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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* 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
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package sun.security.provider.certpath;
import java.security.AlgorithmConstraints;
import java.security.CryptoPrimitive;
import java.security.Timestamp;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.Set;
import java.util.EnumSet;
import java.math.BigInteger;
import java.security.PublicKey;
import java.security.KeyFactory;
import java.security.AlgorithmParameters;
import java.security.GeneralSecurityException;
import java.security.cert.Certificate;
import java.security.cert.X509CRL;
import java.security.cert.X509Certificate;
import java.security.cert.PKIXCertPathChecker;
import java.security.cert.TrustAnchor;
import java.security.cert.CRLException;
import java.security.cert.CertificateException;
import java.security.cert.CertPathValidatorException;
import java.security.cert.CertPathValidatorException.BasicReason;
import java.security.cert.PKIXReason;
import java.security.interfaces.DSAParams;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.DSAPublicKeySpec;
import sun.security.util.AnchorCertificates;
import sun.security.util.CertConstraintParameters;
import sun.security.util.Debug;
import sun.security.util.DisabledAlgorithmConstraints;
import sun.security.x509.X509CertImpl;
import sun.security.x509.X509CRLImpl;
import sun.security.x509.AlgorithmId;
/**
* A {@code PKIXCertPathChecker} implementation to check whether a
* specified certificate contains the required algorithm constraints.
* <p>
* Certificate fields such as the subject public key, the signature
* algorithm, key usage, extended key usage, etc. need to conform to
* the specified algorithm constraints.
*
* @see PKIXCertPathChecker
* @see PKIXParameters
*/
public final class AlgorithmChecker extends PKIXCertPathChecker {
private static final Debug debug = Debug.getInstance("certpath");
private final AlgorithmConstraints constraints;
private final PublicKey trustedPubKey;
private final Date pkixdate;
private PublicKey prevPubKey;
private final Timestamp jarTimestamp;
private static final Set<CryptoPrimitive> SIGNATURE_PRIMITIVE_SET =
Collections.unmodifiableSet(EnumSet.of(CryptoPrimitive.SIGNATURE));
private static final Set<CryptoPrimitive> KU_PRIMITIVE_SET =
Collections.unmodifiableSet(EnumSet.of(
CryptoPrimitive.SIGNATURE,
CryptoPrimitive.KEY_ENCAPSULATION,
CryptoPrimitive.PUBLIC_KEY_ENCRYPTION,
CryptoPrimitive.KEY_AGREEMENT));
private static final DisabledAlgorithmConstraints
certPathDefaultConstraints = new DisabledAlgorithmConstraints(
DisabledAlgorithmConstraints.PROPERTY_CERTPATH_DISABLED_ALGS);
// If there is no "cacerts" keyword, then disable anchor checking
private static final boolean publicCALimits =
certPathDefaultConstraints.checkProperty("jdkCA");
// If anchor checking enabled, this will be true if the trust anchor
// has a match in the cacerts file
private boolean trustedMatch = false;
/**
* Create a new {@code AlgorithmChecker} with the algorithm
* constraints specified in security property
* "jdk.certpath.disabledAlgorithms".
*
* @param anchor the trust anchor selected to validate the target
* certificate
*/
public AlgorithmChecker(TrustAnchor anchor) {
this(anchor, certPathDefaultConstraints, null);
}
/**
* Create a new {@code AlgorithmChecker} with the
* given {@code TrustAnchor} and {@code AlgorithmConstraints}.
*
* @param anchor the trust anchor selected to validate the target
* certificate
* @param constraints the algorithm constraints (or null)
*
* @throws IllegalArgumentException if the {@code anchor} is null
*/
public AlgorithmChecker(TrustAnchor anchor,
AlgorithmConstraints constraints) {
this(anchor, constraints, null);
}
/**
* Create a new {@code AlgorithmChecker} with the
* given {@code AlgorithmConstraints}.
* <p>
* Note that this constructor will be used to check a certification
* path where the trust anchor is unknown, or a certificate list which may
* contain the trust anchor. This constructor is used by SunJSSE.
*
* @param constraints the algorithm constraints (or null)
*/
public AlgorithmChecker(AlgorithmConstraints constraints) {
this.prevPubKey = null;
this.trustedPubKey = null;
this.constraints = constraints;
this.pkixdate = null;
this.jarTimestamp = null;
}
/**
* Create a new {@code AlgorithmChecker} with the given
* {@code Timestamp}.
* <p>
* Note that this constructor will be used to check a certification
* path for signed JAR files that are timestamped.
*
* @param jarTimestamp Timestamp passed for JAR timestamp constraint
* checking. Set to null if not applicable.
*/
public AlgorithmChecker(Timestamp jarTimestamp) {
this.prevPubKey = null;
this.trustedPubKey = null;
this.constraints = certPathDefaultConstraints;
if (jarTimestamp == null) {
throw new IllegalArgumentException(
"Timestamp cannot be null");
}
this.pkixdate = jarTimestamp.getTimestamp();
this.jarTimestamp = jarTimestamp;
}
/**
* Create a new {@code AlgorithmChecker} with the
* given {@code TrustAnchor} and {@code AlgorithmConstraints}.
