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	/*
	* Copyright (c) 1997, 2021, 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.provider;

	import java.security.Key;
	import java.security.PublicKey;
	import java.security.PrivateKey;
	import java.security.KeyFactorySpi;
	import java.security.InvalidKeyException;
	import java.security.interfaces.DSAParams;
	import java.security.spec.DSAPublicKeySpec;
	import java.security.spec.DSAPrivateKeySpec;
	import java.security.spec.KeySpec;
	import java.security.spec.InvalidKeySpecException;
	import java.security.spec.X509EncodedKeySpec;
	import java.security.spec.PKCS8EncodedKeySpec;
	import java.util.Arrays;

	/**
	* This class implements the DSA key factory of the Sun provider.
	*
	* @author Jan Luehe
	*
	*
	* @since 1.2
	*/

	public class DSAKeyFactory extends KeyFactorySpi {
	/**
	* 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 DSAPublicKeySpec) {
	DSAPublicKeySpec dsaPubKeySpec = (DSAPublicKeySpec)keySpec;
	return new DSAPublicKeyImpl(dsaPubKeySpec.getY(),
	dsaPubKeySpec.getP(),
	dsaPubKeySpec.getQ(),
	dsaPubKeySpec.getG());
	} else if (keySpec instanceof X509EncodedKeySpec) {
	return new DSAPublicKeyImpl
	(((X509EncodedKeySpec)keySpec).getEncoded());
	} else {
	throw new InvalidKeySpecException
	("Inappropriate key specification");
	}
	} catch (InvalidKeyException e) {
	throw new InvalidKeySpecException
	("Inappropriate key specification: " + e.getMessage());
	}
	}

	/**
	* 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 DSAPrivateKeySpec) {
	DSAPrivateKeySpec dsaPrivKeySpec = (DSAPrivateKeySpec)keySpec;
	return new DSAPrivateKey(dsaPrivKeySpec.getX(),
	dsaPrivKeySpec.getP(),
	dsaPrivKeySpec.getQ(),
	dsaPrivKeySpec.getG());

	} else if (keySpec instanceof PKCS8EncodedKeySpec) {
	byte[] encoded = ((PKCS8EncodedKeySpec)keySpec).getEncoded();
	try {
	return new DSAPrivateKey(encoded);
	} finally {
	Arrays.fill(encoded, (byte) 0);
	}
	} else {
	throw new InvalidKeySpecException
	("Inappropriate key specification");
	}
	} catch (InvalidKeyException e) {
	throw new InvalidKeySpecException
	("Inappropriate key specification: " + e.getMessage());
	}
	}

	/**
	* 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 {

	DSAParams params;

	try {

	if (key instanceof java.security.interfaces.DSAPublicKey) {

	// Determine valid key specs
	Class<?> dsaPubKeySpec = Class.forName
	("java.security.spec.DSAPublicKeySpec");
	Class<?> x509KeySpec = Class.forName
	("java.security.spec.X509EncodedKeySpec");

	if (keySpec.isAssignableFrom(dsaPubKeySpec)) {
	java.security.interfaces.DSAPublicKey dsaPubKey
	= (java.security.interfaces.DSAPublicKey)key;
	params = dsaPubKey.getParams();
	return keySpec.cast(new DSAPublicKeySpec(dsaPubKey.getY(),
	params.getP(),
	params.getQ(),
	params.getG()));

	} else if (keySpec.isAssignableFrom(x509KeySpec)) {
	return keySpec.cast(new X509EncodedKeySpec(key.getEncoded()));

	} else {
	throw new InvalidKeySpecException
	("Inappropriate key specification");
	}

	} else if (key instanceof java.security.interfaces.DSAPrivateKey) {

	// Determine valid key specs
	Class<?> dsaPrivKeySpec = Class.forName
	("java.security.spec.DSAPrivateKeySpec");
	Class<?> pkcs8KeySpec = Class.forName
	("java.security.spec.PKCS8EncodedKeySpec");

	if (keySpec.isAssignableFrom(dsaPrivKeySpec)) {
	java.security.interfaces.DSAPrivateKey dsaPrivKey
	= (java.security.interfaces.DSAPrivateKey)key;
	params = dsaPrivKey.getParams();
	return keySpec.cast(new DSAPrivateKeySpec(dsaPrivKey.getX(),
	params.getP(),
	params.getQ(),
	params.getG()));

	} else if (keySpec.isAssignableFrom(pkcs8KeySpec)) {
	byte[] encoded = key.getEncoded();
	try {
	return keySpec.cast(new PKCS8EncodedKeySpec(encoded));
	} finally {
	Arrays.fill(encoded, (byte)0);
	}
	} else {
	throw new InvalidKeySpecException
	("Inappropriate key specification");
	}

	} else {
	throw new InvalidKeySpecException("Inappropriate key type");
	}

	} catch (ClassNotFoundException e) {
	throw new InvalidKeySpecException
	("Unsupported key specification: " + e.getMessage());
	}
	}

	/**
	* 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 java.security.interfaces.DSAPublicKey) {
	// Check if key originates from this factory
	if (key instanceof sun.security.provider.DSAPublicKey) {
	return key;
	}
	// Convert key to spec
	DSAPublicKeySpec dsaPubKeySpec
	= engineGetKeySpec(key, DSAPublicKeySpec.class);
	// Create key from spec, and return it
	return engineGeneratePublic(dsaPubKeySpec);

	} else if (key instanceof java.security.interfaces.DSAPrivateKey) {
	// Check if key originates from this factory
	if (key instanceof sun.security.provider.DSAPrivateKey) {
	return key;
	}
	// Convert key to spec
	DSAPrivateKeySpec dsaPrivKeySpec
	= engineGetKeySpec(key, DSAPrivateKeySpec.class);
	// Create key from spec, and return it
	return engineGeneratePrivate(dsaPrivKeySpec);

	} else {
	throw new InvalidKeyException("Wrong algorithm type");
	}

	} catch (InvalidKeySpecException e) {
	throw new InvalidKeyException("Cannot translate key: "
	+ e.getMessage());
	}
	}
	}

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