Java 3DES 加密 解密 示例

代码：

package des3;

import java.io.IOException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

@SuppressWarnings("restriction")
public class TripleDESTest {

	/**
	 * 根据参数生成Key;
	 * 
	 * @param strKey
	 */
	private Key getKey(String strKey) {
		Key key = null;
		try {
			KeyGenerator _generator = KeyGenerator.getInstance("DES");
			_generator.init(new SecureRandom(strKey.getBytes()));
			key = _generator.generateKey();
			_generator = null;
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		return key;
	}

	/**
	 * 获得一次3DES加密后的密文
	 * 
	 * @param
	 * @return strMi
	 */
	public String getEncString(String strMing, String strKey) {
		byte[] byteMi = null;
		byte[] byteMing = null;
		String strMi = "";
		Key key = getKey(strKey);
		BASE64Encoder encoder = new BASE64Encoder();
		try {
			byteMing = strMing.getBytes("utf-8");
			byteMi = getEncCode(byteMing, key);
			strMi = encoder.encode(byteMi);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			encoder = null;
			byteMi = null;
			byteMing = null;
		}
		return strMi;
	}

	/**
	 * 获得两次3DES加密后的密文
	 * 
	 * @param
	 * @return strMi
	 */
	public String getTwiceEncString(String strMing, String strKey) {
		return getEncString(getEncString(strMing, strKey), strKey);
	}

	/**
	 * 获得一次3DES解密后的明文
	 * 
	 * @param
	 * @return strMing
	 */
	public String getDecString(String strMi, String strKey) {
		BASE64Decoder base64Decoder = new BASE64Decoder();
		byte[] byteMing = null;
		byte[] byteMi = null;
		String strMing = "";
		Key key = getKey(strKey);
		try {
			byteMi = base64Decoder.decodeBuffer(strMi);
			byteMing = getDecCode(byteMi, key);
			strMing = new String(byteMing, "utf-8");
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			base64Decoder = null;
			byteMing = null;
			byteMi = null;
		}
		return strMing;
	}

	/**
	 * 获得两次3DES解密后的明文
	 * 
	 * @param
	 * @return strMing
	 */
	public String getTwiceDecString(String strMi, String strKey) {
		return getDecString(getDecString(strMi, strKey), strKey);
	}

	/**
	 * 获得一次3DES加密后的密文
	 * 
	 * @param byts
	 * @return
	 */
	private byte[] getEncCode(byte[] byts, Key key) {
		byte[] byteFina = null;
		Cipher cipher;
		try {
			cipher = Cipher.getInstance("DES");
			cipher.init(Cipher.ENCRYPT_MODE, key);
			byteFina = cipher.doFinal(byts);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			cipher = null;
		}
		return byteFina;
	}

	/**
	 * 获得一次3DES解密后的明文
	 * 
	 * @param bytd
	 * @return
	 */
	private byte[] getDecCode(byte[] bytd, Key key) {
		byte[] byteFina = null;
		Cipher cipher = null;
		try {
			cipher = Cipher.getInstance("DES");
			cipher.init(Cipher.DECRYPT_MODE, key);
			byteFina = cipher.doFinal(bytd);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			cipher = null;
		}
		return byteFina;
	}

	public static void main(String[] args) {
		TripleDESTest td = new TripleDESTest();
		Key k = td.getKey("Key");
		System.out.println("获得的密钥key是:" + k);
		String encyStr = td.getEncString("Test", "Key");
		System.out.println("一次加密后的密文是:" + encyStr);
		String decyStr = td.getDecString(encyStr, "Key");
		System.out.println("一次解密后的明文是:" + decyStr);
		encyStr = td.getTwiceEncString("Test", "Key");
		System.out.println("两次加密后的密文是:" + encyStr);
		decyStr = td.getTwiceDecString(encyStr, "Key");
		System.out.println("两次解密后的明文是:" + decyStr);
	}

}

运行结果：

获得的密钥key是:com.sun.crypto.provider.DESKey@fffe7bef
一次加密后的密文是:dh2ue38w81g=
一次解密后的明文是:Test
两次加密后的密文是:8EBUOcWqIZlpg1n1YaqW+A==
两次解密后的明文是:Test