src/edu/internet2/middleware/shibboleth/common/provider/ShibbolethTrust.java

   1 /*
   2  * The Shibboleth License, Version 1. Copyright (c) 2002 University Corporation for Advanced Internet Development, Inc.
   3  * All rights reserved Redistribution and use in source and binary forms, with or without modification, are permitted
   4  * provided that the following conditions are met: Redistributions of source code must retain the above copyright
   5  * notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above
   6  * copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials
   7  * provided with the distribution, if any, must include the following acknowledgment: "This product includes software
   8  * developed by the University Corporation for Advanced Internet Development <http://www.ucaid.edu> Internet2 Project.
   9  * Alternately, this acknowledegement may appear in the software itself, if and wherever such third-party
  10  * acknowledgments normally appear. Neither the name of Shibboleth nor the names of its contributors, nor Internet2, nor
  11  * the University Corporation for Advanced Internet Development, Inc., nor UCAID may be used to endorse or promote
  12  * products derived from this software without specific prior written permission. For written permission, please contact
  13  * shibboleth@shibboleth.org Products derived from this software may not be called Shibboleth, Internet2, UCAID, or the
  14  * University Corporation for Advanced Internet Development, nor may Shibboleth appear in their name, without prior
  15  * written permission of the University Corporation for Advanced Internet Development. THIS SOFTWARE IS PROVIDED BY THE
  16  * COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND WITH ALL FAULTS. ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT ARE
  18  * DISCLAIMED AND THE ENTIRE RISK OF SATISFACTORY QUALITY, PERFORMANCE, ACCURACY, AND EFFORT IS WITH LICENSEE. IN NO
  19  * EVENT SHALL THE COPYRIGHT OWNER, CONTRIBUTORS OR THE UNIVERSITY CORPORATION FOR ADVANCED INTERNET DEVELOPMENT, INC.
  20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  21  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  23  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 package edu.internet2.middleware.shibboleth.common.provider;
  27
  28 import java.security.GeneralSecurityException;
  29 import java.security.cert.CertPathBuilder;
  30 import java.security.cert.CertPathValidator;
  31 import java.security.cert.CertPathValidatorException;
  32 import java.security.cert.CertStore;
  33 import java.security.cert.CertificateParsingException;
  34 import java.security.cert.CollectionCertStoreParameters;
  35 import java.security.cert.PKIXBuilderParameters;
  36 import java.security.cert.PKIXCertPathBuilderResult;
  37 import java.security.cert.PKIXCertPathValidatorResult;
  38 import java.security.cert.TrustAnchor;
  39 import java.security.cert.X509CertSelector;
  40 import java.security.cert.X509Certificate;
  41 import java.util.ArrayList;
  42 import java.util.Arrays;
  43 import java.util.Collection;
  44 import java.util.HashSet;
  45 import java.util.Iterator;
  46 import java.util.List;
  47 import java.util.Set;
  48 import java.util.regex.Matcher;
  49 import java.util.regex.Pattern;
  50
  51 import javax.security.auth.x500.X500Principal;
  52
  53 import org.apache.log4j.Logger;
  54 import org.apache.xml.security.exceptions.XMLSecurityException;
  55 import org.apache.xml.security.keys.KeyInfo;
  56 import org.apache.xml.security.keys.content.KeyName;
  57 import org.apache.xml.security.keys.content.X509Data;
  58 import org.apache.xml.security.keys.content.x509.XMLX509Certificate;
  59
  60 import edu.internet2.middleware.shibboleth.common.Trust;
  61 import edu.internet2.middleware.shibboleth.metadata.EntitiesDescriptor;
  62 import edu.internet2.middleware.shibboleth.metadata.EntityDescriptor;
  63 import edu.internet2.middleware.shibboleth.metadata.ExtendedEntitiesDescriptor;
  64 import edu.internet2.middleware.shibboleth.metadata.ExtendedEntityDescriptor;
  65 import edu.internet2.middleware.shibboleth.metadata.KeyAuthority;
  66 import edu.internet2.middleware.shibboleth.metadata.KeyDescriptor;
  67 import edu.internet2.middleware.shibboleth.metadata.RoleDescriptor;
  68
  69 /**
  70  * @author Walter Hoehn
  71  */
  72 public class ShibbolethTrust extends Trust {
  73
  74         private static Logger log = Logger.getLogger(ShibbolethTrust.class.getName());
  75         private static Pattern regex = Pattern.compile(".*?CN=([^,/]+).*");
  76
  77         public boolean validate(RoleDescriptor descriptor, X509Certificate[] certificateChain, int keyUse) {
  78
  79                 // If we can successfully validate with an inline key, that's fine
  80                 boolean defaultValidation = super.validate(descriptor, certificateChain, keyUse);
  81                 if (defaultValidation == true) { return true; }
  82
  83                 // Make sure we have the data we need
  84                 if (descriptor == null || certificateChain == null || certificateChain.length < 1) {
  85                         log.error("Appropriate data was not supplied for trust evaluation.");
  86                         return false;
  87                 }
  88                 log.debug("Inline validation was unsuccessful.  Attmping PKIX...");
  89                 // If not, try PKIX validation against the shib-custom metadata extensions
  90
  91                 // First, we want to see if we can match a keyName from the metadata against the cert
  92                 // Iterator through all the keys in the metadata
  93                 Iterator keyDescriptors = descriptor.getKeyDescriptors();
