desencrypt.java

加密解密采用DES ENC技术基于java的图形化 界面应用程序

package desencrypt;

/**
 * <p>Title: DES ENC 加密解密</p>
 *
 * <p>Description: 加密解密</p>
 *
 * <p>Copyright: Copyright (c) 2007</p>
 *
 * <p>Company: juaby</p>
 *
 * @author not attributable
 * @version 1.0
 */

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

/**
 *
 *   使用DES加密与解密,可对byte[],String类型进行加密与解密
 *   密文可使用String,byte[]存储.
 *
 *   方法:
 *   void   getKey(String   strKey)从strKey的字条生成一个Key
 *
 *   String   getEncString(String   strMing)对strMing进行加密,返回String密文
 *   String   getDesString(String   strMi)对strMin进行解密,返回String明文
 *
 *byte[]   getEncCode(byte[]   byteS)byte[]型的加密
 *byte[]   getDesCode(byte[]   byteD)byte[]型的解密
 */
public class DesEncrypt {

    Key key;

    /**
     *   根据参数生成KEY
     *   @param   strKey
     */
    public Key getKey(String strKey) {
        try {
            KeyGenerator _generator = KeyGenerator.getInstance("DES");
            _generator.init(new SecureRandom(strKey.getBytes()));
            this.key = _generator.generateKey();
            _generator = null;

        } catch (Exception e) {
            e.printStackTrace();
        }
        return this.key;
    }

    public void setKey(Key strKey)
    {
        this.key = strKey;
    }

    /**
     *   加密String明文输入,String密文输出
     *   @param   strMing
     *   @return
     */
    public String getEncString(String strMing) {
        byte[] byteMi = null;
        byte[] byteMing = null;
        String strMi = "";
        BASE64Encoder base64en = new BASE64Encoder();
        try {
            byteMing = strMing.getBytes("UTF8");
            byteMi = this.getEncCode(byteMing);
            strMi = base64en.encode(byteMi);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            base64en = null;
            byteMing = null;
            byteMi = null;
        }
        return strMi;
    }

    /**
     *   解密   以String密文输入,String明文输出
     *   @param   strMi
     *   @return
     */
    public String getDesString(String strMi) {
        BASE64Decoder base64De = new BASE64Decoder();
        byte[] byteMing = null;
        byte[] byteMi = null;
        String strMing = "";
        try {
            byteMi = base64De.decodeBuffer(strMi);
            byteMing = this.getDesCode(byteMi);
            strMing = new String(byteMing, "UTF8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            base64De = null;
            byteMing = null;
            byteMi = null;
        }
        return strMing;
    }

    /**
     *   加密以byte[]明文输入,byte[]密文输出
     *   @param   byteS
     *   @return
     */
    private byte[] getEncCode(byte[] byteS) {
        byte[] byteFina = null;
        Cipher cipher;
        try {
            cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byteFina = cipher.doFinal(byteS);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            cipher = null;
        }
        return byteFina;
    }

    /**
     *   解密以byte[]密文输入,以byte[]明文输出
     *   @param   byteD
     *   @return
     */
    private byte[] getDesCode(byte[] byteD) {
        Cipher cipher;
        byte[] byteFina = null;
        try {
            cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.DECRYPT_MODE, key);
            byteFina = cipher.doFinal(byteD);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            cipher = null;
        }
        return byteFina;

    }

}