shibsp/attribute/resolver/impl/SimpleAggregationAttributeResolver.cpp

   1 /*
   2  *  Copyright 2009 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  * SimpleAggregationAttributeResolver.cpp
  19  *
  20  * AttributeResolver based on SAML queries to third-party AA sources.
  21  */
  22
  23 #include "internal.h"
  24 #include "exceptions.h"
  25 #include "Application.h"
  26 #include "ServiceProvider.h"
  27 #include "SessionCache.h"
  28 #include "attribute/NameIDAttribute.h"
  29 #include "attribute/filtering/AttributeFilter.h"
  30 #include "attribute/filtering/BasicFilteringContext.h"
  31 #include "attribute/resolver/AttributeExtractor.h"
  32 #include "attribute/resolver/AttributeResolver.h"
  33 #include "attribute/resolver/ResolutionContext.h"
  34 #include "binding/SOAPClient.h"
  35 #include "metadata/MetadataProviderCriteria.h"
  36 #include "security/SecurityPolicy.h"
  37 #include "util/SPConstants.h"
  38
  39 #include <saml/exceptions.h>
  40 #include <saml/SAMLConfig.h>
  41 #include <saml/saml2/binding/SAML2SOAPClient.h>
  42 #include <saml/saml2/core/Protocols.h>
  43 #include <saml/saml2/metadata/Metadata.h>
  44 #include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  45 #include <saml/saml2/metadata/MetadataProvider.h>
  46 #include <xmltooling/XMLToolingConfig.h>
  47 #include <xmltooling/security/TrustEngine.h>
  48 #include <xmltooling/util/NDC.h>
  49 #include <xmltooling/util/XMLHelper.h>
  50 #include <xercesc/util/XMLUniDefs.hpp>
  51
  52 using namespace shibsp;
  53 using namespace opensaml::saml2;
  54 using namespace opensaml::saml2p;
  55 using namespace opensaml::saml2md;
  56 using namespace opensaml;
  57 using namespace xmltooling;
  58 using namespace std;
  59
  60 namespace shibsp {
  61
  62     class SHIBSP_DLLLOCAL SimpleAggregationContext : public ResolutionContext
  63     {
  64     public:
  65         SimpleAggregationContext(const Application& application, const Session& session)
  66             : m_app(application),
  67               m_session(&session),
  68               m_nameid(NULL),
  69               m_class(XMLString::transcode(session.getAuthnContextClassRef())),
  70               m_decl(XMLString::transcode(session.getAuthnContextDeclRef())),
  71               m_inputTokens(NULL),
  72               m_inputAttributes(NULL) {
  73         }
  74
  75         SimpleAggregationContext(
  76             const Application& application,
  77             const NameID* nameid=NULL,
  78             const XMLCh* authncontext_class=NULL,
  79             const XMLCh* authncontext_decl=NULL,
  80             const vector<const opensaml::Assertion*>* tokens=NULL,
  81             const vector<shibsp::Attribute*>* attributes=NULL
  82             ) : m_app(application),
  83                 m_session(NULL),
  84                 m_nameid(nameid),
  85                 m_class(const_cast<XMLCh*>(authncontext_class)),
  86                 m_decl(const_cast<XMLCh*>(authncontext_decl)),
  87                 m_inputTokens(tokens),
  88                 m_inputAttributes(attributes) {
  89         }
  90
  91         ~SimpleAggregationContext() {
  92             for_each(m_attributes.begin(), m_attributes.end(), xmltooling::cleanup<shibsp::Attribute>());
