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 log4cpp;
  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".SAML2SSO")) {
  66         }
  67         virtual ~SAML2Consumer() {}
  68
  69     private:
  70 #ifndef SHIBSP_LITE
  71         string implementProtocol(
  72             const Application& application,
  73             const HTTPRequest& httpRequest,
  74             SecurityPolicy& policy,
  75             const PropertySet* settings,
  76             const XMLObject& xmlObject
  77             ) const;
  78 #endif
  79     };
  80
  81 #if defined (_MSC_VER)
  82     #pragma warning( pop )
  83 #endif
  84
  85     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
  86     {
  87         return new SAML2Consumer(p.first, p.second);
  88     }
  89
  90 };
  91
  92 #ifndef SHIBSP_LITE
  93
  94 string SAML2Consumer::implementProtocol(
  95     const Application& application,
  96     const HTTPRequest& httpRequest,
  97     SecurityPolicy& policy,
  98     const PropertySet* settings,
  99     const XMLObject& xmlObject
 100     ) const
 101 {
 102     // Implementation of SAML 2.0 SSO profile(s).
 103     m_log.debug("processing message against SAML 2.0 SSO profile");
 104
 105     // Remember whether we already established trust.
 106     // None of the SAML 2 bindings require security at the protocol layer.
 107     bool alreadySecured = policy.isSecure();
 108
 109     // Check for errors...this will throw if it's not a successful message.
 110     checkError(&xmlObject);
 111
 112     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 113     if (!response)
 114         throw FatalProfileException("Incoming message was not a samlp:Response.");
 115
 116     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 117     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 118     if (assertions.empty() && encassertions.empty())
 119         throw FatalProfileException("Incoming message contained no SAML assertions.");
 120
 121     // Maintain list of "legit" tokens to feed to SP subsystems.
 122     const Subject* ssoSubject=NULL;
 123     const AuthnStatement* ssoStatement=NULL;
 124     vector<const opensaml::Assertion*> tokens;
 125
 126     // Also track "bad" tokens that we'll cache but not use.
 127     // This is necessary because there may be valid tokens not aimed at us.
 128     vector<const opensaml::Assertion*> badtokens;
 129
 130     // And also track "owned" tokens that we decrypt here.
 131     vector<saml2::Assertion*> ownedtokens;
 132
 133     // Profile validator.
 134     time_t now = time(NULL);
 135     string dest = httpRequest.getRequestURL();
 136     BrowserSSOProfileValidator ssoValidator(application.getAudiences(), now, dest.substr(0,dest.find('?')).c_str());
 137
 138     // With this flag on, we ignore any unsigned assertions.
 139     pair<bool,bool> flag = settings->getBool("signedAssertions");
 140
 141     // Saves off IP-mismatch error message because it's potentially helpful for users.
 142     string addressMismatch;
 143
 144     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 145         // Skip unsigned assertion?
 146         if (!(*a)->getSignature() && flag.first && flag.second) {
 147             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 148             badtokens.push_back(*a);
 149             continue;
 150         }
 151
 152         try {
 153             // We clear the security flag, so we can tell whether the token was secured on its own.
 154             policy.setSecure(false);
 155
 156             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 157             // and signature verification, assuming the relevant rules are configured.
 158             policy.evaluate(*(*a));
 159
 160             // If no security is in place now, we kick it.
 161             if (!alreadySecured && !policy.isSecure()) {
 162                 m_log.warn("unable to establish security of assertion");
 163                 badtokens.push_back(*a);
 164                 continue;
 165             }
 166
 167             // Now do profile and core semantic validation to ensure we can use it for SSO.
 168             ssoValidator.validateAssertion(*(*a));
 169
 170             // Address checking.
 171             try {
 172                 if (ssoValidator.getAddress())
 173                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 174             }
 175             catch (exception& ex) {
 176                 // We save off the message if there's no SSO statement yet.
 177                 if (!ssoStatement)
 178                     addressMismatch = ex.what();
 179                 throw;
 180             }
 181
 182             // Track it as a valid token.
