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 # ifndef min
  45 #  define min(a,b)            (((a) < (b)) ? (a) : (b))
  46 # endif
  47 #endif
  48
  49 using namespace shibsp;
  50 using namespace xmltooling;
  51 using namespace std;
  52
  53 namespace shibsp {
  54
  55 #if defined (_MSC_VER)
  56     #pragma warning( push )
  57     #pragma warning( disable : 4250 )
  58 #endif
  59
  60     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  61     {
  62     public:
  63         SAML2Consumer(const DOMElement* e, const char* appId)
  64             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SSO.SAML2")) {
  65         }
  66         virtual ~SAML2Consumer() {}
  67
  68     private:
  69 #ifndef SHIBSP_LITE
  70         string implementProtocol(
  71             const Application& application,
  72             const HTTPRequest& httpRequest,
  73             SecurityPolicy& policy,
  74             const PropertySet* settings,
  75             const XMLObject& xmlObject
  76             ) const;
  77 #endif
  78     };
  79
  80 #if defined (_MSC_VER)
  81     #pragma warning( pop )
  82 #endif
  83
  84     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
  85     {
  86         return new SAML2Consumer(p.first, p.second);
  87     }
  88
  89 };
  90
  91 #ifndef SHIBSP_LITE
  92
  93 string SAML2Consumer::implementProtocol(
  94     const Application& application,
  95     const HTTPRequest& httpRequest,
  96     SecurityPolicy& policy,
  97     const PropertySet* settings,
  98     const XMLObject& xmlObject
  99     ) const
 100 {
 101     // Implementation of SAML 2.0 SSO profile(s).
 102     m_log.debug("processing message against SAML 2.0 SSO profile");
 103
 104     // Remember whether we already established trust.
 105     // None of the SAML 2 bindings require security at the protocol layer.
 106     bool alreadySecured = policy.isSecure();
 107
 108     // Check for errors...this will throw if it's not a successful message.
 109     checkError(&xmlObject);
 110
 111     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 112     if (!response)
 113         throw FatalProfileException("Incoming message was not a samlp:Response.");
 114
 115     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 116     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 117     if (assertions.empty() && encassertions.empty())
 118         throw FatalProfileException("Incoming message contained no SAML assertions.");
 119
 120     // Maintain list of "legit" tokens to feed to SP subsystems.
 121     const Subject* ssoSubject=NULL;
 122     const AuthnStatement* ssoStatement=NULL;
 123     vector<const opensaml::Assertion*> tokens;
 124
 125     // Also track "bad" tokens that we'll cache but not use.
 126     // This is necessary because there may be valid tokens not aimed at us.
 127     vector<const opensaml::Assertion*> badtokens;
 128
 129     // And also track "owned" tokens that we decrypt here.
 130     vector<saml2::Assertion*> ownedtokens;
 131
 132     // Profile validator.
 133     time_t now = time(NULL);
 134     string dest = httpRequest.getRequestURL();
 135     BrowserSSOProfileValidator ssoValidator(application.getAudiences(), now, dest.substr(0,dest.find('?')).c_str());
 136
 137     // With this flag on, we ignore any unsigned assertions.
 138     pair<bool,bool> flag = settings->getBool("signedAssertions");
 139
 140     // Saves off IP-mismatch error message because it's potentially helpful for users.
 141     string addressMismatch;
 142
 143     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 144         // Skip unsigned assertion?
 145         if (!(*a)->getSignature() && flag.first && flag.second) {
 146             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 147             badtokens.push_back(*a);
 148             continue;
 149         }
 150
 151         try {
 152             // We clear the security flag, so we can tell whether the token was secured on its own.
 153             policy.setSecure(false);
 154
 155             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 156             // and signature verification, assuming the relevant rules are configured.
 157             policy.evaluate(*(*a));
 158
 159             // If no security is in place now, we kick it.
 160             if (!alreadySecured && !policy.isSecure()) {
 161                 m_log.warn("unable to establish security of assertion");
 162                 badtokens.push_back(*a);
 163                 continue;
 164             }
 165
 166             // Now do profile and core semantic validation to ensure we can use it for SSO.
 167             ssoValidator.validateAssertion(*(*a));
 168
 169             // Address checking.
