encryption.java

this is example use EJB with jboss.

/*
 * Copyright(C) 2008, NTT AT Co., Ltd.
 * Project: AWGView
 *
 * Notes:
 *  N/A
 *
 * Record of change:
 * Date         Version      Name       Content
 * 2008/12/15   1.0          TriNT      First create       
 */
package jp.co.ntt.awgview.server.common;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Class name : Encryption <BR>
 * Package : jp.co.ntt.awgview.genlicense <BR>
 * 
 * Description : This class provides very basic functionality of data
 * encryption.<BR>
 * Encodes a string into Base64/MD5/SHA format Type Encryption: - Base64:
 * Encoder/Decoder. <BR>
 * - MD5: Encoder <BR>
 * - SHA: Encoder <BR>
 * 
 * @author : AI&T
 * @version : 1.0
 */
public class Encryption {
	public static final String MD5 = "MD5";
	public static final String SHA_256 = "SHA-256";
	public static final String BASE64 = "BASE64";
	private static final String KEY_START = "20e3afade751e898799087f4b081598c47c75b54b6cff224ba38fa71d85d5937";
	private static final String KEY_END = "5c551b8e8a2bc29828eb65c610c01a93b8ed567137bcbb7bad57a633a1c9bf09";

	// Mapping table from 6-bit nibbles to Base64 characters.
	private static char[] map1 = new char[64];
	
	static {
		int i = 0;
		
		for (char c = 'A'; c <= 'Z'; c++){
			map1[i++] = c;
		}
		
		for (char c = 'a'; c <= 'z'; c++){
			map1[i++] = c;
		}	
		
		for (char c = '0'; c <= '9'; c++){
			map1[i++] = c;
		}
		
		map1[i++] = '+';
		map1[i++] = '/';
	}

	/**
	 * Basic functionality of data encryption
	 * 
	 * @param algorithmName
	 *            the message digest algorithm to be used. Example:
	 *            algorithmName is MD5 or SHA-256
	 * @param text
	 * @param endcoding
	 * @return String
	 */
	public static String encrypt(String text, String algorithmName,
			String endcoding) {
		try {
			if ((algorithmName == null) || (text == null) || (endcoding == null)) {
				return null;
			}
			
			if (algorithmName.trim().equalsIgnoreCase(BASE64.trim())) {
				return encodeString(text);
			}
			
			if (text != null) {
				MessageDigest md;
				// md = MessageDigest.getInstance("MD5");
				// md = MessageDigest.getInstance("SHA-256");
				md = MessageDigest.getInstance(algorithmName);
				byte[] md5hash = new byte[32];
				// "utf-8" / "iso-8859-1"
				md.update(text.getBytes(endcoding), 0, text.length());
				md5hash = md.digest();
				return convertToHex(md5hash);
			}
		} catch (NoSuchAlgorithmException e) {
			System.out.println("getStringEncryption:" + e.toString());
		} catch (UnsupportedEncodingException e) {
			System.out.println("getStringEncryption:" + e.toString());
		}
		return null;
	}

	/**
	 * Converts the input data into hexadecimal format.
	 * 
	 * @param data
	 * @return String with hexadecimal format
	 */
	private static String convertToHex(byte[] data) {
		StringBuffer buf = new StringBuffer();
		int length = data.length;
		for (int i = 0; i < length; i++) {
			int halfbyte = (data[i] >>> 4) & 0x0F;
			int two_halfs = 0;
			do {
				if ((0 <= halfbyte) && (halfbyte <= 9)){
					buf.append((char) ('0' + halfbyte));
				}else{
					buf.append((char) ('a' + (halfbyte - 10)));
				}	
				halfbyte = data[i] & 0x0F;
			} while (two_halfs++ < 1);
		}
		return buf.toString();
	}

	// Mapping table from Base64 characters to 6-bit nibbles.
	private static byte[] map2 = new byte[128];	
	static {
		for (int i = 0; i < map2.length; i++){
			map2[i] = -1;
		}
		
		for (int i = 0; i < 64; i++){
			map2[map1[i]] = (byte) i;
		}	
	}

	/**
	 * Encodes a string into Base64 format. No blanks or line breaks are
	 * inserted.
	 * 
	 * @param encodeString
	 *            a String to be encoded.
	 * @return A String with the Base64 encoded data.
	 */
	public static String encodeString(String encodeString) {
		return new String(encode(encodeString.getBytes()));
	}

