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
 188     // We look up decryption credentials based on the peer who did the encrypting.
 189     CredentialCriteria cc;
 190     if (policy.getIssuerMetadata()) {
 191         auto_ptr_char assertingParty(dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent())->getEntityID());
 192         cc.setPeerName(assertingParty.get());
 193     }
 194     CredentialResolver* cr=application.getCredentialResolver();
 195
 196     if (!cr && !encassertions.empty())
 197         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 198
 199     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 200         // Attempt to decrypt it.
 201         saml2::Assertion* decrypted=NULL;
 202         try {
 203             Locker credlocker(cr);
 204             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getXMLString("entityID").second, &cc));
 205             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 206             if (decrypted) {
 207                 wrapper.release();
 208                 ownedtokens.push_back(decrypted);
 209             }
 210         }
 211         catch (exception& ex) {
 212             m_log.error(ex.what());
 213         }
 214         if (!decrypted)
 215             continue;
 216
 217         // Skip unsigned assertion?
 218         if (!decrypted->getSignature() && flag.first && flag.second) {
 219             m_log.warn("found unsigned assertion in SAML response, ignoring it per signedAssertions policy");
 220             badtokens.push_back(decrypted);
 221             continue;
 222         }
 223
 224         try {
 225             // We clear the security flag, so we can tell whether the token was secured on its own.
 226             policy.setSecure(false);
 227
 228             // Run the policy over the assertion. Handles issuer consistency, replay, freshness,
 229             // and signature verification, assuming the relevant rules are configured.
 230             // We have to marshall the object first to ensure signatures can be checked.
 231             decrypted->marshall();
 232             policy.evaluate(*decrypted);
 233
 234             // If no security is in place now, we kick it.
 235             if (!alreadySecured && !policy.isSecure()) {
 236                 m_log.warn("unable to establish security of assertion");
 237                 badtokens.push_back(decrypted);
 238                 continue;
 239             }
 240
 241             // Now do profile and core semantic validation to ensure we can use it for SSO.
 242             ssoValidator.validateAssertion(*decrypted);
 243
 244             // Address checking.
 245             try {
 246                 if (ssoValidator.getAddress())
 247                     checkAddress(application, httpRequest, ssoValidator.getAddress());
 248             }
 249             catch (exception& ex) {
 250                 // We save off the message if there's no SSO statement yet.
 251                 if (!ssoStatement)
 252                     addressMismatch = ex.what();
 253                 throw;
 254             }
 255
 256             // Track it as a valid token.
 257             tokens.push_back(decrypted);
 258
 259             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 260             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 261             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 262                 if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 263                     ssoStatement = *s;
 264             }
 265
 266             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 267             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 268                 ssoSubject = decrypted->getSubject();
 269         }
 270         catch (exception& ex) {
 271             m_log.warn("detected a problem with assertion: %s", ex.what());
 272             badtokens.push_back(decrypted);
 273         }
 274     }
 275
 276     if (!ssoStatement) {
 277         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 278         if (addressMismatch.empty())
 279             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 280         throw FatalProfileException(addressMismatch.c_str());
 281     }
 282
 283     // May need to decrypt NameID.
 284     bool ownedName = false;
 285     NameID* ssoName = ssoSubject->getNameID();
 286     if (!ssoName) {
 287         EncryptedID* encname = ssoSubject->getEncryptedID();
 288         if (encname) {
 289             if (!cr)
 290                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 291             else {
 292                 Locker credlocker(cr);
 293                 try {
 294                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getXMLString("entityID").second,&cc));
 295                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 296                     if (ssoName) {
 297                         ownedName = true;
 298                         decryptedID.release();
 299                     }
 300                 }
 301                 catch (exception& ex) {
 302                     m_log.error(ex.what());
 303                 }
 304             }
 305         }
 306     }
 307
 308     m_log.debug("SSO profile processing completed successfully");
 309
 310     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 311     // To complete processing, we need to resolve attributes and then create the session.
 312
 313     try {
 314         const EntityDescriptor* issuerMetadata = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 315         auto_ptr<ResolutionContext> ctx(
 316             resolveAttributes(application, httpRequest, issuerMetadata, ssoName, &tokens)
 317             );
 318
 319         // Copy over any new tokens, but leave them in the context for cleanup.
 320         tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 321
 322         // Now merge in bad tokens for caching.
 323         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 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") : make_pair(true,28800);
 331         if (!lifetime.first)
 332             lifetime.second = 28800;
 333         if (lifetime.second != 0) {
 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
 340         // Other details...
 341         const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 342         auto_ptr_char authnClass((authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : NULL);
 343         auto_ptr_char authnDecl((authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : NULL);
 344         auto_ptr_char index(ssoStatement->getSessionIndex());
 345         auto_ptr_char authnInstant(ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : NULL);
 346
 347         vector<shibsp::Attribute*>& attrs = ctx->getResolvedAttributes();
 348         string key = application.getServiceProvider().getSessionCache()->insert(
 349             sessionExp,
 350             application,
 351             httpRequest.getRemoteAddr().c_str(),
 352             issuerMetadata,
 353             ssoName,
 354             authnInstant.get(),
 355             index.get(),
 356             authnClass.get(),
 357             authnDecl.get(),
 358             &tokens,
 359             &attrs
 360             );
 361         attrs.clear();  // Attributes are owned by cache now.
 362
 363         if (ownedName)
 364             delete ssoName;
 365         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 366
 367         return key;
 368     }
 369     catch (exception&) {
 370         if (ownedName)
 371             delete ssoName;
 372         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 373         throw;
 374     }
 375 }