3、AES加密算法

墨蓝 2022-06-08 02:51 205阅读 0赞

AES加密算法是密码学中的高级加密标准，该加密算法采用对称分组密码体制，密钥长度的最少支持为128、192、256，分组长度128位，算法应易于各种硬件和软件实现。这种加密算法是美国联邦政府采用的区块加密标准，这个标准用来替代原先的DES，已经被多方分析且广为全世界所使用。

过多原理不做解释，可以参考（AES加密算法原理[http://www.jiamisoft.com/blog/858-aesjiamisuanfa.html][http_www.jiamisoft.com_blog_858-aesjiamisuanfa.html]）

java中的具体使用如下：

public class SecurityAESUtils { 
        private static Logger logger = LogManager.getLogger(SecurityAESUtils.class);
    
        private static final String ENCODEING = "UTF-8";
        private static final String ALGORITHM = "AES";//加密算法
    
        private static final String CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";//算法/工作模式/填充方式 
    
        /** * 加密 * @param plaintext 明文 * @param secureKey 16位长度的密钥 * @return */
        public static String encrypt(String plaintext, String secureKey) throws Exception{
            SecretKeySpec sks = getSecretKeySpec(secureKey);
            Cipher encryptCipher = getCipher(Cipher.ENCRYPT_MODE, sks);
            byte[] result = encryptCipher.doFinal(plaintext.getBytes(ENCODEING));
            return  Base64.encodeBase64String(result);
        }
    
        /** * 加密 * @param bytes * @param secureKey 16位长度的密钥 * @return */
        public static String encryptBytes(byte[] bytes, String secureKey) throws Exception{
            SecretKeySpec sks = getSecretKeySpec(secureKey);
            Cipher encryptCipher = getCipher(Cipher.ENCRYPT_MODE, sks);
            byte[] result = encryptCipher.doFinal(bytes);
            return  Base64.encodeBase64String(result);
        }
    
        /** * 解密 * @param ciphertext 密文 * @return secureKey 16位长度的密钥 * @throws Exception */
        public static String decrypt(String ciphertext, String secureKey) throws Exception {
            SecretKeySpec sks = getSecretKeySpec(secureKey);
            Cipher decryptCiphe = getCipher(Cipher.DECRYPT_MODE, sks);//initDecryptCipher(secureKey);
            byte[] result =  decryptCiphe.doFinal(Base64.decodeBase64(ciphertext));
            return new String(result, ENCODEING);
        }
    
        private static Cipher getCipher(int cipherMode, SecretKeySpec sks) throws Exception{
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
            cipher.init(cipherMode, sks);
            return cipher;
        }
    
        private static SecretKeySpec getSecretKeySpec(String secureKey) throws Exception{
            if(secureKey == null || secureKey.trim().equals("") || secureKey.length() != 16){
                throw new Exception("密钥不能为空或密钥长度不对");
            }
            byte[] raw = secureKey.getBytes(ENCODEING);
            SecretKeySpec skeySpec = new SecretKeySpec(raw, ALGORITHM);
            return skeySpec;
        }
    
        /** * @Comment 加密不限制密码长度 * @Author Ron * @Date 2017年9月12日 下午3:21:59 * @return */
        public static String encryptNotLimit(String plaintext, String secureKey) throws Exception{
            SecretKeySpec sks = getSecretKeySpecByRandomSeed(secureKey);
            Cipher encryptCipher = getCipher(Cipher.ENCRYPT_MODE, sks);
            byte[] result = encryptCipher.doFinal(plaintext.getBytes(ENCODEING));
            return Hex.encodeHexString(result);
        }
    
        /** * @Comment 解密不限制密码长度 * @Author Ron * @Date 2017年9月12日 下午3:22:30 * @return */
        public static String decryptNotLimit(String ciphertext, String secureKey) throws Exception {
            SecretKeySpec sks = getSecretKeySpecByRandomSeed(secureKey);
            Cipher decryptCiphe = getCipher(Cipher.DECRYPT_MODE, sks);
            byte[] result =  decryptCiphe.doFinal(Hex.decodeHex(ciphertext.toCharArray()));
            return new String(result, ENCODEING);
        }
    
        /** * @Comment 构造私钥 * @Author Ron * @Date 2017年9月12日 下午3:22:59 * @return */
        private static SecretKeySpec getSecretKeySpecByRandomSeed(String secureKey){
            SecretKeySpec sks = null;
            try {
                KeyGenerator kgen = KeyGenerator.getInstance(ALGORITHM);
                //安全随机数生成器 
                SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");//使用默认的SHA1PRNG算法
                secureRandom.setSeed(secureKey.getBytes(ENCODEING));
                kgen.init(128, secureRandom); 
                SecretKey secretKey = kgen.generateKey();
                byte[] secretKeyEncoded = secretKey.getEncoded();
                sks = new SecretKeySpec(secretKeyEncoded, ALGORITHM);
            } catch (Exception e) {
                logger.error("",e);
            }
            return sks;
        }
    
        public static void main(String[] args) throws Exception {
            String key = "ron.zheng@tfscha";
            String src = "我是Ron";
            String enString = encrypt(src,key);
            System.out.println("加密后的数据："+enString);
            System.out.println("解密后的数据："+decrypt(enString,key));
    
            //不限制密钥长度
            String nkey = "ron.zheng@tfschang.com";
            enString = encryptNotLimit(src, nkey);
            System.out.println("加密后的数据："+enString);
            System.out.println("解密后的数据："+decryptNotLimit(enString,nkey));
        }
    }

[http_www.jiamisoft.com_blog_858-aesjiamisuanfa.html]: http://www.jiamisoft.com/blog/858-aesjiamisuanfa.html