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*
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* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
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package sun.security.provider.certpath;
import java.math.BigInteger;
import java.util.Collection;
import java.util.Date;
import java.util.Set;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.security.cert.PKIXCertPathChecker;
import java.security.cert.CertPathValidatorException;
import java.security.cert.TrustAnchor;
import java.security.interfaces.DSAParams;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.DSAPublicKeySpec;
import javax.security.auth.x500.X500Principal;
import sun.security.x509.X500Name;
import sun.security.util.Debug;
/**
* BasicChecker is a PKIXCertPathChecker that checks the basic information
* on a PKIX certificate, namely the signature, timestamp, and subject/issuer
* name chaining.
*
* @since 1.4
* @author Yassir Elley
*/
class BasicChecker extends PKIXCertPathChecker {
private static final Debug debug = Debug.getInstance("certpath");
private final PublicKey trustedPubKey;
private final X500Principal caName;
private final Date testDate;
private final String sigProvider;
private final boolean sigOnly;
private X500Principal prevSubject;
private PublicKey prevPubKey;
/**
* Constructor that initializes the input parameters.
*
* @param anchor the anchor selected to validate the target certificate
* @param testDate the time for which the validity of the certificate
* should be determined
* @param sigProvider the name of the signature provider
* @param sigOnly true if only signature checking is to be done;
* if false, all checks are done
*/
BasicChecker(TrustAnchor anchor, Date testDate, String sigProvider,
boolean sigOnly) throws CertPathValidatorException
{
if (anchor.getTrustedCert() != null) {
this.trustedPubKey = anchor.getTrustedCert().getPublicKey();
this.caName = anchor.getTrustedCert().getSubjectX500Principal();
} else {
this.trustedPubKey = anchor.getCAPublicKey();
this.caName = anchor.getCA();
}
this.testDate = testDate;
this.sigProvider = sigProvider;
this.sigOnly = sigOnly;
init(false);
}
/**
* Initializes the internal state of the checker from parameters
* specified in the constructor.
*/
public void init(boolean forward) throws CertPathValidatorException {
if (!forward) {
prevPubKey = trustedPubKey;
prevSubject = caName;
} else {
throw new
CertPathValidatorException("forward checking not supported");
}
}
public boolean isForwardCheckingSupported() {
return false;
}
public Set<String> getSupportedExtensions() {
return null;
}
/**
* Performs the signature, timestamp, and subject/issuer name chaining
* checks on the certificate using its internal state. This method does
* not remove any critical extensions from the Collection.
*
* @param cert the Certificate
* @param unresolvedCritExts a Collection of the unresolved critical
* extensions
* @exception CertPathValidatorException Exception thrown if certificate
* does not verify.
*/
public void check(Certificate cert, Collection<String> unresolvedCritExts)
throws CertPathValidatorException
{
X509Certificate currCert = (X509Certificate) cert;
if (!sigOnly) {
verifyTimestamp(currCert, testDate);
verifyNameChaining(currCert, prevSubject);
}
verifySignature(currCert, prevPubKey, sigProvider);
updateState(currCert);
}
/**
* Verifies the signature on the certificate using the previous public key
* @param cert the Certificate
* @param prevPubKey the previous PublicKey
* @param sigProvider a String containing the signature provider
* @exception CertPathValidatorException Exception thrown if certificate
* does not verify.
*/
private void verifySignature(X509Certificate cert, PublicKey prevPubKey,
String sigProvider) throws CertPathValidatorException
{
String msg = "signature";
if (debug != null)
debug.println("---checking " + msg + "...");
try {
cert.verify(prevPubKey, sigProvider);
} catch (Exception e) {
if (debug != null) {
debug.println(e.getMessage());
e.printStackTrace();
}
throw new CertPathValidatorException(msg + " check failed", e);
}
if (debug != null)
debug.println(msg + " verified.");
}
/**
* Internal method to verify the timestamp on a certificate
*/
private void verifyTimestamp(X509Certificate cert, Date date)
throws CertPathValidatorException
{
String msg = "timestamp";
if (debug != null)
debug.println("---checking " + msg + ":" + date.toString() + "...");
try {
cert.checkValidity(date);
} catch (Exception e) {
if (debug != null) {
debug.println(e.getMessage());
e.printStackTrace();
}
throw new CertPathValidatorException(msg + " check failed", e);
}
if (debug != null)
debug.println(msg + " verified.");
}
/**
* Internal method to check that cert has a valid DN to be next in a chain
*/
private void verifyNameChaining(X509Certificate cert,
X500Principal prevSubject) throws CertPathValidatorException
{
if (prevSubject != null) {
String msg = "subject/issuer name chaining";
if (debug != null)
debug.println("---checking " + msg + "...");
X500Principal currIssuer = cert.getIssuerX500Principal();
// reject null or empty issuer DNs
if (X500Name.asX500Name(currIssuer).isEmpty()) {
throw new CertPathValidatorException(msg + " check failed: " +
"empty/null issuer DN in certificate is invalid");
}
if (!(currIssuer.equals(prevSubject))) {
throw new CertPathValidatorException(msg + " check failed");
}
if (debug != null)
debug.println(msg + " verified.");
}
}
/**
* Internal method to manage state information at each iteration
*/
private void updateState(X509Certificate currCert)
throws CertPathValidatorException
{
PublicKey cKey = currCert.getPublicKey();
if (debug != null) {
debug.println("BasicChecker.updateState issuer: " +
currCert.getIssuerX500Principal().toString() + "; subject: " +
currCert.getSubjectX500Principal() + "; serial#: " +
currCert.getSerialNumber().toString());
}
if (cKey instanceof DSAPublicKey &&
((DSAPublicKey)cKey).getParams() == null) {
//cKey needs to inherit DSA parameters from prev key
cKey = makeInheritedParamsKey(cKey, prevPubKey);
if (debug != null) debug.println("BasicChecker.updateState Made " +
"key with inherited params");
}
prevPubKey = cKey;
prevSubject = currCert.getSubjectX500Principal();
}
/**
* Internal method to create a new key with inherited key parameters
*
* @param keyValueKey key from which to obtain key value
* @param keyParamsKey key from which to obtain key parameters
* @return new public key having value and parameters
* @throws CertPathValidatorException if keys are not appropriate types
* for this operation
*/
static PublicKey makeInheritedParamsKey(PublicKey keyValueKey,
PublicKey keyParamsKey) throws CertPathValidatorException
{
PublicKey usableKey;
if (!(keyValueKey instanceof DSAPublicKey) ||
!(keyParamsKey instanceof DSAPublicKey))
throw new CertPathValidatorException("Input key is not " +
"appropriate type for " +
"inheriting parameters");
DSAParams params = ((DSAPublicKey)keyParamsKey).getParams();
if (params == null)
throw new CertPathValidatorException("Key parameters missing");
try {
BigInteger y = ((DSAPublicKey)keyValueKey).getY();
KeyFactory kf = KeyFactory.getInstance("DSA");
DSAPublicKeySpec ks = new DSAPublicKeySpec(y,
params.getP(),
params.getQ(),
params.getG());
usableKey = kf.generatePublic(ks);
} catch (Exception e) {
throw new CertPathValidatorException("Unable to generate key with" +
" inherited parameters: " +
e.getMessage(), e);
}
return usableKey;
}
/**
* return the public key associated with the last certificate processed
*
* @return PublicKey the last public key processed
*/
PublicKey getPublicKey() {
return prevPubKey;
}
}