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/resolver/ResolutionContext.h"
  29 #include "handler/AssertionConsumerService.h"
  30
  31 #include <saml/saml2/core/Protocols.h>
  32 #include <saml/saml2/profile/BrowserSSOProfileValidator.h>
  33 #include <saml/saml2/metadata/Metadata.h>
  34
  35 using namespace shibsp;
  36 using namespace opensaml::saml2;
  37 using namespace opensaml::saml2p;
  38 using namespace opensaml;
  39 using namespace xmltooling;
  40 using namespace log4cpp;
  41 using namespace std;
  42 using saml2md::EntityDescriptor;
  43
  44 namespace shibsp {
  45
  46 #if defined (_MSC_VER)
  47     #pragma warning( push )
  48     #pragma warning( disable : 4250 )
  49 #endif
  50
  51     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  52     {
  53     public:
  54         SAML2Consumer(const DOMElement* e, const char* appId)
  55                 : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SAML2")) {
  56         }
  57         virtual ~SAML2Consumer() {}
  58
  59     private:
  60         string implementProtocol(
  61             const Application& application,
  62             const HTTPRequest& httpRequest,
  63             SecurityPolicy& policy,
  64             const PropertySet* settings,
  65             const XMLObject& xmlObject
  66             ) const;
  67     };
  68
  69 #if defined (_MSC_VER)
  70     #pragma warning( pop )
  71 #endif
  72
  73     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
  74     {
  75         return new SAML2Consumer(p.first, p.second);
  76     }
  77
  78 };
  79
  80 string SAML2Consumer::implementProtocol(
  81     const Application& application,
  82     const HTTPRequest& httpRequest,
  83     SecurityPolicy& policy,
  84     const PropertySet* settings,
  85     const XMLObject& xmlObject
  86     ) const
  87 {
  88     // Implementation of SAML 2.0 SSO profile(s).
  89     m_log.debug("processing message against SAML 2.0 SSO profile");
  90
  91     // Remember whether we already established trust.
  92     // None of the SAML 2 bindings require security at the protocol layer.
  93     bool alreadySecured = policy.isSecure();
  94
  95     // Check for errors...this will throw if it's not a successful message.
  96     checkError(&xmlObject);
  97
  98     const Response* response = dynamic_cast<const Response*>(&xmlObject);
  99     if (!response)
 100         throw FatalProfileException("Incoming message was not a samlp:Response.");
 101
 102     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 103     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 104     if (assertions.empty() && encassertions.empty())
 105         throw FatalProfileException("Incoming message contained no SAML assertions.");
 106
 107     // Maintain list of "legit" tokens to feed to SP subsystems.
 108     const Subject* ssoSubject=NULL;
 109     const AuthnStatement* ssoStatement=NULL;
 110     vector<const opensaml::Assertion*> tokens;
 111
 112     // Also track "bad" tokens that we'll cache but not use.
 113     // This is necessary because there may be valid tokens not aimed at us.
 114     vector<const opensaml::Assertion*> badtokens;
 115
 116     // And also track "owned" tokens that we decrypt here.
 117     vector<saml2::Assertion*> ownedtokens;
 118
 119     // Profile validator.
 120     time_t now = time(NULL);
 121     string dest = httpRequest.getRequestURL();
 122     BrowserSSOProfileValidator ssoValidator(application.getAudiences(), now, dest.substr(0,dest.find('?')).c_str());
 123
 124     // With this flag on, we ignore any unsigned assertions.
 125     pair<bool,bool> flag = settings->getBool("signedAssertions");
 126
 127     // Saves off IP-mismatch error message because it's potentially helpful for users.
 128     string addressMismatch;
 129
 130     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 131         // Skip unsigned assertion?
 132         if (!(*a)->getSignature() && flag.first && flag.second) {
 133             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 134             badtokens.push_back(*a);
 135             continue;
 136         }
 137
 138         try {
 139             // We clear the security flag, so we can tell whether the token was secured on its own.
 140             policy.setSecure(false);
 141
 142             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 143             // and signature verification, assuming the relevant rules are configured.
 144             policy.evaluate(*(*a));
 145
 146             // If no security is in place now, we kick it.
 147             if (!alreadySecured && !policy.isSecure()) {
 148                 m_log.warn("unable to establish security of assertion");
 149                 badtokens.push_back(*a);
 150                 continue;
 151             }
 152
 153             // Now do profile and core semantic validation to ensure we can use it for SSO.
 154             ssoValidator.validateAssertion(*(*a));
 155
 156             // Address checking.
 157             try {
 158                 if (ssoValidator.getAddress())
 159                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 160             }
 161             catch (exception& ex) {
 162                 // We save off the message if there's no SSO statement yet.
 163                 if (!ssoStatement)
 164                     addressMismatch = ex.what();
 165                 throw;
 166             }
 167
 168             // Track it as a valid token.