	/**
	 * Encodes a byte array into Base64 format. No blanks or line breaks are
	 * inserted.
	 * 
	 * @param in
	 *            an array containing the data bytes to be encoded.
	 * @return A character array with the Base64 encoded data.
	 */
	public static char[] encode(byte[] in) {
		return encode(in, in.length);
	}

	/**
	 * Encodes a byte array into Base64 format. No blanks or line breaks are
	 * inserted.
	 * 
	 * @param in
	 *            an array containing the data bytes to be encoded.
	 * @param iLen
	 *            number of bytes to process in <code>in</code>.
	 * @return A character array with the Base64 encoded data.
	 */
	public static char[] encode(byte[] in, int iLen) {
		int oDataLen = (iLen * 4 + 2) / 3; // output length without padding
		int oLen = ((iLen + 2) / 3) * 4; // output length including padding
		char[] out = new char[oLen];
		int ip = 0;
		int op = 0;
		while (ip < iLen) {
			int i0 = in[ip++] & 0xff;
			int i1 = (ip < iLen) ? (in[ip++] & 0xff) : 0;
			int i2 = (ip < iLen) ? (in[ip++] & 0xff) : 0;
			int o0 = i0 >>> 2;
			int o1 = ((i0 & 3) << 4) | (i1 >>> 4);
			int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);
			int o3 = i2 & 0x3F;
			out[op++] = map1[o0];
			out[op++] = map1[o1];
			out[op] = (op < oDataLen) ? map1[o2] : '=';
			op++;
			out[op] = (op < oDataLen) ? map1[o3] : '=';
			op++;
		}
		return out;
	}

	/**
	 * Decodes a string from Base64 format.
	 * 
	 * @param s
	 *            a Base64 String to be decoded.
	 * @return A String containing the decoded data.
	 * @throws IllegalArgumentException
	 *             if the input is not valid Base64 encoded data.
	 */
	public static String decodeString(String s) {
		return new String(decode(s));
	}

	/**
	 * Decodes a byte array from Base64 format.
	 * 
	 * @param s
	 *            a Base64 String to be decoded.
	 * @return An array containing the decoded data bytes.
	 * @throws IllegalArgumentException
	 *             if the input is not valid Base64 encoded data.
	 */
	public static byte[] decode(String s) {
		return decode(s.toCharArray());
	}

	/**
	 * Decodes a byte array from Base64 format. No blanks or line breaks are
	 * allowed within the Base64 encoded data.
	 * 
	 * @param in
	 *            a character array containing the Base64 encoded data.
	 * @return An array containing the decoded data bytes.
	 * @throws IllegalArgumentException
	 *             if the input is not valid Base64 encoded data.
	 */
	public static byte[] decode(char[] in) {
		int iLen = in.length;
		
		if ((iLen % 4) != 0){
			throw new IllegalArgumentException(
					"Length of Base64 encoded input string is not a multiple of 4.");
		}
		
		while ((iLen > 0) && (in[iLen - 1] == '=')){
			iLen--;
		}
		
		int oLen = (iLen * 3) / 4;
		byte[] out = new byte[oLen];
		int ip = 0;
		int op = 0;
		
		while (ip < iLen) {
			int i0 = in[ip++];
			int i1 = in[ip++];
			int i2 = (ip < iLen) ? in[ip++] : 'A';
			int i3 = (ip < iLen) ? in[ip++] : 'A';
			if ((i0 > 127) || (i1 > 127) || (i2 > 127) || (i3 > 127)){
				throw new IllegalArgumentException(
						"Illegal character in Base64 encoded data.");
			}	
			
			int b0 = map2[i0];
			int b1 = map2[i1];
			int b2 = map2[i2];
			int b3 = map2[i3];
			
			if ((b0 < 0) || (b1 < 0) || (b2 < 0) || (b3 < 0)){
				throw new IllegalArgumentException(
						"Illegal character in Base64 encoded data.");
			}
			
			int o0 = (b0 << 2) | (b1 >>> 4);
			int o1 = ((b1 & 0xf) << 4) | (b2 >>> 2);
			int o2 = ((b2 & 3) << 6) | b3;
			
			out[op++] = (byte) o0;
			
			if (op < oLen){
				out[op++] = (byte) o1;
			}
			
			if (op < oLen){
				out[op++] = (byte) o2;
			}	
		}
		
		return out;
	}

	/***
	 * Generate license
	 * 
	 * @param strMac
	 * @param algorithmName
	 * @return String
	 */
	public static String genLicense(String strMac, String algorithmName) {
		return encrypt(KEY_START + strMac + KEY_END + KEY_START + strMac
				+ KEY_END + KEY_START, algorithmName, "utf-8");
	}
}