shibsp/handler/impl/SAML2Consumer.cpp

   1 /*
   2  *  Copyright 2001-2009 Internet2
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /**
  18  * SAML2Consumer.cpp
  19  *
  20  * SAML 2.0 assertion consumer service
  21  */
  22
  23 #include "internal.h"
  24 #include "handler/AssertionConsumerService.h"
  25
  26 #ifndef SHIBSP_LITE
  27 # include "exceptions.h"
  28 # include "Application.h"
  29 # include "ServiceProvider.h"
  30 # include "SessionCache.h"
  31 # include "attribute/resolver/ResolutionContext.h"
  32 # include <saml/SAMLConfig.h>
  33 # include <saml/saml2/core/Protocols.h>
  34 # include <saml/saml2/metadata/Metadata.h>
  35 # include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  36 # include <saml/saml2/profile/SAML2AssertionPolicy.h>
  37 using namespace opensaml::saml2;
  38 using namespace opensaml::saml2p;
  39 using namespace opensaml::saml2md;
  40 using namespace opensaml;
  41 # ifndef min
  42 #  define min(a,b)            (((a) < (b)) ? (a) : (b))
  43 # endif
  44 #endif
  45
  46 using namespace shibsp;
  47 using namespace xmltooling;
  48 using namespace std;
  49
  50 namespace shibsp {
  51
  52 #if defined (_MSC_VER)
  53     #pragma warning( push )
  54     #pragma warning( disable : 4250 )
  55 #endif
  56
  57     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  58     {
  59     public:
  60         SAML2Consumer(const DOMElement* e, const char* appId)
  61             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SSO.SAML2")) {
  62 #ifndef SHIBSP_LITE
  63             m_ssoRule = NULL;
  64             if (SPConfig::getConfig().isEnabled(SPConfig::OutOfProcess))
  65                 m_ssoRule = SAMLConfig::getConfig().SecurityPolicyRuleManager.newPlugin(BEARER_POLICY_RULE, e);
  66 #endif
  67         }
  68         virtual ~SAML2Consumer() {
  69 #ifndef SHIBSP_LITE
  70             delete m_ssoRule;
  71 #endif
  72         }
  73
  74 #ifndef SHIBSP_LITE
  75         void generateMetadata(SPSSODescriptor& role, const char* handlerURL) const {
  76             AssertionConsumerService::generateMetadata(role, handlerURL);
  77             role.addSupport(samlconstants::SAML20P_NS);
  78         }
  79
  80     private:
  81         void implementProtocol(
  82             const Application& application,
  83             const HTTPRequest& httpRequest,
  84             HTTPResponse& httpResponse,
  85             SecurityPolicy& policy,
  86             const PropertySet* settings,
  87             const XMLObject& xmlObject
  88             ) const;
  89
  90         SecurityPolicyRule* m_ssoRule;
  91 #endif
  92     };
  93
  94 #if defined (_MSC_VER)
  95     #pragma warning( pop )
  96 #endif
  97
  98     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
  99     {
 100         return new SAML2Consumer(p.first, p.second);
 101     }
 102
 103 #ifndef SHIBSP_LITE
 104     class SHIBSP_DLLLOCAL _rulenamed : std::unary_function<const SecurityPolicyRule*,bool>
 105     {
 106     public:
 107         _rulenamed(const char* name) : m_name(name) {}
 108         bool operator()(const SecurityPolicyRule* rule) const {
 109             return rule ? !strcmp(m_name, rule->getType()) : false;
 110         }
 111     private:
 112         const char* m_name;
 113     };
 114 #endif
 115 };
 116
 117 #ifndef SHIBSP_LITE
 118
 119 void SAML2Consumer::implementProtocol(
 120     const Application& application,
 121     const HTTPRequest& httpRequest,
 122     HTTPResponse& httpResponse,
 123     SecurityPolicy& policy,
 124     const PropertySet* settings,
 125     const XMLObject& xmlObject
 126     ) const
 127 {
 128     // Implementation of SAML 2.0 SSO profile(s).
 129     m_log.debug("processing message against SAML 2.0 SSO profile");
 130
 131     // Remember whether we already established trust.
 132     // None of the SAML 2 bindings require security at the protocol layer.
 133     bool alreadySecured = policy.isAuthenticated();
 134
 135     // Check for errors...this will throw if it's not a successful message.
 136     checkError(&xmlObject, policy.getIssuerMetadata());
 137
 138     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 139     if (!response)
 140         throw FatalProfileException("Incoming message was not a samlp:Response.");
 141
 142     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 143     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 144     if (assertions.empty() && encassertions.empty())
 145         throw FatalProfileException("Incoming message contained no SAML assertions.");
 146
 147     // Maintain list of "legit" tokens to feed to SP subsystems.
