shibsp/handler/impl/SAML2Consumer.cpp

   1 /*
   2  *  Copyright 2001-2007 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/Attribute.h"
  32 # include "attribute/filtering/AttributeFilter.h"
  33 # include "attribute/filtering/BasicFilteringContext.h"
  34 # include "attribute/resolver/AttributeExtractor.h"
  35 # include "attribute/resolver/ResolutionContext.h"
  36 # include <saml/saml2/core/Protocols.h>
  37 # include <saml/saml2/profile/BrowserSSOProfileValidator.h>
  38 # include <saml/saml2/metadata/Metadata.h>
  39 # include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  40 using namespace opensaml::saml2;
  41 using namespace opensaml::saml2p;
  42 using namespace opensaml::saml2md;
  43 using namespace opensaml;
  44 #endif
  45
  46 using namespace shibsp;
  47 using namespace xmltooling;
  48 using namespace log4cpp;
  49 using namespace std;
  50
  51 namespace shibsp {
  52
  53 #if defined (_MSC_VER)
  54     #pragma warning( push )
  55     #pragma warning( disable : 4250 )
  56 #endif
  57
  58     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  59     {
  60     public:
  61         SAML2Consumer(const DOMElement* e, const char* appId)
  62             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SAML2")) {
  63         }
  64         virtual ~SAML2Consumer() {}
  65
  66     private:
  67 #ifndef SHIBSP_LITE
  68         string implementProtocol(
  69             const Application& application,
  70             const HTTPRequest& httpRequest,
  71             SecurityPolicy& policy,
  72             const PropertySet* settings,
  73             const XMLObject& xmlObject
  74             ) const;
  75 #endif
  76     };
  77
  78 #if defined (_MSC_VER)
  79     #pragma warning( pop )
  80 #endif
  81
  82     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
  83     {
  84         return new SAML2Consumer(p.first, p.second);
  85     }
  86
  87 };
  88
  89 #ifndef SHIBSP_LITE
  90
  91 string SAML2Consumer::implementProtocol(
  92     const Application& application,
  93     const HTTPRequest& httpRequest,
  94     SecurityPolicy& policy,
  95     const PropertySet* settings,
  96     const XMLObject& xmlObject
  97     ) const
  98 {
  99     // Implementation of SAML 2.0 SSO profile(s).
 100     m_log.debug("processing message against SAML 2.0 SSO profile");
 101
 102     // Remember whether we already established trust.
 103     // None of the SAML 2 bindings require security at the protocol layer.
 104     bool alreadySecured = policy.isSecure();
 105
 106     // Check for errors...this will throw if it's not a successful message.
 107     checkError(&xmlObject);
 108
 109     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 110     if (!response)
 111         throw FatalProfileException("Incoming message was not a samlp:Response.");
 112
 113     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 114     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 115     if (assertions.empty() && encassertions.empty())
 116         throw FatalProfileException("Incoming message contained no SAML assertions.");
 117
 118     // Maintain list of "legit" tokens to feed to SP subsystems.
 119     const Subject* ssoSubject=NULL;
 120     const AuthnStatement* ssoStatement=NULL;
 121     vector<const opensaml::Assertion*> tokens;
 122
 123     // Also track "bad" tokens that we'll cache but not use.
 124     // This is necessary because there may be valid tokens not aimed at us.
 125     vector<const opensaml::Assertion*> badtokens;
 126
 127     // And also track "owned" tokens that we decrypt here.
 128     vector<saml2::Assertion*> ownedtokens;
 129
 130     // Profile validator.
 131     time_t now = time(NULL);
 132     string dest = httpRequest.getRequestURL();
 133     BrowserSSOProfileValidator ssoValidator(application.getAudiences(), now, dest.substr(0,dest.find('?')).c_str());
 134
 135     // With this flag on, we ignore any unsigned assertions.
 136     pair<bool,bool> flag = settings->getBool("signedAssertions");
 137
 138     // Saves off IP-mismatch error message because it's potentially helpful for users.
 139     string addressMismatch;
 140
 141     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 142         // Skip unsigned assertion?
 143         if (!(*a)->getSignature() && flag.first && flag.second) {
 144             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 145             badtokens.push_back(*a);
 146             continue;
 147         }
 148
 149         try {
 150             // We clear the security flag, so we can tell whether the token was secured on its own.
 151             policy.setSecure(false);
 152
 153             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 154             // and signature verification, assuming the relevant rules are configured.
