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