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	/*
	* Copyright (c) 1999, 2013, 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 com.sun.crypto.provider;

	import java.security.Key;
	import java.security.PublicKey;
	import java.security.PrivateKey;
	import java.security.KeyFactory;
	import java.security.InvalidKeyException;
	import java.security.NoSuchProviderException;
	import java.security.NoSuchAlgorithmException;
	import java.security.spec.PKCS8EncodedKeySpec;
	import java.security.spec.X509EncodedKeySpec;
	import java.security.spec.InvalidKeySpecException;

	import javax.crypto.Cipher;
	import javax.crypto.CipherSpi;
	import javax.crypto.SecretKey;
	import javax.crypto.IllegalBlockSizeException;
	import javax.crypto.BadPaddingException;
	import javax.crypto.spec.SecretKeySpec;

	/**
	* This class entends the javax.crypto.CipherSpi class with a concrete
	* implementation of the methods for wrapping and unwrapping
	* keys.
	*
	* @author Sharon Liu
	*
	*
	* @see javax.crypto.CipherSpi
	* @see BlowfishCipher
	* @see DESCipher
	* @see PBEWithMD5AndDESCipher
	*/

	public abstract class CipherWithWrappingSpi extends CipherSpi {

	/**
	* Wrap a key.
	*
	* @param key the key to be wrapped.
	*
	* @return the wrapped key.
	*
	* @exception IllegalBlockSizeException if this cipher is a block
	* cipher, no padding has been requested, and the length of the
	* encoding of the key to be wrapped is not a
	* multiple of the block size.
	*
	* @exception InvalidKeyException if it is impossible or unsafe to
	* wrap the key with this cipher (e.g., a hardware protected key is
	* being passed to a software only cipher).
	*/
	protected final byte[] engineWrap(Key key)
	throws IllegalBlockSizeException, InvalidKeyException
	{
	byte[] result = null;

	try {
	byte[] encodedKey = key.getEncoded();
	if ((encodedKey == null) \|\| (encodedKey.length == 0)) {
	throw new InvalidKeyException("Cannot get an encoding of " +
	"the key to be wrapped");
	}

	result = engineDoFinal(encodedKey, 0, encodedKey.length);
	} catch (BadPaddingException e) {
	// Should never happen
	}

	return result;
	}

	/**
	* Unwrap a previously wrapped key.
	*
	* @param wrappedKey the key to be unwrapped.
	*
	* @param wrappedKeyAlgorithm the algorithm the wrapped key is for.
	*
	* @param wrappedKeyType the type of the wrapped key.
	* This is one of <code>Cipher.SECRET_KEY</code>,
	* <code>Cipher.PRIVATE_KEY</code>, or <code>Cipher.PUBLIC_KEY</code>.
	*
	* @return the unwrapped key.
	*
	* @exception InvalidKeyException if <code>wrappedKey</code> does not
	* represent a wrapped key, or if the algorithm associated with the
	* wrapped key is different from <code>wrappedKeyAlgorithm</code>
	* and/or its key type is different from <code>wrappedKeyType</code>.
	*
	* @exception NoSuchAlgorithmException if no installed providers
	* can create keys for the <code>wrappedKeyAlgorithm</code>.
	*/
	protected final Key engineUnwrap(byte[] wrappedKey,
	String wrappedKeyAlgorithm,
	int wrappedKeyType)
	throws InvalidKeyException, NoSuchAlgorithmException
	{
	byte[] encodedKey;
	Key result = null;

	try {
	encodedKey = engineDoFinal(wrappedKey, 0,
	wrappedKey.length);
	} catch (BadPaddingException ePadding) {
	throw new InvalidKeyException();
	} catch (IllegalBlockSizeException eBlockSize) {
	throw new InvalidKeyException();
	}

	switch (wrappedKeyType) {
	case Cipher.SECRET_KEY:
	result = constructSecretKey(encodedKey,
	wrappedKeyAlgorithm);
	break;
	case Cipher.PRIVATE_KEY:
	result = constructPrivateKey(encodedKey,
	wrappedKeyAlgorithm);
	break;
	case Cipher.PUBLIC_KEY:
	result = constructPublicKey(encodedKey,
	wrappedKeyAlgorithm);
	break;
	}

	return result;

