shibsp/handler/impl/SAML2Consumer.cpp

   1 /*
   2  *  Copyright 2001-2007 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  * SAML2Consumer.cpp
  19  *
  20  * SAML 2.0 assertion consumer service
  21  */
  22
  23 #include "internal.h"
  24 #include "handler/AssertionConsumerService.h"
  25
  26 #ifndef SHIBSP_LITE
  27 # include "exceptions.h"
  28 # include "Application.h"
  29 # include "ServiceProvider.h"
  30 # include "SessionCache.h"
  31 # include "attribute/resolver/ResolutionContext.h"
  32 # include <saml/saml2/core/Protocols.h>
  33 # include <saml/saml2/profile/BrowserSSOProfileValidator.h>
  34 # include <saml/saml2/metadata/Metadata.h>
  35 # include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  36 using namespace opensaml::saml2;
  37 using namespace opensaml::saml2p;
  38 using namespace opensaml::saml2md;
  39 using namespace opensaml;
  40 # ifndef min
  41 #  define min(a,b)            (((a) < (b)) ? (a) : (b))
  42 # endif
  43 #endif
  44
  45 using namespace shibsp;
  46 using namespace xmltooling;
  47 using namespace std;
  48
  49 namespace shibsp {
  50
  51 #if defined (_MSC_VER)
  52     #pragma warning( push )
  53     #pragma warning( disable : 4250 )
  54 #endif
  55
  56     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  57     {
  58     public:
  59         SAML2Consumer(const DOMElement* e, const char* appId)
  60             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SSO.SAML2")) {
  61         }
  62         virtual ~SAML2Consumer() {}
  63
  64 #ifndef SHIBSP_LITE
  65         void generateMetadata(SPSSODescriptor& role, const char* handlerURL) const {
  66             AssertionConsumerService::generateMetadata(role, handlerURL);
  67             role.addSupport(samlconstants::SAML20P_NS);
  68         }
  69
  70     private:
  71         void implementProtocol(
  72             const Application& application,
  73             const HTTPRequest& httpRequest,
  74             HTTPResponse& httpResponse,
  75             SecurityPolicy& policy,
  76             const PropertySet* settings,
  77             const XMLObject& xmlObject
  78             ) const;
  79 #endif
  80     };
  81
  82 #if defined (_MSC_VER)
  83     #pragma warning( pop )
  84 #endif
  85
  86     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
  87     {
  88         return new SAML2Consumer(p.first, p.second);
  89     }
  90
  91 };
  92
  93 #ifndef SHIBSP_LITE
  94
  95 void SAML2Consumer::implementProtocol(
  96     const Application& application,
  97     const HTTPRequest& httpRequest,
  98     HTTPResponse& httpResponse,
  99     SecurityPolicy& policy,
 100     const PropertySet* settings,
 101     const XMLObject& xmlObject
 102     ) const
 103 {
 104     // Implementation of SAML 2.0 SSO profile(s).
 105     m_log.debug("processing message against SAML 2.0 SSO profile");
 106
 107     // Remember whether we already established trust.
 108     // None of the SAML 2 bindings require security at the protocol layer.
 109     bool alreadySecured = policy.isAuthenticated();
 110
 111     // Check for errors...this will throw if it's not a successful message.
 112     checkError(&xmlObject);
 113
 114     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 115     if (!response)
 116         throw FatalProfileException("Incoming message was not a samlp:Response.");
 117
 118     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 119     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 120     if (assertions.empty() && encassertions.empty())
 121         throw FatalProfileException("Incoming message contained no SAML assertions.");
 122
 123     // Maintain list of "legit" tokens to feed to SP subsystems.
 124     const Subject* ssoSubject=NULL;
 125     const AuthnStatement* ssoStatement=NULL;
 126     vector<const opensaml::Assertion*> tokens;
 127
 128     // Also track "bad" tokens that we'll cache but not use.
 129     // This is necessary because there may be valid tokens not aimed at us.
 130     vector<const opensaml::Assertion*> badtokens;
 131
 132     // And also track "owned" tokens that we decrypt here.
 133     vector<saml2::Assertion*> ownedtokens;
 134
 135     // Profile validator.