 170             try {
 171                 if (ssoValidator.getAddress())
 172                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 173             }
 174             catch (exception& ex) {
 175                 // We save off the message if there's no SSO statement yet.
 176                 if (!ssoStatement)
 177                     addressMismatch = ex.what();
 178                 throw;
 179             }
 180
 181             // Track it as a valid token.
 182             tokens.push_back(*a);
 183
 184             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 185             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 186             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 187                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 188                     ssoStatement = *s;
 189             }
 190
 191             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 192             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 193                 ssoSubject = (*a)->getSubject();
 194         }
 195         catch (exception& ex) {
 196             m_log.warn("detected a problem with assertion: %s", ex.what());
 197             badtokens.push_back(*a);
 198         }
 199     }
 200
 201     // In case we need decryption...
 202     CredentialResolver* cr=application.getCredentialResolver();
 203     if (!cr && !encassertions.empty())
 204         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 205
 206     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 207         // Attempt to decrypt it.
 208         saml2::Assertion* decrypted=NULL;
 209         try {
 210             Locker credlocker(cr);
 211             auto_ptr<MetadataCredentialCriteria> mcc(
 212                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 213                 );
 214             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getXMLString("entityID").second, mcc.get()));
 215             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 216             if (decrypted) {
 217                 wrapper.release();
 218                 ownedtokens.push_back(decrypted);
 219             }
 220         }
 221         catch (exception& ex) {
 222             m_log.error(ex.what());
 223         }
 224         if (!decrypted)
 225             continue;
 226
 227         // Skip unsigned assertion?
 228         if (!decrypted->getSignature() && flag.first && flag.second) {
 229             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 230             badtokens.push_back(decrypted);
 231             continue;
 232         }
 233
 234         try {
 235             // We clear the security flag, so we can tell whether the token was secured on its own.
 236             policy.setSecure(false);
 237
 238             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 239             // and signature verification, assuming the relevant rules are configured.
 240             // We have to marshall the object first to ensure signatures can be checked.
 241             policy.evaluate(*decrypted);
 242
 243             // If no security is in place now, we kick it.
 244             if (!alreadySecured && !policy.isSecure()) {
 245                 m_log.warn("unable to establish security of assertion");
 246                 badtokens.push_back(decrypted);
 247                 continue;
 248             }
 249
 250             // Now do profile and core semantic validation to ensure we can use it for SSO.
 251             ssoValidator.validateAssertion(*decrypted);
 252
 253             // Address checking.
 254             try {
 255                 if (ssoValidator.getAddress())
 256                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 257             }
 258             catch (exception& ex) {
 259                 // We save off the message if there's no SSO statement yet.
 260                 if (!ssoStatement)
 261                     addressMismatch = ex.what();
 262                 throw;
 263             }
 264
 265             // Track it as a valid token.
 266             tokens.push_back(decrypted);
 267
 268             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 269             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 270             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 271                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 272                     ssoStatement = *s;
 273             }
 274
 275             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 276             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 277                 ssoSubject = decrypted->getSubject();
 278         }
 279         catch (exception& ex) {
 280             m_log.warn("detected a problem with assertion: %s", ex.what());
 281             badtokens.push_back(decrypted);
 282         }
 283     }
 284
 285     if (!ssoStatement) {
 286         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 287         if (addressMismatch.empty())
 288             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 289         throw FatalProfileException(addressMismatch.c_str());
 290     }
 291
 292     // May need to decrypt NameID.
 293     bool ownedName = false;
 294     NameID* ssoName = ssoSubject->getNameID();
 295     if (!ssoName) {
 296         EncryptedID* encname = ssoSubject->getEncryptedID();
 297         if (encname) {
 298             if (!cr)
 299                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 300             else {
 301                 Locker credlocker(cr);
 302                 auto_ptr<MetadataCredentialCriteria> mcc(
 303                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 304                     );
 305                 try {
 306                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getXMLString("entityID").second,mcc.get()));
 307                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 308                     if (ssoName) {
 309                         ownedName = true;
 310                         decryptedID.release();
 311                     }
 312                 }
 313                 catch (exception& ex) {
 314                     m_log.error(ex.what());
 315                 }
 316             }
 317         }
 318     }
 319
 320     m_log.debug("SSO profile processing completed successfully");
 321
 322     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 323     // To complete processing, we need to extract and resolve attributes and then create the session.
