/*
* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.security.validator;
import java.util.*;
import java.security.*;
import java.security.cert.*;
import javax.security.auth.x500.X500Principal;
import sun.security.action.GetBooleanAction;
import sun.security.provider.certpath.AlgorithmChecker;
/**
* Validator implementation built on the PKIX CertPath API. This
* implementation will be emphasized going forward.<p>
* <p>
* Note that the validate() implementation tries to use a PKIX validator
* if that appears possible and a PKIX builder otherwise. This increases
* performance and currently also leads to better exception messages
* in case of failures.
* <p>
* {@code PKIXValidator} objects are immutable once they have been created.
* Please DO NOT add methods that can change the state of an instance once
* it has been created.
*
* @author Andreas Sterbenz
*/
public final class PKIXValidator extends Validator {
/**
* Flag indicating whether to enable revocation check for the PKIX trust
* manager. Typically, this will only work if the PKIX implementation
* supports CRL distribution points as we do not manually setup CertStores.
*/
private final static boolean checkTLSRevocation =
AccessController.doPrivileged
(new GetBooleanAction("com.sun.net.ssl.checkRevocation"));
// enable use of the validator if possible
private final static boolean TRY_VALIDATOR = true;
private final Set<X509Certificate> trustedCerts;
private final PKIXBuilderParameters parameterTemplate;
private int certPathLength = -1;
// needed only for the validator
private final Map<X500Principal, List<PublicKey>> trustedSubjects;
private final CertificateFactory factory;
private final boolean plugin;
PKIXValidator(String variant, Collection<X509Certificate> trustedCerts) {
super(TYPE_PKIX, variant);
if (trustedCerts instanceof Set) {
this.trustedCerts = (Set<X509Certificate>)trustedCerts;
} else {
this.trustedCerts = new HashSet<X509Certificate>(trustedCerts);
}
Set<TrustAnchor> trustAnchors = new HashSet<TrustAnchor>();
for (X509Certificate cert : trustedCerts) {
trustAnchors.add(new TrustAnchor(cert, null));
}
try {
parameterTemplate = new PKIXBuilderParameters(trustAnchors, null);
} catch (InvalidAlgorithmParameterException e) {
throw new RuntimeException("Unexpected error: " + e.toString(), e);
}
setDefaultParameters(variant);
// initCommon();
if (TRY_VALIDATOR) {
if (TRY_VALIDATOR == false) {
return;
}
trustedSubjects = new HashMap<X500Principal, List<PublicKey>>();
for (X509Certificate cert : trustedCerts) {
X500Principal dn = cert.getSubjectX500Principal();
List<PublicKey> keys;
if (trustedSubjects.containsKey(dn)) {
keys = trustedSubjects.get(dn);
} else {
keys = new ArrayList<PublicKey>();
trustedSubjects.put(dn, keys);
}
keys.add(cert.getPublicKey());
}
try {
factory = CertificateFactory.getInstance("X.509");
} catch (CertificateException e) {
throw new RuntimeException("Internal error", e);
}
plugin = variant.equals(VAR_PLUGIN_CODE_SIGNING);
} else {
plugin = false;
}
}
PKIXValidator(String variant, PKIXBuilderParameters params) {
super(TYPE_PKIX, variant);
trustedCerts = new HashSet<X509Certificate>();
for (TrustAnchor anchor : params.getTrustAnchors()) {
X509Certificate cert = anchor.getTrustedCert();
if (cert != null) {
trustedCerts.add(cert);
}
}
parameterTemplate = params;
// initCommon();
if (TRY_VALIDATOR) {
if (TRY_VALIDATOR == false) {
return;
}
trustedSubjects = new HashMap<X500Principal, List<PublicKey>>();
for (X509Certificate cert : trustedCerts) {
X500Principal dn = cert.getSubjectX500Principal();
List<PublicKey> keys;
if (trustedSubjects.containsKey(dn)) {
keys = trustedSubjects.get(dn);
} else {
keys = new ArrayList<PublicKey>();
trustedSubjects.put(dn, keys);
}
keys.add(cert.getPublicKey());
}
try {
factory = CertificateFactory.getInstance("X.509");
} catch (CertificateException e) {
throw new RuntimeException("Internal error", e);
}
plugin = variant.equals(VAR_PLUGIN_CODE_SIGNING);
} else {
plugin = false;
}
}
public Collection<X509Certificate> getTrustedCertificates() {
return trustedCerts;
}
/**
* Returns the length of the last certification path that is validated by
* CertPathValidator. This is intended primarily as a callback mechanism
* for PKIXCertPathCheckers to determine the length of the certification
* path that is being validated. It is necessary since engineValidate()
* may modify the length of the path.
*
* @return the length of the last certification path passed to
* CertPathValidator.validate, or -1 if it has not been invoked yet
*/
public int getCertPathLength() { // mutable, should be private
return certPathLength;
}
/**
* Set J2SE global default PKIX parameters. Currently, hardcoded to disable
* revocation checking. In the future, this should be configurable.
*/
private void setDefaultParameters(String variant) {
if ((variant == Validator.VAR_TLS_SERVER) ||
(variant == Validator.VAR_TLS_CLIENT)) {
parameterTemplate.setRevocationEnabled(checkTLSRevocation);
} else {
parameterTemplate.setRevocationEnabled(false);
}
}
/**
* Return the PKIX parameters used by this instance. An application may
* modify the parameters but must make sure not to perform any concurrent
* validations.
