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 <saml/exceptions.h>
  37 # include <saml/SAMLConfig.h>
  38 # include <saml/binding/SecurityPolicyRule.h>
  39 # include <saml/saml2/core/Protocols.h>
  40 # include <saml/saml2/metadata/Metadata.h>
  41 # include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  42 # include <saml/saml2/profile/SAML2AssertionPolicy.h>
  43 # include <xmltooling/XMLToolingConfig.h>
  44 # include <xmltooling/io/HTTPRequest.h>
  45 # include <xmltooling/util/DateTime.h>
  46 using namespace opensaml::saml2;
  47 using namespace opensaml::saml2p;
  48 using namespace opensaml::saml2md;
  49 using namespace opensaml;
  50 # ifndef min
  51 #  define min(a,b)            (((a) < (b)) ? (a) : (b))
  52 # endif
  53 #else
  54 # include "lite/SAMLConstants.h"
  55 #endif
  56
  57 using namespace shibsp;
  58 using namespace xmltooling;
  59 using namespace std;
  60
  61 namespace shibsp {
  62
  63 #if defined (_MSC_VER)
  64     #pragma warning( push )
  65     #pragma warning( disable : 4250 )
  66 #endif
  67
  68     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  69     {
  70     public:
  71         SAML2Consumer(const DOMElement* e, const char* appId)
  72             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SSO.SAML2")) {
  73 #ifndef SHIBSP_LITE
  74             m_ssoRule = nullptr;
  75             if (SPConfig::getConfig().isEnabled(SPConfig::OutOfProcess))
  76                 m_ssoRule = SAMLConfig::getConfig().SecurityPolicyRuleManager.newPlugin(BEARER_POLICY_RULE, e);
  77 #endif
  78         }
  79         virtual ~SAML2Consumer() {
  80 #ifndef SHIBSP_LITE
  81             delete m_ssoRule;
  82 #endif
  83         }
  84
  85 #ifndef SHIBSP_LITE
  86         void generateMetadata(SPSSODescriptor& role, const char* handlerURL) const {
  87             AssertionConsumerService::generateMetadata(role, handlerURL);
  88             role.addSupport(samlconstants::SAML20P_NS);
  89         }
  90
  91     private:
  92         void implementProtocol(
  93             const Application& application,
  94             const HTTPRequest& httpRequest,
  95             HTTPResponse& httpResponse,
  96             SecurityPolicy& policy,
  97             const PropertySet*,
  98             const XMLObject& xmlObject
  99             ) const;
 100
 101         SecurityPolicyRule* m_ssoRule;
 102 #else
 103         const XMLCh* getProtocolFamily() const {
 104             return samlconstants::SAML20P_NS;
 105         }
 106 #endif
 107     };
 108
 109 #if defined (_MSC_VER)
 110     #pragma warning( pop )
 111 #endif
 112
 113     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
 114     {
 115         return new SAML2Consumer(p.first, p.second);
 116     }
 117
 118 #ifndef SHIBSP_LITE
 119     class SHIBSP_DLLLOCAL _rulenamed : std::unary_function<const SecurityPolicyRule*,bool>
 120     {
 121     public:
 122         _rulenamed(const char* name) : m_name(name) {}
 123         bool operator()(const SecurityPolicyRule* rule) const {
 124             return rule ? !strcmp(m_name, rule->getType()) : false;
 125         }
 126     private:
 127         const char* m_name;
 128     };
 129 #endif
 130 };
 131
 132 #ifndef SHIBSP_LITE
 133
 134 void SAML2Consumer::implementProtocol(
 135     const Application& application,
 136     const HTTPRequest& httpRequest,
 137     HTTPResponse& httpResponse,
 138     SecurityPolicy& policy,
 139     const PropertySet*,
 140     const XMLObject& xmlObject
 141     ) const
 142 {
 143     // Implementation of SAML 2.0 SSO profile(s).
 144     m_log.debug("processing message against SAML 2.0 SSO profile");
 145
 146     // Remember whether we already established trust.
 147     // None of the SAML 2 bindings require security at the protocol layer.
 148     bool alreadySecured = policy.isAuthenticated();
 149
 150     // Check for errors...this will throw if it's not a successful message.
