com.jwm123.loggly.reporter.TripleDesCipher.java Source code

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Here is the source code for com.jwm123.loggly.reporter.TripleDesCipher.java

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/**
 *    Copyright 2013 jwm123
 *
 *    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 com.jwm123.loggly.reporter;

import org.apache.commons.io.FileUtils;
import org.bouncycastle.util.encoders.Base64;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;

/**
 * com.jwm123.loggly.reporter.TripleDesCipher
 *
 * @author jmcentire
 */
public class TripleDesCipher {
    private static String TRIPLE_DES_TRANSFORMATION = "DESede/ECB/PKCS5Padding";
    private static String ALGORITHM = "DESede";
    private Cipher encrypter;
    private Cipher decrypter;
    private byte[] key;
    public String keyPath;
    public AppDirectory appDir;

    public TripleDesCipher(String keyPath, AppDirectory appDir) throws NoSuchAlgorithmException,
            NoSuchProviderException, NoSuchPaddingException, InvalidKeyException, IOException {
        this.appDir = appDir;
        if (key == null) {
            this.keyPath = keyPath;
            getKey();
        }
        SecretKey keySpec = new SecretKeySpec(key, ALGORITHM);
        encrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION);
        encrypter.init(Cipher.ENCRYPT_MODE, keySpec);
        decrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION);
        decrypter.init(Cipher.DECRYPT_MODE, keySpec);
    }

    public String encode(String str)
            throws IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
        return new String(Base64.encode(encrypter.doFinal(str.getBytes("UTF8"))));
    }

    public String decode(String str)
            throws IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
        return new String(decrypter.doFinal(Base64.decode(str)), "UTF8");
    }

    private void getKey() throws NoSuchAlgorithmException, IOException {
        File keyFile = appDir.getFileDir(keyPath);
        if (keyFile.exists()) {
            key = Base64.decode(FileUtils.readFileToString(keyFile));
        } else {
            KeyGenerator generator = KeyGenerator.getInstance("DESede");
            SecretKey desKey = generator.generateKey();
            key = desKey.getEncoded();
            FileUtils.writeStringToFile(keyFile, new String(Base64.encode(key)));
        }

    }
}