*/
public PKIXBuilderParameters getParameters() { // mutable, should be private
return parameterTemplate;
}
@Override
X509Certificate[] engineValidate(X509Certificate[] chain,
Collection<X509Certificate> otherCerts,
AlgorithmConstraints constraints,
Object parameter) throws CertificateException {
if ((chain == null) || (chain.length == 0)) {
throw new CertificateException
("null or zero-length certificate chain");
}
// add new algorithm constraints checker
PKIXBuilderParameters pkixParameters =
(PKIXBuilderParameters) parameterTemplate.clone();
AlgorithmChecker algorithmChecker = null;
if (constraints != null) {
algorithmChecker = new AlgorithmChecker(constraints);
pkixParameters.addCertPathChecker(algorithmChecker);
}
if (TRY_VALIDATOR) {
// check that chain is in correct order and check if chain contains
// trust anchor
X500Principal prevIssuer = null;
for (int i = 0; i < chain.length; i++) {
X509Certificate cert = chain[i];
X500Principal dn = cert.getSubjectX500Principal();
if (i != 0 &&
!dn.equals(prevIssuer)) {
// chain is not ordered correctly, call builder instead
return doBuild(chain, otherCerts, pkixParameters);
}
// Check if chain[i] is already trusted. It may be inside
// trustedCerts, or has the same dn and public key as a cert
// inside trustedCerts. The latter happens when a CA has
// updated its cert with a stronger signature algorithm in JRE
// but the weak one is still in circulation.
if (trustedCerts.contains(cert) || // trusted cert
(trustedSubjects.containsKey(dn) && // replacing ...
trustedSubjects.get(dn).contains( // ... weak cert
cert.getPublicKey()))) {
if (i == 0) {
return new X509Certificate[] {chain[0]};
}
// Remove and call validator on partial chain [0 .. i-1]
X509Certificate[] newChain = new X509Certificate[i];
System.arraycopy(chain, 0, newChain, 0, i);
return doValidate(newChain, pkixParameters);
}
prevIssuer = cert.getIssuerX500Principal();
}
// apparently issued by trust anchor?
X509Certificate last = chain[chain.length - 1];
X500Principal issuer = last.getIssuerX500Principal();
X500Principal subject = last.getSubjectX500Principal();
if (trustedSubjects.containsKey(issuer) &&
isSignatureValid(trustedSubjects.get(issuer), last)) {
return doValidate(chain, pkixParameters);
}
// don't fallback to builder if called from plugin/webstart
if (plugin) {
// Validate chain even if no trust anchor is found. This
// allows plugin/webstart to make sure the chain is
// otherwise valid
if (chain.length > 1) {
X509Certificate[] newChain =
new X509Certificate[chain.length-1];
System.arraycopy(chain, 0, newChain, 0, newChain.length);
// temporarily set last cert as sole trust anchor
try {
pkixParameters.setTrustAnchors
(Collections.singleton(new TrustAnchor
(chain[chain.length-1], null)));
} catch (InvalidAlgorithmParameterException iape) {
// should never occur, but ...
throw new CertificateException(iape);
}
doValidate(newChain, pkixParameters);
}
// if the rest of the chain is valid, throw exception
// indicating no trust anchor was found
throw new ValidatorException
(ValidatorException.T_NO_TRUST_ANCHOR);
}
// otherwise, fall back to builder
}
return doBuild(chain, otherCerts, pkixParameters);
}
private boolean isSignatureValid(List<PublicKey> keys,
X509Certificate sub) {
if (plugin) {
for (PublicKey key: keys) {
try {
sub.verify(key);
return true;
} catch (Exception ex) {
continue;
}
}
return false;
}
return true; // only check if PLUGIN is set
}
private static X509Certificate[] toArray(CertPath path, TrustAnchor anchor)
throws CertificateException {
List<? extends java.security.cert.Certificate> list =
path.getCertificates();
X509Certificate[] chain = new X509Certificate[list.size() + 1];
list.toArray(chain);
X509Certificate trustedCert = anchor.getTrustedCert();
if (trustedCert == null) {
throw new ValidatorException
("TrustAnchor must be specified as certificate");
}
chain[chain.length - 1] = trustedCert;
return chain;
}
/**
* Set the check date (for debugging).
*/
private void setDate(PKIXBuilderParameters params) {
Date date = validationDate;
if (date != null) {
params.setDate(date);
}
}
private X509Certificate[] doValidate(X509Certificate[] chain,
PKIXBuilderParameters params) throws CertificateException {
try {
setDate(params);
// do the validation
CertPathValidator validator = CertPathValidator.getInstance("PKIX");
CertPath path = factory.generateCertPath(Arrays.asList(chain));
certPathLength = chain.length;
PKIXCertPathValidatorResult result =
(PKIXCertPathValidatorResult)validator.validate(path, params);
return toArray(path, result.getTrustAnchor());
} catch (GeneralSecurityException e) {
throw new ValidatorException
("PKIX path validation failed: " + e.toString(), e);
}
}
private X509Certificate[] doBuild(X509Certificate[] chain,
Collection<X509Certificate> otherCerts,
PKIXBuilderParameters params) throws CertificateException {
try {
setDate(params);
// setup target constraints
X509CertSelector selector = new X509CertSelector();
selector.setCertificate(chain[0]);
params.setTargetCertConstraints(selector);
// setup CertStores
Collection<X509Certificate> certs =
new ArrayList<X509Certificate>();
certs.addAll(Arrays.asList(chain));
if (otherCerts != null) {
certs.addAll(otherCerts);
}
CertStore store = CertStore.getInstance("Collection",
new CollectionCertStoreParameters(certs));
params.addCertStore(store);
// do the build
CertPathBuilder builder = CertPathBuilder.getInstance("PKIX");
PKIXCertPathBuilderResult result =
(PKIXCertPathBuilderResult)builder.build(params);
return toArray(result.getCertPath(), result.getTrustAnchor());
} catch (GeneralSecurityException e) {
throw new ValidatorException
("PKIX path building failed: " + e.toString(), e);
}
}
}