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.io.ByteArrayInputStream;
  29 import java.security.GeneralSecurityException;
  30 import java.security.cert.CertPathBuilder;
  31 import java.security.cert.CertPathValidator;
  32 import java.security.cert.CertPathValidatorException;
  33 import java.security.cert.CertStore;
  34 import java.security.cert.CertificateFactory;
  35 import java.security.cert.CertificateParsingException;
  36 import java.security.cert.CollectionCertStoreParameters;
  37 import java.security.cert.PKIXBuilderParameters;
  38 import java.security.cert.PKIXCertPathBuilderResult;
  39 import java.security.cert.PKIXCertPathValidatorResult;
  40 import java.security.cert.TrustAnchor;
  41 import java.security.cert.X509CRL;
  42 import java.security.cert.X509CertSelector;
  43 import java.security.cert.X509Certificate;
  44 import java.util.ArrayList;
  45 import java.util.Arrays;
  46 import java.util.Collection;
  47 import java.util.HashSet;
  48 import java.util.Iterator;
  49 import java.util.List;
  50 import java.util.Set;
  51 import java.util.regex.Matcher;
  52 import java.util.regex.Pattern;
  53
  54 import javax.security.auth.x500.X500Principal;
  55
  56 import org.apache.log4j.Logger;
  57 import org.apache.xml.security.exceptions.XMLSecurityException;
  58 import org.apache.xml.security.keys.KeyInfo;
  59 import org.apache.xml.security.keys.content.KeyName;
  60 import org.apache.xml.security.keys.content.X509Data;
  61 import org.apache.xml.security.keys.content.x509.XMLX509CRL;
  62 import org.apache.xml.security.keys.content.x509.XMLX509Certificate;
  63 import org.opensaml.SAMLException;
  64 import org.opensaml.SAMLSignedObject;
  65
  66 import edu.internet2.middleware.shibboleth.common.Trust;
  67 import edu.internet2.middleware.shibboleth.metadata.EntitiesDescriptor;
  68 import edu.internet2.middleware.shibboleth.metadata.EntityDescriptor;
  69 import edu.internet2.middleware.shibboleth.metadata.ExtendedEntitiesDescriptor;
  70 import edu.internet2.middleware.shibboleth.metadata.ExtendedEntityDescriptor;
  71 import edu.internet2.middleware.shibboleth.metadata.KeyAuthority;
  72 import edu.internet2.middleware.shibboleth.metadata.KeyDescriptor;
  73 import edu.internet2.middleware.shibboleth.metadata.RoleDescriptor;
  74
  75 /**
  76  * <code>Trust</code> implementation that does PKIX validation against key authorities included in shibboleth-specific
  77  * extensions to SAML 2 metadata.
  78  *
  79  * @author Walter Hoehn
  80  */
  81 public class ShibbolethTrust extends BasicTrust implements Trust {
  82
  83         private static Logger log = Logger.getLogger(ShibbolethTrust.class.getName());
  84         private static Pattern regex = Pattern.compile(".*?CN=([^,/]+).*");
  85
  86         /*
  87          * @see edu.internet2.middleware.shibboleth.common.Trust#validate(java.security.cert.X509Certificate,
  88          *      java.security.cert.X509Certificate[], edu.internet2.middleware.shibboleth.metadata.RoleDescriptor)
  89          */
  90         public boolean validate(X509Certificate certificateEE, X509Certificate[] certificateChain, RoleDescriptor descriptor) {
  91
  92                 return validate(certificateEE, certificateChain, descriptor, true);
  93         }
  94
  95         /*
  96          * @see edu.internet2.middleware.shibboleth.common.Trust#validate(org.opensaml.SAMLSignedObject,
  97          *      edu.internet2.middleware.shibboleth.metadata.RoleDescriptor)
  98          */
  99         public boolean validate(SAMLSignedObject token, RoleDescriptor descriptor) {
 100
 101                 if (super.validate(token, descriptor)) return true;
 102
 103                 /* Certificates supplied with the signed object */
 104                 ArrayList/* <X509Certificate> */certificates = new ArrayList/* <X509Certificate> */();
 105                 X509Certificate certificateEE = null;
 106
 107                 /* Iterate to count the certificates, and look for the signer */
 108                 Iterator icertificates;
 109                 try {
 110                         icertificates = token.getX509Certificates();
 111                 } catch (SAMLException e1) {
 112                         return false;
 113                 }
 114                 while (icertificates.hasNext()) {
 115                         X509Certificate certificate = (X509Certificate) icertificates.next();
 116                         try {
 117                                 token.verify(certificate);
 118                                 // This is the certificate that signed the object
 119                                 certificateEE = certificate;
 120                                 certificates.add(certificate);
 121                         } catch (SAMLException e) {
 122                                 certificates.add(certificate);
 123                         }
 124                 }
 125
 126                 if (certificateEE == null) return false; // No key validates the signature
 127
 128                 // With a count we can now build a typed array
 129                 X509Certificate[] certificateChain = new X509Certificate[certificates.size()];
 130                 int i = 0;
 131                 for (icertificates = certificates.iterator(); icertificates.hasNext();) {
 132                         certificateChain[i++] = (X509Certificate) icertificates.next();
 133                 }
 134                 return validate(certificateEE, certificateChain, descriptor);
 135         }
 136
 137         /*
 138          * @see edu.internet2.middleware.shibboleth.common.Trust#validate(java.security.cert.X509Certificate,
 139          *      java.security.cert.X509Certificate[], edu.internet2.middleware.shibboleth.metadata.RoleDescriptor, boolean)