 155             policy.evaluate(*(*a));
 156
 157             // If no security is in place now, we kick it.
 158             if (!alreadySecured && !policy.isSecure()) {
 159                 m_log.warn("unable to establish security of assertion");
 160                 badtokens.push_back(*a);
 161                 continue;
 162             }
 163
 164             // Now do profile and core semantic validation to ensure we can use it for SSO.
 165             ssoValidator.validateAssertion(*(*a));
 166
 167             // Address checking.
 168             try {
 169                 if (ssoValidator.getAddress())
 170                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 171             }
 172             catch (exception& ex) {
 173                 // We save off the message if there's no SSO statement yet.
 174                 if (!ssoStatement)
 175                     addressMismatch = ex.what();
 176                 throw;
 177             }
 178
 179             // Track it as a valid token.
 180             tokens.push_back(*a);
 181
 182             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 183             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 184             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 185                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 186                     ssoStatement = *s;
 187             }
 188
 189             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 190             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 191                 ssoSubject = (*a)->getSubject();
 192         }
 193         catch (exception& ex) {
 194             m_log.warn("detected a problem with assertion: %s", ex.what());
 195             badtokens.push_back(*a);
 196         }
 197     }
 198
 199     // In case we need decryption...
 200     CredentialResolver* cr=application.getCredentialResolver();
 201     if (!cr && !encassertions.empty())
 202         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 203
 204     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 205         // Attempt to decrypt it.
 206         saml2::Assertion* decrypted=NULL;
 207         try {
 208             Locker credlocker(cr);
 209             auto_ptr<MetadataCredentialCriteria> mcc(
 210                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 211                 );
 212             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getXMLString("entityID").second, mcc.get()));
 213             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 214             if (decrypted) {
 215                 wrapper.release();
 216                 ownedtokens.push_back(decrypted);
 217             }
 218         }
 219         catch (exception& ex) {
 220             m_log.error(ex.what());
 221         }
 222         if (!decrypted)
 223             continue;
 224
 225         // Skip unsigned assertion?
 226         if (!decrypted->getSignature() && flag.first && flag.second) {
 227             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 228             badtokens.push_back(decrypted);
 229             continue;
 230         }
 231
 232         try {
 233             // We clear the security flag, so we can tell whether the token was secured on its own.
 234             policy.setSecure(false);
 235
 236             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 237             // and signature verification, assuming the relevant rules are configured.
 238             // We have to marshall the object first to ensure signatures can be checked.
 239             policy.evaluate(*decrypted);
 240
 241             // If no security is in place now, we kick it.
 242             if (!alreadySecured && !policy.isSecure()) {
 243                 m_log.warn("unable to establish security of assertion");
 244                 badtokens.push_back(decrypted);
 245                 continue;
 246             }
 247
 248             // Now do profile and core semantic validation to ensure we can use it for SSO.
 249             ssoValidator.validateAssertion(*decrypted);
 250
 251             // Address checking.
 252             try {
 253                 if (ssoValidator.getAddress())
 254                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 255             }
 256             catch (exception& ex) {
 257                 // We save off the message if there's no SSO statement yet.
 258                 if (!ssoStatement)
 259                     addressMismatch = ex.what();
 260                 throw;
 261             }
 262
 263             // Track it as a valid token.
 264             tokens.push_back(decrypted);
 265
 266             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 267             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 268             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 269                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 270                     ssoStatement = *s;
 271             }
 272
 273             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 274             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 275                 ssoSubject = decrypted->getSubject();
 276         }
 277         catch (exception& ex) {
 278             m_log.warn("detected a problem with assertion: %s", ex.what());
 279             badtokens.push_back(decrypted);
 280         }
 281     }
 282
 283     if (!ssoStatement) {
 284         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 285         if (addressMismatch.empty())
 286             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 287         throw FatalProfileException(addressMismatch.c_str());
 288     }
 289
 290     // May need to decrypt NameID.
 291     bool ownedName = false;
 292     NameID* ssoName = ssoSubject->getNameID();
 293     if (!ssoName) {
 294         EncryptedID* encname = ssoSubject->getEncryptedID();
 295         if (encname) {
 296             if (!cr)
 297                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 298             else {
 299                 Locker credlocker(cr);
 300                 auto_ptr<MetadataCredentialCriteria> mcc(
 301                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 302                     );
 303                 try {
 304                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getXMLString("entityID").second,mcc.get()));
 305                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 306                     if (ssoName) {
 307                         ownedName = true;
 308                         decryptedID.release();
 309                     }
 310                 }
 311                 catch (exception& ex) {
 312                     m_log.error(ex.what());
 313                 }
 314             }
 315         }
 316     }
 317
 318     m_log.debug("SSO profile processing completed successfully");
 319
 320     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 321     // To complete processing, we need to extract and resolve attributes and then create the session.
