shibsp/handler/impl/SAML2Consumer.cpp

   1 /*
   2  *  Copyright 2001-2010 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 "Application.h"
  28 # include "ServiceProvider.h"
  29 # include "SessionCache.h"
  30 # include "attribute/resolver/ResolutionContext.h"
  31 # include <saml/exceptions.h>
  32 # include <saml/SAMLConfig.h>
  33 # include <saml/binding/SecurityPolicyRule.h>
  34 # include <saml/saml2/core/Protocols.h>
  35 # include <saml/saml2/metadata/Metadata.h>
  36 # include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  37 # include <saml/saml2/profile/SAML2AssertionPolicy.h>
  38 # include <xmltooling/XMLToolingConfig.h>
  39 # include <xmltooling/io/HTTPRequest.h>
  40 # include <xmltooling/util/DateTime.h>
  41 using namespace opensaml::saml2;
  42 using namespace opensaml::saml2p;
  43 using namespace opensaml::saml2md;
  44 using namespace opensaml;
  45 # ifndef min
  46 #  define min(a,b)            (((a) < (b)) ? (a) : (b))
  47 # endif
  48 #else
  49 # include "lite/SAMLConstants.h"
  50 #endif
  51
  52 using namespace shibsp;
  53 using namespace xmltooling;
  54 using namespace std;
  55
  56 namespace shibsp {
  57
  58 #if defined (_MSC_VER)
  59     #pragma warning( push )
  60     #pragma warning( disable : 4250 )
  61 #endif
  62
  63     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  64     {
  65     public:
  66         SAML2Consumer(const DOMElement* e, const char* appId)
  67             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SSO.SAML2")) {
  68 #ifndef SHIBSP_LITE
  69             m_ssoRule = nullptr;
  70             if (SPConfig::getConfig().isEnabled(SPConfig::OutOfProcess))
  71                 m_ssoRule = SAMLConfig::getConfig().SecurityPolicyRuleManager.newPlugin(BEARER_POLICY_RULE, e);
  72 #endif
  73         }
  74         virtual ~SAML2Consumer() {
  75 #ifndef SHIBSP_LITE
  76             delete m_ssoRule;
  77 #endif
  78         }
  79
  80 #ifndef SHIBSP_LITE
  81         void generateMetadata(SPSSODescriptor& role, const char* handlerURL) const {
  82             AssertionConsumerService::generateMetadata(role, handlerURL);
  83             role.addSupport(samlconstants::SAML20P_NS);
  84         }
  85
  86     private:
  87         void implementProtocol(
  88             const Application& application,
  89             const HTTPRequest& httpRequest,
  90             HTTPResponse& httpResponse,
  91             SecurityPolicy& policy,
  92             const PropertySet*,
  93             const XMLObject& xmlObject
  94             ) const;
  95
  96         SecurityPolicyRule* m_ssoRule;
  97 #else
  98         const XMLCh* getProtocolFamily() const {
  99             return samlconstants::SAML20P_NS;
 100         }
 101 #endif
 102     };
 103
 104 #if defined (_MSC_VER)
 105     #pragma warning( pop )
 106 #endif
 107
 108     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
 109     {
 110         return new SAML2Consumer(p.first, p.second);
 111     }
 112
 113 #ifndef SHIBSP_LITE
 114     class SHIBSP_DLLLOCAL _rulenamed : std::unary_function<const SecurityPolicyRule*,bool>
 115     {
 116     public:
 117         _rulenamed(const char* name) : m_name(name) {}
 118         bool operator()(const SecurityPolicyRule* rule) const {
 119             return rule ? !strcmp(m_name, rule->getType()) : false;
 120         }
 121     private:
 122         const char* m_name;
 123     };
 124 #endif
 125 };
 126
 127 #ifndef SHIBSP_LITE
 128
 129 void SAML2Consumer::implementProtocol(
 130     const Application& application,
 131     const HTTPRequest& httpRequest,
 132     HTTPResponse& httpResponse,
 133     SecurityPolicy& policy,
 134     const PropertySet*,
 135     const XMLObject& xmlObject
 136     ) const
 137 {
 138     // Implementation of SAML 2.0 SSO profile(s).
 139     m_log.debug("processing message against SAML 2.0 SSO profile");
 140
 141     // Remember whether we already established trust.
 142     // None of the SAML 2 bindings require security at the protocol layer.
 143     bool alreadySecured = policy.isAuthenticated();
 144
 145     // Check for errors...this will throw if it's not a successful message.
 146     checkError(&xmlObject, policy.getIssuerMetadata());
 147
 148     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 149     if (!response)
 150         throw FatalProfileException("Incoming message was not a samlp:Response.");
 151
 152     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 153     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 154     if (assertions.empty() && encassertions.empty())
 155         throw FatalProfileException("Incoming message contained no SAML assertions.");
 156
 157     // Maintain list of "legit" tokens to feed to SP subsystems.
