java对称加密(DES/DESESE/AES)的简单使用

一时失言乱红尘 2022-07-16 10:20 145阅读 0赞

主类：

/**
     * Created by cuboo on 2016/10/14.
     */
    public class Main {
        public static void main(String agrs[]) throws Exception {
            //String keyType = "DES"; DES的使用
            //int keysize = 56;
    
            //DESede加密的使用
           // String keyType = "DESede";
            //int keysize = 168;//112/168
    
            //AES的加密
            String keyType = "AES";
            int keysize = 128;//192/256
    
            byte[] data = "abcdefg".getBytes();
            byte[] key = DEScode.InitKey(keyType,keysize);
            byte[] encryptDate = DEScode.encrypt(key,keyType,data);
            byte[] decryptData = DEScode.decrypt(key,keyType,encryptDate);
    
            System.out.println(bytesToHexString(key));
            System.out.println(bytesToHexString(encryptDate));
            System.out.println(new String(decryptData));
            
        }
    
        public static String bytesToHexString(byte[] data){
            StringBuilder strb = new StringBuilder();
            for (int i = 0; i < data.length; i++) {
                int s = data[i] & 0xff;
                String str = Integer.toHexString(s);
                 if (str.length() < 2){
                     strb.append(0);
                 }else {
                     strb.append(str);
                 }
    
            }
            return strb.toString();
        }
    
    }

方法类：

import javax.crypto.*;
    import javax.crypto.spec.SecretKeySpec;
    import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    
    /**
     * Created by cuboo on 2016/10/14.
     */
    public class DEScode {
        /*
         *生成秘钥
         */
        public static byte[] InitKey(String keyType,int keysize) throws NoSuchAlgorithmException {
                KeyGenerator keyGenerator = KeyGenerator.getInstance(keyType);
                keyGenerator.init(keysize);
                SecretKey secretKey = keyGenerator.generateKey();
            return  secretKey.getEncoded();
        }
        /*
         *加密
         */
        public static byte[] encrypt(byte[] key,String keyType,byte[] data)
                throws NoSuchPaddingException, NoSuchAlgorithmException,
                InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
    
            SecretKey secretKey = new SecretKeySpec(key,keyType);
            Cipher cipher = Cipher.getInstance(keyType);
            cipher.init(Cipher.ENCRYPT_MODE,secretKey);
            return cipher.doFinal(data);
        }
    
        /*
         *解密
         */
        public static byte[] decrypt(byte[] key,String keyType,byte[] data)
                throws NoSuchPaddingException, NoSuchAlgorithmException,
                InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
    
            SecretKey secretKey = new SecretKeySpec(key,keyType);
            Cipher cipher = Cipher.getInstance(keyType);
            cipher.init(Cipher.DECRYPT_MODE,secretKey);
            return cipher.doFinal(data);
        }
    }