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.io.IOException;
  30 import java.security.GeneralSecurityException;
  31 import java.security.cert.CertPathBuilder;
  32 import java.security.cert.CertPathValidator;
  33 import java.security.cert.CertPathValidatorException;
  34 import java.security.cert.CertStore;
  35 import java.security.cert.CertificateFactory;
  36 import java.security.cert.CertificateParsingException;
  37 import java.security.cert.CollectionCertStoreParameters;
  38 import java.security.cert.PKIXBuilderParameters;
  39 import java.security.cert.PKIXCertPathBuilderResult;
  40 import java.security.cert.PKIXCertPathValidatorResult;
  41 import java.security.cert.TrustAnchor;
  42 import java.security.cert.X509CRL;
  43 import java.security.cert.X509CertSelector;
  44 import java.security.cert.X509Certificate;
  45 import java.util.ArrayList;
  46 import java.util.Arrays;
  47 import java.util.Collection;
  48 import java.util.HashSet;
  49 import java.util.Iterator;
  50 import java.util.List;
  51 import java.util.Set;
  52
  53 import javax.security.auth.x500.X500Principal;
  54
  55 import org.apache.log4j.Logger;
  56 import org.apache.xml.security.exceptions.XMLSecurityException;
  57 import org.apache.xml.security.keys.KeyInfo;
  58 import org.apache.xml.security.keys.content.KeyName;
  59 import org.apache.xml.security.keys.content.X509Data;
  60 import org.apache.xml.security.keys.content.x509.XMLX509CRL;
  61 import org.apache.xml.security.keys.content.x509.XMLX509Certificate;
  62 import org.bouncycastle.asn1.ASN1InputStream;
  63 import org.bouncycastle.asn1.DERObject;
  64 import org.bouncycastle.asn1.DERObjectIdentifier;
  65 import org.bouncycastle.asn1.DERPrintableString;
  66 import org.bouncycastle.asn1.DERSequence;
  67 import org.bouncycastle.asn1.DERSet;
  68 import org.opensaml.SAMLException;
  69 import org.opensaml.SAMLSignedObject;
  70
  71 import edu.internet2.middleware.shibboleth.common.Trust;
  72 import edu.internet2.middleware.shibboleth.metadata.EntitiesDescriptor;
  73 import edu.internet2.middleware.shibboleth.metadata.EntityDescriptor;
  74 import edu.internet2.middleware.shibboleth.metadata.ExtendedEntitiesDescriptor;
  75 import edu.internet2.middleware.shibboleth.metadata.ExtendedEntityDescriptor;
  76 import edu.internet2.middleware.shibboleth.metadata.KeyAuthority;
  77 import edu.internet2.middleware.shibboleth.metadata.KeyDescriptor;
  78 import edu.internet2.middleware.shibboleth.metadata.RoleDescriptor;
  79
  80 /**
  81  * <code>Trust</code> implementation that does PKIX validation against key authorities included in shibboleth-specific
  82  * extensions to SAML 2 metadata.