 158     const Subject* ssoSubject=nullptr;
 159     const AuthnStatement* ssoStatement=nullptr;
 160     vector<const opensaml::Assertion*> tokens;
 161
 162     // Also track "bad" tokens that we'll cache but not use.
 163     // This is necessary because there may be valid tokens not aimed at us.
 164     vector<const opensaml::Assertion*> badtokens;
 165
 166     // And also track "owned" tokens that we decrypt here.
 167     vector<saml2::Assertion*> ownedtokens;
 168
 169     // With this flag on, we ignore any unsigned assertions.
 170     const EntityDescriptor* entity = nullptr;
 171     pair<bool,bool> flag = make_pair(false,false);
 172     if (alreadySecured && policy.getIssuerMetadata()) {
 173         entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 174         flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 175     }
 176
 177     // authnskew allows rejection of SSO if AuthnInstant is too old.
 178     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 179     pair<bool,unsigned int> authnskew = sessionProps ? sessionProps->getUnsignedInt("maxTimeSinceAuthn") : pair<bool,unsigned int>(false,0);
 180
 181     // Saves off error messages potentially helpful for users.
 182     string contextualError;
 183
 184     // Ensure the Bearer rule is in the policy set.
 185     if (find_if(policy.getRules(), _rulenamed(BEARER_POLICY_RULE)) == nullptr)
 186         policy.getRules().push_back(m_ssoRule);
 187
 188     // Populate recipient as audience.
 189     policy.getAudiences().push_back(application.getRelyingParty(entity)->getXMLString("entityID").second);
 190
 191     time_t now = time(nullptr);
 192     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 193         try {
 194             // Skip unsigned assertion?
 195             if (!(*a)->getSignature() && flag.first && flag.second)
 196                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 197
 198             // We clear the security flag, so we can tell whether the token was secured on its own.
 199             policy.setAuthenticated(false);
 200             policy.reset(true);
 201
 202             // Extract message bits and re-verify Issuer information.
 203             extractMessageDetails(*(*a), samlconstants::SAML20P_NS, policy);
 204
 205             // Run the policy over the assertion. Handles replay, freshness, and
 206             // signature verification, assuming the relevant rules are configured,
 207             // along with condition and profile enforcement.
 208             policy.evaluate(*(*a), &httpRequest);
 209
 210             // If no security is in place now, we kick it.
 211             if (!alreadySecured && !policy.isAuthenticated())
 212                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 213
 214             // If we hadn't established Issuer yet, redo the signedAssertions check.
 215             if (!entity && policy.getIssuerMetadata()) {
 216                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 217                 flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 218                 if (!(*a)->getSignature() && flag.first && flag.second)
 219                     throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 220             }
 221
 222             // Address checking.
 223             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 224                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 225                 );
 226             if (subcondata && subcondata->getAddress()) {
 227                 auto_ptr_char boundip(subcondata->getAddress());
 228                 checkAddress(application, httpRequest, boundip.get());
 229             }
 230
 231             // Track it as a valid token.
 232             tokens.push_back(*a);
 233
 234             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 235             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 236             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 237                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 238                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 239                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 240                     ssoStatement = *s;
 241             }
 242
 243             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 244             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 245                 ssoSubject = (*a)->getSubject();
 246         }
 247         catch (exception& ex) {
 248             m_log.warn("detected a problem with assertion: %s", ex.what());
 249             if (!ssoStatement)
 250                 contextualError = ex.what();
 251             badtokens.push_back(*a);
 252         }
 253     }
 254
 255     // In case we need decryption...
 256     CredentialResolver* cr=application.getCredentialResolver();
 257     if (!cr && !encassertions.empty())
 258         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 259
 260     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 261         // Attempt to decrypt it.
 262         saml2::Assertion* decrypted=nullptr;
 263         try {
 264             Locker credlocker(cr);
 265             auto_ptr<MetadataCredentialCriteria> mcc(
 266                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 267                 );
 268             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getRelyingParty(entity)->getXMLString("entityID").second, mcc.get()));
 269             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 270             if (decrypted) {
 271                 wrapper.release();
 272                 ownedtokens.push_back(decrypted);
 273                 if (m_log.isDebugEnabled())
 274                     m_log.debugStream() << "decrypted Assertion: " << *decrypted << logging::eol;
 275             }
 276         }
 277         catch (exception& ex) {
 278             m_log.error(ex.what());
 279         }
 280         if (!decrypted)
 281             continue;
 282
 283         try {
 284             // We clear the security flag, so we can tell whether the token was secured on its own.
 285             policy.setAuthenticated(false);
 286             policy.reset(true);
 287
 288             // Extract message bits and re-verify Issuer information.
