shibsp/security/PKIXTrustEngine.cpp

   1 /*
   2  *  Copyright 2001-2009 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  * PKIXTrustEngine.cpp
  19  *
  20  * Shibboleth-specific PKIX-validation TrustEngine
  21  */
  22
  23 #include "internal.h"
  24 #include "metadata/MetadataExt.h"
  25 #include "security/PKIXTrustEngine.h"
  26
  27 #include <saml/saml2/metadata/Metadata.h>
  28 #include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  29 #include <saml/saml2/metadata/ObservableMetadataProvider.h>
  30 #include <xmltooling/XMLToolingConfig.h>
  31 #include <xmltooling/security/AbstractPKIXTrustEngine.h>
  32 #include <xmltooling/security/KeyInfoResolver.h>
  33 #include <xmltooling/security/X509Credential.h>
  34
  35 using namespace shibsp;
  36 using namespace opensaml::saml2md;
  37 using namespace xmlsignature;
  38 using namespace xmltooling;
  39 using namespace std;
  40
  41 namespace shibsp {
  42
  43     class SHIBSP_DLLLOCAL PKIXTrustEngine : public AbstractPKIXTrustEngine, public ObservableMetadataProvider::Observer
  44     {
  45     public:
  46         PKIXTrustEngine(const DOMElement* e=NULL) : AbstractPKIXTrustEngine(e), m_credLock(RWLock::create()) {
  47         }
  48         virtual ~PKIXTrustEngine() {
  49             for (map<const ObservableMetadataProvider*,credmap_t>::iterator i=m_credentialMap.begin(); i!=m_credentialMap.end(); ++i) {
  50                 i->first->removeObserver(this);
  51                 for (credmap_t::iterator creds = i->second.begin(); creds!=i->second.end(); ++creds)
  52                     for_each(creds->second.begin(), creds->second.end(), xmltooling::cleanup<X509Credential>());
  53             }
  54             delete m_credLock;
  55         }
  56
  57         AbstractPKIXTrustEngine::PKIXValidationInfoIterator* getPKIXValidationInfoIterator(
  58             const CredentialResolver& pkixSource, CredentialCriteria* criteria=NULL
  59             ) const;
  60
  61         void onEvent(const ObservableMetadataProvider& metadata) const {
  62             // Destroy credentials we cached from this provider.
  63             m_credLock->wrlock();
  64             credmap_t& cmap = m_credentialMap[&metadata];
  65             for (credmap_t::iterator creds = cmap.begin(); creds!=cmap.end(); ++creds)
  66                 for_each(creds->second.begin(), creds->second.end(), xmltooling::cleanup<X509Credential>());
  67             cmap.clear();
  68             m_credLock->unlock();
  69         }
  70
  71         const KeyInfoResolver* getKeyInfoResolver() const {
  72             return m_keyInfoResolver ? m_keyInfoResolver : XMLToolingConfig::getConfig().getKeyInfoResolver();
  73         }
  74
  75     private:
  76         friend class SHIBSP_DLLLOCAL MetadataPKIXIterator;
  77         mutable RWLock* m_credLock;
  78         typedef map< const KeyAuthority*,vector<X509Credential*> > credmap_t;
  79         mutable map<const ObservableMetadataProvider*,credmap_t> m_credentialMap;
  80     };
  81
  82     SHIBSP_DLLLOCAL PluginManager<TrustEngine,string,const DOMElement*>::Factory PKIXTrustEngineFactory;
  83
  84     TrustEngine* SHIBSP_DLLLOCAL PKIXTrustEngineFactory(const DOMElement* const & e)
  85     {
  86         return new PKIXTrustEngine(e);
  87     }
  88
  89     class SHIBSP_DLLLOCAL MetadataPKIXIterator : public AbstractPKIXTrustEngine::PKIXValidationInfoIterator
  90     {
  91     public:
  92         MetadataPKIXIterator(const PKIXTrustEngine& engine, const MetadataProvider& pkixSource, MetadataCredentialCriteria& criteria);
  93
  94         virtual ~MetadataPKIXIterator() {
  95             if (m_caching)
  96                 m_engine.m_credLock->unlock();
  97             for_each(m_ownedCreds.begin(), m_ownedCreds.end(), xmltooling::cleanup<Credential>());
  98         }
  99
 100         bool next();
 101
 102         int getVerificationDepth() const {
