org.soulwing.credo.service.crypto.jca.JcaEncryptedPrivateKeyWrapper.java Source code

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Here is the source code for org.soulwing.credo.service.crypto.jca.JcaEncryptedPrivateKeyWrapper.java

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/*
 * File created on Mar 3, 2014 
 *
 * Copyright (c) 2014 Virginia Polytechnic Institute and State University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package org.soulwing.credo.service.crypto.jca;

import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang.Validate;
import org.soulwing.credo.service.crypto.PrivateKeyWrapper;
import org.soulwing.credo.service.crypto.SecretKeyWrapper;
import org.soulwing.credo.service.pem.PemObjectBuilderFactory;

/**
 * A {@link PrivateKeyWrapper} that delegates to a JCA {@link PrivateKey}.
 *
 * @author Carl Harris
 */
public class JcaEncryptedPrivateKeyWrapper implements PrivateKeyWrapper {

    private final String transform;
    private final byte[] iv;
    private final byte[] cipherText;
    private final PemObjectBuilderFactory objectBuilderFactory;

    private SecretKeyWrapper secretKey;

    /**
     * Constructs a new instance.
     * @param transform the cryptographic transform that was applied to 
     *    encrypt the key
     * @param iv initialization vector
     * @param cipherText cipher text of secret key's DER encoding
     * @param objectBuilderFactory PEM object builder factory
     */
    public JcaEncryptedPrivateKeyWrapper(String transform, byte[] iv, byte[] cipherText,
            PemObjectBuilderFactory objectBuilderFactory) {
        this.transform = transform;
        this.iv = iv;
        this.cipherText = cipherText;
        this.objectBuilderFactory = objectBuilderFactory;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isProtected() {
        return false;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public SecretKeyWrapper getProtectionParameter() {
        return secretKey;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setProtectionParameter(Object parameter) {
        Validate.isTrue(parameter instanceof SecretKeyWrapper,
                "requires a " + SecretKeyWrapper.class.getSimpleName());
        this.secretKey = (SecretKeyWrapper) parameter;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getContent() {
        return objectBuilderFactory.newBuilder().setType("RSA PRIVATE KEY").setHeader("Proc-Type", "4,ENCRYPTED")
                .setHeader("DEK-Info", transform + "," + Hex.encodeHexString(iv)).append(cipherText).build()
                .getEncoded();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public PrivateKey derive() {
        int delimiter = transform.indexOf('/');
        if (delimiter == -1) {
            throw new IllegalArgumentException("illegal transform syntax: " + transform);
        }
        try {
            String algorithm = transform.substring(0, delimiter);
            Cipher cipher = Cipher.getInstance(transform);
            cipher.init(Cipher.UNWRAP_MODE, secretKey.derive(), new IvParameterSpec(iv));
            return (PrivateKey) cipher.unwrap(cipherText, algorithm, Cipher.SECRET_KEY);
        } catch (NoSuchAlgorithmException ex) {
            throw new RuntimeException(ex);
        } catch (NoSuchPaddingException ex) {
            throw new RuntimeException(ex);
        } catch (InvalidAlgorithmParameterException ex) {
            throw new RuntimeException(ex);
        } catch (InvalidKeyException ex) {
            throw new RuntimeException(ex);
        }
    }

}