*
* @param anchor the trust anchor selected to validate the target
* certificate
* @param constraints the algorithm constraints (or null)
* @param pkixdate Date the constraints are checked against. The value is
* either the PKIXParameter date or null for the current date.
*
* @throws IllegalArgumentException if the {@code anchor} is null
*/
public AlgorithmChecker(TrustAnchor anchor,
AlgorithmConstraints constraints,
Date pkixdate) {
if (anchor != null) {
if (anchor.getTrustedCert() != null) {
this.trustedPubKey = anchor.getTrustedCert().getPublicKey();
// Check for anchor certificate restrictions
trustedMatch = checkFingerprint(anchor.getTrustedCert());
if (trustedMatch && debug != null) {
debug.println("trustedMatch = true");
}
} else {
this.trustedPubKey = anchor.getCAPublicKey();
}
} else {
this.trustedPubKey = null;
if (debug != null) {
debug.println("TrustAnchor is null, trustedMatch is false.");
}
}
this.prevPubKey = trustedPubKey;
this.constraints = constraints;
this.pkixdate = pkixdate;
this.jarTimestamp = null;
}
/**
* Create a new {@code AlgorithmChecker} with the
* given {@code TrustAnchor} and {@code PKIXParameter} date.
*
* @param anchor the trust anchor selected to validate the target
* certificate
* @param pkixdate Date the constraints are checked against. The value is
* either the PKIXParameter date or null for the current date.
*
* @throws IllegalArgumentException if the {@code anchor} is null
*/
public AlgorithmChecker(TrustAnchor anchor, Date pkixdate) {
this(anchor, certPathDefaultConstraints, pkixdate);
}
// Check this 'cert' for restrictions in the AnchorCertificates
// trusted certificates list
private static boolean checkFingerprint(X509Certificate cert) {
if (!publicCALimits) {
return false;
}
if (debug != null) {
debug.println("AlgorithmChecker.contains: " + cert.getSigAlgName());
}
return AnchorCertificates.contains(cert);
}
Timestamp getJarTimestamp() {
return jarTimestamp;
}
@Override
public void init(boolean forward) throws CertPathValidatorException {
// Note that this class does not support forward mode.
if (!forward) {
if (trustedPubKey != null) {
prevPubKey = trustedPubKey;
} else {
prevPubKey = null;
}
} else {
throw new
CertPathValidatorException("forward checking not supported");
}
}
@Override
public boolean isForwardCheckingSupported() {
// Note that as this class does not support forward mode, the method
// will always returns false.
return false;
}
@Override
public Set<String> getSupportedExtensions() {
return null;
}
@Override
public void check(Certificate cert,
Collection<String> unresolvedCritExts)
throws CertPathValidatorException {
if (!(cert instanceof X509Certificate) || constraints == null) {
// ignore the check for non-x.509 certificate or null constraints
return;
}
// check the key usage and key size
boolean[] keyUsage = ((X509Certificate) cert).getKeyUsage();
if (keyUsage != null && keyUsage.length < 9) {
throw new CertPathValidatorException(
"incorrect KeyUsage extension",
null, null, -1, PKIXReason.INVALID_KEY_USAGE);
}
// Assume all key usage bits are set if key usage is not present
Set<CryptoPrimitive> primitives = KU_PRIMITIVE_SET;
if (keyUsage != null) {
primitives = EnumSet.noneOf(CryptoPrimitive.class);
if (keyUsage[0] || keyUsage[1] || keyUsage[5] || keyUsage[6]) {
// keyUsage[0]: KeyUsage.digitalSignature
// keyUsage[1]: KeyUsage.nonRepudiation
// keyUsage[5]: KeyUsage.keyCertSign
// keyUsage[6]: KeyUsage.cRLSign
primitives.add(CryptoPrimitive.SIGNATURE);
}
if (keyUsage[2]) { // KeyUsage.keyEncipherment
primitives.add(CryptoPrimitive.KEY_ENCAPSULATION);
}
if (keyUsage[3]) { // KeyUsage.dataEncipherment
primitives.add(CryptoPrimitive.PUBLIC_KEY_ENCRYPTION);
}
if (keyUsage[4]) { // KeyUsage.keyAgreement
primitives.add(CryptoPrimitive.KEY_AGREEMENT);
}
// KeyUsage.encipherOnly and KeyUsage.decipherOnly are
// undefined in the absence of the keyAgreement bit.
if (primitives.isEmpty()) {
throw new CertPathValidatorException(
"incorrect KeyUsage extension bits",
null, null, -1, PKIXReason.INVALID_KEY_USAGE);
}
}
PublicKey currPubKey = cert.getPublicKey();
if (constraints instanceof DisabledAlgorithmConstraints) {
// Check against DisabledAlgorithmConstraints certpath constraints.
// permits() will throw exception on failure.
