shibsp/handler/impl/SAML2Consumer.cpp

   1 /**
   2  * Licensed to the University Corporation for Advanced Internet
   3  * Development, Inc. (UCAID) under one or more contributor license
   4  * agreements. See the NOTICE file distributed with this work for
   5  * additional information regarding copyright ownership.
   6  *
   7  * UCAID licenses this file to you under the Apache License,
   8  * Version 2.0 (the "License"); you may not use this file except
   9  * in compliance with the License. You may obtain a copy of the
  10  * License at
  11  *
  12  * http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing,
  15  * software distributed under the License is distributed on an
  16  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
  17  * either express or implied. See the License for the specific
  18  * language governing permissions and limitations under the License.
  19  */
  20
  21 /**
  22  * SAML2Consumer.cpp
  23  *
  24  * SAML 2.0 assertion consumer service.
  25  */
  26
  27 #include "internal.h"
  28 #include "handler/AssertionConsumerService.h"
  29
  30 #ifndef SHIBSP_LITE
  31 # include "Application.h"
  32 # include "ServiceProvider.h"
  33 # include "SessionCache.h"
  34 # include "TransactionLog.h"
  35 # include "attribute/resolver/ResolutionContext.h"
  36 # include <boost/iterator/indirect_iterator.hpp>
  37 # include <saml/exceptions.h>
  38 # include <saml/SAMLConfig.h>
  39 # include <saml/binding/SecurityPolicyRule.h>
  40 # include <saml/saml2/core/Protocols.h>
  41 # include <saml/saml2/metadata/Metadata.h>
  42 # include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  43 # include <saml/saml2/profile/SAML2AssertionPolicy.h>
  44 # include <xmltooling/XMLToolingConfig.h>
  45 # include <xmltooling/io/HTTPRequest.h>
  46 # include <xmltooling/util/DateTime.h>
  47 using namespace opensaml::saml2;
  48 using namespace opensaml::saml2p;
  49 using namespace opensaml::saml2md;
  50 using namespace opensaml;
  51 using namespace boost;
  52 # ifndef min
  53 #  define min(a,b)            (((a) < (b)) ? (a) : (b))
  54 # endif
  55 #else
  56 # include "lite/SAMLConstants.h"
  57 #endif
  58
  59 using namespace shibsp;
  60 using namespace xmltooling;
  61 using namespace std;
  62
  63 namespace shibsp {
  64
  65 #if defined (_MSC_VER)
  66     #pragma warning( push )
  67     #pragma warning( disable : 4250 )
  68 #endif
  69
  70     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  71     {
  72     public:
  73         SAML2Consumer(const DOMElement* e, const char* appId)
  74             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SSO.SAML2")) {
  75 #ifndef SHIBSP_LITE
  76             if (SPConfig::getConfig().isEnabled(SPConfig::OutOfProcess))
  77                 m_ssoRule.reset(SAMLConfig::getConfig().SecurityPolicyRuleManager.newPlugin(BEARER_POLICY_RULE, e));
  78 #endif
  79         }
  80         virtual ~SAML2Consumer() {}
  81
  82 #ifndef SHIBSP_LITE
  83         void generateMetadata(SPSSODescriptor& role, const char* handlerURL) const {
  84             AssertionConsumerService::generateMetadata(role, handlerURL);
  85             role.addSupport(samlconstants::SAML20P_NS);
  86         }
  87
  88     private:
  89         void implementProtocol(
  90             const Application& application,
  91             const HTTPRequest& httpRequest,
  92             HTTPResponse& httpResponse,
  93             SecurityPolicy& policy,
  94             const PropertySet*,
  95             const XMLObject& xmlObject
  96             ) const;
  97
  98         scoped_ptr<SecurityPolicyRule> m_ssoRule;
  99 #else
 100         const XMLCh* getProtocolFamily() const {
 101             return samlconstants::SAML20P_NS;
 102         }
 103 #endif
 104     };
 105
 106 #if defined (_MSC_VER)
 107     #pragma warning( pop )
 108 #endif
 109
