DES 加密解密算法 java 版

小鱼儿 2022-01-31 05:27 297阅读 0赞

#### 前言： ####

工作需求：所有参数（数据库连接，服务器连接，都不能使用明文传参），所以需要一个加密解密算法，本来是想写 AES 的，但是 python 环境下各种改东西调试，好烦，所以退而求其次用 DES；  
DES 算法写了 java 版和 python 版，这个是 java 版，python 可以在我的博客里找一下。[python版][python]

###### 1.直接上代码 ######

import javax.crypto.Cipher;
    import javax.crypto.SecretKey;
    import javax.crypto.SecretKeyFactory;
    import javax.crypto.spec.DESKeySpec;
    import javax.crypto.spec.IvParameterSpec;
    
    
    public class DesEnAndDe {
    
        public static String DES_CBC_Encrypt(String secretKey, String str) {
            try {
                byte[] keyBytes = secretKey.getBytes();
                byte[] content = str.getBytes();
                DESKeySpec keySpec = new DESKeySpec(keyBytes);
                SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
                SecretKey key = keyFactory.generateSecret(keySpec);
    
                Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
                cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(keySpec.getKey()));
                byte[] result = cipher.doFinal(content);
                return byteToHexString(result);
            } catch (Exception e) {
                System.out.println("exception:" + e.toString());
            }
            return null;
        }
    
        public static String DES_CBC_Decrypt(String secretKey, String str) {
            try {
                byte[] keyBytes = secretKey.getBytes();
                byte[] content = hexToByteArray(str);
                DESKeySpec keySpec = new DESKeySpec(keyBytes);
                SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
                SecretKey key = keyFactory.generateSecret(keySpec);
    
                Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
                cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(keyBytes));
                byte[] result = cipher.doFinal(content);
                return new String(result);
            } catch (Exception e) {
                System.out.println("exception:" + e.toString());
            }
            return null;
        }
    
        private static String byteToHexString(byte[] bytes) {
            StringBuilder sb = new StringBuilder(bytes.length);
            String sTemp;
            for (byte aByte : bytes) {
                sTemp = Integer.toHexString(0xFF & aByte);
                if (sTemp.length() < 2)
                    sb.append(0);
                sb.append(sTemp.toUpperCase());
            }
            return sb.toString();
        }
    
        private static byte[] hexToByteArray(String inHex) {
            int hexLen = inHex.length();
            byte[] result;
            if (hexLen % 2 == 1) {
                hexLen++;
                result = new byte[(hexLen / 2)];
                inHex = "0" + inHex;
            } else {
                result = new byte[(hexLen / 2)];
            }
            int j = 0;
            for (int i = 0; i < hexLen; i += 2) {
                result[j] = (byte) Integer.parseInt(inHex.substring(i, i + 2), 16);
                j++;
            }
            return result;
        }
    
        public static void main(String[] o) {
            String secretKey = "wo/**bhd"; // 密钥
            String str = "xgsqrfyw1hr38*/-ff?"; // 加密内容
            String secret_pwd = DesEnAndDe.DES_CBC_Encrypt(secretKey, str);
            System.out.println("密文：" + secret_pwd);
            String clear_pwd = DesEnAndDe.DES_CBC_Decrypt(secretKey, secret_pwd);
            System.out.println("明文：" + clear_pwd);
    
        }
    
    }

##### 2.运行主函数结果 #####

密文：E2EEA3378DF26770E7D0BED76FAB4B2AF9F9886134706D56
    明文：xgsqrfyw1hr38*/-ff?

##### 3.tips #####

DES 算法要求密钥的位数必须是 8 位。

[python]: https://blog.csdn.net/qingquanyingyue/article/details/90243123