com.springcryptoutils.core.cipher.symmetric.Base64EncodedCiphererImpl.java Source code

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Here is the source code for com.springcryptoutils.core.cipher.symmetric.Base64EncodedCiphererImpl.java

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/*
 * Copyright 2012 Mirko Caserta
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this software 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.springcryptoutils.core.cipher.symmetric;

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

import org.apache.commons.codec.binary.Base64;

import com.springcryptoutils.core.cipher.Mode;

/**
 * Default implementation for performing symmetric encryption with strings
 * containing base64 encoded versions of raw byte arrays.
 *
 * @author Mirko Caserta (mirko.caserta@gmail.com)
 */
public class Base64EncodedCiphererImpl implements Base64EncodedCipherer {

    private String keyAlgorithm = "DESede";
    private String cipherAlgorithm = "DESede/CBC/PKCS5Padding";
    private String charsetName = "UTF-8";
    private String provider;
    private Mode mode;
    private boolean chunkOutput;

    /**
     * The symmetric key algorithm. The default is DESede (triple DES).
     *
     * @param keyAlgorithm the symmetric key algorithm
     */
    public void setKeyAlgorithm(String keyAlgorithm) {
        this.keyAlgorithm = keyAlgorithm;
    }

    /**
     * The cipher algorithm. The default is DESede/CBC/PKCS5Padding (triple DES
     * with Cipher Block Chaining and PKCS 5 padding).
     *
     * @param cipherAlgorithm the cipher algorithm
     */
    public void setCipherAlgorithm(String cipherAlgorithm) {
        this.cipherAlgorithm = cipherAlgorithm;
    }

    /**
     * The charset to use when converting a string into a raw byte array
     * representation. The default is UTF-8.
     *
     * @param charsetName the charset name (default: UTF-8)
     */
    public void setCharsetName(String charsetName) {
        this.charsetName = charsetName;
    }

    /**
     * Sets the provider name of the specific implementation requested (e.g.,
     * "BC" for BouncyCastle, "SunJCE" for the default Sun JCE provider).
     *
     * @param provider the provider to set
     */
    public void setProvider(String provider) {
        this.provider = provider;
    }

    /**
     * Sets the encryption/decryption mode.
     *
     * @param mode the encryption/decryption mode
     */
    public void setMode(Mode mode) {
        this.mode = mode;
    }

    /**
     * When outputting long base64 encoded strings, should the output be
     * formatted so it's easier to read? This may not work well with some base64
     * decoders which don't accept whitespace in the input so the default is
     * false.
     *
     * @param chunkOutput should the output be formatted?
     */
    public void setChunkOutput(boolean chunkOutput) {
        this.chunkOutput = chunkOutput;
    }

    /**
     * Encrypts or decrypts a message. The encryption/decryption mode depends on
     * the configuration of the mode parameter.
     *
     * @param key a base64 encoded version of the symmetric key
     * @param initializationVector a base64 encoded version of the
     *        initialization vector
     * @param message if in encryption mode, the clear-text message to encrypt,
     *        otherwise a base64 encoded version of the message to decrypt
     * @return if in encryption mode, returns a base64 encoded version of the
     *         encrypted message, otherwise returns the decrypted clear-text
     *         message
     * @throws SymmetricEncryptionException on runtime errors
     * @see #setMode(com.google.code.springcryptoutils.core.cipher.Mode)
     */
    public String encrypt(String key, String initializationVector, String message) {
        try {
            IvParameterSpec initializationVectorSpec = new IvParameterSpec(
                    Base64.decodeBase64(initializationVector));
            final SecretKeySpec keySpec = new SecretKeySpec(Base64.decodeBase64(key), keyAlgorithm);
            final Cipher cipher = (((provider == null) || (provider.length() == 0))
                    ? Cipher.getInstance(cipherAlgorithm)
                    : Cipher.getInstance(cipherAlgorithm, provider));
            byte[] messageAsByteArray;

            switch (mode) {
            case ENCRYPT:
                cipher.init(Cipher.ENCRYPT_MODE, keySpec, initializationVectorSpec);
                messageAsByteArray = message.getBytes(charsetName);
                final byte[] encryptedMessage = cipher.doFinal(messageAsByteArray);
                return new String(Base64.encodeBase64(encryptedMessage, chunkOutput));
            case DECRYPT:
                cipher.init(Cipher.DECRYPT_MODE, keySpec, initializationVectorSpec);
                messageAsByteArray = Base64.decodeBase64(message);
                final byte[] decryptedMessage = cipher.doFinal(messageAsByteArray);
                return new String(decryptedMessage, charsetName);
            default:
                return null;
            }
        } catch (Exception e) {
            throw new SymmetricEncryptionException("error encrypting/decrypting message; mode=" + mode, e);
        }
    }

}