	}

	/**
	* Construct a public key from its encoding.
	*
	* @param encodedKey the encoding of a public key.
	*
	* @param encodedKeyAlgorithm the algorithm the encodedKey is for.
	*
	* @return a public key constructed from the encodedKey.
	*/
	private final PublicKey constructPublicKey(byte[] encodedKey,
	String encodedKeyAlgorithm)
	throws InvalidKeyException, NoSuchAlgorithmException
	{
	PublicKey key = null;

	try {
	KeyFactory keyFactory =
	KeyFactory.getInstance(encodedKeyAlgorithm,
	SunJCE.getInstance());
	X509EncodedKeySpec keySpec = new X509EncodedKeySpec(encodedKey);
	key = keyFactory.generatePublic(keySpec);
	} catch (NoSuchAlgorithmException nsae) {
	// Try to see whether there is another
	// provider which supports this algorithm
	try {
	KeyFactory keyFactory =
	KeyFactory.getInstance(encodedKeyAlgorithm);
	X509EncodedKeySpec keySpec =
	new X509EncodedKeySpec(encodedKey);
	key = keyFactory.generatePublic(keySpec);
	} catch (NoSuchAlgorithmException nsae2) {
	throw new NoSuchAlgorithmException("No installed providers " +
	"can create keys for the " +
	encodedKeyAlgorithm +
	"algorithm");
	} catch (InvalidKeySpecException ikse2) {
	// Should never happen.
	}
	} catch (InvalidKeySpecException ikse) {
	// Should never happen.
	}

	return key;
	}

	/**
	* Construct a private key from its encoding.
	*
	* @param encodedKey the encoding of a private key.
	*
	* @param encodedKeyAlgorithm the algorithm the wrapped key is for.
	*
	* @return a private key constructed from the encodedKey.
	*/
	private final PrivateKey constructPrivateKey(byte[] encodedKey,
	String encodedKeyAlgorithm)
	throws InvalidKeyException, NoSuchAlgorithmException
	{
	PrivateKey key = null;

	try {
	KeyFactory keyFactory =
	KeyFactory.getInstance(encodedKeyAlgorithm,
	SunJCE.getInstance());
	PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(encodedKey);
	return keyFactory.generatePrivate(keySpec);
	} catch (NoSuchAlgorithmException nsae) {
	// Try to see whether there is another
	// provider which supports this algorithm
	try {
	KeyFactory keyFactory =
	KeyFactory.getInstance(encodedKeyAlgorithm);
	PKCS8EncodedKeySpec keySpec =
	new PKCS8EncodedKeySpec(encodedKey);
	key = keyFactory.generatePrivate(keySpec);
	} catch (NoSuchAlgorithmException nsae2) {
	throw new NoSuchAlgorithmException("No installed providers " +
	"can create keys for the " +
	encodedKeyAlgorithm +
	"algorithm");
	} catch (InvalidKeySpecException ikse2) {
	// Should never happen.
	}
	} catch (InvalidKeySpecException ikse) {
	// Should never happen.
	}

	return key;
	}

	/**
	* Construct a secret key from its encoding.
	*
	* @param encodedKey the encoding of a secret key.
	*
	* @param encodedKeyAlgorithm the algorithm the secret key is for.
	*
	* @return a secret key constructed from the encodedKey.
	*/
	private final SecretKey constructSecretKey(byte[] encodedKey,
	String encodedKeyAlgorithm)
	{
	return (new SecretKeySpec(encodedKey, encodedKeyAlgorithm));
	}
	}

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