  93             for_each(m_assertions.begin(), m_assertions.end(), xmltooling::cleanup<opensaml::Assertion>());
  94             if (m_session) {
  95                 XMLString::release(&m_class);
  96                 XMLString::release(&m_decl);
  97             }
  98         }
  99
 100         const Application& getApplication() const {
 101             return m_app;
 102         }
 103         const NameID* getNameID() const {
 104             return m_session ? m_session->getNameID() : m_nameid;
 105         }
 106         const XMLCh* getClassRef() const {
 107             return m_class;
 108         }
 109         const XMLCh* getDeclRef() const {
 110             return m_decl;
 111         }
 112         const Session* getSession() const {
 113             return m_session;
 114         }
 115         const vector<shibsp::Attribute*>* getInputAttributes() const {
 116             return m_inputAttributes;
 117         }
 118         const vector<const opensaml::Assertion*>* getInputTokens() const {
 119             return m_inputTokens;
 120         }
 121         vector<shibsp::Attribute*>& getResolvedAttributes() {
 122             return m_attributes;
 123         }
 124         vector<opensaml::Assertion*>& getResolvedAssertions() {
 125             return m_assertions;
 126         }
 127
 128     private:
 129         const Application& m_app;
 130         const Session* m_session;
 131         const NameID* m_nameid;
 132         XMLCh* m_class;
 133         XMLCh* m_decl;
 134         const vector<const opensaml::Assertion*>* m_inputTokens;
 135         const vector<shibsp::Attribute*>* m_inputAttributes;
 136         vector<shibsp::Attribute*> m_attributes;
 137         vector<opensaml::Assertion*> m_assertions;
 138     };
 139
 140     class SHIBSP_DLLLOCAL SimpleAggregationResolver : public AttributeResolver
 141     {
 142     public:
 143         SimpleAggregationResolver(const DOMElement* e);
 144         ~SimpleAggregationResolver() {
 145             delete m_trust;
 146             delete m_metadata;
 147             for_each(m_designators.begin(), m_designators.end(), xmltooling::cleanup<saml2::Attribute>());
 148         }
 149
 150         Lockable* lock() {return this;}
 151         void unlock() {}
 152
 153         ResolutionContext* createResolutionContext(
 154             const Application& application,
 155             const EntityDescriptor* issuer,
 156             const XMLCh* protocol,
 157             const NameID* nameid=NULL,
 158             const XMLCh* authncontext_class=NULL,
 159             const XMLCh* authncontext_decl=NULL,
 160             const vector<const opensaml::Assertion*>* tokens=NULL,
 161             const vector<shibsp::Attribute*>* attributes=NULL
 162             ) const {
 163             return new SimpleAggregationContext(application,nameid,authncontext_class,authncontext_decl,tokens,attributes);
 164         }
 165
 166         ResolutionContext* createResolutionContext(const Application& application, const Session& session) const {
 167             return new SimpleAggregationContext(application,session);
 168         }
 169
 170         void resolveAttributes(ResolutionContext& ctx) const;
 171
 172         void getAttributeIds(vector<string>& attributes) const {
 173             // Nothing to do, only the extractor would actually generate them.