 140          */
 141         public boolean validate(X509Certificate certificateEE, X509Certificate[] certificateChain,
 142                         RoleDescriptor descriptor, boolean checkName) {
 143
 144                 // If we can successfully validate with an inline key, that's fine
 145                 boolean defaultValidation = super.validate(certificateEE, certificateChain, descriptor, checkName);
 146                 if (defaultValidation == true) { return true; }
 147
 148                 // Make sure we have the data we need
 149                 if (descriptor == null || certificateEE == null) {
 150                         log.error("Appropriate data was not supplied for trust evaluation.");
 151                         return false;
 152                 }
 153                 log.debug("Inline validation was unsuccessful.  Attmping PKIX...");
 154                 // If not, try PKIX validation against the shib-custom metadata extensions
 155
 156                 // First, we want to see if we can match a keyName from the metadata against the cert
 157                 // Iterator through all the keys in the metadata
 158                 if (checkName) {
 159
 160                         if (matchProviderId(certificateChain[0], descriptor.getEntityDescriptor().getId())) {
 161                                 checkName = false;
 162                         } else {
 163
 164                                 Iterator keyDescriptors = descriptor.getKeyDescriptors();
 165                                 while (checkName && keyDescriptors.hasNext()) {
 166                                         // Look for a key descriptor with the right usage bits
 167                                         KeyDescriptor keyDescriptor = (KeyDescriptor) keyDescriptors.next();
 168                                         if (keyDescriptor.getUse() == KeyDescriptor.ENCRYPTION) {
 169                                                 log.debug("Skipping key descriptor with inappropriate usage indicator.");
 170                                                 continue;
 171                                         }
 172
 173                                         // We found one, see if we can match the metadata's keyName against the cert
 174                                         KeyInfo keyInfo = keyDescriptor.getKeyInfo();
 175                                         if (keyInfo.containsKeyName()) {
 176                                                 for (int i = 0; i < keyInfo.lengthKeyName(); i++) {
 177                                                         try {
 178                                                                 if (matchKeyName(certificateChain[0], keyInfo.itemKeyName(i))) {
 179                                                                         checkName = false;
 180                                                                         break;
 181                                                                 }
 182                                                         } catch (XMLSecurityException e) {
 183                                                                 log.error("Problem retrieving key name from metadata: " + e);
 184                                                         }
 185                                                 }
 186                                         }
 187                                 }
 188                         }
 189                 }
 190
 191                 if (checkName) {
 192                         log.error("cannot match certificate subject against acceptable key names based on the "
 193                                         + "metadata entityId or KeyDescriptors");
 194                         return false;
 195                 }
 196
 197                 if (pkixValidate(certificateEE, certificateChain, descriptor.getEntityDescriptor())) { return true; }
 198                 return false;
 199         }
 200
 201         private boolean pkixValidate(X509Certificate certEE, X509Certificate[] certChain, EntityDescriptor entity) {
 202
 203                 if (entity instanceof ExtendedEntityDescriptor) {
 204                         Iterator keyAuthorities = ((ExtendedEntityDescriptor) entity).getKeyAuthorities();
 205                         // if we have any key authorities, construct a flat list of trust anchors representing each and attempt to
 206                         // validate against them in turn
 207                         while (keyAuthorities.hasNext()) {
 208                                 if (pkixValidate(certEE, certChain, (KeyAuthority) keyAuthorities.next())) { return true; }
 209                         }
 210                 }
 211
 212                 // We couldn't do path validation based on metadata attached to the entity, we now need to walk up the chain of
 213                 // nested entities and attempt to validate at each group level
 214                 EntitiesDescriptor group = entity.getEntitiesDescriptor();
 215                 if (group != null) {
 216                         if (pkixValidate(certEE, certChain, group)) { return true; }
 217                 }
 218
 219                 // We've walked the entire metadata chain with no success, so fail
 220                 return false;
 221         }
 222
 223         private boolean pkixValidate(X509Certificate certEE, X509Certificate[] certChain, EntitiesDescriptor group) {
 224
 225                 log.debug("Attemping to validate against parent group.");
 226                 if (group instanceof ExtendedEntitiesDescriptor) {
 227                         Iterator keyAuthorities = ((ExtendedEntitiesDescriptor) group).getKeyAuthorities();
 228                         // if we have any key authorities, construct a flat list of trust anchors representing each and attempt to