 136     time_t now = time(NULL);
 137     string dest = httpRequest.getRequestURL();
 138     BrowserSSOProfileValidator ssoValidator(application.getAudiences(), now, dest.substr(0,dest.find('?')).c_str());
 139
 140     // With this flag on, we ignore any unsigned assertions.
 141     const EntityDescriptor* entity = NULL;
 142     pair<bool,bool> flag = make_pair(false,false);
 143     if (alreadySecured && policy.getIssuerMetadata()) {
 144         entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 145         flag = application.getRelyingParty(entity)->getBool("signedAssertions");
 146     }
 147
 148     // authnskew allows rejection of SSO if AuthnInstant is too old.
 149     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 150     pair<bool,unsigned int> authnskew = sessionProps ? sessionProps->getUnsignedInt("maxTimeSinceAuthn") : pair<bool,unsigned int>(false,0);
 151
 152     // Saves off error messages potentially helpful for users.
 153     string contextualError;
 154
 155     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 156         try {
 157             // Skip unsigned assertion?
 158             if (!(*a)->getSignature() && flag.first && flag.second)
 159                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 160
 161             // We clear the security flag, so we can tell whether the token was secured on its own.
 162             policy.setAuthenticated(false);
 163             policy.reset(true);
 164
 165             // Extract message bits and re-verify Issuer information.
 166             extractMessageDetails(*(*a), samlconstants::SAML20P_NS, policy);
 167
 168             // Run the policy over the assertion. Handles replay, freshness, and
 169             // signature verification, assuming the relevant rules are configured.
 170             policy.evaluate(*(*a));
 171
 172             // If no security is in place now, we kick it.
 173             if (!alreadySecured && !policy.isAuthenticated())
 174                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 175
 176             // If we hadn't established Issuer yet, redo the signedAssertions check.
 177             if (!entity && policy.getIssuerMetadata()) {
 178                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 179                 flag = application.getRelyingParty(entity)->getBool("signedAssertions");
 180                 if (!(*a)->getSignature() && flag.first && flag.second)
 181                     throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 182             }
 183
 184             // Now do profile and core semantic validation to ensure we can use it for SSO.
 185             ssoValidator.validateAssertion(*(*a));
 186
 187             // Address checking.
 188             checkAddress(application, httpRequest, ssoValidator.getAddress());
 189
 190             // Track it as a valid token.
 191             tokens.push_back(*a);
 192
 193             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 194             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 195             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 196                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 197                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 198                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 199                     ssoStatement = *s;
 200             }
 201
 202             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 203             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 204                 ssoSubject = (*a)->getSubject();
 205         }
 206         catch (exception& ex) {
 207             m_log.warn("detected a problem with assertion: %s", ex.what());
 208             if (!ssoStatement)
 209                 contextualError = ex.what();
 210             badtokens.push_back(*a);
 211         }
 212     }
 213
 214     // In case we need decryption...
 215     CredentialResolver* cr=application.getCredentialResolver();
 216     if (!cr && !encassertions.empty())
 217         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 218
 219     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 220         // Attempt to decrypt it.
 221         saml2::Assertion* decrypted=NULL;
 222         try {
 223             Locker credlocker(cr);
 224             auto_ptr<MetadataCredentialCriteria> mcc(
 225                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 226                 );
 227             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getXMLString("entityID").second, mcc.get()));
 228             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 229             if (decrypted) {
 230                 wrapper.release();
 231                 ownedtokens.push_back(decrypted);
 232                 if (m_log.isDebugEnabled())
 233                     m_log.debugStream() << "decrypted Assertion:" << logging::eol << *decrypted << logging::eol;
 234             }
 235         }
 236         catch (exception& ex) {
 237             m_log.error(ex.what());
 238         }
 239         if (!decrypted)
 240             continue;
 241
 242         try {
 243             // Skip unsigned assertion?
 244             if (!decrypted->getSignature() && flag.first && flag.second)
 245                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 246
 247             // We clear the security flag, so we can tell whether the token was secured on its own.
 248             policy.setAuthenticated(false);
 249             policy.reset(true);
 250
 251             // Extract message bits and re-verify Issuer information.
 252             extractMessageDetails(*decrypted, samlconstants::SAML20P_NS, policy);
 253
 254             // Run the policy over the assertion. Handles replay, freshness, and
 255             // signature verification, assuming the relevant rules are configured.
