saml/saml1/binding/impl/SAML1POSTDecoder.cpp

   1 /*
   2  *  Copyright 2001-2006 Internet2
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /**
  18  * SAML1POSTDecoder.cpp
  19  *
  20  * SAML 1.x POST binding/profile message encoder
  21  */
  22
  23 #include "internal.h"
  24 #include "exceptions.h"
  25 #include "saml/binding/ReplayCache.h"
  26 #include "saml1/binding/SAML1POSTDecoder.h"
  27 #include "saml2/metadata/Metadata.h"
  28 #include "saml2/metadata/MetadataProvider.h"
  29 #include "security/X509TrustEngine.h"
  30
  31 #include <log4cpp/Category.hh>
  32 #include <xercesc/util/Base64.hpp>
  33 #include <xmltooling/util/NDC.h>
  34
  35 using namespace opensaml::saml2md;
  36 using namespace opensaml::saml1p;
  37 using namespace opensaml::saml1;
  38 using namespace opensaml;
  39 using namespace xmlsignature;
  40 using namespace xmltooling;
  41 using namespace log4cpp;
  42 using namespace std;
  43
  44 namespace opensaml {
  45     namespace saml1p {
  46         MessageDecoder* SAML_DLLLOCAL SAML1POSTDecoderFactory(const DOMElement* const & e)
  47         {
  48             return new SAML1POSTDecoder(e);
  49         }
  50     };
  51 };
  52
  53 SAML1POSTDecoder::SAML1POSTDecoder(const DOMElement* e) {}
  54
  55 SAML1POSTDecoder::~SAML1POSTDecoder() {}
  56
  57 Response* SAML1POSTDecoder::decode(
  58     string& relayState,
  59     const RoleDescriptor*& issuer,
  60     bool& issuerTrusted,
  61     const HTTPRequest& httpRequest,
  62     const MetadataProvider* metadataProvider,
  63     const QName* role,
  64     const X509TrustEngine* trustEngine
  65     ) const
  66 {
  67 #ifdef _DEBUG
  68     xmltooling::NDC ndc("decode");
  69 #endif
  70     Category& log = Category::getInstance(SAML_LOGCAT".MessageDecoder.SAML1POST");
  71
  72     log.debug("validating input");
  73     if (strcmp(httpRequest.getMethod(),"POST"))
  74         return NULL;
  75     const char* samlResponse = httpRequest.getParameter("SAMLResponse");
  76     const char* TARGET = httpRequest.getParameter("TARGET");
  77     if (!samlResponse || !TARGET)
  78         return NULL;
  79     relayState = TARGET;
  80
  81     // Decode the base64 into SAML.
  82     unsigned int x;
  83     XMLByte* decoded=Base64::decode(reinterpret_cast<const XMLByte*>(samlResponse),&x);
  84     if (!decoded)
  85         throw BindingException("Unable to decode base64 in POST profile response.");
  86     log.debug("decoded SAML response:\n%s", decoded);
  87     istringstream is(reinterpret_cast<char*>(decoded));
  88     XMLString::release(&decoded);
  89
  90     // Parse and bind the document into an XMLObject.
  91     DOMDocument* doc = (m_validate ? XMLToolingConfig::getConfig().getValidatingParser()
  92         : XMLToolingConfig::getConfig().getParser()).parse(is);
  93     XercesJanitor<DOMDocument> janitor(doc);
  94     auto_ptr<XMLObject> xmlObject(XMLObjectBuilder::buildOneFromElement(doc->getDocumentElement(), true));
  95     janitor.release();
  96
  97     Response* response = dynamic_cast<Response*>(xmlObject.get());
  98     if (!response)
  99         throw BindingException("Decoded message was not a SAML 1.x Response.");
 100
 101     try {
 102         if (!m_validate)
 103             SchemaValidators.validate(xmlObject.get());
 104
 105         // Check recipient URL.