 103             pair<bool,int> vd = m_current->getVerifyDepth();
 104             return vd.first ? vd.second : 1;
 105         }
 106
 107         const vector<XSECCryptoX509*>& getTrustAnchors() const {
 108             return m_certs;
 109         }
 110
 111         const vector<XSECCryptoX509CRL*>& getCRLs() const {
 112             return m_crls;
 113         }
 114
 115     private:
 116         void populate();
 117         bool m_caching;
 118         const PKIXTrustEngine& m_engine;
 119         map<const ObservableMetadataProvider*,PKIXTrustEngine::credmap_t>::iterator m_credCache;
 120         const XMLObject* m_obj;
 121         const Extensions* m_extBlock;
 122         const KeyAuthority* m_current;
 123         vector<XMLObject*>::const_iterator m_iter;
 124         vector<XSECCryptoX509*> m_certs;
 125         vector<XSECCryptoX509CRL*> m_crls;
 126         vector<X509Credential*> m_ownedCreds;
 127     };
 128 };
 129
 130 void shibsp::registerPKIXTrustEngine()
 131 {
 132     XMLToolingConfig::getConfig().TrustEngineManager.registerFactory(SHIBBOLETH_PKIX_TRUSTENGINE, PKIXTrustEngineFactory);
 133 }
 134
 135 AbstractPKIXTrustEngine::PKIXValidationInfoIterator* PKIXTrustEngine::getPKIXValidationInfoIterator(
 136     const CredentialResolver& pkixSource, CredentialCriteria* criteria
 137     ) const
 138 {
 139     // Make sure these are metadata objects.
 140     const MetadataProvider& metadata = dynamic_cast<const MetadataProvider&>(pkixSource);
 141     MetadataCredentialCriteria* metacrit = dynamic_cast<MetadataCredentialCriteria*>(criteria);
 142     if (!metacrit)
 143         throw MetadataException("Cannot obtain PKIX information without a MetadataCredentialCriteria object.");
 144
 145     return new MetadataPKIXIterator(*this, metadata,*metacrit);
 146 }
 147
 148 MetadataPKIXIterator::MetadataPKIXIterator(
 149     const PKIXTrustEngine& engine, const MetadataProvider& pkixSource, MetadataCredentialCriteria& criteria
 150     ) : m_caching(false), m_engine(engine), m_obj(criteria.getRole().getParent()), m_extBlock(NULL), m_current(NULL)
 151 {
 152     // If we can't hook the metadata for changes, then we can't do any caching and the rest of this is academic.
 153     const ObservableMetadataProvider* observable = dynamic_cast<const ObservableMetadataProvider*>(&pkixSource);
 154     if (!observable)
 155         return;
 156
 157     // While holding read lock, see if this metadata plugin has been seen before.
 158     m_engine.m_credLock->rdlock();
 159     m_credCache = m_engine.m_credentialMap.find(observable);
 160     if (m_credCache==m_engine.m_credentialMap.end()) {
 161
 162         // We need to elevate the lock and retry.
 163         m_engine.m_credLock->unlock();
 164         m_engine.m_credLock->wrlock();
 165         m_credCache = m_engine.m_credentialMap.find(observable);
 166         if (m_credCache==m_engine.m_credentialMap.end()) {
 167
 168             // It's still brand new, so hook it for cache activation.
 169             observable->addObserver(&m_engine);
 170
 171             // Prime the map reference with an empty credential map.
 172             m_credCache = m_engine.m_credentialMap.insert(make_pair(observable,PKIXTrustEngine::credmap_t())).first;
 173
 174             // Downgrade the lock.
 175             // We don't have to recheck because we never erase the master map entry entirely, even on changes.
 176             m_engine.m_credLock->unlock();
 177             m_engine.m_credLock->rdlock();
 178         }
 179     }
 180
 181     // We've hooked the metadata for changes, and we know we can cache against it.
 182     m_caching = true;
 183 }
 184
 185
 186 bool MetadataPKIXIterator::next()
 187 {
 188     // If we had an active block, look for another in the same block.
 189     if (m_extBlock) {
 190         // Keep going until we hit the end of the block.