 183             tokens.push_back(*a);
 184
 185             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 186             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 187             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 188                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 189                     ssoStatement = *s;
 190             }
 191
 192             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 193             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 194                 ssoSubject = (*a)->getSubject();
 195         }
 196         catch (exception& ex) {
 197             m_log.warn("detected a problem with assertion: %s", ex.what());
 198             badtokens.push_back(*a);
 199         }
 200     }
 201
 202     // In case we need decryption...
 203     CredentialResolver* cr=application.getCredentialResolver();
 204     if (!cr && !encassertions.empty())
 205         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 206
 207     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 208         // Attempt to decrypt it.
 209         saml2::Assertion* decrypted=NULL;
 210         try {
 211             Locker credlocker(cr);
 212             auto_ptr<MetadataCredentialCriteria> mcc(
 213                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 214                 );
 215             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getXMLString("entityID").second, mcc.get()));
 216             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 217             if (decrypted) {
 218                 wrapper.release();
 219                 ownedtokens.push_back(decrypted);
 220             }
 221         }
 222         catch (exception& ex) {
 223             m_log.error(ex.what());
 224         }
 225         if (!decrypted)
 226             continue;
 227
 228         // Skip unsigned assertion?
 229         if (!decrypted->getSignature() && flag.first && flag.second) {
 230             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 231             badtokens.push_back(decrypted);
 232             continue;
 233         }
 234
 235         try {
 236             // We clear the security flag, so we can tell whether the token was secured on its own.
 237             policy.setSecure(false);
 238
 239             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 240             // and signature verification, assuming the relevant rules are configured.
 241             // We have to marshall the object first to ensure signatures can be checked.
 242             policy.evaluate(*decrypted);
 243
 244             // If no security is in place now, we kick it.
 245             if (!alreadySecured && !policy.isSecure()) {
 246                 m_log.warn("unable to establish security of assertion");
 247                 badtokens.push_back(decrypted);
 248                 continue;
 249             }
 250
 251             // Now do profile and core semantic validation to ensure we can use it for SSO.
 252             ssoValidator.validateAssertion(*decrypted);
 253
 254             // Address checking.
 255             try {
 256                 if (ssoValidator.getAddress())
 257                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 258             }
 259             catch (exception& ex) {
 260                 // We save off the message if there's no SSO statement yet.
 261                 if (!ssoStatement)
 262                     addressMismatch = ex.what();
 263                 throw;
 264             }
 265
 266             // Track it as a valid token.
 267             tokens.push_back(decrypted);
 268
 269             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 270             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 271             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 272                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 273                     ssoStatement = *s;
 274             }
 275
 276             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 277             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 278                 ssoSubject = decrypted->getSubject();
 279         }
 280         catch (exception& ex) {
 281             m_log.warn("detected a problem with assertion: %s", ex.what());
 282             badtokens.push_back(decrypted);
 283         }
 284     }
 285
 286     if (!ssoStatement) {
 287         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 288         if (addressMismatch.empty())
 289             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 290         throw FatalProfileException(addressMismatch.c_str());
 291     }
 292
 293     // May need to decrypt NameID.
 294     bool ownedName = false;
 295     NameID* ssoName = ssoSubject->getNameID();
 296     if (!ssoName) {
 297         EncryptedID* encname = ssoSubject->getEncryptedID();
 298         if (encname) {
 299             if (!cr)
 300                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 301             else {
 302                 Locker credlocker(cr);
 303                 auto_ptr<MetadataCredentialCriteria> mcc(
 304                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : NULL
 305                     );
 306                 try {
 307                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getXMLString("entityID").second,mcc.get()));
 308                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 309                     if (ssoName) {
 310                         ownedName = true;
 311                         decryptedID.release();
 312                     }
 313                 }
 314                 catch (exception& ex) {
 315                     m_log.error(ex.what());
 316                 }
 317             }
 318         }
 319     }
 320
 321     m_log.debug("SSO profile processing completed successfully");
 322
 323     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 324     // To complete processing, we need to extract and resolve attributes and then create the session.
 325
 326     // Now we have to extract the authentication details for session setup.