((DisabledAlgorithmConstraints)constraints).permits(primitives,
new CertConstraintParameters((X509Certificate)cert,
trustedMatch, pkixdate, jarTimestamp));
// If there is no previous key, set one and exit
if (prevPubKey == null) {
prevPubKey = currPubKey;
return;
}
}
X509CertImpl x509Cert;
AlgorithmId algorithmId;
try {
x509Cert = X509CertImpl.toImpl((X509Certificate)cert);
algorithmId = (AlgorithmId)x509Cert.get(X509CertImpl.SIG_ALG);
} catch (CertificateException ce) {
throw new CertPathValidatorException(ce);
}
AlgorithmParameters currSigAlgParams = algorithmId.getParameters();
String currSigAlg = x509Cert.getSigAlgName();
// If 'constraints' is not of DisabledAlgorithmConstraints, check all
// everything individually
if (!(constraints instanceof DisabledAlgorithmConstraints)) {
// Check the current signature algorithm
if (!constraints.permits(
SIGNATURE_PRIMITIVE_SET,
currSigAlg, currSigAlgParams)) {
throw new CertPathValidatorException(
"Algorithm constraints check failed on signature " +
"algorithm: " + currSigAlg, null, null, -1,
BasicReason.ALGORITHM_CONSTRAINED);
}
if (!constraints.permits(primitives, currPubKey)) {
throw new CertPathValidatorException(
"Algorithm constraints check failed on keysize: " +
sun.security.util.KeyUtil.getKeySize(currPubKey),
null, null, -1, BasicReason.ALGORITHM_CONSTRAINED);
}
}
// Check with previous cert for signature algorithm and public key
if (prevPubKey != null) {
if (!constraints.permits(
SIGNATURE_PRIMITIVE_SET,
currSigAlg, prevPubKey, currSigAlgParams)) {
throw new CertPathValidatorException(
"Algorithm constraints check failed on " +
"signature algorithm: " + currSigAlg,
null, null, -1, BasicReason.ALGORITHM_CONSTRAINED);
}
// Inherit key parameters from previous key
if (PKIX.isDSAPublicKeyWithoutParams(currPubKey)) {
// Inherit DSA parameters from previous key
if (!(prevPubKey instanceof DSAPublicKey)) {
throw new CertPathValidatorException("Input key is not " +
"of a appropriate type for inheriting parameters");
}
DSAParams params = ((DSAPublicKey)prevPubKey).getParams();
if (params == null) {
throw new CertPathValidatorException(
"Key parameters missing from public key.");
}
try {
BigInteger y = ((DSAPublicKey)currPubKey).getY();
KeyFactory kf = KeyFactory.getInstance("DSA");
DSAPublicKeySpec ks = new DSAPublicKeySpec(y,
params.getP(),
params.getQ(),
params.getG());
currPubKey = kf.generatePublic(ks);
} catch (GeneralSecurityException e) {
throw new CertPathValidatorException("Unable to generate " +
"key with inherited parameters: " + e.getMessage(), e);
}
}
}
// reset the previous public key
prevPubKey = currPubKey;
// check the extended key usage, ignore the check now
// List<String> extendedKeyUsages = x509Cert.getExtendedKeyUsage();
// DO NOT remove any unresolved critical extensions
}
/**
* Try to set the trust anchor of the checker.
* <p>
* If there is no trust anchor specified and the checker has not started,
* set the trust anchor.
*
* @param anchor the trust anchor selected to validate the target
* certificate
*/
void trySetTrustAnchor(TrustAnchor anchor) {
// Don't bother if the check has started or trust anchor has already
// specified.
if (prevPubKey == null) {
if (anchor == null) {
throw new IllegalArgumentException(
"The trust anchor cannot be null");
}
// Don't bother to change the trustedPubKey.
if (anchor.getTrustedCert() != null) {
prevPubKey = anchor.getTrustedCert().getPublicKey();
// Check for anchor certificate restrictions
trustedMatch = checkFingerprint(anchor.getTrustedCert());
if (trustedMatch && debug != null) {
debug.println("trustedMatch = true");
}
} else {
prevPubKey = anchor.getCAPublicKey();
}
}
}
/**
* Check the signature algorithm with the specified public key.
*
* @param key the public key to verify the CRL signature
* @param crl the target CRL
*/
static void check(PublicKey key, X509CRL crl)
throws CertPathValidatorException {
X509CRLImpl x509CRLImpl = null;
try {
x509CRLImpl = X509CRLImpl.toImpl(crl);
} catch (CRLException ce) {
throw new CertPathValidatorException(ce);
}
AlgorithmId algorithmId = x509CRLImpl.getSigAlgId();
check(key, algorithmId);
}
/**
* Check the signature algorithm with the specified public key.
*
* @param key the public key to verify the CRL signature
* @param algorithmId signature algorithm Algorithm ID
*/
static void check(PublicKey key, AlgorithmId algorithmId)
throws CertPathValidatorException {
String sigAlgName = algorithmId.getName();
AlgorithmParameters sigAlgParams = algorithmId.getParameters();
if (!certPathDefaultConstraints.permits(
SIGNATURE_PRIMITIVE_SET, sigAlgName, key, sigAlgParams)) {
throw new CertPathValidatorException(
"Algorithm constraints check failed on signature algorithm: " +
sigAlgName + " is disabled",
null, null, -1, BasicReason.ALGORITHM_CONSTRAINED);
}
}
}