 256             // We have to marshall the object first to ensure signatures can be checked.
 257             if (!decrypted->getDOM())
 258                 decrypted->marshall();
 259             policy.evaluate(*decrypted);
 260
 261             // If no security is in place now, we kick it.
 262             if (!alreadySecured && !policy.isAuthenticated())
 263                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 264
 265             // Now do profile and core semantic validation to ensure we can use it for SSO.
 266             ssoValidator.validateAssertion(*decrypted);
 267
 268             // Address checking.
 269             checkAddress(application, httpRequest, ssoValidator.getAddress());
 270
 271             // Track it as a valid token.
 272             tokens.push_back(decrypted);
 273
 274             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 275             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 276             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 277                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 278                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 279                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 280                     ssoStatement = *s;
 281             }
 282
 283             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 284             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 285                 ssoSubject = decrypted->getSubject();
 286         }
 287         catch (exception& ex) {
 288             m_log.warn("detected a problem with assertion: %s", ex.what());
 289             if (!ssoStatement)
 290                 contextualError = ex.what();
 291             badtokens.push_back(decrypted);
 292         }
 293     }
 294
 295     if (!ssoStatement) {
 296         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 297         if (contextualError.empty())
 298             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 299         throw FatalProfileException(contextualError.c_str());
 300     }
 301
 302     // May need to decrypt NameID.
 303     bool ownedName = false;
 304     NameID* ssoName = ssoSubject->getNameID();
 305     if (!ssoName) {
 306         EncryptedID* encname = ssoSubject->getEncryptedID();
 307         if (encname) {
 308             if (!cr)
 309                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 310             else {
 311                 Locker credlocker(cr);
 312                 auto_ptr<MetadataCredentialCriteria> mcc(
 313                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 314                     );
 315                 try {
 316                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getXMLString("entityID").second,mcc.get()));
 317                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 318                     if (ssoName) {
 319                         ownedName = true;
 320                         decryptedID.release();
 321                         if (m_log.isDebugEnabled())
 322                             m_log.debugStream() << "decrypted NameID:" << logging::eol << *ssoName << logging::eol;
 323                     }
 324                 }
 325                 catch (exception& ex) {
 326                     m_log.error(ex.what());
 327                 }
 328             }
 329         }
 330     }
 331
 332     m_log.debug("SSO profile processing completed successfully");
 333
 334     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 335     // To complete processing, we need to extract and resolve attributes and then create the session.
 336
 337     // Now we have to extract the authentication details for session setup.
 338
 339     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 340     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ? ssoStatement->getSessionNotOnOrAfterEpoch() : 0;
 341     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 342     if (!lifetime.first || lifetime.second == 0)
 343         lifetime.second = 28800;
 344     if (sessionExp == 0)
 345         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 346     else
 347         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 348
 349     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 350
 351     try {
 352         // The context will handle deleting attributes and new tokens.
 353         auto_ptr<ResolutionContext> ctx(
 354             resolveAttributes(
 355                 application,
 356                 policy.getIssuerMetadata(),
 357                 samlconstants::SAML20P_NS,
 358                 NULL,
 359                 ssoName,
 360                 (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 361                 (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 362                 &tokens
 363                 )
 364             );
 365
 366         if (ctx.get()) {
 367             // Copy over any new tokens, but leave them in the context for cleanup.
 368             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 369         }
 370
 371         // Now merge in bad tokens for caching.
 372         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 373
 374         application.getServiceProvider().getSessionCache()->insert(
 375             application,
 376             httpRequest,
 377             httpResponse,
 378             sessionExp,
 379             entity,
 380             samlconstants::SAML20P_NS,
 381             ssoName,
 382             ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : NULL,
 383             ssoStatement->getSessionIndex(),
 384             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 385             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 386             &tokens,
 387             ctx.get() ? &ctx->getResolvedAttributes() : NULL
 388             );
 389
 390         if (ownedName)
 391             delete ssoName;
 392         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 393     }
 394     catch (exception&) {
 395         if (ownedName)
 396             delete ssoName;
 397         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 398         throw;
 399     }
 400 }
 401
 402 #endif