  83  *
  84  * @author Walter Hoehn
  85  */
  86 public class ShibbolethTrust extends BasicTrust implements Trust {
  87
  88         private static Logger log = Logger.getLogger(ShibbolethTrust.class.getName());
  89         private static final String CN_OID = "2.5.4.3";
  90
  91         /*
  92          * @see edu.internet2.middleware.shibboleth.common.Trust#validate(java.security.cert.X509Certificate,
  93          *      java.security.cert.X509Certificate[], edu.internet2.middleware.shibboleth.metadata.RoleDescriptor)
  94          */
  95         public boolean validate(X509Certificate certificateEE, X509Certificate[] certificateChain, RoleDescriptor descriptor) {
  96
  97                 return validate(certificateEE, certificateChain, descriptor, true);
  98         }
  99
 100         /*
 101          * @see edu.internet2.middleware.shibboleth.common.Trust#validate(org.opensaml.SAMLSignedObject,
 102          *      edu.internet2.middleware.shibboleth.metadata.RoleDescriptor)
 103          */
 104         public boolean validate(SAMLSignedObject token, RoleDescriptor descriptor) {
 105
 106                 if (super.validate(token, descriptor)) return true;
 107
 108                 /* Certificates supplied with the signed object */
 109                 ArrayList/* <X509Certificate> */certificates = new ArrayList/* <X509Certificate> */();
 110                 X509Certificate certificateEE = null;
 111
 112                 /* Iterate to count the certificates, and look for the signer */
 113                 Iterator icertificates;
 114                 try {
 115                         icertificates = token.getX509Certificates();
 116                 } catch (SAMLException e1) {
 117                         return false;
 118                 }
 119                 while (icertificates.hasNext()) {
 120                         X509Certificate certificate = (X509Certificate) icertificates.next();
 121                         try {
 122                                 token.verify(certificate);
 123                                 // This is the certificate that signed the object
 124                                 certificateEE = certificate;
 125                                 certificates.add(certificate);
 126                         } catch (SAMLException e) {
 127                                 certificates.add(certificate);
 128                         }
 129                 }
 130
 131                 if (certificateEE == null) return false; // No key validates the signature
 132
 133                 // With a count we can now build a typed array
 134                 X509Certificate[] certificateChain = new X509Certificate[certificates.size()];
 135                 int i = 0;
 136                 for (icertificates = certificates.iterator(); icertificates.hasNext();) {
 137                         certificateChain[i++] = (X509Certificate) icertificates.next();
 138                 }
 139                 return validate(certificateEE, certificateChain, descriptor);
 140         }
 141
 142         /*
 143          * @see edu.internet2.middleware.shibboleth.common.Trust#validate(java.security.cert.X509Certificate,
 144          *      java.security.cert.X509Certificate[], edu.internet2.middleware.shibboleth.metadata.RoleDescriptor, boolean)
 145          */
 146         public boolean validate(X509Certificate certificateEE, X509Certificate[] certificateChain,
 147                         RoleDescriptor descriptor, boolean checkName) {
 148
 149                 // If we can successfully validate with an inline key, that's fine
 150                 boolean defaultValidation = super.validate(certificateEE, certificateChain, descriptor, checkName);
 151                 if (defaultValidation == true) { return true; }
 152
 153                 // Make sure we have the data we need
 154                 if (descriptor == null || certificateEE == null) {
 155                         log.error("Appropriate data was not supplied for trust evaluation.");
 156                         return false;
 157                 }
 158                 log.debug("Inline validation was unsuccessful.  Attmping PKIX...");
 159                 // If not, try PKIX validation against the shib-custom metadata extensions
 160
 161                 // First, we want to see if we can match a keyName from the metadata against the cert
 162                 // Iterator through all the keys in the metadata
 163                 if (checkName) {
 164
 165                         if (matchProviderId(certificateChain[0], descriptor.getEntityDescriptor().getId())) {
 166                                 checkName = false;
 167                         } else {
 168
 169                                 Iterator keyDescriptors = descriptor.getKeyDescriptors();
 170                                 while (checkName && keyDescriptors.hasNext()) {
 171                                         // Look for a key descriptor with the right usage bits
 172                                         KeyDescriptor keyDescriptor = (KeyDescriptor) keyDescriptors.next();
 173                                         if (keyDescriptor.getUse() == KeyDescriptor.ENCRYPTION) {
 174                                                 log.debug("Skipping key descriptor with inappropriate usage indicator.");
 175                                                 continue;
 176                                         }
 177
 178                                         // We found one, see if we can match the metadata's keyName against the cert
 179                                         KeyInfo keyInfo = keyDescriptor.getKeyInfo();
 180                                         if (keyInfo.containsKeyName()) {
 181                                                 for (int i = 0; i < keyInfo.lengthKeyName(); i++) {
 182                                                         try {