 110     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
 111     {
 112         return new SAML2Consumer(p.first, p.second);
 113     }
 114
 115 #ifndef SHIBSP_LITE
 116     class SHIBSP_DLLLOCAL _rulenamed : std::unary_function<const SecurityPolicyRule*,bool>
 117     {
 118     public:
 119         _rulenamed(const char* name) : m_name(name) {}
 120         bool operator()(const SecurityPolicyRule* rule) const {
 121             return rule ? !strcmp(m_name, rule->getType()) : false;
 122         }
 123     private:
 124         const char* m_name;
 125     };
 126 #endif
 127 };
 128
 129 #ifndef SHIBSP_LITE
 130
 131 void SAML2Consumer::implementProtocol(
 132     const Application& application,
 133     const HTTPRequest& httpRequest,
 134     HTTPResponse& httpResponse,
 135     SecurityPolicy& policy,
 136     const PropertySet*,
 137     const XMLObject& xmlObject
 138     ) const
 139 {
 140     // Implementation of SAML 2.0 SSO profile(s).
 141     m_log.debug("processing message against SAML 2.0 SSO profile");
 142
 143     // Remember whether we already established trust.
 144     // None of the SAML 2 bindings require security at the protocol layer.
 145     bool alreadySecured = policy.isAuthenticated();
 146
 147     // Check for errors...this will throw if it's not a successful message.
 148     checkError(&xmlObject, policy.getIssuerMetadata());
 149
 150     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 151     if (!response)
 152         throw FatalProfileException("Incoming message was not a samlp:Response.");
 153
 154     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 155     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 156     if (assertions.empty() && encassertions.empty())
 157         throw FatalProfileException("Incoming message contained no SAML assertions.");
 158
 159     // Maintain list of "legit" tokens to feed to SP subsystems.
 160     const Subject* ssoSubject=nullptr;
 161     const AuthnStatement* ssoStatement=nullptr;
 162     vector<const opensaml::Assertion*> tokens;
 163
 164     // Also track "bad" tokens that we'll cache but not use.
 165     // This is necessary because there may be valid tokens not aimed at us.
 166     vector<const opensaml::Assertion*> badtokens;
 167
 168     // And also track "owned" tokens that we decrypt here.
 169     vector< boost::shared_ptr<saml2::Assertion> > ownedtokens;
 170
 171     // With this flag on, we block unauthenticated ciphertext when decrypting,
 172     // unless the protocol was authenticated.
 173     pair<bool,bool> requireAuthenticatedEncryption = application.getBool("requireAuthenticatedEncryption");
 174     if (alreadySecured)
 175         requireAuthenticatedEncryption.second = false;
 176
 177     // With this flag on, we ignore any unsigned assertions.
 178     const EntityDescriptor* entity = nullptr;
 179     pair<bool,bool> requireSignedAssertions = make_pair(false,false);
 180     if (alreadySecured && policy.getIssuerMetadata()) {
 181         entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 182         const PropertySet* rp = application.getRelyingParty(entity);
 183         requireSignedAssertions = rp->getBool("requireSignedAssertions");
 184     }
 185
 186     // authnskew allows rejection of SSO if AuthnInstant is too old.
 187     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 188     pair<bool,unsigned int> authnskew = sessionProps ? sessionProps->getUnsignedInt("maxTimeSinceAuthn") : pair<bool,unsigned int>(false,0);
 189
 190     // Saves off error messages potentially helpful for users.
 191     string contextualError;
 192
 193     // Ensure the Bearer rule is in the policy set.
 194     if (find_if(policy.getRules(), _rulenamed(BEARER_POLICY_RULE)) == nullptr)
 195         policy.getRules().push_back(m_ssoRule.get());
 196
 197     // Populate recipient as audience.
