+/*
+ * Copyright 2001-2006 Internet2
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * SAML2RedirectDecoder.cpp
+ *
+ * SAML 2.0 HTTP Redirect binding message encoder
+ */
+
+#include "internal.h"
+#include "exceptions.h"
+#include "saml2/binding/SAML2Redirect.h"
+#include "saml2/binding/SAML2RedirectDecoder.h"
+#include "saml2/core/Protocols.h"
+#include "saml2/metadata/Metadata.h"
+#include "saml2/metadata/MetadataProvider.h"
+#include "security/X509TrustEngine.h"
+
+#include <log4cpp/Category.hh>
+#include <xercesc/util/Base64.hpp>
+#include <xmltooling/util/NDC.h>
+#include <xmltooling/util/ReplayCache.h>
+#include <xmltooling/validation/ValidatorSuite.h>
+
+using namespace opensaml::saml2md;
+using namespace opensaml::saml2p;
+using namespace opensaml::saml2;
+using namespace opensaml;
+using namespace xmlsignature;
+using namespace xmltooling;
+using namespace log4cpp;
+using namespace std;
+
+namespace opensaml {
+ namespace saml2p {
+ MessageDecoder* SAML_DLLLOCAL SAML2RedirectDecoderFactory(const DOMElement* const & e)
+ {
+ return new SAML2RedirectDecoder(e);
+ }
+ };
+};
+
+SAML2RedirectDecoder::SAML2RedirectDecoder(const DOMElement* e) {}
+
+SAML2RedirectDecoder::~SAML2RedirectDecoder() {}
+
+XMLObject* SAML2RedirectDecoder::decode(
+ string& relayState,
+ const RoleDescriptor*& issuer,
+ const XMLCh*& securityMech,
+ const HTTPRequest& httpRequest,
+ const MetadataProvider* metadataProvider,
+ const QName* role,
+ const opensaml::TrustEngine* trustEngine
+ ) const
+{
+#ifdef _DEBUG
+ xmltooling::NDC ndc("decode");
+#endif
+ Category& log = Category::getInstance(SAML_LOGCAT".MessageDecoder.SAML2Redirect");
+
+ log.debug("validating input");
+ if (strcmp(httpRequest.getMethod(),"GET"))
+ return NULL;
+ const char* msg = httpRequest.getParameter("SAMLResponse");
+ if (!msg)
+ msg = httpRequest.getParameter("SAMLRequest");
+ if (!msg)
+ return NULL;
+ const char* state = httpRequest.getParameter("RelayState");
+ if (state)
+ relayState = state;
+ else
+ relayState.erase();
+ state = httpRequest.getParameter("SAMLEncoding");
+ if (state && strcmp(state,samlconstants::SAML20_BINDING_URL_ENCODING_DEFLATE)) {
+ log.warn("SAMLEncoding (%s) was not recognized", state);
+ return NULL;
+ }
+
+ // Decode the compressed message into SAML. First we base64-decode it.
+ unsigned int x;
+ XMLByte* decoded=Base64::decode(reinterpret_cast<const XMLByte*>(msg),&x);
+ if (!decoded)
+ throw BindingException("Unable to decode base64 in Redirect binding message.");
+
+ // Now we have to inflate it.
+ stringstream str;
+ if (inflate((char*)decoded, x, str)==0) {
+ XMLString::release(&decoded);
+ throw BindingException("Unable to inflate Redirect binding message.");
+ }
+
+ XMLString::release(&decoded);
+
+ // Parse and bind the document into an XMLObject.
+ DOMDocument* doc = (m_validate ? XMLToolingConfig::getConfig().getValidatingParser()
+ : XMLToolingConfig::getConfig().getParser()).parse(str);
+ XercesJanitor<DOMDocument> janitor(doc);
+ auto_ptr<XMLObject> xmlObject(XMLObjectBuilder::buildOneFromElement(doc->getDocumentElement(), true));
+ janitor.release();
+
+ StatusResponseType* response = NULL;
+ RequestAbstractType* request = dynamic_cast<RequestAbstractType*>(xmlObject.get());
+ if (!request) {
+ response = dynamic_cast<StatusResponseType*>(xmlObject.get());
+ if (!response)
+ throw BindingException("XML content for SAML 2.0 HTTP-Redirect Decoder must be a SAML 2.0 protocol message.");
+ }
+
+ /* For SAML 2, the issuer can be established either from the message, or in some profiles
+ * it's possible to omit it and defer to assertions in a Response.
+ * The Issuer is later matched against metadata, and then trust checking can be applied.
+ */
+ const Issuer* claimedIssuer = request ? request->getIssuer() : response->getIssuer();
+ if (!claimedIssuer) {
+ // Check assertion option. I cannot resist the variable name, for the sake of google.