 151     checkError(&xmlObject, policy.getIssuerMetadata());
 152
 153     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 154     if (!response)
 155         throw FatalProfileException("Incoming message was not a samlp:Response.");
 156
 157     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 158     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 159     if (assertions.empty() && encassertions.empty())
 160         throw FatalProfileException("Incoming message contained no SAML assertions.");
 161
 162     // Maintain list of "legit" tokens to feed to SP subsystems.
 163     const Subject* ssoSubject=nullptr;
 164     const AuthnStatement* ssoStatement=nullptr;
 165     vector<const opensaml::Assertion*> tokens;
 166
 167     // Also track "bad" tokens that we'll cache but not use.
 168     // This is necessary because there may be valid tokens not aimed at us.
 169     vector<const opensaml::Assertion*> badtokens;
 170
 171     // And also track "owned" tokens that we decrypt here.
 172     vector<saml2::Assertion*> ownedtokens;
 173
 174     // With this flag on, we ignore any unsigned assertions.
 175     const EntityDescriptor* entity = nullptr;
 176     pair<bool,bool> flag = make_pair(false,false);
 177     if (alreadySecured && policy.getIssuerMetadata()) {
 178         entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 179         flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 180     }
 181
 182     // authnskew allows rejection of SSO if AuthnInstant is too old.
 183     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 184     pair<bool,unsigned int> authnskew = sessionProps ? sessionProps->getUnsignedInt("maxTimeSinceAuthn") : pair<bool,unsigned int>(false,0);
 185
 186     // Saves off error messages potentially helpful for users.
 187     string contextualError;
 188
 189     // Ensure the Bearer rule is in the policy set.
 190     if (find_if(policy.getRules(), _rulenamed(BEARER_POLICY_RULE)) == nullptr)
 191         policy.getRules().push_back(m_ssoRule);
 192
 193     // Populate recipient as audience.
 194     policy.getAudiences().push_back(application.getRelyingParty(entity)->getXMLString("entityID").second);
 195
 196     time_t now = time(nullptr);
 197     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 198         try {
 199             // Skip unsigned assertion?
 200             if (!(*a)->getSignature() && flag.first && flag.second)
 201                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 202
 203             // We clear the security flag, so we can tell whether the token was secured on its own.
 204             policy.setAuthenticated(false);
 205             policy.reset(true);
 206
 207             // Extract message bits and re-verify Issuer information.
 208             extractMessageDetails(*(*a), samlconstants::SAML20P_NS, policy);
 209
 210             // Run the policy over the assertion. Handles replay, freshness, and
 211             // signature verification, assuming the relevant rules are configured,
 212             // along with condition and profile enforcement.
 213             policy.evaluate(*(*a), &httpRequest);
 214
 215             // If no security is in place now, we kick it.
 216             if (!alreadySecured && !policy.isAuthenticated())
 217                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 218
 219             // If we hadn't established Issuer yet, redo the signedAssertions check.
 220             if (!entity && policy.getIssuerMetadata()) {
 221                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 222                 flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 223                 if (!(*a)->getSignature() && flag.first && flag.second)
 224                     throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 225             }
 226
 227             // Address checking.
 228             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 229                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 230                 );
 231             if (subcondata && subcondata->getAddress()) {
 232                 auto_ptr_char boundip(subcondata->getAddress());
 233                 checkAddress(application, httpRequest, boundip.get());
 234             }
 235
 236             // Track it as a valid token.
 237             tokens.push_back(*a);
 238
 239             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 240             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 241             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=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 (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 (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 275         // Attempt to decrypt it.