 198     policy.getAudiences().push_back(application.getRelyingParty(entity)->getXMLString("entityID").second);
 199
 200     time_t now = time(nullptr);
 201     for (indirect_iterator<vector<saml2::Assertion*>::const_iterator> a = make_indirect_iterator(assertions.begin());
 202             a != make_indirect_iterator(assertions.end()); ++a) {
 203         try {
 204             // Skip unsigned assertion?
 205             if (!a->getSignature() && requireSignedAssertions.first && requireSignedAssertions.second)
 206                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 207
 208             // We clear the security flag, so we can tell whether the token was secured on its own.
 209             policy.setAuthenticated(false);
 210             policy.reset(true);
 211
 212             // Extract message bits and re-verify Issuer information.
 213             extractMessageDetails(*a, samlconstants::SAML20P_NS, policy);
 214
 215             // Run the policy over the assertion. Handles replay, freshness, and
 216             // signature verification, assuming the relevant rules are configured,
 217             // along with condition and profile enforcement.
 218             policy.evaluate(*a, &httpRequest);
 219
 220             // If no security is in place now, we kick it.
 221             if (!alreadySecured && !policy.isAuthenticated())
 222                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 223
 224             // If we hadn't established Issuer yet, redo the signedAssertions check.
 225             if (!entity && policy.getIssuerMetadata()) {
 226                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 227                 requireSignedAssertions = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 228                 if (!a->getSignature() && requireSignedAssertions.first && requireSignedAssertions.second)
 229                     throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 230             }
 231
 232             // Address checking.
 233             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 234                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 235                 );
 236             if (subcondata && subcondata->getAddress()) {
 237                 auto_ptr_char boundip(subcondata->getAddress());
 238                 checkAddress(application, httpRequest, boundip.get());
 239             }
 240
 241             // Track it as a valid token.
 242             tokens.push_back(&(*a));
 243
 244             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 245             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion&>(*a).getAuthnStatements();
 246             for (indirect_iterator<vector<AuthnStatement*>::const_iterator> s = make_indirect_iterator(statements.begin());
 247                     s != make_indirect_iterator(statements.end()); ++s) {
 248                 if (s->getAuthnInstant() && s->getAuthnInstantEpoch() - XMLToolingConfig::getConfig().clock_skew_secs > now) {
 249                     contextualError = "The login time at your identity provider was future-dated.";
 250                 }
 251                 else if (authnskew.first && authnskew.second && s->getAuthnInstant() &&
 252                         s->getAuthnInstantEpoch() <= now && (now - s->getAuthnInstantEpoch() > authnskew.second)) {
 253                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the allowed limit.";
 254                 }
 255                 else if (authnskew.first && authnskew.second && s->getAuthnInstant() == nullptr) {
 256                     contextualError = "Your identity provider did not supply a time of login, violating local policy.";
 257                 }
 258                 else if (!ssoStatement || s->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch()) {
 259                     ssoStatement = &(*s);
 260                 }
 261             }
 262
 263             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 264             if (!ssoSubject || (!ssoSubject->getNameID() && a->getSubject()->getNameID()))
 265                 ssoSubject = a->getSubject();
 266         }
 267         catch (std::exception& ex) {
 268             m_log.warn("detected a problem with assertion: %s", ex.what());
 269             if (!ssoStatement)
 270                 contextualError = ex.what();
 271             badtokens.push_back(&(*a));
 272         }
 273     }
 274
 275     // In case we need decryption...
 276     CredentialResolver* cr = application.getCredentialResolver();
 277     if (!cr && !encassertions.empty())
 278         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 279
 280     for (indirect_iterator<vector<saml2::EncryptedAssertion*>::const_iterator> ea = make_indirect_iterator(encassertions.begin());
 281             ea != make_indirect_iterator(encassertions.end()); ++ea) {
 282         // Attempt to decrypt it.