 183                                                                 if (matchKeyName(certificateChain[0], keyInfo.itemKeyName(i))) {
 184                                                                         checkName = false;
 185                                                                         break;
 186                                                                 }
 187                                                         } catch (XMLSecurityException e) {
 188                                                                 log.error("Problem retrieving key name from metadata: " + e);
 189                                                         }
 190                                                 }
 191                                         }
 192                                 }
 193                         }
 194                 }
 195
 196                 if (checkName) {
 197                         log.error("cannot match certificate subject against acceptable key names based on the "
 198                                         + "metadata entityId or KeyDescriptors");
 199                         return false;
 200                 }
 201
 202                 if (pkixValidate(certificateEE, certificateChain, descriptor.getEntityDescriptor())) { return true; }
 203                 return false;
 204         }
 205
 206         private boolean pkixValidate(X509Certificate certEE, X509Certificate[] certChain, EntityDescriptor entity) {
 207
 208                 if (entity instanceof ExtendedEntityDescriptor) {
 209                         Iterator keyAuthorities = ((ExtendedEntityDescriptor) entity).getKeyAuthorities();
 210                         // if we have any key authorities, construct a flat list of trust anchors representing each and attempt to
 211                         // validate against them in turn
 212                         while (keyAuthorities.hasNext()) {
 213                                 if (pkixValidate(certEE, certChain, (KeyAuthority) keyAuthorities.next())) { return true; }
 214                         }
 215                 }
 216
 217                 // We couldn't do path validation based on metadata attached to the entity, we now need to walk up the chain of
 218                 // nested entities and attempt to validate at each group level
 219                 EntitiesDescriptor group = entity.getEntitiesDescriptor();
 220                 if (group != null) {
 221                         if (pkixValidate(certEE, certChain, group)) { return true; }
 222                 }
 223
 224                 // We've walked the entire metadata chain with no success, so fail
 225                 return false;
 226         }
 227
 228         private boolean pkixValidate(X509Certificate certEE, X509Certificate[] certChain, EntitiesDescriptor group) {
 229
 230                 log.debug("Attemping to validate against parent group.");
 231                 if (group instanceof ExtendedEntitiesDescriptor) {
 232                         Iterator keyAuthorities = ((ExtendedEntitiesDescriptor) group).getKeyAuthorities();
 233                         // if we have any key authorities, construct a flat list of trust anchors representing each and attempt to
 234                         // validate against them in turn
 235                         while (keyAuthorities.hasNext()) {
 236                                 if (pkixValidate(certEE, certChain, (KeyAuthority) keyAuthorities.next())) { return true; }
 237                         }
 238                 }
 239
 240                 // If not, attempt to walk up the chain for validation
 241                 EntitiesDescriptor parent = group.getEntitiesDescriptor();
 242                 if (parent != null) {
 243                         if (pkixValidate(certEE, certChain, parent)) { return true; }
 244                 }
 245
 246                 return false;
 247         }
 248
 249         private boolean pkixValidate(X509Certificate certEE, X509Certificate[] certChain, KeyAuthority authority) {
 250
 251                 Set anchors = new HashSet();
 252                 Set crls = new HashSet();
 253                 Iterator keyInfos = authority.getKeyInfos();
 254                 while (keyInfos.hasNext()) {
 255                         KeyInfo keyInfo = (KeyInfo) keyInfos.next();
 256                         if (keyInfo.containsX509Data()) {
 257                                 try {
 258                                         // Add all certificates in the authority as trust anchors
 259                                         for (int i = 0; i < keyInfo.lengthX509Data(); i++) {
 260                                                 X509Data data = keyInfo.itemX509Data(i);
 261                                                 if (data.containsCertificate()) {
 262                                                         for (int j = 0; j < data.lengthCertificate(); j++) {
 263                                                                 XMLX509Certificate xmlCert = data.itemCertificate(j);
 264                                                                 anchors.add(new TrustAnchor(xmlCert.getX509Certificate(), null));
 265                                                         }
 266                                                 }
 267                                                 // Compile all CRLs in the authority
 268                                                 if (data.containsCRL()) {
 269                                                         for (int j = 0; j < data.lengthCRL(); j++) {
 270                                                                 XMLX509CRL xmlCrl = data.itemCRL(j);
 271                                                                 try {
 272                                                                         X509CRL crl = (X509CRL) CertificateFactory.getInstance("X.509").generateCRL(
