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