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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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
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*
* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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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));
}
}