大批量字符加解密时报 Cipher not initialized

在使用Cipher类最加密的时候，如果需要大量进行加解密工作，需要避免Cipher类的大量实例化，本文用MAP记录已经实例化的Cipher，如果已经存在则不需要在实例化、避免内存浪费、导致 Cipher not initialized    错误。

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import java.util.HashMap;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import sun.misc.BASE64Decoder;

/**
 * 解密
 */
public class DESTool {
	private static String Algorithm = "DESede";// 加密算法的名称
	private static Cipher c;// 密码器
	//private static byte[] cipherByte;
	private static SecretKey deskey;// 密钥
	private static String keyString = "XXXXXXXXXXXXXXXXXXXXXXXXX";// 获得密钥的参数
    private static HashMap decryptCipherMap=new HashMap(); 
   // Logger  log =Logger.getLogger(DESTool.class);
	// 对base64编码的string解码成byte数组
	public byte[] deBase64(String parm) throws IOException {
		BASE64Decoder dec = new BASE64Decoder();
		byte[] dnParm = dec.decodeBuffer(parm);
		//System.out.println(dnParm.length);
		//System.out.println(dnParm);
		return dnParm;
	}

	// 把密钥参数转为byte数组
	public byte[] dBase64(String parm) throws IOException {
		BASE64Decoder dec = new BASE64Decoder();
		byte[] dnParm = dec.decodeBuffer(parm);
		return dnParm;
	}

	/**
	 * 对 Byte 数组进行解密
	 * 
	 * @param buff
	 *            要解密的数据
	 * @return 返回加密后的 String
	 */
	public static String createDecryptor(byte[] buff)
			throws NoSuchPaddingException, NoSuchAlgorithmException,
			UnsupportedEncodingException {
		 byte[] cipherByte = buff ;
		try {
		
			  cipherByte = c.doFinal(buff);
		} catch (javax.crypto.BadPaddingException ex) {
			
			ex.printStackTrace();
			
			return null;
		} catch (javax.crypto.IllegalBlockSizeException ex) {
			ex.printStackTrace();
			return null;
		}
		return (new String(cipherByte, "UTF-8"));
	}

	public void init(String key) throws IOException, InvalidKeyException,
			InvalidKeySpecException {
		byte[] dKey = dBase64(key);
		try {
			
			if(decryptCipherMap.get("keyString")==null){//判断是否已经存在实例，如果存在不在实例化。
				deskey = new javax.crypto.spec.SecretKeySpec(dKey, Algorithm);
				c = Cipher.getInstance(Algorithm);
			    c.init(Cipher.DECRYPT_MODE, deskey);// 初始化密码器，用密钥deskey,进入解密模式
				decryptCipherMap.put("keyString", c);   
			
			}	
		} catch (NoSuchPaddingException ex) {
		} catch (NoSuchAlgorithmException ex) {
		}
	}
	
	
	/**
	 * 
	 * @param strEncryption 加密字符串
	 * @return 返回解密后的字符串
	 * @throws IOException
	 * @throws NoSuchAlgorithmException
	 * @throws NoSuchPaddingException
	 * @throws InvalidKeySpecException
	 * @throws InvalidKeyException
	 * @throws IOException
	 */
	public static String decryptScore(String strEncryption)throws IOException,
	NoSuchAlgorithmException, NoSuchPaddingException,
	InvalidKeySpecException, InvalidKeyException, IOException{
		DESTool des = new DESTool();
		des.init(keyString);
		byte[] dBy = des.deBase64(strEncryption);
		return des.createDecryptor(dBy);
	}
	

	public static void main(String args[]) throws IOException,
			NoSuchAlgorithmException, NoSuchPaddingException,
			InvalidKeySpecException, InvalidKeyException, IOException {
		DESTool des = new DESTool();
		des.init(keyString);
		//byte[] dBy = des.deBase64("1ZVasdJJco1qccDnnfQfb8QeaARxhkR6");
		byte[] dBy = des.deBase64("JdTkEPNsw8E=");
		String dStr = des.createDecryptor(dBy);
		System.out.println("解：" + decryptScore("JdTkEPNsw8E="));
	}
	

}

评论

2 楼 douglozy 2014-07-29  

Exception in thread "main" java.security.InvalidKeyException: Invalid key length: 18 bytes
at com.sun.crypto.provider.DESedeCipher.engineGetKeySize(DashoA13*..)
at javax.crypto.Cipher.b(DashoA13*..)
at javax.crypto.Cipher.a(DashoA13*..)
at javax.crypto.Cipher.a(DashoA13*..)
at javax.crypto.Cipher.a(DashoA13*..)
at javax.crypto.Cipher.init(DashoA13*..)
at javax.crypto.Cipher.init(DashoA13*..)
at com.douglas.test.DESTool.init(DESTool.java:91)
at com.douglas.test.DESTool.main(DESTool.java:126)

1 楼 douglozy 2014-07-29  

运行错误？