package org.apache.xml.security.keys.keyresolver.implementations;
import java.security.PublicKey;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.Iterator;
import javax.crypto.SecretKey;
import org.apache.xml.security.exceptions.XMLSecurityException;
import org.apache.xml.security.keys.content.X509Data;
import org.apache.xml.security.keys.content.x509.XMLX509Digest;
import org.apache.xml.security.keys.keyresolver.KeyResolverException;
import org.apache.xml.security.keys.keyresolver.KeyResolverSpi;
import org.apache.xml.security.keys.storage.StorageResolver;
import org.apache.xml.security.utils.Constants;
import org.apache.xml.security.utils.XMLUtils;
import org.w3c.dom.Element;
/**
* KeyResolverSpi implementation which resolves public keys and X.509 certificates from a
* <code>dsig11:X509Digest</code> element.
*
* @author Brent Putman (putmanb@georgetown.edu)
*/
public class X509DigestResolver extends KeyResolverSpi {
/** {@link org.apache.commons.logging} logging facility */
private static org.apache.commons.logging.Log log =
org.apache.commons.logging.LogFactory.getLog(X509DigestResolver.class);
/** {@inheritDoc}. */
public boolean engineCanResolve(Element element, String baseURI, StorageResolver storage) {
if (XMLUtils.elementIsInSignatureSpace(element, Constants._TAG_X509DATA)) {
try {
X509Data x509Data = new X509Data(element, baseURI);
return x509Data.containsDigest();
} catch (XMLSecurityException e) {
return false;
}
} else {
return false;
}
}
/** {@inheritDoc}. */
public PublicKey engineLookupAndResolvePublicKey(Element element, String baseURI, StorageResolver storage)
throws KeyResolverException {
X509Certificate cert = this.engineLookupResolveX509Certificate(element, baseURI, storage);
if (cert != null) {
return cert.getPublicKey();
}
return null;
}
/** {@inheritDoc}. */
public X509Certificate engineLookupResolveX509Certificate(Element element, String baseURI, StorageResolver storage)
throws KeyResolverException {
if (log.isDebugEnabled()) {
log.debug("Can I resolve " + element.getTagName());
}
if (!engineCanResolve(element, baseURI, storage)) {
return null;
}
try {
return resolveCertificate(element, baseURI, storage);
} catch (XMLSecurityException e) {
if (log.isDebugEnabled()) {
log.debug("XMLSecurityException", e);
}
}
return null;
}
/** {@inheritDoc}. */
public SecretKey engineLookupAndResolveSecretKey(Element element, String baseURI, StorageResolver storage)
throws KeyResolverException {
return null;
}
/**
* Resolves from the storage resolver the actual certificate represented by the digest.
*
* @param element
* @param baseURI
* @param storage
* @return
* @throws XMLSecurityException
*/
private X509Certificate resolveCertificate(Element element, String baseURI, StorageResolver storage)
throws XMLSecurityException {
XMLX509Digest x509Digests[] = null;
Element x509childNodes[] = XMLUtils.selectDs11Nodes(element.getFirstChild(), Constants._TAG_X509DIGEST);
if (x509childNodes == null || x509childNodes.length <= 0) {
return null;
}
try {
checkStorage(storage);
x509Digests = new XMLX509Digest[x509childNodes.length];
for (int i = 0; i < x509childNodes.length; i++) {
x509Digests[i] = new XMLX509Digest(x509childNodes[i], baseURI);
}
Iterator<Certificate> storageIterator = storage.getIterator();
while (storageIterator.hasNext()) {
X509Certificate cert = (X509Certificate) storageIterator.next();
for (int i = 0; i < x509Digests.length; i++) {
XMLX509Digest keyInfoDigest = x509Digests[i];
byte[] certDigestBytes = XMLX509Digest.getDigestBytesFromCert(cert, keyInfoDigest.getAlgorithm());
if (Arrays.equals(keyInfoDigest.getDigestBytes(), certDigestBytes)) {
if (log.isDebugEnabled()) {
log.debug("Found certificate with: " + cert.getSubjectX500Principal().getName());
}
return cert;
}
}
}
} catch (XMLSecurityException ex) {
throw new KeyResolverException("empty", ex);
}
return null;
}
/**
* Method checkSrorage
*
* @param storage
* @throws KeyResolverException
*/
private void checkStorage(StorageResolver storage) throws KeyResolverException {
if (storage == null) {
Object exArgs[] = { Constants._TAG_X509DIGEST };
KeyResolverException ex = new KeyResolverException("KeyResolver.needStorageResolver", exArgs);
if (log.isDebugEnabled()) {
log.debug("", ex);
}
throw ex;
}
}
}