 273                                                                                         new ByteArrayInputStream(xmlCrl.getCRLBytes()));
 274                                                                         if (crl.getRevokedCertificates() != null && crl.getRevokedCertificates().size() > 0) {
 275                                                                                 crls.add(crl);
 276                                                                         }
 277                                                                 } catch (GeneralSecurityException e) {
 278                                                                         log.error("Encountered an error parsing CRL from shibboleth metadata: " + e);
 279                                                                 }
 280                                                         }
 281                                                 }
 282                                         }
 283
 284                                 } catch (XMLSecurityException e) {
 285                                         log.error("Encountered an error constructing trust list from shibboleth metadata: " + e);
 286                                 }
 287                         }
 288                 }
 289
 290                 // alright, if we were able to create a trust list, attempt a pkix validation against the list
 291                 if (anchors.size() > 0) {
 292                         log.debug("Constructed a trust list from key authority.  Attempting path validation...");
 293                         try {
 294                                 CertPathValidator validator = CertPathValidator.getInstance("PKIX");
 295
 296                                 X509CertSelector selector = new X509CertSelector();
 297                                 selector.setCertificate(certEE);
 298                                 PKIXBuilderParameters params = new PKIXBuilderParameters(anchors, selector);
 299                                 params.setMaxPathLength(authority.getVerifyDepth());
 300                                 List storeMaterial = new ArrayList(crls);
 301                                 storeMaterial.addAll(Arrays.asList(certChain));
 302                                 CertStore store = CertStore.getInstance("Collection", new CollectionCertStoreParameters(storeMaterial));
 303                                 List stores = new ArrayList();
 304                                 stores.add(store);
 305                                 params.setCertStores(stores);
 306                                 if (crls.size() > 0) {
 307                                         params.setRevocationEnabled(true);
 308                                 } else {
 309                                         params.setRevocationEnabled(false);
 310                                 }
 311                                 // System.err.println(params.toString());
 312                                 CertPathBuilder builder = CertPathBuilder.getInstance("PKIX");
 313                                 PKIXCertPathBuilderResult buildResult = (PKIXCertPathBuilderResult) builder.build(params);
 314
 315                                 PKIXCertPathValidatorResult result = (PKIXCertPathValidatorResult) validator.validate(buildResult
 316                                                 .getCertPath(), params);
 317                                 log.debug("Path successfully validated.");
 318                                 return true;
 319
 320                         } catch (CertPathValidatorException e) {
 321                                 log.debug("Path failed to validate: " + e);
 322                         } catch (GeneralSecurityException e) {
 323                                 log.error("Encountered an error during validation: " + e);
 324                         }
 325                 }
 326                 return false;
 327         }
 328
 329         private static boolean matchKeyName(X509Certificate certificate, KeyName keyName) {
 330
 331                 // First, try to match DN against metadata
 332                 try {
 333                         if (certificate.getSubjectX500Principal().getName(X500Principal.RFC2253).equals(
 334                                         new X500Principal(keyName.getKeyName()).getName(X500Principal.RFC2253))) {
 335                                 log.debug("Matched against DN.");
 336                                 return true;
 337                         }
 338                 } catch (IllegalArgumentException iae) {
 339                         // squelch this runtime exception, since
 340                         // this might be a valid case
 341                 }
 342
 343                 // If that doesn't work, we try matching against
 344                 // some Subject Alt Names
 345                 try {
 346                         Collection altNames = certificate.getSubjectAlternativeNames();
 347                         if (altNames != null) {
 348                                 for (Iterator nameIterator = altNames.iterator(); nameIterator.hasNext();) {
 349                                         List altName = (List) nameIterator.next();
 350                                         if (altName.get(0).equals(new Integer(2)) || altName.get(0).equals(new Integer(6))) {
 351                                                 // 2 is DNS, 6 is URI
 352                                                 if (altName.get(0).equals(keyName.getKeyName())) {
 353                                                         log.debug("Matched against SubjectAltName.");
 354                                                         return true;
 355                                                 }
 356                                         }