+ const Response* assbag = dynamic_cast<const Response*>(response);
+ if (assbag) {
+ const vector<Assertion*>& assertions=assbag->getAssertions();
+ if (!assertions.empty())
+ claimedIssuer = assertions.front()->getIssuer();
+ }
+ }
+
+ const EntityDescriptor* provider=NULL;
+ try {
+ if (!m_validate)
+ SchemaValidators.validate(xmlObject.get());
+
+ // Check destination URL.
+ auto_ptr_char dest(request ? request->getDestination() : response->getDestination());
+ const char* dest2 = httpRequest.getRequestURL();
+ if (!dest.get() || !*(dest.get())) {
+ log.error("signed SAML message missing Destination attribute");
+ throw BindingException("Signed SAML message missing Destination attribute identifying intended destination.");
+ }
+ else if (dest.get() && (!dest2 || !*dest2 || strcmp(dest.get(),dest2))) {
+ log.error("Redirect targeted at (%s), but delivered to (%s)", dest.get(), dest2 ? dest2 : "none");
+ throw BindingException("SAML message delivered with Redirect to incorrect server URL.");
+ }
+
+ // Check freshness.
+ time_t now = time(NULL);
+ if ((request ? request->getIssueInstant()->getEpoch() : response->getIssueInstant()->getEpoch())
+ < now-(2*XMLToolingConfig::getConfig().clock_skew_secs))
+ throw BindingException("Detected expired Redirect binding message.");
+
+ // Check replay.
+ ReplayCache* replayCache = XMLToolingConfig::getConfig().getReplayCache();
+ if (replayCache) {
+ auto_ptr_char id(xmlObject->getXMLID());
+ if (!replayCache->check("SAML2Redirect", id.get(), response->getIssueInstant()->getEpoch() + (2*XMLToolingConfig::getConfig().clock_skew_secs))) {
+ log.error("replay detected of message ID (%s)", id.get());
+ throw BindingException("Rejecting replayed message ID ($1).", params(1,id.get()));
+ }
+ }
+ else
+ log.warn("replay cache was not provided, this is a serious security risk!");
+
+ issuer = NULL;
+ securityMech = false;
+ log.debug("attempting to establish issuer and integrity of message...");
+
+ // If we can't identify the issuer, we're done, since we can't lookup or verify anything.
+ if (!claimedIssuer || !claimedIssuer->getName()) {
+ log.warn("unable to establish identity of message issuer");
+ return xmlObject.release();
+ }
+ else if (claimedIssuer->getFormat() && !XMLString::equals(claimedIssuer->getFormat(), NameIDType::ENTITY)) {
+ auto_ptr_char iformat(claimedIssuer->getFormat());
+ log.warn("message issuer was in an unsupported format (%s)", iformat.get());
+ return xmlObject.release();
+ }
+
+ log.debug("searching metadata for assertion issuer...");
+ provider=metadataProvider ? metadataProvider->getEntityDescriptor(claimedIssuer->getName()) : NULL;
+ if (provider) {
+ log.debug("matched assertion issuer against metadata, searching for applicable role...");
+ issuer=provider->getRoleDescriptor(*role, samlconstants::SAML20P_NS);
+ if (issuer) {
+ /*
+ if (trustEngine && signature) {
+ if (!trustEngine->validate(*signature, *issuer, metadataProvider->getKeyResolver())) {
+ log.error("unable to verify signature on message with supplied trust engine");
+ throw BindingException("Message signature failed verification.");
+ }
+ else {
+ securityMech = samlconstants::SAML20P_NS;
+ }
+ }
+ else {
+ log.warn("unable to authenticate the message, leaving untrusted");
+ }
+ */
+ }
+ else {
+ log.warn("unable to find compatible SAML 2.0 role (%s) in metadata", role->toString().c_str());
+ }
+ if (log.isDebugEnabled()) {
+ auto_ptr_char iname(provider->getEntityID());
+ log.debug("message from (%s), integrity %sverified", iname.get(), securityMech ? "" : "NOT ");
+ }
+ }
+ else {
+ auto_ptr_char temp(claimedIssuer->getName());
+ log.warn("no metadata found, can't establish identity of issuer (%s)", temp.get());
+ }
+ }
+ catch (XMLToolingException& ex) {
+ if (!provider) {
+ if (!claimedIssuer || !claimedIssuer->getName())
+ throw;
+ if (!metadataProvider || !(provider=metadataProvider->getEntityDescriptor(claimedIssuer->getName(), false))) {
+ // Just record it.
+ auto_ptr_char iname(claimedIssuer->getName());
+ if (iname.get())
+ ex.addProperty("entityID", iname.get());
+ throw;
+ }
+ }
+ if (!issuer)
+ issuer=provider->getRoleDescriptor(*role, samlconstants::SAML20P_NS);
+ if (issuer) annotateException(&ex,issuer); // throws it
+ annotateException(&ex,provider); // throws it
+ }
+
+ return xmlObject.release();
+}