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