 191         vector<XMLObject*>::const_iterator end = m_extBlock->getUnknownXMLObjects().end();
 192         while (m_iter != end) {
 193             // If we hit a KeyAuthority, remember it and signal.
 194             if (m_current=dynamic_cast<KeyAuthority*>(*m_iter++)) {
 195                 populate();
 196                 return true;
 197             }
 198         }
 199
 200         // If we get here, we hit the end of this Extensions block.
 201         // Climb a level, if possible.
 202         m_obj = m_obj->getParent();
 203         m_current = NULL;
 204         m_extBlock = NULL;
 205     }
 206
 207     // If we get here, we try and find an Extensions block.
 208     while (m_obj) {
 209         const EntityDescriptor* entity = dynamic_cast<const EntityDescriptor*>(m_obj);
 210         if (entity) {
 211             m_extBlock = entity->getExtensions();
 212         }
 213         else {
 214             const EntitiesDescriptor* entities = dynamic_cast<const EntitiesDescriptor*>(m_obj);
 215             if (entities) {
 216                 m_extBlock = entities->getExtensions();
 217             }
 218         }
 219
 220         if (m_extBlock) {
 221             m_iter = m_extBlock->getUnknownXMLObjects().begin();
 222             return next();
 223         }
 224
 225         // Jump a level and try again.
 226         m_obj = m_obj->getParent();
 227     }
 228
 229     return false;
 230 }
 231
 232 void MetadataPKIXIterator::populate()
 233 {
 234     // Dump anything old.
 235     m_certs.clear();
 236     m_crls.clear();
 237     for_each(m_ownedCreds.begin(), m_ownedCreds.end(), xmltooling::cleanup<Credential>());
 238
 239     if (m_caching) {
 240         // We're holding a read lock. Search for "resolved" creds.
 241         PKIXTrustEngine::credmap_t::iterator cached = m_credCache->second.find(m_current);
 242         if (cached!=m_credCache->second.end()) {
 243             // Copy over the information.
 244             for (vector<X509Credential*>::const_iterator c=cached->second.begin(); c!=cached->second.end(); ++c) {
 245                 m_certs.insert(m_certs.end(), (*c)->getEntityCertificateChain().begin(), (*c)->getEntityCertificateChain().end());
 246                 if ((*c)->getCRL())
 247                     m_crls.push_back((*c)->getCRL());
 248             }
 249             return;
 250         }
 251     }
 252
 253     // We're either not caching or didn't find the results we need, so we have to resolve them.
 254     const vector<KeyInfo*>& keyInfos = m_current->getKeyInfos();
 255     for (vector<KeyInfo*>::const_iterator k = keyInfos.begin(); k!=keyInfos.end(); ++k) {
 256         auto_ptr<Credential> cred (m_engine.getKeyInfoResolver()->resolve(*k, X509Credential::RESOLVE_CERTS | X509Credential::RESOLVE_CRLS));
 257         X509Credential* xcred = dynamic_cast<X509Credential*>(cred.get());
 258         if (xcred) {
 259             m_ownedCreds.push_back(xcred);
 260             cred.release();
 261         }
 262     }
 263
 264     // Copy over the new information.
 265     for (vector<X509Credential*>::const_iterator c=m_ownedCreds.begin(); c!=m_ownedCreds.end(); ++c) {
 266         m_certs.insert(m_certs.end(), (*c)->getEntityCertificateChain().begin(), (*c)->getEntityCertificateChain().end());
 267         if ((*c)->getCRL())
 268             m_crls.push_back((*c)->getCRL());
 269     }
 270
 271     // As a last step, if we're caching, try and elevate to a write lock for cache insertion.
 272     if (m_caching) {
 273         m_engine.m_credLock->unlock();
 274         m_engine.m_credLock->wrlock();
 275         if (m_credCache->second.count(m_current)==0) {
 276             // Transfer objects into cache.
 277             m_credCache->second[m_current] = m_ownedCreds;
 278             m_ownedCreds.clear();
 279         }
 280         m_engine.m_credLock->unlock();
 281         m_engine.m_credLock->rdlock();
 282
 283         // In theory we could have lost the objects but that shouldn't be possible
 284         // since the metadata itself is locked and shouldn't change behind us.
 285     }
 286 }