 148     const Subject* ssoSubject=NULL;
 149     const AuthnStatement* ssoStatement=NULL;
 150     vector<const opensaml::Assertion*> tokens;
 151
 152     // Also track "bad" tokens that we'll cache but not use.
 153     // This is necessary because there may be valid tokens not aimed at us.
 154     vector<const opensaml::Assertion*> badtokens;
 155
 156     // And also track "owned" tokens that we decrypt here.
 157     vector<saml2::Assertion*> ownedtokens;
 158
 159     // With this flag on, we ignore any unsigned assertions.
 160     const EntityDescriptor* entity = NULL;
 161     pair<bool,bool> flag = make_pair(false,false);
 162     if (alreadySecured && policy.getIssuerMetadata()) {
 163         entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 164         flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 165     }
 166
 167     // authnskew allows rejection of SSO if AuthnInstant is too old.
 168     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 169     pair<bool,unsigned int> authnskew = sessionProps ? sessionProps->getUnsignedInt("maxTimeSinceAuthn") : pair<bool,unsigned int>(false,0);
 170
 171     // Saves off error messages potentially helpful for users.
 172     string contextualError;
 173
 174     // Ensure the Bearer rule is in the policy set.
 175     if (find_if(policy.getRules(), _rulenamed(BEARER_POLICY_RULE)) == NULL)
 176         policy.getRules().push_back(m_ssoRule);
 177
 178     // Populate recipient as audience.
 179     policy.getAudiences().push_back(application.getRelyingParty(entity)->getXMLString("entityID").second);
 180
 181     time_t now = time(NULL);
 182     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 183         try {
 184             // Skip unsigned assertion?
 185             if (!(*a)->getSignature() && flag.first && flag.second)
 186                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 187
 188             // We clear the security flag, so we can tell whether the token was secured on its own.
 189             policy.setAuthenticated(false);
 190             policy.reset(true);
 191
 192             // Extract message bits and re-verify Issuer information.
 193             extractMessageDetails(*(*a), samlconstants::SAML20P_NS, policy);
 194
 195             // Run the policy over the assertion. Handles replay, freshness, and
 196             // signature verification, assuming the relevant rules are configured,
 197             // along with condition and profile enforcement.
 198             policy.evaluate(*(*a));
 199
 200             // If no security is in place now, we kick it.
 201             if (!alreadySecured && !policy.isAuthenticated())
 202                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 203
 204             // If we hadn't established Issuer yet, redo the signedAssertions check.
 205             if (!entity && policy.getIssuerMetadata()) {
 206                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 207                 flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 208                 if (!(*a)->getSignature() && flag.first && flag.second)
 209                     throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 210             }
 211
 212             // Address checking.
 213             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 214                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 215                 );
 216             if (subcondata && subcondata->getAddress()) {
 217                 auto_ptr_char boundip(subcondata->getAddress());
 218                 checkAddress(application, httpRequest, boundip.get());
 219             }
 220
 221             // Track it as a valid token.
 222             tokens.push_back(*a);
 223
 224             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 225             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 226             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 227                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 228                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 229                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 230                     ssoStatement = *s;
 231             }
 232
 233             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 234             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 235                 ssoSubject = (*a)->getSubject();
 236         }
 237         catch (exception& ex) {
 238             m_log.warn("detected a problem with assertion: %s", ex.what());
 239             if (!ssoStatement)
 240                 contextualError = ex.what();
 241             badtokens.push_back(*a);
 242         }
 243     }
 244
 245     // In case we need decryption...
 246     CredentialResolver* cr=application.getCredentialResolver();
 247     if (!cr && !encassertions.empty())
 248         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 249
 250     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 251         // Attempt to decrypt it.
 252         saml2::Assertion* decrypted=NULL;
 253         try {
 254             Locker credlocker(cr);
 255             auto_ptr<MetadataCredentialCriteria> mcc(
 256                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 257                 );
 258             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getRelyingParty(entity)->getXMLString("entityID").second, mcc.get()));
 259             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 260             if (decrypted) {
 261                 wrapper.release();
 262                 ownedtokens.push_back(decrypted);
 263                 if (m_log.isDebugEnabled())
 264                     m_log.debugStream() << "decrypted Assertion: " << *decrypted << logging::eol;
 265             }
 266         }
 267         catch (exception& ex) {
 268             m_log.error(ex.what());
 269         }
 270         if (!decrypted)
 271             continue;
 272
 273         try {
 274             // We clear the security flag, so we can tell whether the token was secured on its own.
 275             policy.setAuthenticated(false);
 276             policy.reset(true);
 277
 278             // Extract message bits and re-verify Issuer information.