  94                 while (keyDescriptors.hasNext()) {
  95                         // Look for a key descriptor with the right usage bits
  96                         KeyDescriptor keyDescriptor = (KeyDescriptor) keyDescriptors.next();
  97                         if (keyDescriptor.getUse() != KeyDescriptor.UNSPECIFIED && keyDescriptor.getUse() != keyUse) {
  98                                 log.debug("Role contains a key descriptor, but the usage specification is not valid for this action.");
  99                                 continue;
 100                         }
 101
 102                         // We found one, see if we can match the metadata's keyName against the cert
 103                         KeyInfo keyInfo = keyDescriptor.getKeyInfo();
 104                         if (keyInfo.containsKeyName()) {
 105                                 for (int i = 0; i < keyInfo.lengthKeyName(); i++) {
 106                                         try {
 107                                                 if (matchKeyName(certificateChain[0], keyInfo.itemKeyName(i))) {
 108                                                         // If we find a match, try to do path validation against any key authorities we might have
 109                                                         // in the metadata
 110                                                         if (pkixValidate(certificateChain, descriptor.getEntityDescriptor())) { return true; }
 111                                                 }
 112                                         } catch (XMLSecurityException e) {
 113                                                 log.error("Problem retrieving key name from metadata: " + e);
 114                                         }
 115                                 }
 116                         }
 117                 }
 118                 return false;
 119         }
 120
 121         private boolean pkixValidate(X509Certificate[] certChain, EntityDescriptor entity) {
 122
 123                 if (entity instanceof ExtendedEntityDescriptor) {
 124                         Iterator keyAuthorities = ((ExtendedEntityDescriptor) entity).getKeyAuthorities();
 125                         // if we have any key authorities, construct a flat list of trust anchors representing each and attempt to
 126                         // validate against them in turn
 127                         while (keyAuthorities.hasNext()) {
 128                                 if (pkixValidate(certChain, (KeyAuthority) keyAuthorities.next())) { return true; }
 129                         }
 130                 }
 131
 132                 // We couldn't do path validation based on metadata attached to the entity, we now need to walk up the chain of
 133                 // nested entities and attempt to validate at each group level
 134                 EntitiesDescriptor group = entity.getEntitiesDescriptor();
 135                 if (group != null) {
 136                         if (pkixValidate(certChain, group)) { return true; }
 137                 }
 138
 139                 // We've walked the entire metadata chain with no success, so fail
 140                 return false;
 141         }
 142
 143         private boolean pkixValidate(X509Certificate[] certChain, EntitiesDescriptor group) {
 144
 145                 log.debug("Attemping to validate against parent group.");
 146                 if (group instanceof ExtendedEntitiesDescriptor) {
 147                         Iterator keyAuthorities = ((ExtendedEntitiesDescriptor) group).getKeyAuthorities();
 148                         // if we have any key authorities, construct a flat list of trust anchors representing each and attempt to
 149                         // validate against them in turn
 150                         while (keyAuthorities.hasNext()) {
 151                                 if (pkixValidate(certChain, (KeyAuthority) keyAuthorities.next())) { return true; }
 152                         }
 153                 }
 154
 155                 // If not, attempt to walk up the chain for validation
 156                 EntitiesDescriptor parent = group.getEntitiesDescriptor();
 157                 if (parent != null) {
 158                         if (pkixValidate(certChain, parent)) { return true; }
 159                 }
 160
 161                 return false;
 162         }
 163
 164         private boolean pkixValidate(X509Certificate[] certChain, KeyAuthority authority) {
 165
 166                 Set anchors = new HashSet();
 167                 Iterator keyInfos = authority.getKeyInfos();
 168                 while (keyInfos.hasNext()) {
 169                         KeyInfo keyInfo = (KeyInfo) keyInfos.next();
 170                         if (keyInfo.containsX509Data()) {
 171                                 try {
 172                                         for (int i = 0; i < keyInfo.lengthX509Data(); i++) {
 173                                                 X509Data data = keyInfo.itemX509Data(i);
 174                                                 if (data.containsCertificate()) {
 175                                                         for (int j = 0; j < data.lengthCertificate(); j++) {
 176                                                                 XMLX509Certificate xmlCert = data.itemCertificate(j);
 177                                                                 anchors.add(new TrustAnchor(xmlCert.getX509Certificate(), null));
 178                                                         }
 179                                                 }
 180                                         }
 181                                 } catch (XMLSecurityException e) {