 174         }
 175
 176     private:
 177         bool doQuery(SimpleAggregationContext& ctx, const char* entityID, const NameID* name) const;
 178
 179         Category& m_log;
 180         string m_policyId;
 181         vector<string> m_attributeIds;
 182         xstring m_format;
 183         MetadataProvider* m_metadata;
 184         TrustEngine* m_trust;
 185         vector<saml2::Attribute*> m_designators;
 186         vector< pair<string,bool> > m_sources;
 187     };
 188
 189     AttributeResolver* SHIBSP_DLLLOCAL SimpleAggregationResolverFactory(const DOMElement* const & e)
 190     {
 191         return new SimpleAggregationResolver(e);
 192     }
 193
 194     static const XMLCh attributeId[] =          UNICODE_LITERAL_11(a,t,t,r,i,b,u,t,e,I,d);
 195     static const XMLCh Entity[] =               UNICODE_LITERAL_6(E,n,t,i,t,y);
 196     static const XMLCh EntityReference[] =      UNICODE_LITERAL_15(E,n,t,i,t,y,R,e,f,e,r,e,n,c,e);
 197     static const XMLCh format[] =               UNICODE_LITERAL_6(f,o,r,m,a,t);
 198     static const XMLCh _MetadataProvider[] =    UNICODE_LITERAL_16(M,e,t,a,d,a,t,a,P,r,o,v,i,d,e,r);
 199     static const XMLCh policyId[] =             UNICODE_LITERAL_8(p,o,l,i,c,y,I,d);
 200     static const XMLCh _TrustEngine[] =         UNICODE_LITERAL_11(T,r,u,s,t,E,n,g,i,n,e);
 201     static const XMLCh _type[] =                UNICODE_LITERAL_4(t,y,p,e);
 202 };
 203
 204 SimpleAggregationResolver::SimpleAggregationResolver(const DOMElement* e)
 205     : m_log(Category::getInstance(SHIBSP_LOGCAT".AttributeResolver.SimpleAggregation")), m_metadata(NULL), m_trust(NULL)
 206 {
 207 #ifdef _DEBUG
 208     xmltooling::NDC ndc("SimpleAggregationResolver");
 209 #endif
 210
 211     const XMLCh* pid = e ? e->getAttributeNS(NULL, policyId) : NULL;
 212     if (pid && *pid) {
 213         auto_ptr_char temp(pid);
 214         m_policyId = temp.get();
 215     }
 216
 217     pid = e ? e->getAttributeNS(NULL, attributeId) : NULL;
 218     if (pid && *pid) {
 219         char* dup = XMLString::transcode(pid);
 220         char* pos;
 221         char* start = dup;
 222         while (start && *start) {
 223             while (*start && isspace(*start))
 224                 start++;
 225             if (!*start)
 226                 break;
 227             pos = strchr(start,' ');
 228             if (pos)
 229                 *pos=0;
 230             m_attributeIds.push_back(start);
 231             start = pos ? pos+1 : NULL;
 232         }
 233         XMLString::release(&dup);
 234
 235         pid = e->getAttributeNS(NULL, format);
 236         if (pid && *pid)
 237             m_format = pid;
 238
 239     }
 240
 241     DOMElement* child = XMLHelper::getFirstChildElement(e, _MetadataProvider);
 242     if (child) {
 243         auto_ptr_char type(child->getAttributeNS(NULL, _type));
 244         if (!type.get() || !*type.get())
 245             throw ConfigurationException("MetadataProvider element missing type attribute.");
 246         m_log.info("building MetadataProvider of type %s...", type.get());
 247         auto_ptr<MetadataProvider> mp(SAMLConfig::getConfig().MetadataProviderManager.newPlugin(type.get(), child));
 248         mp->init();
 249         m_metadata = mp.release();
 250     }
 251
 252     child = XMLHelper::getFirstChildElement(e,  _TrustEngine);
 253     if (child) {
 254         try {
 255             auto_ptr_char type(child->getAttributeNS(NULL, _type));
 256             if (!type.get() || !*type.get())
 257                 throw ConfigurationException("TrustEngine element missing type attribute.");
 258             m_log.info("building TrustEngine of type %s...", type.get());
 259             m_trust = XMLToolingConfig::getConfig().TrustEngineManager.newPlugin(type.get(), child);
 260         }
 261         catch (exception&) {
 262             delete m_metadata;
 263             throw;
 264         }
 265     }
 266
 267     child = XMLHelper::getFirstChildElement(e);
 268     while (child) {
 269         if (child->hasChildNodes() && XMLString::equals(child->getLocalName(), Entity)) {
