com.jk.security.JKEncDec.java Source code

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Here is the source code for com.jk.security.JKEncDec.java

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/*
 * Copyright 2002-2016 Jalal Kiswani.
 *
 * 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.jk.security;

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

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

import com.jk.exceptions.JKEmptyReportException;
import com.jk.exceptions.JKSecurityException;

/**
 * The Class JKEncDec.
 *
 * @author Jalal Kiswani
 */
public class JKEncDec {
    static String IV = "AAAAAAAAAAAAAAAA";
    static String plaintext = "test text 123\0\0\0"; /* Note null padding */
    static String encryptionKey = "0123456789abcdef";

    /**
     * The main method.
     *
     * @param args
     *            the arguments
     * @throws Exception
     *             the exception
     */
    public static void main(String[] args) throws Exception {
        String encrypt = encrypt("123");
        System.out.println(encrypt);
        System.out.println(decrypt("97,-32,64,9,-124,-41,-95,94,-73,-72,28,-126,-76,79,-108,109"));

        System.out.println(encode("3"));

    }

    /**
     * Encrypt.
     *
     * @param plainText
     *            the plain text
     * @return the string
     */
    public static String encrypt(String plainText) {
        try {
            plainText = fixText(plainText);
            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding", "SunJCE");
            SecretKeySpec key = new SecretKeySpec(encryptionKey.getBytes("UTF-8"), "AES");
            cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(IV.getBytes("UTF-8")));
            return toString(cipher.doFinal(plainText.getBytes("UTF-8")));
        } catch (Exception e) {
            throw new JKSecurityException(e);
        }
    }

    /**
     * 
     * @param bytes
     * @return
     */
    private static String toString(byte[] bytes) {
        StringBuffer buf = new StringBuffer();
        int i = 0;
        for (byte b : bytes) {
            if (i++ != 0) {
                buf.append(",");
            }
            buf.append(b);
        }
        return buf.toString();
    }

    /**
     * Decrypt.
     *
     * @param cipherText
     *            the cipher text
     * @return the string
     */
    public static String decrypt(String cipherText) {
        try {
            byte[] cipherBytes = toBytes(cipherText);
            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding", "SunJCE");
            SecretKeySpec key = new SecretKeySpec(encryptionKey.getBytes("UTF-8"), "AES");
            cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(IV.getBytes("UTF-8")));
            return new String(cipher.doFinal(cipherBytes), "UTF-8").trim();
        } catch (Exception e) {
            throw new JKSecurityException(e);
        }
    }

    /**
     * 
     * @param cipherText
     * @return
     */
    private static byte[] toBytes(String cipherText) {
        // rever to bytes from string called from toString(byte[]) method
        String[] split = cipherText.split(",");
        byte[] bytes = new byte[split.length];
        int i = 0;
        for (String b : split) {
            bytes[i++] = Byte.parseByte(b);
        }
        return bytes;
    }

    /**
     * 
     * @param plainText
     * @return
     */
    private static String fixText(String plainText) {
        int mod = plainText.length() % 16;
        for (int i = 0; i < plaintext.length() - mod; i++) {
            plainText += " ";
        }
        return plainText;
    }

    /**
     * Decode.
     *
     * @param source
     *            the source
     * @return the string
     */
    public static String decode(final String source) {
        return decodeFromBase64(source);
    }

    /**
     * Decode from base 64.
     *
     * @param string
     *            the string
     * @return the string
     */
    public static String decodeFromBase64(final String string) {
        return new String(Base64.decodeBase64(string));
    }

    /**
     * Encode.
     *
     * @param source
     *            the source
     * @return the string
     */
    public static String encode(final String source) {
        return encodeInToBase64(source);
    }

    /**
     * Encode in to base 64.
     *
     * @param string
     *            the string
     * @return the string
     */
    public static String encodeInToBase64(final String string) {
        return Base64.encodeBase64String(string.getBytes());
    }

}