 169             tokens.push_back(*a);
 170
 171             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 172             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 173             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 174                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 175                     ssoStatement = *s;
 176             }
 177
 178             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 179             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 180                 ssoSubject = (*a)->getSubject();
 181         }
 182         catch (exception& ex) {
 183             m_log.warn("detected a problem with assertion: %s", ex.what());
 184             badtokens.push_back(*a);
 185         }
 186     }
 187 \r
 188     CredentialResolver* cr=NULL;\r
 189     const PropertySet* credUse = application.getCredentialUse(\r
 190         policy.getIssuerMetadata() ? dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent()) : NULL\r
 191         );\r
 192     if (credUse)\r
 193         cr = application.getServiceProvider().getCredentialResolver(credUse->getString("Encryption").second);
 194     if (!cr && !encassertions.empty())
 195         m_log.warn("found encrypted assertions, but no decryption credential was available");
 196
 197     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 198         // Attempt to decrypt it.
 199         saml2::Assertion* decrypted=NULL;
 200         try {
 201             Locker credlocker(cr);
 202             auto_ptr<XMLObject> wrapper((*ea)->decrypt(cr, application.getXMLString("providerId").second));
 203             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 204             if (decrypted) {
 205                 wrapper.release();
 206                 ownedtokens.push_back(decrypted);
 207             }
 208         }
 209         catch (exception& ex) {
 210             m_log.error(ex.what());
 211         }
 212         if (!decrypted)
 213             continue;
 214
 215         // Skip unsigned assertion?
 216         if (!decrypted->getSignature() && flag.first && flag.second) {
 217             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 218             badtokens.push_back(decrypted);
 219             continue;
 220         }
 221
 222         try {
 223             // We clear the security flag, so we can tell whether the token was secured on its own.
 224             policy.setSecure(false);
 225
 226             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 227             // and signature verification, assuming the relevant rules are configured.
 228             // We have to marshall the object first to ensure signatures can be checked.
 229             decrypted->marshall();
 230             policy.evaluate(*decrypted);
 231
 232             // If no security is in place now, we kick it.
 233             if (!alreadySecured && !policy.isSecure()) {
 234                 m_log.warn("unable to establish security of assertion");
 235                 badtokens.push_back(decrypted);
 236                 continue;
 237             }
 238
 239             // Now do profile and core semantic validation to ensure we can use it for SSO.
 240             ssoValidator.validateAssertion(*decrypted);
 241
 242             // Address checking.
 243             try {
 244                 if (ssoValidator.getAddress())
 245                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 246             }
 247             catch (exception& ex) {
 248                 // We save off the message if there's no SSO statement yet.
 249                 if (!ssoStatement)
 250                     addressMismatch = ex.what();
 251                 throw;
 252             }
 253
 254             // Track it as a valid token.
 255             tokens.push_back(decrypted);
 256
 257             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 258             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 259             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 260                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 261                     ssoStatement = *s;
 262             }
 263
 264             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 265             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 266                 ssoSubject = decrypted->getSubject();
 267         }
 268         catch (exception& ex) {
 269             m_log.warn("detected a problem with assertion: %s", ex.what());
 270             badtokens.push_back(decrypted);
 271         }
 272     }
 273
 274     if (!ssoStatement) {
 275         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 276         if (addressMismatch.empty())
 277             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 278         throw FatalProfileException(addressMismatch.c_str());
 279     }
 280
 281     // May need to decrypt NameID.
 282     bool ownedName = false;
 283     NameID* ssoName = ssoSubject->getNameID();
 284     if (!ssoName) {
 285         EncryptedID* encname = ssoSubject->getEncryptedID();
 286         if (encname) {
 287             if (!cr)
 288                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 289             else {
 290                 Locker credlocker(cr);
 291                 try {
 292                     auto_ptr<XMLObject> decryptedID(encname->decrypt(cr,application.getXMLString("providerId").second));
 293                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 294                     if (ssoName) {
 295                         ownedName = true;
 296                         decryptedID.release();
 297                     }
 298                 }
 299                 catch (exception& ex) {
 300                     m_log.error(ex.what());
 301                 }
 302             }
 303         }
 304     }
 305
 306     m_log.debug("SSO profile processing completed successfully");
 307
 308     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 309     // To complete processing, we need to resolve attributes and then create the session.
 310
 311     try {
 312         const EntityDescriptor* issuerMetadata = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 313         auto_ptr<ResolutionContext> ctx(
 314             resolveAttributes(application, httpRequest, issuerMetadata, ssoName, &tokens)
 315             );
 316
 317         // Copy over any new tokens, but leave them in the context for cleanup.
 318         tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 319
 320         // Now merge in bad tokens for caching.
 321         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 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         vector<shibsp::Attribute*>& attrs = ctx->getResolvedAttributes();
 346         string key = application.getServiceProvider().getSessionCache()->insert(
 347             sessionExp,
 348             application,
 349             httpRequest.getRemoteAddr().c_str(),
 350             issuerMetadata,
 351             ssoName,
 352             authnInstant.get(),
 353             index.get(),
 354             authnClass.get(),
 355             authnDecl.get(),
 356             &tokens,
 357             &attrs
 358             );
 359         attrs.clear();  // Attributes are owned by cache now.
 360
 361         if (ownedName)
 362             delete ssoName;
 363         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 364
 365         return key;
 366     }
 367     catch (exception&) {
 368         if (ownedName)
 369             delete ssoName;
 370         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 371         throw;
 372     }
 373 }