 324
 325     // Now we have to extract the authentication details for session setup.
 326
 327     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 328     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ? ssoStatement->getSessionNotOnOrAfterEpoch() : 0;
 329     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 330     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 331     if (!lifetime.first || lifetime.second == 0)
 332         lifetime.second = 28800;
 333     if (sessionExp == 0)
 334         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 335     else
 336         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 337
 338     vector<Attribute*> resolvedAttributes;
 339     AttributeExtractor* extractor = application.getAttributeExtractor();
 340     if (extractor) {
 341         m_log.debug("extracting pushed attributes...");
 342         Locker extlocker(extractor);
 343         try {
 344             extractor->extractAttributes(application, policy.getIssuerMetadata(), *ssoName, resolvedAttributes);
 345         }
 346         catch (exception& ex) {
 347             m_log.error("caught exception extracting attributes: %s", ex.what());
 348         }
 349         for (vector<const opensaml::Assertion*>::const_iterator t = tokens.begin(); t!=tokens.end(); ++t) {
 350             try {
 351                 extractor->extractAttributes(application, policy.getIssuerMetadata(), *(*t), resolvedAttributes);
 352             }
 353             catch (exception& ex) {
 354                 m_log.error("caught exception extracting attributes: %s", ex.what());
 355             }
 356         }
 357     }
 358
 359     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 360
 361     AttributeFilter* filter = application.getAttributeFilter();
 362     if (filter && !resolvedAttributes.empty()) {
 363         BasicFilteringContext fc(
 364             application,
 365             resolvedAttributes,
 366             policy.getIssuerMetadata(),
 367             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 368             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL
 369             );
 370         Locker filtlocker(filter);
 371         try {
 372             filter->filterAttributes(fc, resolvedAttributes);
 373         }
 374         catch (exception& ex) {
 375             m_log.error("caught exception filtering attributes: %s", ex.what());
 376             m_log.error("dumping extracted attributes due to filtering exception");
 377             for_each(resolvedAttributes.begin(), resolvedAttributes.end(), xmltooling::cleanup<shibsp::Attribute>());
 378             resolvedAttributes.clear();
 379         }
 380     }
 381
 382     try {
 383         const EntityDescriptor* issuerMetadata =
 384             policy.getIssuerMetadata() ? dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent()) : NULL;
 385         auto_ptr<ResolutionContext> ctx(
 386             resolveAttributes(
 387                 application,
 388                 issuerMetadata,
 389                 samlconstants::SAML20P_NS,
 390                 ssoName,
 391                 (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 392                 (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 393                 &tokens,
 394                 &resolvedAttributes
 395                 )
 396             );
 397
 398         if (ctx.get()) {
 399             // Copy over any new tokens, but leave them in the context for cleanup.
 400             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 401
 402             // Copy over new attributes, and transfer ownership.
 403             resolvedAttributes.insert(resolvedAttributes.end(), ctx->getResolvedAttributes().begin(), ctx->getResolvedAttributes().end());
 404             ctx->getResolvedAttributes().clear();
 405         }
 406
 407         // Now merge in bad tokens for caching.
 408         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 409
 410         string key = application.getServiceProvider().getSessionCache()->insert(
 411             sessionExp,
 412             application,
 413             httpRequest.getRemoteAddr().c_str(),
 414             issuerMetadata,
 415             samlconstants::SAML20P_NS,
 416             ssoName,
 417             ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : NULL,
 418             ssoStatement->getSessionIndex(),
 419             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 420             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 421             &tokens,
 422             &resolvedAttributes
 423             );
 424
 425         if (ownedName)
 426             delete ssoName;
 427         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 428         for_each(resolvedAttributes.begin(), resolvedAttributes.end(), xmltooling::cleanup<shibsp::Attribute>());
 429         return key;
 430     }
 431     catch (exception&) {
 432         if (ownedName)
 433             delete ssoName;
 434         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 435         for_each(resolvedAttributes.begin(), resolvedAttributes.end(), xmltooling::cleanup<shibsp::Attribute>());
 436         throw;
 437     }
 438 }
 439
 440 #endif