 270             pid = child->getFirstChild()->getNodeValue();
 271             if (pid && *pid) {
 272                 auto_ptr_char tpid(pid);
 273                 m_sources.push_back(pair<string,bool>(tpid.get(),true));
 274             }
 275         }
 276         else if (child->hasChildNodes() && XMLString::equals(child->getLocalName(), EntityReference)) {
 277             pid = child->getFirstChild()->getNodeValue();
 278             if (pid && *pid) {
 279                 auto_ptr_char tpid(pid);
 280                 m_sources.push_back(pair<string,bool>(tpid.get(),false));
 281             }
 282         }
 283         else if (XMLHelper::isNodeNamed(child, samlconstants::SAML20_NS, saml2::Attribute::LOCAL_NAME)) {
 284             try {
 285                 auto_ptr<XMLObject> obj(saml2::AttributeBuilder::buildOneFromElement(child));
 286                 saml2::Attribute* down = dynamic_cast<saml2::Attribute*>(obj.get());
 287                 if (down) {
 288                     m_designators.push_back(down);
 289                     obj.release();
 290                 }
 291             }
 292             catch (exception& ex) {
 293                 m_log.error("exception loading attribute designator: %s", ex.what());
 294             }
 295         }
 296         child = XMLHelper::getNextSiblingElement(child);
 297     }
 298
 299 }
 300
 301 bool SimpleAggregationResolver::doQuery(SimpleAggregationContext& ctx, const char* entityID, const NameID* name) const
 302 {
 303 #ifdef _DEBUG
 304     xmltooling::NDC ndc("doQuery");
 305 #endif
 306     const Application& application = ctx.getApplication();
 307     MetadataProviderCriteria mc(application, entityID, &AttributeAuthorityDescriptor::ELEMENT_QNAME, samlconstants::SAML20P_NS);
 308     Locker mlocker(m_metadata);
 309     const AttributeAuthorityDescriptor* AA=NULL;
 310     pair<const EntityDescriptor*,const RoleDescriptor*> mdresult =
 311         (m_metadata ? m_metadata : application.getMetadataProvider())->getEntityDescriptor(mc);
 312     if (!mdresult.first) {
 313         m_log.warn("unable to locate metadata for provider (%s)", entityID);
 314         return false;
 315     }
 316     else if (!(AA=dynamic_cast<const AttributeAuthorityDescriptor*>(mdresult.second))) {
 317         m_log.warn("no SAML 2 AttributeAuthority role found in metadata for (%s)", entityID);
 318         return false;
 319     }
 320
 321     const PropertySet* relyingParty = application.getRelyingParty(mdresult.first);
 322
 323     // Locate policy key.
 324     const char* policyId = m_policyId.empty() ? application.getString("policyId").second : m_policyId.c_str();
 325
 326     // Access policy properties.
 327     const PropertySet* settings = application.getServiceProvider().getPolicySettings(policyId);
 328     pair<bool,bool> validate = settings->getBool("validate");
 329
 330     pair<bool,bool> signedAssertions = relyingParty->getBool("requireSignedAssertions");
 331     pair<bool,const char*> encryption = relyingParty->getString("encryption");
 332
 333     shibsp::SecurityPolicy policy(application, NULL, validate.first && validate.second, policyId);
 334     if (m_metadata)
 335         policy.setMetadataProvider(m_metadata);
 336     if (m_trust)
 337         policy.setTrustEngine(m_trust);
 338     policy.getAudiences().push_back(relyingParty->getXMLString("entityID").second);
 339
 340     MetadataCredentialCriteria mcc(*AA);
 341     shibsp::SOAPClient soaper(policy);
 342
 343     auto_ptr_XMLCh binding(samlconstants::SAML20_BINDING_SOAP);
 344     saml2p::StatusResponseType* srt=NULL;
 345     const vector<AttributeService*>& endpoints=AA->getAttributeServices();
 346     for (vector<AttributeService*>::const_iterator ep=endpoints.begin(); !srt && ep!=endpoints.end(); ++ep) {
 347         if (!XMLString::equals((*ep)->getBinding(),binding.get())  || !(*ep)->getLocation())
 348             continue;
 349         auto_ptr_char loc((*ep)->getLocation());
 350         try {
 351             auto_ptr<saml2::Subject> subject(saml2::SubjectBuilder::buildSubject());
 352
 353             // Encrypt the NameID?
