com.kixeye.chassis.transport.crypto.SymmetricKeyCryptoUtils.java Source code

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Here is the source code for com.kixeye.chassis.transport.crypto.SymmetricKeyCryptoUtils.java

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package com.kixeye.chassis.transport.crypto;

/*
 * #%L
 * Java Transport API
 * %%
 * Copyright (C) 2014 KIXEYE, Inc
 * %%
 * 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.
 * #L%
 */

import java.security.GeneralSecurityException;
import java.security.Key;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.lang3.StringUtils;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

/**
 * Does symmetric key encrypt/decrypt.
 * 
 * @author ebahtijaragic
 */
public class SymmetricKeyCryptoUtils {
    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    /**
     * Loads a raw secret key.
     * 
     * @param key
     * @param keyAlgorithm
     * @return
     * @throws GeneralSecurityException
     */
    public static Key loadRawSecretKey(byte[] key, String keyAlgorithm) throws GeneralSecurityException {
        return new SecretKeySpec(key, keyAlgorithm);
    }

    /**
     * Loads a cipher.
     * 
     * @param transformation
     * @param provider
     * @return
     * @throws GeneralSecurityException
     */
    public static Cipher loadCipher(String transformation, String provider) throws GeneralSecurityException {
        if (StringUtils.isNotBlank(provider)) {
            return Cipher.getInstance(transformation, provider);
        } else {
            return Cipher.getInstance(transformation);
        }
    }

    /**
     * Encrypts a data blob using the given key and cipher.
     * 
     * @param data
     * @param offset
     * @param length
     * @param key
     * @param cipher
     * @return
     * @throws GeneralSecurityException
     */
    public static byte[] encrypt(byte[] data, int offset, int length, Key key, String cipherTransformation,
            String cipherProvider) throws GeneralSecurityException {
        Cipher cipher = loadCipher(cipherTransformation, cipherProvider);
        cipher.init(Cipher.ENCRYPT_MODE, key);

        return cipher.doFinal(data, offset, length);
    }

    /**
     * Decrypts a data blob using the given key and cipher.
     * 
     * @param data
     * @param offset
     * @param length
     * @param key
     * @param cipher
     * @return
     * @throws GeneralSecurityException
     */
    public static byte[] decrypt(byte[] data, int offset, int length, Key key, String cipherTransformation,
            String cipherProvider) throws GeneralSecurityException {
        Cipher cipher = loadCipher(cipherTransformation, cipherProvider);
        cipher.init(Cipher.DECRYPT_MODE, key);

        return cipher.doFinal(data, offset, length);
    }
}