 322
 323     // Now we have to extract the authentication details for session setup.
 324
 325     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 326     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ? ssoStatement->getSessionNotOnOrAfterEpoch() : 0;
 327     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 328     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : make_pair(true,28800);
 329     if (!lifetime.first)
 330         lifetime.second = 28800;
 331     if (lifetime.second != 0) {
 332         if (sessionExp == 0)
 333             sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 334         else
 335             sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 336     }
 337
 338     // Other details...
 339     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 340     auto_ptr_char authnClass((authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL);
 341     auto_ptr_char authnDecl((authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL);
 342     auto_ptr_char index(ssoStatement->getSessionIndex());
 343     auto_ptr_char authnInstant(ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : NULL);
 344
 345     multimap<string,Attribute*> resolvedAttributes;
 346     AttributeExtractor* extractor = application.getAttributeExtractor();
 347     if (extractor) {
 348         m_log.debug("extracting pushed attributes...");
 349         Locker extlocker(extractor);
 350         try {
 351             extractor->extractAttributes(application, policy.getIssuerMetadata(), *ssoName, resolvedAttributes);
 352         }
 353         catch (exception& ex) {
 354             m_log.error("caught exception extracting attributes: %s", ex.what());
 355         }
 356         for (vector<const opensaml::Assertion*>::const_iterator t = tokens.begin(); t!=tokens.end(); ++t) {
 357             try {
 358                 extractor->extractAttributes(application, policy.getIssuerMetadata(), *(*t), resolvedAttributes);
 359             }
 360             catch (exception& ex) {
 361                 m_log.error("caught exception extracting attributes: %s", ex.what());
 362             }
 363         }
 364     }
 365
 366     AttributeFilter* filter = application.getAttributeFilter();
 367     if (filter && !resolvedAttributes.empty()) {
 368         BasicFilteringContext fc(application, resolvedAttributes, policy.getIssuerMetadata(), authnClass.get(), authnDecl.get());
 369         Locker filtlocker(filter);
 370         try {
 371             filter->filterAttributes(fc, resolvedAttributes);
 372         }
 373         catch (exception& ex) {
 374             m_log.error("caught exception filtering attributes: %s", ex.what());
 375             m_log.error("dumping extracted attributes due to filtering exception");
 376             for_each(resolvedAttributes.begin(), resolvedAttributes.end(), cleanup_pair<string,shibsp::Attribute>());
 377             resolvedAttributes.clear();
 378         }
 379     }
 380
 381     try {
 382         const EntityDescriptor* issuerMetadata =
 383             policy.getIssuerMetadata() ? dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent()) : NULL;
 384         auto_ptr<ResolutionContext> ctx(
 385             resolveAttributes(application, issuerMetadata, ssoName, authnClass.get(), authnDecl.get(), &tokens, &resolvedAttributes)
 386             );
 387
 388         if (ctx.get()) {
 389             // Copy over any new tokens, but leave them in the context for cleanup.
 390             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 391
 392             // Copy over new attributes, and transfer ownership.
 393             resolvedAttributes.insert(ctx->getResolvedAttributes().begin(), ctx->getResolvedAttributes().end());
 394             ctx->getResolvedAttributes().clear();
 395         }
 396
 397         // Now merge in bad tokens for caching.
 398         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 399
 400         string key = application.getServiceProvider().getSessionCache()->insert(
 401             sessionExp,
 402             application,
 403             httpRequest.getRemoteAddr().c_str(),
 404             issuerMetadata,
 405             ssoName,
 406             authnInstant.get(),
 407             index.get(),
 408             authnClass.get(),
 409             authnDecl.get(),
 410             &tokens,
 411             &resolvedAttributes
 412             );
 413         resolvedAttributes.clear();  // Attributes are owned by cache now.
 414
 415         if (ownedName)
 416             delete ssoName;
 417         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 418
 419         return key;
 420     }
 421     catch (exception&) {
 422         if (ownedName)
 423             delete ssoName;
 424         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 425         for_each(resolvedAttributes.begin(), resolvedAttributes.end(), cleanup_pair<string,Attribute>());
 426         throw;
 427     }
 428 }
 429
 430 #endif