 229                         // validate against them in turn
 230                         while (keyAuthorities.hasNext()) {
 231                                 if (pkixValidate(certEE, certChain, (KeyAuthority) keyAuthorities.next())) { return true; }
 232                         }
 233                 }
 234
 235                 // If not, attempt to walk up the chain for validation
 236                 EntitiesDescriptor parent = group.getEntitiesDescriptor();
 237                 if (parent != null) {
 238                         if (pkixValidate(certEE, certChain, parent)) { return true; }
 239                 }
 240
 241                 return false;
 242         }
 243
 244         private boolean pkixValidate(X509Certificate certEE, X509Certificate[] certChain, KeyAuthority authority) {
 245
 246                 Set anchors = new HashSet();
 247                 Set crls = new HashSet();
 248                 Iterator keyInfos = authority.getKeyInfos();
 249                 while (keyInfos.hasNext()) {
 250                         KeyInfo keyInfo = (KeyInfo) keyInfos.next();
 251                         if (keyInfo.containsX509Data()) {
 252                                 try {
 253                                         // Add all certificates in the authority as trust anchors
 254                                         for (int i = 0; i < keyInfo.lengthX509Data(); i++) {
 255                                                 X509Data data = keyInfo.itemX509Data(i);
 256                                                 if (data.containsCertificate()) {
 257                                                         for (int j = 0; j < data.lengthCertificate(); j++) {
 258                                                                 XMLX509Certificate xmlCert = data.itemCertificate(j);
 259                                                                 anchors.add(new TrustAnchor(xmlCert.getX509Certificate(), null));
 260                                                         }
 261                                                 }
 262                                                 // Compile all CRLs in the authority
 263                                                 if (data.containsCRL()) {
 264                                                         for (int j = 0; j < data.lengthCRL(); j++) {
 265                                                                 XMLX509CRL xmlCrl = data.itemCRL(j);
 266                                                                 try {
 267                                                                         X509CRL crl = (X509CRL) CertificateFactory.getInstance("X.509").generateCRL(
 268                                                                                         new ByteArrayInputStream(xmlCrl.getCRLBytes()));
 269                                                                         if (crl.getRevokedCertificates() != null && crl.getRevokedCertificates().size() > 0) {
 270                                                                                 crls.add(crl);
 271                                                                         }
 272                                                                 } catch (GeneralSecurityException e) {
 273                                                                         log.error("Encountered an error parsing CRL from shibboleth metadata: " + e);
 274                                                                 }
 275                                                         }
 276                                                 }
 277                                         }
 278
 279                                 } catch (XMLSecurityException e) {
 280                                         log.error("Encountered an error constructing trust list from shibboleth metadata: " + e);
 281                                 }
 282                         }
 283                 }
 284
 285                 // alright, if we were able to create a trust list, attempt a pkix validation against the list
 286                 if (anchors.size() > 0) {
 287                         log.debug("Constructed a trust list from key authority.  Attempting path validation...");
 288                         try {
 289                                 CertPathValidator validator = CertPathValidator.getInstance("PKIX");
 290
 291                                 X509CertSelector selector = new X509CertSelector();
 292                                 selector.setCertificate(certEE);
 293                                 PKIXBuilderParameters params = new PKIXBuilderParameters(anchors, selector);
 294                                 params.setMaxPathLength(authority.getVerifyDepth());
 295                                 List storeMaterial = new ArrayList(crls);
 296                                 storeMaterial.addAll(Arrays.asList(certChain));
 297                                 CertStore store = CertStore.getInstance("Collection", new CollectionCertStoreParameters(storeMaterial));
 298                                 List stores = new ArrayList();
 299                                 stores.add(store);
 300                                 params.setCertStores(stores);
 301                                 if (crls.size() > 0) {
 302                                         params.setRevocationEnabled(true);
 303                                 } else {
 304                                         params.setRevocationEnabled(false);
 305                                 }
 306                                 // System.err.println(params.toString());
 307                                 CertPathBuilder builder = CertPathBuilder.getInstance("PKIX");