 182                                         log.error("Encountered an error constructing trust list from shibboleth metadata: " + e);
 183                                 }
 184                         }
 185                 }
 186
 187                 // alright, if we were able to create a trust list, attempt a pkix validation against the list
 188                 if (anchors.size() > 0) {
 189                         log.debug("Constructed a trust list from key authority.  Attempting path validation...");
 190                         try {
 191                                 CertPathValidator validator = CertPathValidator.getInstance("PKIX");
 192
 193                                 X509CertSelector selector = new X509CertSelector();
 194                                 selector.setCertificate(certChain[0]);
 195                                 PKIXBuilderParameters params = new PKIXBuilderParameters(anchors, selector);
 196                                 params.setMaxPathLength(authority.getVerifyDepth());
 197                                 CertStore store = CertStore.getInstance("Collection", new CollectionCertStoreParameters(Arrays
 198                                                 .asList(certChain)));
 199                                 List stores = new ArrayList();
 200                                 stores.add(store);
 201                                 params.setCertStores(stores);
 202                                 //TODO hmm... what about revocation
 203                                 params.setRevocationEnabled(false);
 204
 205                                 CertPathBuilder builder = CertPathBuilder.getInstance("PKIX");
 206                                 PKIXCertPathBuilderResult buildResult = (PKIXCertPathBuilderResult) builder.build(params);
 207
 208                                 PKIXCertPathValidatorResult result = (PKIXCertPathValidatorResult) validator.validate(buildResult
 209                                                 .getCertPath(), params);
 210                                 log.debug("Path successfully validated.");
 211                                 return true;
 212
 213                         } catch (CertPathValidatorException e) {
 214                                 log.debug("Path failed to validate: " + e);
 215                         } catch (GeneralSecurityException e) {
 216                                 log.error("Encountered an error during validation: " + e);
 217                         }
 218                 }
 219                 return false;
 220         }
 221
 222         private static boolean matchKeyName(X509Certificate certificate, KeyName keyName) {
 223
 224                 // First, try to match DN against metadata
 225                 try {
 226                         if (certificate.getSubjectX500Principal().getName(X500Principal.RFC2253).equals(
 227                                         new X500Principal(keyName.getKeyName()).getName(X500Principal.RFC2253))) {
 228                                 log.debug("Matched against DN.");
 229                                 return true;
 230                         }
 231                 } catch (IllegalArgumentException iae) {
 232                         // squelch this runtime exception, since
 233                         // this might be a valid case
 234                 }
 235
 236                 // If that doesn't work, we try matching against
 237                 // some Subject Alt Names
 238                 try {
 239                         Collection altNames = certificate.getSubjectAlternativeNames();
 240                         if (altNames != null) {
 241                                 for (Iterator nameIterator = altNames.iterator(); nameIterator.hasNext();) {
 242                                         List altName = (List) nameIterator.next();
 243                                         if (altName.get(0).equals(new Integer(2)) || altName.get(0).equals(new Integer(6))) {
 244                                                 // 2 is DNS, 6 is URI
 245                                                 if (altName.get(0).equals(keyName.getKeyName())) {
 246                                                         log.debug("Matched against SubjectAltName.");
 247                                                         return true;
 248                                                 }
 249                                         }
 250                                 }
 251                         }
 252                 } catch (CertificateParsingException e1) {
 253                         log.error("Encountered an problem trying to extract Subject Alternate "
 254                                         + "Name from supplied certificate: " + e1);
 255                 }
 256
 257                 // If that doesn't work, try to match using
 258                 // SSL-style hostname matching
 259                 if (getHostNameFromDN(certificate.getSubjectX500Principal()).equals(keyName.getKeyName())) {
 260                         log.debug("Matched against hostname.");
 261                         return true;
 262                 }
 263
 264                 return false;
 265         }
 266
 267         private static String getHostNameFromDN(X500Principal dn) {
 268
 269                 Matcher matches = regex.matcher(dn.getName(X500Principal.RFC2253));
 270                 if (!matches.find() || matches.groupCount() > 1) {
 271                         log.error("Unable to extract host name name from certificate subject DN.");
 272                         return null;
 273                 }
 274                 return matches.group(1);
 275         }
 276
 277 }