+/*
+ * 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.
+ */
+
+/**
+ * SAML2ArtifactDecoder.cpp
+ *
+ * SAML 2.0 Artifact binding message decoder
+ */
+
+#include "internal.h"
+#include "exceptions.h"
+#include "saml/binding/SAMLArtifact.h"
+#include "saml2/core/Protocols.h"
+#include "saml2/metadata/Metadata.h"
+#include "saml2/metadata/MetadataProvider.h"
+#include "saml2/binding/SAML2Artifact.h"
+#include "saml2/binding/SAML2ArtifactDecoder.h"
+#include "security/X509TrustEngine.h"
+
+#include <log4cpp/Category.hh>
+#include <xmltooling/util/NDC.h>
+#include <xmltooling/util/ReplayCache.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 SAML2ArtifactDecoderFactory(const DOMElement* const & e)
+ {
+ return new SAML2ArtifactDecoder(e);
+ }
+ };
+};
+
+SAML2ArtifactDecoder::SAML2ArtifactDecoder(const DOMElement* e) {}
+
+SAML2ArtifactDecoder::~SAML2ArtifactDecoder() {}
+
+XMLObject* SAML2ArtifactDecoder::decode(
+ string& relayState,
+ const RoleDescriptor*& issuer,
+ bool& issuerTrusted,
+ 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.SAML2Artifact");
+
+ log.debug("validating input");
+ const char* SAMLart = httpRequest.getParameter("SAMLart");
+ if (!SAMLart)
+ return NULL;
+ const char* state = httpRequest.getParameter("RelayState");
+ if (state)
+ relayState = state;
+
+ if (!m_artifactResolver || !metadataProvider)
+ throw BindingException("Artifact binding requires ArtifactResolver and MetadataProvider implementations be supplied.");
+
+ // Import the artifact.
+ SAMLArtifact* artifact=NULL;
+ ReplayCache* replayCache = XMLToolingConfig::getConfig().getReplayCache();
+ try {
+ log.debug("processing encoded artifact (%s)", SAMLart);
+
+ // Check replay.
+ if (replayCache) {
+ if (!replayCache->check("SAML2Artifact", SAMLart, time(NULL) + (2*XMLToolingConfig::getConfig().clock_skew_secs))) {
+ log.error("replay detected of artifact (%s)", SAMLart);
+ throw BindingException("Rejecting replayed artifact ($1).", params(1,SAMLart));
+ }
+ }
+ else
+ log.warn("replay cache was not provided, this is a serious security risk!");
+
+ artifact = SAMLArtifact::parse(SAMLart);
+ }
+ catch (ArtifactException&) {
+ log.error("error parsing artifact (%s)", SAMLart);
+ throw;
+ }
+
+ // Check the type.
+ auto_ptr<SAML2Artifact> artifact2(dynamic_cast<SAML2Artifact*>(artifact));
+ if (!artifact2.get()) {
+ throw BindingException("Artifact binding requires SAML 2.0 artifact.");
+ delete artifact;
+ }
+
+ issuer = NULL;
+ issuerTrusted = false;
+ log.debug("attempting to determine source of artifact...");
+ const EntityDescriptor* provider=metadataProvider->getEntityDescriptor(artifact);
+ if (!provider) {
+ log.error(
+ "metadata lookup failed, unable to determine issuer of artifact (0x%s)",
+ SAMLArtifact::toHex(artifact->getBytes()).c_str()
+ );
+ throw BindingException("Metadata lookup failed, unable to determine artifact issuer.");
+ }
+
+ if (log.isDebugEnabled()) {
+ auto_ptr_char issuer(provider->getEntityID());
+ log.debug("lookup succeeded, artifact issued by (%s)", issuer.get());
+ }
+
+ log.debug("attempting to find artifact issuing role...");
+ issuer=provider->getRoleDescriptor(*role, SAMLConstants::SAML20P_NS);
+ if (!issuer || !dynamic_cast<const SSODescriptorType*>(issuer)) {
+ log.error("unable to find compatible SAML role (%s) in metadata", role->toString().c_str());
+ BindingException ex("Unable to find compatible metadata role for artifact issuer.");
+ annotateException(&ex,provider); // throws it
+ }
+
+ try {
+ auto_ptr<ArtifactResponse> response(
+ m_artifactResolver->resolve(
+ issuerTrusted,
+ *(artifact2.get()),
+ dynamic_cast<const SSODescriptorType&>(*issuer),
+ dynamic_cast<const X509TrustEngine*>(trustEngine)
+ )
+ );
+
+ // Check Issuer of outer message.