 357                                 }
 358                         }
 359                 } catch (CertificateParsingException e1) {
 360                         log.error("Encountered an problem trying to extract Subject Alternate "
 361                                         + "Name from supplied certificate: " + e1);
 362                 }
 363
 364                 // If that doesn't work, try to match using
 365                 // SSL-style hostname matching
 366                 if (getHostNameFromDN(certificate.getSubjectX500Principal()).equals(keyName.getKeyName())) {
 367                         log.debug("Matched against hostname.");
 368                         return true;
 369                 }
 370
 371                 return false;
 372         }
 373
 374         private static boolean matchProviderId(X509Certificate certificate, String id) {
 375
 376                 // Try matching against URI Subject Alt Names
 377                 try {
 378                         Collection altNames = certificate.getSubjectAlternativeNames();
 379                         if (altNames != null) {
 380                                 for (Iterator nameIterator = altNames.iterator(); nameIterator.hasNext();) {
 381                                         List altName = (List) nameIterator.next();
 382                                         if (altName.get(0).equals(new Integer(6))) { // 6 is URI
 383                                                 if (altName.get(0).equals(id)) {
 384                                                         log.debug("Entity ID matched against SubjectAltName.");
 385                                                         return true;
 386                                                 }
 387                                         }
 388                                 }
 389                         }
 390                 } catch (CertificateParsingException e1) {
 391                         log.error("Encountered an problem trying to extract Subject Alternate "
 392                                         + "Name from supplied certificate: " + e1);
 393                 }
 394
 395                 // If that doesn't work, try to match using
 396                 // SSL-style hostname matching
 397                 if (getHostNameFromDN(certificate.getSubjectX500Principal()).equals(id)) {
 398                         log.debug("Entity ID matched against hostname.");
 399                         return true;
 400                 }
 401
 402                 return false;
 403         }
 404
 405         public static String getHostNameFromDN(X500Principal dn) {
 406
 407                 // Parse the ASN.1 representation of the dn and grab the last CN component that we find
 408                 // We used to do this with the dn string, but the JDK's default parsing caused problems with some DNs
 409
 410                 try {
 411                         ASN1InputStream asn1Stream = new ASN1InputStream(dn.getEncoded());
 412                         DERObject parent = asn1Stream.readObject();
 413
 414                         if (!(parent instanceof DERSequence)) {
 415                                 log.error("Unable to extract host name name from certificate subject DN: incorrect ASN.1 encoding.");
 416                                 return null;
 417                         }
 418
 419                         String cn = null;
 420                         for (int i = 0; i < ((DERSequence) parent).size(); i++) {
 421                                 DERObject dnComponent = ((DERSequence) parent).getObjectAt(i).getDERObject();
 422                                 if (!(dnComponent instanceof DERSet)) {
 423                                         continue;
 424                                 }
 425
 426                                 // Each DN component is a set
 427                                 for (int j = 0; j < ((DERSet) dnComponent).size(); j++) {
 428                                         DERObject grandChild = ((DERSet) dnComponent).getObjectAt(j).getDERObject();
 429
 430                                         if (((DERSequence) grandChild).getObjectAt(0) != null
 431                                                         && ((DERSequence) grandChild).getObjectAt(0).getDERObject() instanceof DERObjectIdentifier) {
 432                                                 DERObjectIdentifier componentId = (DERObjectIdentifier) ((DERSequence) grandChild).getObjectAt(
 433                                                                 0).getDERObject();
 434
 435                                                 if (CN_OID.equals(componentId.getId())) {
 436                                                         // OK, this dn component is actually a cn attribute
 437                                                         if (((DERSequence) grandChild).getObjectAt(1) != null
 438                                                                         && ((DERSequence) grandChild).getObjectAt(1).getDERObject() instanceof DERPrintableString) {
 439                                                                 cn = ((DERPrintableString) ((DERSequence) grandChild).getObjectAt(1).getDERObject())
 440                                                                                 .getString();
 441                                                         }
 442                                                 }
 443                                         }
 444                                 }
 445                         }
 446                         asn1Stream.close();
 447                         return cn;
 448
 449                 } catch (IOException e) {
 450                         log.error("Unable to extract host name name from certificate subject DN: ASN.1 parsing failed: " + e);
 451                         return null;
 452                 }
 453         }
 454
 455 }