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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
* accompanied this code).
*
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package com.sun.crypto.provider;
import java.security.Key;
import java.security.PublicKey;
import java.security.PrivateKey;
import java.security.KeyFactorySpi;
import java.security.InvalidKeyException;
import java.security.spec.KeySpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import javax.crypto.spec.DHPublicKeySpec;
import javax.crypto.spec.DHPrivateKeySpec;
import javax.crypto.spec.DHParameterSpec;
/**
* This class implements the Diffie-Hellman key factory of the Sun provider.
*
* @author Jan Luehe
*
*/
public final class DHKeyFactory extends KeyFactorySpi {
/**
* Empty constructor
*/
public DHKeyFactory() {
}
/**
* Generates a public key object from the provided key specification
* (key material).
*
* @param keySpec the specification (key material) of the public key
*
* @return the public key
*
* @exception InvalidKeySpecException if the given key specification
* is inappropriate for this key factory to produce a public key.
*/
protected PublicKey engineGeneratePublic(KeySpec keySpec)
throws InvalidKeySpecException
{
try {
if (keySpec instanceof DHPublicKeySpec) {
DHPublicKeySpec dhPubKeySpec = (DHPublicKeySpec)keySpec;
return new DHPublicKey(dhPubKeySpec.getY(),
dhPubKeySpec.getP(),
dhPubKeySpec.getG());
} else if (keySpec instanceof X509EncodedKeySpec) {
return new DHPublicKey
(((X509EncodedKeySpec)keySpec).getEncoded());
} else {
throw new InvalidKeySpecException
("Inappropriate key specification");
}
} catch (InvalidKeyException e) {
throw new InvalidKeySpecException
("Inappropriate key specification", e);
}
}
/**
* Generates a private key object from the provided key specification
* (key material).
*
* @param keySpec the specification (key material) of the private key
*
* @return the private key
*
* @exception InvalidKeySpecException if the given key specification
* is inappropriate for this key factory to produce a private key.
*/
protected PrivateKey engineGeneratePrivate(KeySpec keySpec)
throws InvalidKeySpecException
{
try {
if (keySpec instanceof DHPrivateKeySpec) {
DHPrivateKeySpec dhPrivKeySpec = (DHPrivateKeySpec)keySpec;
return new DHPrivateKey(dhPrivKeySpec.getX(),
dhPrivKeySpec.getP(),
dhPrivKeySpec.getG());
} else if (keySpec instanceof PKCS8EncodedKeySpec) {
return new DHPrivateKey
(((PKCS8EncodedKeySpec)keySpec).getEncoded());
} else {
throw new InvalidKeySpecException
("Inappropriate key specification");
}
} catch (InvalidKeyException e) {
throw new InvalidKeySpecException
("Inappropriate key specification", e);
}
}
/**
* Returns a specification (key material) of the given key object
* in the requested format.
*
* @param key the key
*
* @param keySpec the requested format in which the key material shall be
* returned
*
* @return the underlying key specification (key material) in the
* requested format
*
* @exception InvalidKeySpecException if the requested key specification is
* inappropriate for the given key, or the given key cannot be processed
* (e.g., the given key has an unrecognized algorithm or format).
*/
protected <T extends KeySpec>
T engineGetKeySpec(Key key, Class<T> keySpec)
throws InvalidKeySpecException {
DHParameterSpec params;
if (key instanceof javax.crypto.interfaces.DHPublicKey) {
if (DHPublicKeySpec.class.isAssignableFrom(keySpec)) {
javax.crypto.interfaces.DHPublicKey dhPubKey
= (javax.crypto.interfaces.DHPublicKey) key;
params = dhPubKey.getParams();
return keySpec.cast(new DHPublicKeySpec(dhPubKey.getY(),
params.getP(),
params.getG()));
} else if (X509EncodedKeySpec.class.isAssignableFrom(keySpec)) {
return keySpec.cast(new X509EncodedKeySpec(key.getEncoded()));
} else {
throw new InvalidKeySpecException
("Inappropriate key specification");
}
} else if (key instanceof javax.crypto.interfaces.DHPrivateKey) {
if (DHPrivateKeySpec.class.isAssignableFrom(keySpec)) {
javax.crypto.interfaces.DHPrivateKey dhPrivKey
= (javax.crypto.interfaces.DHPrivateKey)key;
params = dhPrivKey.getParams();
return keySpec.cast(new DHPrivateKeySpec(dhPrivKey.getX(),
params.getP(),
params.getG()));
} else if (PKCS8EncodedKeySpec.class.isAssignableFrom(keySpec)) {
return keySpec.cast(new PKCS8EncodedKeySpec(key.getEncoded()));
} else {
throw new InvalidKeySpecException
("Inappropriate key specification");
}
} else {
throw new InvalidKeySpecException("Inappropriate key type");
}
}
/**
* Translates a key object, whose provider may be unknown or potentially
* untrusted, into a corresponding key object of this key factory.
*
* @param key the key whose provider is unknown or untrusted
*
* @return the translated key
*
* @exception InvalidKeyException if the given key cannot be processed by
* this key factory.
*/
protected Key engineTranslateKey(Key key)
throws InvalidKeyException
{
try {
if (key instanceof javax.crypto.interfaces.DHPublicKey) {
// Check if key originates from this factory
if (key instanceof com.sun.crypto.provider.DHPublicKey) {
return key;
}
// Convert key to spec
DHPublicKeySpec dhPubKeySpec
= engineGetKeySpec(key, DHPublicKeySpec.class);
// Create key from spec, and return it
return engineGeneratePublic(dhPubKeySpec);
} else if (key instanceof javax.crypto.interfaces.DHPrivateKey) {
// Check if key originates from this factory
if (key instanceof com.sun.crypto.provider.DHPrivateKey) {
return key;
}
// Convert key to spec
DHPrivateKeySpec dhPrivKeySpec
= engineGetKeySpec(key, DHPrivateKeySpec.class);
// Create key from spec, and return it
return engineGeneratePrivate(dhPrivKeySpec);
} else {
throw new InvalidKeyException("Wrong algorithm type");
}
} catch (InvalidKeySpecException e) {
throw new InvalidKeyException("Cannot translate key", e);
}
}
}