Fixed a bug in trust processing that would cause validation to fail when empty CRLs...
[java-idp.git] / 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 }