 106         auto_ptr_char recipient(response->getRecipient());
 107         const char* recipient2 = httpRequest.getRequestURL();
 108         if (!recipient2 || !*recipient2 || strcmp(recipient.get(),recipient2)) {
 109             log.error("POST targeted at (%s), but delivered to (%s)", recipient.get(), recipient2 ? recipient2 : "none");
 110             throw BindingException("SAML message delivered with POST to incorrect server URL.");
 111         }
 112
 113         time_t now = time(NULL);
 114         if (response->getIssueInstant()->getEpoch() < now-(2*XMLToolingConfig::getConfig().clock_skew_secs))
 115             throw BindingException("Detected expired POST profile response.");
 116
 117         ReplayCache* replayCache = SAMLConfig::getConfig().getReplayCache();
 118         if (replayCache) {
 119             auto_ptr_char id(response->getResponseID());
 120             if (!replayCache->check("SAML1POST", id.get(), response->getIssueInstant()->getEpoch() + (2*XMLToolingConfig::getConfig().clock_skew_secs)))
 121                 throw BindingException("Rejecting replayed response ID ($1).", params(1,id.get()));
 122         }
 123         else
 124             log.warn("replay cache was not provided, this is a serious security risk!");
 125
 126         issuer = NULL;
 127         issuerTrusted = false;
 128         log.debug("attempting to establish issuer and integrity of message...");
 129         const vector<Assertion*>& assertions=const_cast<const Response*>(response)->getAssertions();
 130         if (!assertions.empty()) {
 131             const EntityDescriptor* provider=
 132                 metadataProvider ? metadataProvider->getEntityDescriptor(assertions.front()->getIssuer()) : NULL;
 133             if (provider) {
 134                 pair<bool,int> minor = response->getMinorVersion();
 135                 issuer=provider->getRoleDescriptor(
 136                     *role,
 137                     (minor.first && minor.second==0) ? SAMLConstants::SAML10_PROTOCOL_ENUM : SAMLConstants::SAML11_PROTOCOL_ENUM
 138                     );
 139                 if (issuer && trustEngine && response->getSignature()) {
 140                     issuerTrusted = static_cast<const TrustEngine*>(trustEngine)->validate(
 141                         *(response->getSignature()), *issuer, metadataProvider->getKeyResolver()
 142                         );
 143                     if (!issuerTrusted)
 144                         log.error("signature on message could not be verified by supplied trust engine");
 145                 }
 146                 if (log.isDebugEnabled()) {
 147                     auto_ptr_char iname(assertions.front()->getIssuer());
 148                     log.debug("message from (%s), integrity %sverified", iname.get(), issuerTrusted ? "" : "NOT ");
 149                 }
 150             }
 151             else
 152                 log.warn("no metadata provider supplied, can't establish identity of issuer");
 153         }
 154         else
 155             log.warn("no assertions found, can't establish identity of issuer");
 156     }
 157     catch (XMLToolingException& ex) {
 158         // Check for an Issuer.
 159         const vector<Assertion*>& assertions=const_cast<const Response*>(response)->getAssertions();
 160         if (!assertions.empty()) {
 161             if (!metadataProvider) {
 162                 // Just record it.
 163                 auto_ptr_char issuer(assertions.front()->getIssuer());
 164                 if (issuer.get())
 165                     ex.addProperty("entityID", issuer.get());
 166                 throw;
 167             }
 168             // Try and locate metadata for error handling.
 169             const EntityDescriptor* provider=metadataProvider->getEntityDescriptor(assertions.front()->getIssuer(),false);
 170             if (provider) {
 171                 pair<bool,int> minor = response->getMinorVersion();
 172                 const IDPSSODescriptor* role=provider->getIDPSSODescriptor(
 173                     (minor.first && minor.second==0) ? SAMLConstants::SAML10_PROTOCOL_ENUM : SAMLConstants::SAML11_PROTOCOL_ENUM
 174                     );
 175                 if (role) annotateException(&ex,role); // throws it
 176                 annotateException(&ex,provider);  // throws it
 177             }
 178         }
 179     }
 180
 181     xmlObject.release();
 182     return response;
 183 }