public static class AESEncryptionUtility
    {
        public static string Encrypt(string data, string key, string iv = null, CipherMode mode= CipherMode.CBC, PaddingMode paddingMode= PaddingMode.PKCS7)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(data);
            RijndaelManaged rijndaelManaged = new RijndaelManaged
            {
                Key = Convert.FromBase64String(key),
                Mode = CipherMode.ECB,
                Padding = PaddingMode.PKCS7
            };
            if (!string.IsNullOrEmpty(iv))
            {
                rijndaelManaged.IV = Encoding.UTF8.GetBytes(iv);
            }
            rijndaelManaged.Mode = mode;
            rijndaelManaged.Padding = paddingMode;
            ICryptoTransform cryptoTransform = rijndaelManaged.CreateEncryptor();
            byte[] array = cryptoTransform.TransformFinalBlock(bytes, 0, bytes.Length);
            var result = Convert.ToBase64String(array, 0, array.Length);
            return result;
        }

        public static string Decrypt(string data, string key, string iv=null, CipherMode mode = CipherMode.CBC, PaddingMode paddingMode = PaddingMode.PKCS7)
        {
            byte[] array = Convert.FromBase64String(data);

            RijndaelManaged rijndaelManaged = new RijndaelManaged
            {
                Key = Convert.FromBase64String(key),
                Mode = CipherMode.ECB,
                Padding = PaddingMode.PKCS7
            };
            if (!string.IsNullOrEmpty(iv))
            {
                rijndaelManaged.IV = Encoding.UTF8.GetBytes(iv);
            }
            rijndaelManaged.Mode = mode;
            rijndaelManaged.Padding = paddingMode;
            ICryptoTransform cryptoTransform = rijndaelManaged.CreateDecryptor();
            byte[] bytes = cryptoTransform.TransformFinalBlock(array, 0, array.Length);

            var result = Encoding.UTF8.GetString(bytes);
            return result;
        }

        public static string AesGenKey(int size,CipherMode mode = CipherMode.CBC, PaddingMode paddingMode = PaddingMode.PKCS7)
        {
            RijndaelManaged rijndaelManaged = new RijndaelManaged
            {
                KeySize = size,
                Mode = mode,
                Padding = paddingMode
            };
            rijndaelManaged.GenerateKey();
            return Convert.ToBase64String(rijndaelManaged.Key);
        }
    }

使用方式

[TestMethod]
        public void AES()
        {
            var key=AESEncryptionUtility.AesGenKey(128);
            var input = "HelloWorld1";
            var secret = AESEncryptionUtility.Encrypt(input, key, "FFFFF09839694AC6");
            Console.WriteLine(secret);
        }
        [TestMethod]
        public void DeAES()
        {
            var key = AESEncryptionUtility.AesGenKey(128);
            var input = "HelloWorld1";
            var secret = AESEncryptionUtility.Encrypt(input, key, "FFFFF09839694AC6");
            var result = AESEncryptionUtility.Decrypt(secret, key, "FFFFF09839694AC6");
            Console.WriteLine(result);
        }