com.salesmanager.core.util.EncryptionUtil.java Source code

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Here is the source code for com.salesmanager.core.util.EncryptionUtil.java

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/*
 * Licensed to csti consulting 
 * You may obtain a copy of the License at
 *
 * http://www.csticonsulting.com
 * Copyright (c) 2006-Aug 24, 2010 Consultation CS-TI inc. 
 *
 * 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.salesmanager.core.util;

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

import org.apache.commons.lang.StringUtils;

/**
 * Can be used to encrypt/decrypt from java-php
 * 
 * @author Administrator
 * 
 */
public class EncryptionUtil {

    private EncryptionUtil() {
    }

    public static String generatekey(String value) {
        String key = StringUtils.rightPad(value, 16, "0");
        return key;
    }

    public static String decryptFromExternal(String key, String value) throws Exception {

        if (value == null || value.equals(""))
            return "";

        Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
        SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivSpec = new IvParameterSpec("fedcba9876543210".getBytes());
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
        byte[] outText;
        outText = cipher.doFinal(hexToBytes(value));
        return new String(outText);

    }

    public static String decrypt(String key, String value) throws Exception {

        if (value == null || value.equals(""))
            return "";

        // NEED TO UNDERSTAND WHY PKCS5Padding DOES NOT WORK
        // Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivSpec = new IvParameterSpec("fedcba9876543210".getBytes());
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
        byte[] outText;
        outText = cipher.doFinal(hexToBytes(value));
        return new String(outText);

    }

    public static String encrypt(String key, String value) throws Exception {

        // value = StringUtils.rightPad(value, 16,"*");
        // Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
        // NEED TO UNDERSTAND WHY PKCS5Padding DOES NOT WORK
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivSpec = new IvParameterSpec("fedcba9876543210".getBytes());
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
        byte[] inpbytes = value.getBytes();
        byte[] encrypted = cipher.doFinal(inpbytes);
        return new String(bytesToHex(encrypted));

    }

    public static String bytesToHex(byte[] data) {
        if (data == null) {
            return null;
        } else {
            int len = data.length;
            String str = "";
            for (int i = 0; i < len; i++) {
                if ((data[i] & 0xFF) < 16) {
                    str = str + "0" + java.lang.Integer.toHexString(data[i] & 0xFF);
                } else {
                    str = str + java.lang.Integer.toHexString(data[i] & 0xFF);
                }

            }
            return str;
        }
    }

    private static byte[] hexToBytes(String str) {
        if (str == null) {
            return null;
        } else if (str.length() < 2) {
            return null;
        } else {
            int len = str.length() / 2;
            byte[] buffer = new byte[len];
            for (int i = 0; i < len; i++) {
                buffer[i] = (byte) Integer.parseInt(str.substring(i * 2, i * 2 + 2), 16);
            }
            return buffer;
        }
    }

}