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

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Here is the source code for com.springcryptoutils.core.cipher.symmetric.CiphererWithStaticKeyImpl.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 java.io.UnsupportedEncodingException;

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

import org.apache.commons.codec.binary.Base64;
import org.springframework.beans.factory.InitializingBean;

import com.springcryptoutils.core.cipher.Mode;

/**
 * The default implementation for performing symmetric encryption/decryption
 * using a static key.
 *
 * @author Mirko Caserta (mirko.caserta@gmail.com)
 */
public class CiphererWithStaticKeyImpl implements CiphererWithStaticKey, InitializingBean {

    private String keyAlgorithm = "DESede";
    private String cipherAlgorithm = "DESede/CBC/PKCS5Padding";
    private String provider;
    private Mode mode;
    private IvParameterSpec initializationVectorSpec;
    private String key;
    private SecretKeySpec keySpec;

    /**
     * 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;
    }

    /**
     * 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;
    }

    /**
     * A base64 encoded representation of the raw byte array containing the
     * initialization vector.
     *
     * @param initializationVector the initialization vector
     * @throws SymmetricEncryptionException on runtime errors
     */
    public void setInitializationVector(String initializationVector) {
        try {
            this.initializationVectorSpec = new IvParameterSpec(
                    Base64.decodeBase64(initializationVector.getBytes("UTF-8")));
        } catch (UnsupportedEncodingException e) {
            throw new SymmetricEncryptionException("UTF-8 is an unsupported encoding on this platform", e);
        }
    }

    /**
     * A base64 encoded representation of the raw byte array containing the
     * cryptographic key.
     *
     * @param key the cryptographic key
     */
    public void setKey(String key) {
        this.key = key;
    }

    /**
     * Encrypts/decrypts a message based on the underlying mode of operation.
     *
     * @param message if in encryption mode, the clear-text message, otherwise
     *        the message to decrypt
     * @return if in encryption mode, the encrypted message, otherwise the
     *         decrypted message
     * @throws SymmetricEncryptionException on runtime errors
     * @see #setMode(Mode)
     */
    public byte[] encrypt(byte[] message) {
        try {
            final Cipher cipher = (((provider == null) || (provider.length() == 0))
                    ? Cipher.getInstance(cipherAlgorithm)
                    : Cipher.getInstance(cipherAlgorithm, provider));
            switch (mode) {
            case ENCRYPT:
                cipher.init(Cipher.ENCRYPT_MODE, keySpec, initializationVectorSpec);
                break;
            case DECRYPT:
                cipher.init(Cipher.DECRYPT_MODE, keySpec, initializationVectorSpec);
                break;
            default:
                throw new SymmetricEncryptionException(
                        "error encrypting/decrypting message: invalid mode; mode=" + mode);
            }
            return cipher.doFinal(message);
        } catch (Exception e) {
            throw new SymmetricEncryptionException("error encrypting/decrypting message; mode=" + mode, e);
        }
    }

    public void afterPropertiesSet() {
        this.keySpec = new SecretKeySpec(Base64.decodeBase64(key), keyAlgorithm);
    }

}