
if (m_err.empty() == false) {
err << m_err;
}
ms_dbg_a(transaction, 4, err.str());
return true;
}
xmlSchemaSetParserErrors(m_parserCtx,
(xmlSchemaValidityErrorFunc)error_load,
(xmlSchemaValidityWarningFunc)warn_load, &m_err);
xmlThrDefSetGenericErrorFunc(m_parserCtx,
null_error);
xmlSetGenericErrorFunc(m_parserCtx,
null_error);
m_schema = xmlSchemaParse(m_parserCtx);
if (m_schema == NULL) {
std::stringstream err;
err << "XML: Failed to load Schema: ";
err << m_resource;
err << ".";
if (m_err.empty() == false) {
err << " " << m_err;
}
ms_dbg_a(transaction, 4, err.str());
xmlSchemaFreeParserCtxt(m_parserCtx);
return true;
}
m_validCtx = xmlSchemaNewValidCtxt(m_schema);
if (m_validCtx == NULL) {
std::stringstream err("XML: Failed to create validation context.");
if (m_err.empty() == false) {
err << " " << m_err;
}
ms_dbg_a(transaction, 4, err.str());
return true;
}
/* Send validator errors/warnings to msr_log */
xmlSchemaSetValidErrors(m_validCtx,
(xmlSchemaValidityErrorFunc)error_runtime,
(xmlSchemaValidityWarningFunc)warn_runtime, transaction);
if (transaction->m_xml->m_data.doc == NULL) {
ms_dbg_a(transaction, 4, "XML document tree could not be found for " \
"schema validation.");
return true;
}
if (transaction->m_xml->m_data.well_formed != 1) {
ms_dbg_a(transaction, 4, "XML: Schema validation failed because " \
"content is not well formed.");
return true;
}
/* Make sure there were no other generic processing errors */
/*
if (msr->msc_reqbody_error) {
ms_dbg_a(t, 4, "XML: Schema validation could not proceed due to previous"
" processing errors.");
return true;
}
*/
rc = xmlSchemaValidateDoc(m_validCtx, transaction->m_xml->m_data.doc);
if (rc != 0) {
ms_dbg_a(transaction, 4, "XML: Schema validation failed.");
xmlSchemaFree(m_schema);
xmlSchemaFreeParserCtxt(m_parserCtx);
return true; /* No match. */
}
ms_dbg_a(transaction, 4, "XML: Successfully validated payload against " \
"Schema: " + m_resource);
xmlSchemaFree(m_schema);
xmlSchemaFreeParserCtxt(m_parserCtx);
return false;
}
#endif
} // namespace operators
} // namespace modsecurity