 276         saml2::Assertion* decrypted=nullptr;
 277         try {
 278             Locker credlocker(cr);
 279             auto_ptr<MetadataCredentialCriteria> mcc(
 280                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 281                 );
 282             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getRelyingParty(entity)->getXMLString("entityID").second, mcc.get()));
 283             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 284             if (decrypted) {
 285                 wrapper.release();
 286                 ownedtokens.push_back(decrypted);
 287                 if (m_log.isDebugEnabled())
 288                     m_log.debugStream() << "decrypted Assertion: " << *decrypted << logging::eol;
 289             }
 290         }
 291         catch (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);
 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)->getAuthnStatements();
 339             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 340                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 341                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 342                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 343                     ssoStatement = *s;
 344             }
 345
 346             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 347             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 348                 ssoSubject = decrypted->getSubject();
 349         }
 350         catch (exception& ex) {
 351             m_log.warn("detected a problem with assertion: %s", ex.what());
 352             if (!ssoStatement)
 353                 contextualError = ex.what();
 354             badtokens.push_back(decrypted);
 355         }
 356     }
 357
 358     if (!ssoStatement) {
 359         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 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     bool ownedName = false;
 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                 auto_ptr<MetadataCredentialCriteria> mcc(
 376                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 377                     );
 378                 try {
 379                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getRelyingParty(entity)->getXMLString("entityID").second,mcc.get()));
 380                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 381                     if (ssoName) {
 382                         ownedName = true;
 383                         decryptedID.release();
 384                         if (m_log.isDebugEnabled())
 385                             m_log.debugStream() << "decrypted NameID: " << *ssoName << logging::eol;
 386                     }
 387                 }
 388                 catch (exception& ex) {
 389                     m_log.error(ex.what());
 390                 }
 391             }
 392         }
 393     }
 394
 395     m_log.debug("SSO profile processing completed successfully");
 396
 397     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 398     // To complete processing, we need to extract and resolve attributes and then create the session.
 399
 400     // Now we have to extract the authentication details for session setup.
 401
 402     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 403     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ?
 404         (ssoStatement->getSessionNotOnOrAfterEpoch() + XMLToolingConfig::getConfig().clock_skew_secs) : 0;
 405     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 406     if (!lifetime.first || lifetime.second == 0)
 407         lifetime.second = 28800;
 408     if (sessionExp == 0)
 409         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 410     else
 411         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 412
 413     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 414
 415     try {
 416         // The context will handle deleting attributes and new tokens.
 417         auto_ptr<ResolutionContext> ctx(
 418             resolveAttributes(
 419                 application,
 420                 policy.getIssuerMetadata(),
 421                 samlconstants::SAML20P_NS,
 422                 nullptr,
 423                 nullptr,
 424                 ssoName,
 425                 ssoStatement,
 426                 (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 427                 (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 428                 &tokens
 429                 )
 430             );
 431
 432         if (ctx.get()) {
 433             // Copy over any new tokens, but leave them in the context for cleanup.
 434             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 435         }
 436
 437         // Now merge in bad tokens for caching.
 438         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 439
 440         string session_id;
 441         application.getServiceProvider().getSessionCache()->insert(
 442             session_id,
 443             application,
 444             httpRequest,
 445             httpResponse,
 446             sessionExp,
 447             entity,
 448             samlconstants::SAML20P_NS,
 449             ssoName,
 450             ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : nullptr,
 451             ssoStatement->getSessionIndex(),
 452             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 453             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 454             &tokens,
 455             ctx.get() ? &ctx->getResolvedAttributes() : nullptr
 456             );
 457
 458         try {
 459             auto_ptr<TransactionLog::Event> event(newLoginEvent(application, httpRequest));
 460             LoginEvent* login_event = dynamic_cast<LoginEvent*>(event.get());
 461             if (login_event) {
 462                 login_event->m_sessionID = session_id.c_str();
 463                 login_event->m_peer = entity;
 464                 auto_ptr_char prot(getProtocolFamily());
 465                 login_event->m_protocol = prot.get();
 466                 login_event->m_nameID = ssoName;
 467                 login_event->m_saml2AuthnStatement = ssoStatement;
 468                 login_event->m_saml2Response = response;
 469                 if (ctx.get())
 470                     login_event->m_attributes = &ctx->getResolvedAttributes();
 471                 application.getServiceProvider().getTransactionLog()->write(*login_event);
 472             }
 473             else {
 474                 m_log.warn("unable to audit event, log event object was of an incorrect type");
 475             }
 476         }
 477         catch (exception& ex) {
 478             m_log.warn("exception auditing event: %s", ex.what());
 479         }
 480
 481         if (ownedName)
 482             delete ssoName;
 483         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 484     }
 485     catch (exception&) {
 486         if (ownedName)
 487             delete ssoName;
 488         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 489         throw;
 490     }
 491 }
 492
 493 #endif