 283         boost::shared_ptr<saml2::Assertion> decrypted;
 284         try {
 285             Locker credlocker(cr);
 286             scoped_ptr<MetadataCredentialCriteria> mcc(
 287                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 288                 );
 289             boost::shared_ptr<XMLObject> wrapper(
 290                 ea->decrypt(
 291                     *cr,
 292                     application.getRelyingParty(entity)->getXMLString("entityID").second,
 293                     mcc.get(),
 294                     requireAuthenticatedEncryption.first && requireAuthenticatedEncryption.second
 295                     )
 296                 );
 297             decrypted = dynamic_pointer_cast<saml2::Assertion>(wrapper);
 298             if (decrypted) {
 299                 ownedtokens.push_back(decrypted);
 300                 if (m_log.isDebugEnabled())
 301                     m_log.debugStream() << "decrypted Assertion: " << *decrypted << logging::eol;
 302             }
 303         }
 304         catch (std::exception& ex) {
 305             m_log.error("failed to decrypt assertion: %s", ex.what());
 306         }
 307         if (!decrypted)
 308             continue;
 309
 310         try {
 311             // Skip unsigned assertion?
 312             if (!decrypted->getSignature() && requireSignedAssertions.first && requireSignedAssertions.second)
 313                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 314
 315             // We clear the security flag, so we can tell whether the token was secured on its own.
 316             policy.setAuthenticated(false);
 317             policy.reset(true);
 318
 319             // Extract message bits and re-verify Issuer information.
 320             extractMessageDetails(*decrypted, samlconstants::SAML20P_NS, policy);
 321
 322             // Run the policy over the assertion. Handles replay, freshness, and
 323             // signature verification, assuming the relevant rules are configured,
 324             // along with condition and profile enforcement.
 325             // We have to marshall the object first to ensure signatures can be checked.
 326             if (!decrypted->getDOM())
 327                 decrypted->marshall();
 328             policy.evaluate(*decrypted, &httpRequest);
 329
 330             // If no security is in place now, we kick it.
 331             if (!alreadySecured && !policy.isAuthenticated())
 332                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 333
 334             // If we hadn't established Issuer yet, redo the signedAssertions check.
 335             if (!entity && policy.getIssuerMetadata()) {
 336                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 337                 requireSignedAssertions = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 338                 if (!decrypted->getSignature() && requireSignedAssertions.first && requireSignedAssertions.second)
 339                     throw SecurityPolicyException("The decrypted assertion was unsigned, violating local security policy.");
 340             }
 341
 342             // Address checking.
 343             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 344                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 345                 );
 346             if (subcondata && subcondata->getAddress()) {
 347                 auto_ptr_char boundip(subcondata->getAddress());
 348                 checkAddress(application, httpRequest, boundip.get());
 349             }
 350
 351             // Track it as a valid token.
 352             tokens.push_back(decrypted.get());
 353
 354             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 355             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted.get())->getAuthnStatements();
 356             for (indirect_iterator<vector<AuthnStatement*>::const_iterator> s = make_indirect_iterator(statements.begin());
 357                     s != make_indirect_iterator(statements.end()); ++s) {
 358                 if (authnskew.first && authnskew.second && s->getAuthnInstant() && (now - s->getAuthnInstantEpoch() > authnskew.second))
 359                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 360                 else if (!ssoStatement || s->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 361                     ssoStatement = &(*s);
 362             }
 363
 364             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 365             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 366                 ssoSubject = decrypted->getSubject();
 367         }
 368         catch (std::exception& ex) {
 369             m_log.warn("detected a problem with assertion: %s", ex.what());
 370             if (!ssoStatement)
 371                 contextualError = ex.what();
 372             badtokens.push_back(decrypted.get());
 373         }
 374     }
 375
 376     if (!ssoStatement) {
 377         if (contextualError.empty())
 378             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 379         throw FatalProfileException(contextualError.c_str());
 380     }
 381
 382     // May need to decrypt NameID.