 327
 328     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 329     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ? ssoStatement->getSessionNotOnOrAfterEpoch() : 0;
 330     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 331     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 332     if (!lifetime.first || lifetime.second == 0)
 333         lifetime.second = 28800;
 334     if (sessionExp == 0)
 335         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 336     else
 337         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 338
 339     multimap<string,Attribute*> resolvedAttributes;
 340     AttributeExtractor* extractor = application.getAttributeExtractor();
 341     if (extractor) {
 342         m_log.debug("extracting pushed attributes...");
 343         Locker extlocker(extractor);
 344         try {
 345             extractor->extractAttributes(application, policy.getIssuerMetadata(), *ssoName, resolvedAttributes);
 346         }
 347         catch (exception& ex) {
 348             m_log.error("caught exception extracting attributes: %s", ex.what());
 349         }
 350         for (vector<const opensaml::Assertion*>::const_iterator t = tokens.begin(); t!=tokens.end(); ++t) {
 351             try {
 352                 extractor->extractAttributes(application, policy.getIssuerMetadata(), *(*t), resolvedAttributes);
 353             }
 354             catch (exception& ex) {
 355                 m_log.error("caught exception extracting attributes: %s", ex.what());
 356             }
 357         }
 358     }
 359
 360     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 361
 362     AttributeFilter* filter = application.getAttributeFilter();
 363     if (filter && !resolvedAttributes.empty()) {
 364         BasicFilteringContext fc(
 365             application,
 366             resolvedAttributes,
 367             policy.getIssuerMetadata(),
 368             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 369             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL
 370             );
 371         Locker filtlocker(filter);
 372         try {
 373             filter->filterAttributes(fc, resolvedAttributes);
 374         }
 375         catch (exception& ex) {
 376             m_log.error("caught exception filtering attributes: %s", ex.what());
 377             m_log.error("dumping extracted attributes due to filtering exception");
 378             for_each(resolvedAttributes.begin(), resolvedAttributes.end(), cleanup_pair<string,shibsp::Attribute>());
 379             resolvedAttributes.clear();
 380         }
 381     }
 382
 383     try {
 384         const EntityDescriptor* issuerMetadata =
 385             policy.getIssuerMetadata() ? dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent()) : NULL;
 386         auto_ptr<ResolutionContext> ctx(
 387             resolveAttributes(
 388                 application,
 389                 issuerMetadata,
 390                 samlconstants::SAML20P_NS,
 391                 ssoName,
 392                 (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 393                 (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 394                 &tokens,
 395                 &resolvedAttributes
 396                 )
 397             );
 398
 399         if (ctx.get()) {
 400             // Copy over any new tokens, but leave them in the context for cleanup.
 401             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 402
 403             // Copy over new attributes, and transfer ownership.
 404             resolvedAttributes.insert(ctx->getResolvedAttributes().begin(), ctx->getResolvedAttributes().end());
 405             ctx->getResolvedAttributes().clear();
 406         }
 407
 408         // Now merge in bad tokens for caching.
 409         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 410
 411         string key = application.getServiceProvider().getSessionCache()->insert(
 412             sessionExp,
 413             application,
 414             httpRequest.getRemoteAddr().c_str(),
 415             issuerMetadata,
 416             samlconstants::SAML20P_NS,
 417             ssoName,
 418             ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : NULL,
 419             ssoStatement->getSessionIndex(),
 420             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL,
 421             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL,
 422             &tokens,
 423             &resolvedAttributes
 424             );
 425         resolvedAttributes.clear();  // Attributes are owned by cache now.
 426
 427         if (ownedName)
 428             delete ssoName;
 429         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 430         for_each(resolvedAttributes.begin(), resolvedAttributes.end(), cleanup_pair<string,Attribute>());
 431         return key;
 432     }
 433     catch (exception&) {
 434         if (ownedName)
 435             delete ssoName;
 436         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 437         for_each(resolvedAttributes.begin(), resolvedAttributes.end(), cleanup_pair<string,Attribute>());
 438         throw;
 439     }
 440 }
 441
 442 #endif