 279             extractMessageDetails(*decrypted, samlconstants::SAML20P_NS, policy);
 280
 281             // Run the policy over the assertion. Handles replay, freshness, and
 282             // signature verification, assuming the relevant rules are configured,
 283             // along with condition and profile enforcement.
 284             // We have to marshall the object first to ensure signatures can be checked.
 285             if (!decrypted->getDOM())
 286                 decrypted->marshall();
 287             policy.evaluate(*decrypted);
 288
 289             // If no security is in place now, we kick it.
 290             if (!alreadySecured && !policy.isAuthenticated())
 291                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 292
 293             // If we hadn't established Issuer yet, redo the signedAssertions check.
 294             if (!entity && policy.getIssuerMetadata()) {
 295                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 296                 flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 297                 if (!decrypted->getSignature() && flag.first && flag.second)
 298                     throw SecurityPolicyException("The decrypted assertion was unsigned, violating local security policy.");
 299             }
 300
 301             // Address checking.
 302             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 303                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 304                 );
 305             if (subcondata && subcondata->getAddress()) {
 306                 auto_ptr_char boundip(subcondata->getAddress());
 307                 checkAddress(application, httpRequest, boundip.get());
 308             }
 309
 310             // Track it as a valid token.
 311             tokens.push_back(decrypted);
 312
 313             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 314             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 315             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 316                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 317                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 318                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 319                     ssoStatement = *s;
 320             }
 321
 322             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 323             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 324                 ssoSubject = decrypted->getSubject();
 325         }
 326         catch (exception& ex) {
 327             m_log.warn("detected a problem with assertion: %s", ex.what());
 328             if (!ssoStatement)
 329                 contextualError = ex.what();
 330             badtokens.push_back(decrypted);
 331         }
 332     }
 333
 334     if (!ssoStatement) {
 335         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 336         if (contextualError.empty())
 337             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 338         throw FatalProfileException(contextualError.c_str());
 339     }
 340
 341     // May need to decrypt NameID.
 342     bool ownedName = false;
 343     NameID* ssoName = ssoSubject->getNameID();
 344     if (!ssoName) {
 345         EncryptedID* encname = ssoSubject->getEncryptedID();
 346         if (encname) {
 347             if (!cr)
 348                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 349             else {
 350                 Locker credlocker(cr);
 351                 auto_ptr<MetadataCredentialCriteria> mcc(
 352                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 353                     );
 354                 try {
 355                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getRelyingParty(entity)->getXMLString("entityID").second,mcc.get()));
 356                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 357                     if (ssoName) {
 358                         ownedName = true;
 359                         decryptedID.release();
 360                         if (m_log.isDebugEnabled())
 361                             m_log.debugStream() << "decrypted NameID: " << *ssoName << logging::eol;
 362                     }
 363                 }
 364                 catch (exception& ex) {
 365                     m_log.error(ex.what());
 366                 }
 367             }
 368         }
 369     }
 370
 371     m_log.debug("SSO profile processing completed successfully");
 372
 373     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 374     // To complete processing, we need to extract and resolve attributes and then create the session.
 375
 376     // Now we have to extract the authentication details for session setup.
 377
 378     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 379     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ?
 380         (ssoStatement->getSessionNotOnOrAfterEpoch() + XMLToolingConfig::getConfig().clock_skew_secs) : 0;
 381     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 382     if (!lifetime.first || lifetime.second == 0)
 383         lifetime.second = 28800;
 384     if (sessionExp == 0)
 385         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 386     else
 387         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 388
 389     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 390
 391     try {
 392         // The context will handle deleting attributes and new tokens.
 393         auto_ptr<ResolutionContext> ctx(
 394             resolveAttributes(
 395                 application,
 396                 policy.getIssuerMetadata(),
 397                 samlconstants::SAML20P_NS,
 398                 NULL,
 399                 ssoName,
 400                 (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 401                 (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 402                 &tokens
 403                 )
 404             );
 405
 406         if (ctx.get()) {
 407             // Copy over any new tokens, but leave them in the context for cleanup.
 408             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 409         }
 410
 411         // Now merge in bad tokens for caching.
 412         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 413
 414         application.getServiceProvider().getSessionCache()->insert(
 415             application,
 416             httpRequest,
 417             httpResponse,
 418             sessionExp,
 419             entity,
 420             samlconstants::SAML20P_NS,
 421             ssoName,
 422             ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : NULL,
 423             ssoStatement->getSessionIndex(),
 424             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 425             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 426             &tokens,
 427             ctx.get() ? &ctx->getResolvedAttributes() : NULL
 428             );
 429
 430         if (ownedName)
 431             delete ssoName;
 432         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 433     }
 434     catch (exception&) {
 435         if (ownedName)
 436             delete ssoName;
 437         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 438         throw;
 439     }
 440 }
 441
 442 #endif