 383     scoped_ptr<XMLObject> decryptedID;
 384     NameID* ssoName = ssoSubject->getNameID();
 385     if (!ssoName) {
 386         EncryptedID* encname = ssoSubject->getEncryptedID();
 387         if (encname) {
 388             if (!cr)
 389                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 390             else {
 391                 Locker credlocker(cr);
 392                 scoped_ptr<MetadataCredentialCriteria> mcc(
 393                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 394                     );
 395                 try {
 396                     decryptedID.reset(encname->decrypt(*cr, application.getRelyingParty(entity)->getXMLString("entityID").second, mcc.get()));
 397                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 398                     if (ssoName) {
 399                         if (m_log.isDebugEnabled())
 400                             m_log.debugStream() << "decrypted NameID: " << *ssoName << logging::eol;
 401                     }
 402                 }
 403                 catch (std::exception& ex) {
 404                     m_log.error("failed to decrypt NameID: %s", ex.what());
 405                 }
 406             }
 407         }
 408     }
 409
 410     m_log.debug("SSO profile processing completed successfully");
 411
 412     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 413     // To complete processing, we need to extract and resolve attributes and then create the session.
 414
 415     // Now we have to extract the authentication details for session setup.
 416
 417     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 418     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ?
 419         (ssoStatement->getSessionNotOnOrAfterEpoch() + XMLToolingConfig::getConfig().clock_skew_secs) : 0;
 420     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 421     if (!lifetime.first || lifetime.second == 0)
 422         lifetime.second = 28800;
 423     if (sessionExp == 0)
 424         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 425     else
 426         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 427
 428     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 429
 430     // The context will handle deleting attributes and new tokens.
 431     scoped_ptr<ResolutionContext> ctx(
 432         resolveAttributes(
 433             application,
 434             &httpRequest,
 435             policy.getIssuerMetadata(),
 436             samlconstants::SAML20P_NS,
 437             response,
 438             nullptr,
 439             nullptr,
 440             ssoName,
 441             ssoStatement,
 442             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 443             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 444             &tokens
 445             )
 446         );
 447
 448     if (ctx) {
 449         // Copy over any new tokens, but leave them in the context for cleanup.
 450         tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 451     }
 452
 453     // Now merge in bad tokens for caching.
 454     tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 455
 456     string session_id;
 457     application.getServiceProvider().getSessionCache()->insert(
 458         session_id,
 459         application,
 460         httpRequest,
 461         httpResponse,
 462         sessionExp,
 463         entity,
 464         samlconstants::SAML20P_NS,
 465         ssoName,
 466         ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : nullptr,
 467         ssoStatement->getSessionIndex(),
 468         (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 469         (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 470         &tokens,
 471         ctx ? &ctx->getResolvedAttributes() : nullptr
 472         );
 473
 474     try {
 475         scoped_ptr<TransactionLog::Event> event(newLoginEvent(application, httpRequest));
 476         LoginEvent* login_event = dynamic_cast<LoginEvent*>(event.get());
 477         if (login_event) {
 478             login_event->m_sessionID = session_id.c_str();
 479             login_event->m_peer = entity;
 480             auto_ptr_char prot(getProtocolFamily());
 481             login_event->m_protocol = prot.get();
 482             login_event->m_nameID = ssoName;
 483             login_event->m_saml2AuthnStatement = ssoStatement;
 484             login_event->m_saml2Response = response;
 485             if (ctx)
 486                 login_event->m_attributes = &ctx->getResolvedAttributes();
 487             application.getServiceProvider().getTransactionLog()->write(*login_event);
 488         }
 489         else {
 490             m_log.warn("unable to audit event, log event object was of an incorrect type");
 491         }
 492     }
 493     catch (std::exception& ex) {
 494         m_log.warn("exception auditing event: %s", ex.what());
 495     }
 496 }
 497
 498 #endif