Encrypt.java

package jtweet.web;

import java.util.logging.Logger;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

public class Encrypt {
	private static Logger log = Logger.getLogger(Encrypt.class.getName());
	public final static String accountSeperator = ":";

	private static String key = "1234abcd"; // 8个字母或数字

	private static String decrypt(String message) throws Exception {
		byte[] bytesrc = convertHexString(message);
		Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
		DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
		IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));

		cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
		byte[] retByte = cipher.doFinal(bytesrc);
		return new String(retByte);
	}

	private static String encrypt(String message) throws Exception {
		Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
		DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
		IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
		cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
		return toHexString(cipher.doFinal(message.getBytes("UTF-8")));
	}

	private static byte[] convertHexString(String ss) {
		byte digest[] = new byte[ss.length() / 2];
		for (int i = 0; i < digest.length; i++) {
			String byteString = ss.substring(2 * i, 2 * i + 2);
			int byteValue = Integer.parseInt(byteString, 16);
			digest[i] = (byte) byteValue;
		}
		return digest;
	}

	private static String toHexString(byte b[]) {
		StringBuffer hexString = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
			String plainText = Integer.toHexString(0xff & b[i]);
			if (plainText.length() < 2)
				plainText = "0" + plainText;
			hexString.append(plainText);
		}
		return hexString.toString();
	}

	public static String[] decodeAccount(String cookieValue) {
		try {
			String origi = Encrypt.decrypt(cookieValue);
			String[] parts = origi.split(Encrypt.accountSeperator);
			if (parts.length == 4 && !parts[0].equals("") && !parts[2].equals("") && !parts[3].equals("")) {
				return parts;
			}
		} catch (Exception e) {
			e.printStackTrace();
			log.warning(e.getMessage());
		}
		return null;
	}

	public static String encodeAccount(String username, String password) {
		String encryptString = null;
		try {
			encryptString = Encrypt.encrypt(username + Encrypt.accountSeperator + password);
		} catch (Exception e) {
			log.warning(e.getMessage());
		}
		return encryptString;
	}

	public static String encodeAccount(String[] info) {
		String encryptString = null;
		try {
			String infostring = combine(info, accountSeperator);
			encryptString = Encrypt.encrypt(infostring);
		} catch (Exception e) {
			log.warning(e.getMessage());
		}
		return encryptString;
	}

	static String combine(String[] s, String glue) {
		int k = s.length;
		if (k == 0)
			return null;
		StringBuilder out = new StringBuilder();
		out.append(s[0]);
		for (int x = 1; x < k; ++x)
			out.append(glue).append(s[x]);

		return out.toString();
	}

}