+ if (!issuerMatches(response->getIssuer(), provider->getEntityID())) {
+ log.error("issuer of ArtifactResponse did not match source of artifact");
+ throw BindingException("Issuer of ArtifactResponse did not match source of artifact.");
+ }
+
+ // Extract payload and check that Issuer.
+ XMLObject* payload = response->getPayload();
+ RequestAbstractType* req = NULL;
+ StatusResponseType* res = dynamic_cast<StatusResponseType*>(payload);
+ if (!res)
+ req = dynamic_cast<RequestAbstractType*>(payload);
+ if (!res && !req)
+ throw BindingException("ArtifactResponse payload was not a recognized SAML 2.0 protocol message.");
+
+ if (!issuerMatches(res ? res->getIssuer() : req->getIssuer(), provider->getEntityID())) {
+ log.error("issuer of ArtifactResponse payload did not match source of artifact");
+ throw BindingException("Issuer of ArtifactResponse payload did not match source of artifact.");
+ }
+
+ // Check payload freshness.
+ time_t now = time(NULL);
+ if ((res ? res->getIssueInstant() : req->getIssueInstant())->getEpoch() < now-(2*XMLToolingConfig::getConfig().clock_skew_secs))
+ throw BindingException("Detected expired ArtifactResponse payload.");
+
+ // Check replay.
+ if (replayCache) {
+ auto_ptr_char mid(res ? res->getID() : req->getID());
+ if (!replayCache->check("SAML2ArtifactPayload", mid.get(), now + (2*XMLToolingConfig::getConfig().clock_skew_secs))) {
+ log.error("replay detected of ArtifactResponse payload message ID (%s)", mid.get());
+ throw BindingException("Rejecting replayed ArtifactResponse payload ($1).", params(1,mid.get()));
+ }
+ }
+
+ // Check signatures.
+ if (trustEngine) {
+ if (response->getSignature()) {
+ issuerTrusted = trustEngine->validate(*(response->getSignature()), *issuer, metadataProvider->getKeyResolver());
+ if (!issuerTrusted) {
+ log.error("unable to verify signature on ArtifactResponse message with supplied trust engine");
+ throw BindingException("Message signature failed verification.");
+ }
+ }
+ Signature* sig = (res ? res->getSignature() : req->getSignature());
+ if (sig) {
+ issuerTrusted = trustEngine->validate(*sig, *issuer, metadataProvider->getKeyResolver());
+ if (!issuerTrusted) {
+ log.error("unable to verify signature on ArtifactResponse payload with supplied trust engine");
+ throw BindingException("Message signature failed verification.");
+ }
+ }
+ }
+
+ if (!issuerTrusted) {
+ log.warn("unable to verify integrity of ArtifactResponse message or payload, leaving untrusted");
+ }
+
+ // Return the payload only.
+ response.release();
+ payload->detach();
+ return payload;
+ }
+ catch (XMLToolingException& ex) {
+ annotateException(&ex,issuer,false);
+ throw;
+ }
+}
+
+bool SAML2ArtifactDecoder::issuerMatches(const Issuer* messageIssuer, const XMLCh* expectedIssuer) const
+{
+ if (messageIssuer && messageIssuer->getName()) {
+ if (messageIssuer->getFormat() && !XMLString::equals(messageIssuer->getFormat(), NameIDType::ENTITY))
+ return false;
+ else if (!XMLString::equals(expectedIssuer, messageIssuer->getName()))
+ return false;
+ }
+ return true;
+}
+