 289             extractMessageDetails(*decrypted, samlconstants::SAML20P_NS, policy);
 290
 291             // Run the policy over the assertion. Handles replay, freshness, and
 292             // signature verification, assuming the relevant rules are configured,
 293             // along with condition and profile enforcement.
 294             // We have to marshall the object first to ensure signatures can be checked.
 295             if (!decrypted->getDOM())
 296                 decrypted->marshall();
 297             policy.evaluate(*decrypted, &httpRequest);
 298
 299             // If no security is in place now, we kick it.
 300             if (!alreadySecured && !policy.isAuthenticated())
 301                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 302
 303             // If we hadn't established Issuer yet, redo the signedAssertions check.
 304             if (!entity && policy.getIssuerMetadata()) {
 305                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 306                 flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 307                 if (!decrypted->getSignature() && flag.first && flag.second)
 308                     throw SecurityPolicyException("The decrypted assertion was unsigned, violating local security policy.");
 309             }
 310
 311             // Address checking.
 312             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 313                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 314                 );
 315             if (subcondata && subcondata->getAddress()) {
 316                 auto_ptr_char boundip(subcondata->getAddress());
 317                 checkAddress(application, httpRequest, boundip.get());
 318             }
 319
 320             // Track it as a valid token.
 321             tokens.push_back(decrypted);
 322
 323             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 324             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 325             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 326                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 327                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 328                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 329                     ssoStatement = *s;
 330             }
 331
 332             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 333             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 334                 ssoSubject = decrypted->getSubject();
 335         }
 336         catch (exception& ex) {
 337             m_log.warn("detected a problem with assertion: %s", ex.what());
 338             if (!ssoStatement)
 339                 contextualError = ex.what();
 340             badtokens.push_back(decrypted);
 341         }
 342     }
 343
 344     if (!ssoStatement) {
 345         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 346         if (contextualError.empty())
 347             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 348         throw FatalProfileException(contextualError.c_str());
 349     }
 350
 351     // May need to decrypt NameID.
 352     bool ownedName = false;
 353     NameID* ssoName = ssoSubject->getNameID();
 354     if (!ssoName) {
 355         EncryptedID* encname = ssoSubject->getEncryptedID();
 356         if (encname) {
 357             if (!cr)
 358                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 359             else {
 360                 Locker credlocker(cr);
 361                 auto_ptr<MetadataCredentialCriteria> mcc(
 362                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 363                     );
 364                 try {
 365                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getRelyingParty(entity)->getXMLString("entityID").second,mcc.get()));
 366                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 367                     if (ssoName) {
 368                         ownedName = true;
 369                         decryptedID.release();
 370                         if (m_log.isDebugEnabled())
 371                             m_log.debugStream() << "decrypted NameID: " << *ssoName << logging::eol;
 372                     }
 373                 }
 374                 catch (exception& ex) {
 375                     m_log.error(ex.what());
 376                 }
 377             }
 378         }
 379     }
 380
 381     m_log.debug("SSO profile processing completed successfully");
 382
 383     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 384     // To complete processing, we need to extract and resolve attributes and then create the session.
 385
 386     // Now we have to extract the authentication details for session setup.
 387
 388     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 389     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ?
 390         (ssoStatement->getSessionNotOnOrAfterEpoch() + XMLToolingConfig::getConfig().clock_skew_secs) : 0;
 391     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 392     if (!lifetime.first || lifetime.second == 0)
 393         lifetime.second = 28800;
 394     if (sessionExp == 0)
 395         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 396     else
 397         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 398
 399     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 400
 401     try {
 402         // The context will handle deleting attributes and new tokens.
 403         auto_ptr<ResolutionContext> ctx(
 404             resolveAttributes(
 405                 application,
 406                 policy.getIssuerMetadata(),
 407                 samlconstants::SAML20P_NS,
 408                 nullptr,
 409                 ssoName,
 410                 (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 411                 (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 412                 &tokens
 413                 )
 414             );
 415
 416         if (ctx.get()) {
 417             // Copy over any new tokens, but leave them in the context for cleanup.
 418             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 419         }
 420
 421         // Now merge in bad tokens for caching.
 422         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 423
 424         application.getServiceProvider().getSessionCache()->insert(
 425             application,
 426             httpRequest,
 427             httpResponse,
 428             sessionExp,
 429             entity,
 430             samlconstants::SAML20P_NS,
 431             ssoName,
 432             ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : nullptr,
 433             ssoStatement->getSessionIndex(),
 434             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 435             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 436             &tokens,
 437             ctx.get() ? &ctx->getResolvedAttributes() : nullptr
 438             );
 439
 440         if (ownedName)
 441             delete ssoName;
 442         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 443     }
 444     catch (exception&) {
 445         if (ownedName)
 446             delete ssoName;
 447         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 448         throw;
 449     }
 450 }
 451
 452 #endif