加密解密（Base64、AES、MD5、HMACSHA256）

/// 

        /// Base64加密
        /// 
        /// 待加密的明文
        /// 编码方式
        /// 
        public static string EncodeBase64(string source, Encoding encode)
        {
            byte[] bytes = encode.GetBytes(source);
            return Convert.ToBase64String(bytes);
        }

        /// 

        /// Base64加密
        /// 
        /// 待加密的明文
        /// 
        /// 
        ///   
        /// 参看SecurityUtil.EncodeBase64(string,Encoding)方法的说明   
        public static string EncodeBase64(string source)
        {
            return EncodeBase64(source, Encoding.UTF8);
        }

        /// 

        /// Base64解密
        /// 
        /// 待解密的明文
        /// 编码方式
        /// 
        public static string DecodeBase64(string source, Encoding encode)
        {
            string decode = "";
            byte[] bytes = Convert.FromBase64String(source);
            decode = encode.GetString(bytes);
            return decode;
        }

        /// 

        /// AES加密 
        /// 
        /// 待加密的内容
        /// 加密密钥
        /// 
        /// 
        /// 
        /// 
        public static string AESEncrypt(string context, byte[] keyBytes,int keySize,int blockSize,byte[] ivBytes)
        {
            RijndaelManaged rijndaelCipher = new RijndaelManaged();

            rijndaelCipher.Mode = CipherMode.CBC;
            rijndaelCipher.Padding = PaddingMode.PKCS7;
            rijndaelCipher.KeySize = keySize;
            rijndaelCipher.BlockSize = blockSize;


            // 加密密钥
            rijndaelCipher.Key = keyBytes;
            rijndaelCipher.IV = ivBytes;

            ICryptoTransform transform = rijndaelCipher.CreateEncryptor();

            byte[] plainText = Encoding.UTF8.GetBytes(context);
            byte[] cipherBytes = transform.TransformFinalBlock(plainText, 0, plainText.Length);
            return Convert.ToBase64String(cipherBytes);
        }

        /// 

        /// AES解密
        /// 
        /// 
        /// 
        /// 
        /// 
        /// 
        /// 
        public static string AESDecrypt(string context, byte[] keyBytes, int keySize, int blockSize, byte[] ivBytes)
        {
            RijndaelManaged rijndaelCipher = new RijndaelManaged();

            rijndaelCipher.Mode = CipherMode.CBC;
            rijndaelCipher.Padding = PaddingMode.PKCS7;
            rijndaelCipher.KeySize = keySize;
            rijndaelCipher.BlockSize = blockSize;

            byte[] encryptedData = Convert.FromBase64String(context);
            rijndaelCipher.Key = keyBytes;
            rijndaelCipher.IV = ivBytes;

            ICryptoTransform transform = rijndaelCipher.CreateDecryptor();

            byte[] plainText = transform.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
            return Encoding.UTF8.GetString(plainText);
        }

        //16位加密
        /// 

        /// MD516位加密
        /// 
        /// 待加密的数据
        /// 编码方式
        /// 
        public static string Encrypt16(string encryptData, Encoding encodingType)
        {
            byte[] bEncrypt = encodingType.GetBytes(encryptData);
            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            string t2 = BitConverter.ToString(md5.ComputeHash(bEncrypt, 4, 8));
            t2 = t2.Replace("-", "");
            return t2;
        }

        //32位加密
        /// 

        /// MD532位加密(大写)
        /// 
        /// 待加密的数据
        /// 编码方式
        /// 
        public static string Encrypt32(string encryptData, Encoding encodingType)
        {
            byte[] bEncrypt = encodingType.GetBytes(encryptData);
            byte[] bComputeHash = MD5.Create().ComputeHash(bEncrypt);
            StringBuilder sb = new StringBuilder();
            foreach (byte item in bComputeHash)
            {
                sb.Append(item.ToString("X2"));
            }
            return sb.ToString();
        }



        //32位加密
        /// 

        /// MD532位加密(小写)
        /// 
        /// 待加密的数据
        /// 编码方式
        /// 
        public static string Encrypt32Lower(string encryptData, Encoding encodingType)
        {
            byte[] bEncrypt = encodingType.GetBytes(encryptData);
            byte[] bComputeHash = MD5.Create().ComputeHash(bEncrypt);
            StringBuilder sb = new StringBuilder();
            foreach (byte item in bComputeHash)
            {
                sb.Append(item.ToString("x2"));
            }
            return sb.ToString();
        }

        //64位加密
        /// 

        /// MD564位加密
        /// 
        /// 待加密的数据
        /// 编码方式
        /// 
        public static string Encrypt64(string encryptData, Encoding encodingType)
        {
            byte[] bEncrypt = encodingType.GetBytes(encryptData);
            //string pwd = "";
            MD5 md5 = MD5.Create(); //实例化一个md5对像
            // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　
            byte[] s = md5.ComputeHash(bEncrypt);
            return Convert.ToBase64String(s);
        }

        /// 

        /// 字符串 str 按照简体中文(ASCIIEncoding.ASCII)的编码方式
        /// 
        /// 待编码的内容
        /// 
        public static byte[] GetBytesByASCIIEncoding(string encodingData) {
            return ASCIIEncoding.ASCII.GetBytes(encodingData);
        }

        public static byte[] GetSHA1HashBytes(byte[] encryptData) {
           return new SHA1CryptoServiceProvider().ComputeHash(encryptData);
        }

        /// 

        /// HmacSHA256加密64位
        /// 
        /// 待加密内容
        /// 加密密钥
        /// 
        public static string HmacSHA256Encrypt64(string message,string secret) {
            return HmacSHA256Encrypt64(message,secret,new System.Text.ASCIIEncoding());
        }

        /// 

        /// HmacSHA256加密64位
        /// 
        /// 待加密内容
        /// 加密密钥
        /// 编码方式
        /// 
        public static string HmacSHA256Encrypt64(string message, string secret,Encoding encoding)
        {
            secret = secret ?? "";
            byte[] keyByte = encoding.GetBytes(secret);
            byte[] messageBytes = encoding.GetBytes(message);
            using (var hmacsha256 = new HMACSHA256(keyByte))
            {
                byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);
                return Convert.ToBase64String(hashmessage);
            }
        }