 308                                 PKIXCertPathBuilderResult buildResult = (PKIXCertPathBuilderResult) builder.build(params);
 309
 310                                 PKIXCertPathValidatorResult result = (PKIXCertPathValidatorResult) validator.validate(buildResult
 311                                                 .getCertPath(), params);
 312                                 log.debug("Path successfully validated.");
 313                                 return true;
 314
 315                         } catch (CertPathValidatorException e) {
 316                                 log.debug("Path failed to validate: " + e);
 317                         } catch (GeneralSecurityException e) {
 318                                 log.error("Encountered an error during validation: " + e);
 319                         }
 320                 }
 321                 return false;
 322         }
 323
 324         private static boolean matchKeyName(X509Certificate certificate, KeyName keyName) {
 325
 326                 // First, try to match DN against metadata
 327                 try {
 328                         if (certificate.getSubjectX500Principal().getName(X500Principal.RFC2253).equals(
 329                                         new X500Principal(keyName.getKeyName()).getName(X500Principal.RFC2253))) {
 330                                 log.debug("Matched against DN.");
 331                                 return true;
 332                         }
 333                 } catch (IllegalArgumentException iae) {
 334                         // squelch this runtime exception, since
 335                         // this might be a valid case
 336                 }
 337
 338                 // If that doesn't work, we try matching against
 339                 // some Subject Alt Names
 340                 try {
 341                         Collection altNames = certificate.getSubjectAlternativeNames();
 342                         if (altNames != null) {
 343                                 for (Iterator nameIterator = altNames.iterator(); nameIterator.hasNext();) {
 344                                         List altName = (List) nameIterator.next();
 345                                         if (altName.get(0).equals(new Integer(2)) || altName.get(0).equals(new Integer(6))) {
 346                                                 // 2 is DNS, 6 is URI
 347                                                 if (altName.get(0).equals(keyName.getKeyName())) {
 348                                                         log.debug("Matched against SubjectAltName.");
 349                                                         return true;
 350                                                 }
 351                                         }
 352                                 }
 353                         }
 354                 } catch (CertificateParsingException e1) {
 355                         log.error("Encountered an problem trying to extract Subject Alternate "
 356                                         + "Name from supplied certificate: " + e1);
 357                 }
 358
 359                 // If that doesn't work, try to match using
 360                 // SSL-style hostname matching
 361                 if (getHostNameFromDN(certificate.getSubjectX500Principal()).equals(keyName.getKeyName())) {
 362                         log.debug("Matched against hostname.");
 363                         return true;
 364                 }
 365
 366                 return false;
 367         }
 368
 369         private static boolean matchProviderId(X509Certificate certificate, String id) {
 370
 371                 // Try matching against URI Subject Alt Names
 372                 try {
 373                         Collection altNames = certificate.getSubjectAlternativeNames();
 374                         if (altNames != null) {
 375                                 for (Iterator nameIterator = altNames.iterator(); nameIterator.hasNext();) {
 376                                         List altName = (List) nameIterator.next();
 377                                         if (altName.get(0).equals(new Integer(6))) { // 6 is URI
 378                                                 if (altName.get(0).equals(id)) {
 379                                                         log.debug("Entity ID matched against SubjectAltName.");
 380                                                         return true;
 381                                                 }
 382                                         }
 383                                 }
 384                         }
 385                 } catch (CertificateParsingException e1) {
 386                         log.error("Encountered an problem trying to extract Subject Alternate "
 387                                         + "Name from supplied certificate: " + e1);
 388                 }
 389
 390                 // If that doesn't work, try to match using
 391                 // SSL-style hostname matching
 392                 if (getHostNameFromDN(certificate.getSubjectX500Principal()).equals(id)) {
 393                         log.debug("Entity ID matched against hostname.");
 394                         return true;
 395                 }
 396
 397                 return false;
 398         }
 399
 400         private static String getHostNameFromDN(X500Principal dn) {
 401
 402                 Matcher matches = regex.matcher(dn.getName(X500Principal.RFC2253));
 403                 if (!matches.find() || matches.groupCount() > 1) {
 404                         log.error("Unable to extract host name name from certificate subject DN.");
 405                         return null;
 406                 }
 407                 return matches.group(1);
 408         }
 409
 410 }