 354             if (encryption.first && (!strcmp(encryption.second, "true") || !strcmp(encryption.second, "back"))) {
 355                 auto_ptr<EncryptedID> encrypted(EncryptedIDBuilder::buildEncryptedID());
 356                 MetadataCredentialCriteria mcc(*AA);
 357                 encrypted->encrypt(
 358                     *name,
 359                     *(policy.getMetadataProvider()),
 360                     mcc,
 361                     false,
 362                     relyingParty->getXMLString("encryptionAlg").second
 363                     );
 364                 subject->setEncryptedID(encrypted.release());
 365             }
 366             else {
 367                 subject->setNameID(name->cloneNameID());
 368             }
 369
 370             saml2p::AttributeQuery* query = saml2p::AttributeQueryBuilder::buildAttributeQuery();
 371             query->setSubject(subject.release());
 372             Issuer* iss = IssuerBuilder::buildIssuer();
 373             iss->setName(relyingParty->getXMLString("entityID").second);
 374             query->setIssuer(iss);
 375             for (vector<saml2::Attribute*>::const_iterator ad = m_designators.begin(); ad!=m_designators.end(); ++ad)
 376                 query->getAttributes().push_back((*ad)->cloneAttribute());
 377
 378             SAML2SOAPClient client(soaper, false);
 379             client.sendSAML(query, application.getId(), mcc, loc.get());
 380             srt = client.receiveSAML();
 381         }
 382         catch (exception& ex) {
 383             m_log.error("exception during SAML query to %s: %s", loc.get(), ex.what());
 384             soaper.reset();
 385         }
 386     }
 387
 388     if (!srt) {
 389         m_log.error("unable to obtain a SAML response from attribute authority (%s)", entityID);
 390         return false;
 391     }
 392     saml2p::Response* response = dynamic_cast<saml2p::Response*>(srt);
 393     if (!response) {
 394         delete srt;
 395         m_log.error("message was not a samlp:Response");
 396         return true;
 397     }
 398     else if (!response->getStatus() || !response->getStatus()->getStatusCode() ||
 399             !XMLString::equals(response->getStatus()->getStatusCode()->getValue(), saml2p::StatusCode::SUCCESS)) {
 400         delete srt;
 401         m_log.error("attribute authority (%s) returned a SAML error", entityID);
 402         return true;
 403     }
 404
 405     const vector<saml2::Assertion*>& assertions = const_cast<const saml2p::Response*>(response)->getAssertions();
 406     if (assertions.empty()) {
 407         delete srt;
 408         m_log.warn("response from attribute authority (%s) was empty", entityID);
 409         return true;
 410     }
 411     else if (assertions.size()>1)
 412         m_log.warn("resolver only supports one assertion in the query response");
 413
 414     auto_ptr<saml2p::StatusResponseType> wrapper(srt);
 415     saml2::Assertion* newtoken = assertions.front();
 416
 417     if (!newtoken->getSignature() && signedAssertions.first && signedAssertions.second) {
 418         m_log.error("assertion unsigned, rejecting it based on signedAssertions policy");
 419         return true;
 420     }
 421
 422     try {
 423         // We're going to insist that the assertion issuer is the same as the peer.
 424         // Reset the policy's message bits and extract them from the assertion.
 425         policy.reset(true);
 426         policy.setMessageID(newtoken->getID());
 427         policy.setIssueInstant(newtoken->getIssueInstantEpoch());
 428         policy.setIssuer(newtoken->getIssuer());
 429         policy.evaluate(*newtoken);
 430
 431         // Now we can check the security status of the policy.
 432         if (!policy.isAuthenticated())
 433             throw SecurityPolicyException("Security of SAML 2.0 query result not established.");
 434     }
 435     catch (exception& ex) {
 436         m_log.error("assertion failed policy validation: %s", ex.what());
 437         return true;
 438     }
 439
 440     newtoken->detach();
 441     wrapper.release();
 442     ctx.getResolvedAssertions().push_back(newtoken);
 443
 444     // Finally, extract and filter the result.
 445     try {
 446         AttributeExtractor* extractor = application.getAttributeExtractor();
 447         if (extractor) {
 448             Locker extlocker(extractor);
 449             extractor->extractAttributes(application, AA, *newtoken, ctx.getResolvedAttributes());
 450         }
 451
 452         AttributeFilter* filter = application.getAttributeFilter();
 453         if (filter) {
 454             BasicFilteringContext fc(application, ctx.getResolvedAttributes(), AA, ctx.getClassRef(), ctx.getDeclRef());
 455             Locker filtlocker(filter);
 456             filter->filterAttributes(fc, ctx.getResolvedAttributes());
 457         }
 458     }
 459     catch (exception& ex) {
 460         m_log.error("caught exception extracting/filtering attributes from query result: %s", ex.what());
 461         for_each(ctx.getResolvedAttributes().begin(), ctx.getResolvedAttributes().end(), xmltooling::cleanup<shibsp::Attribute>());
 462         ctx.getResolvedAttributes().clear();
 463     }
 464
 465     return true;
 466 }
 467
 468 void SimpleAggregationResolver::resolveAttributes(ResolutionContext& ctx) const
 469 {
 470 #ifdef _DEBUG
 471     xmltooling::NDC ndc("resolveAttributes");
 472 #endif
 473
 474     SimpleAggregationContext& qctx = dynamic_cast<SimpleAggregationContext&>(ctx);
 475
 476     // First we manufacture the appropriate NameID to use.
 477     NameID* n=NULL;
 478     for (vector<string>::const_iterator a = m_attributeIds.begin(); !n && a != m_attributeIds.end(); ++a) {
 479         const Attribute* attr=NULL;
 480         if (qctx.getSession()) {
 481             // Input attributes should be available via multimap.
 482             pair<multimap<string,const Attribute*>::const_iterator, multimap<string,const Attribute*>::const_iterator> range =
 483                 qctx.getSession()->getIndexedAttributes().equal_range(*a);
 484             for (; !attr && range.first != range.second; ++range.first) {
 485                 if (range.first->second->valueCount() > 0)
 486                     attr = range.first->second;
 487             }
 488         }
 489         else if (qctx.getInputAttributes()) {
 490             // Have to loop over unindexed set.
 491             const vector<Attribute*>* matches = qctx.getInputAttributes();
 492             for (vector<Attribute*>::const_iterator match = matches->begin(); !attr && match != matches->end(); ++match) {
 493                 if (*a == (*match)->getId() && (*match)->valueCount() > 0)
 494                     attr = *match;
 495             }
 496         }
 497
 498         if (attr) {
 499             m_log.debug("using input attribute (%s) as identifier for queries", attr->getId());
 500             n = NameIDBuilder::buildNameID();
 501             const NameIDAttribute* down = dynamic_cast<const NameIDAttribute*>(attr);
 502             if (down) {
 503                 // We can create a NameID directly from the source material.
 504                 const NameIDAttribute::Value& v = down->getValues().front();
 505                 XMLCh* val = fromUTF8(v.m_Name.c_str());
 506                 n->setName(val);
 507                 delete[] val;
 508                 if (!v.m_Format.empty()) {
 509                     val = fromUTF8(v.m_Format.c_str());
 510                     n->setFormat(val);
 511                     delete[] val;
 512                 }
 513                 if (!v.m_NameQualifier.empty()) {
 514                     val = fromUTF8(v.m_NameQualifier.c_str());
 515                     n->setNameQualifier(val);
 516                     delete[] val;
 517                 }
 518                 if (!v.m_SPNameQualifier.empty()) {
 519                     val = fromUTF8(v.m_SPNameQualifier.c_str());
 520                     n->setSPNameQualifier(val);
 521                     delete[] val;
 522                 }
 523                 if (!v.m_SPProvidedID.empty()) {
 524                     val = fromUTF8(v.m_SPProvidedID.c_str());
 525                     n->setSPProvidedID(val);
 526                     delete[] val;
 527                 }
 528             }
 529             else {
 530                 // We have to mock up the NameID.
 531                 XMLCh* val = fromUTF8(attr->getSerializedValues().front().c_str());
 532                 n->setName(val);
 533                 delete[] val;
 534                 if (!m_format.empty())
 535                     n->setFormat(m_format.c_str());
 536             }
 537         }
 538     }
 539
 540     if (!n) {
 541         if (qctx.getNameID() && m_attributeIds.empty()) {
 542             m_log.debug("using authenticated NameID as identifier for queries");
 543         }
 544         else {
 545             m_log.warn("unable to resolve attributes, no suitable query identifier found");
 546             return;
 547         }
 548     }
 549
 550     auto_ptr<NameID> wrapper(n);
 551
 552     set<string> history;
 553
 554     // We have a master loop over all the possible sources of material.
 555     for (vector< pair<string,bool> >::const_iterator source = m_sources.begin(); source != m_sources.end(); ++source) {
 556         if (source->second) {
 557             // A literal entityID to query.
 558             if (history.count(source->first) == 0) {
 559                 m_log.debug("issuing SAML query to (%s)", source->first.c_str());
 560                 doQuery(qctx, source->first.c_str(), n ? n : qctx.getNameID());
 561                 history.insert(source->first);
 562             }
 563             else {
 564                 m_log.debug("skipping previously queried attribute source (%s)", source->first.c_str());
 565             }
 566         }
 567         else {
 568             m_log.debug("using attribute sources referenced in attribute (%s)", source->first.c_str());
 569             if (qctx.getSession()) {
 570                 // Input attributes should be available via multimap.
 571                 pair<multimap<string,const Attribute*>::const_iterator, multimap<string,const Attribute*>::const_iterator> range =
 572                     qctx.getSession()->getIndexedAttributes().equal_range(source->first);
 573                 for (; range.first != range.second; ++range.first) {
 574                     const vector<string>& links = range.first->second->getSerializedValues();
 575                     for (vector<string>::const_iterator link = links.begin(); link != links.end(); ++link) {
 576                         if (history.count(*link) == 0) {
 577                             m_log.debug("issuing SAML query to (%s)", link->c_str());
 578                             doQuery(qctx, link->c_str(), n ? n : qctx.getNameID());
 579                             history.insert(*link);
 580                         }
 581                         else {
 582                             m_log.debug("skipping previously queried attribute source (%s)", link->c_str());
 583                         }
 584                     }
 585                 }
 586             }
 587             else if (qctx.getInputAttributes()) {
 588                 // Have to loop over unindexed set.
 589                 const vector<Attribute*>* matches = qctx.getInputAttributes();
 590                 for (vector<Attribute*>::const_iterator match = matches->begin(); match != matches->end(); ++match) {
 591                     if (source->first == (*match)->getId()) {
 592                         const vector<string>& links = (*match)->getSerializedValues();
 593                         for (vector<string>::const_iterator link = links.begin(); link != links.end(); ++link) {
 594                             if (history.count(*link) == 0) {
 595                                 m_log.debug("issuing SAML query to (%s)", link->c_str());
 596                                 doQuery(qctx, link->c_str(), n ? n : qctx.getNameID());
 597                                 history.insert(*link);
 598                             }
 599                             else {
 600                                 m_log.debug("skipping previously queried attribute source (%s)", link->c_str());
 601                             }
 602                         }
 603                     }
 604                 }
 605             }
 606         }
 607     }
 608 }