C#实现md5加密 sha1加密 sha256加密 sha384加密 sha512加密 des加密解密

using System.Security;


       //MD5不区分大小写的
     //type 类型，16位还是32位，16位就是取32位的第8到16位
     public string DoMd5Encode(string pwd,string type)
       {
            byte[] result = Encoding.Default.GetBytes(pwd);
            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] output = md5.ComputeHash(result);
            if (type == "16")
                return BitConverter.ToString(output).Replace("-", "").ToLower().Substring(8,16);    
            else
                return BitConverter.ToString(output).Replace("-", "").ToLower();    
            
        }


        /// <summary>
        /// 对字符串进行SHA1加密
      /// </summary>
        /// <param name="strIN">需要加密的字符串</param>
        /// <returns>密文</returns>
        public string SHA1_Encrypt(string Source_String)
        {
            byte[] StrRes = Encoding.Default.GetBytes(Source_String);
            HashAlgorithm iSHA = new SHA1CryptoServiceProvider();
            StrRes = iSHA.ComputeHash(StrRes);
            StringBuilder EnText = new StringBuilder();
            foreach (byte iByte in StrRes)
            {
                EnText.AppendFormat("{0:x2}", iByte);
            }
            return EnText.ToString();
        }

        /// <summary>
        /// SHA256加密，不可逆转
      /// </summary>
        /// <param name="str">string str:被加密的字符串</param>
        /// <returns>返回加密后的字符串</returns>
        private string SHA256Encrypt(string str)
        {
            System.Security.Cryptography.SHA256 s256 = new System.Security.Cryptography.SHA256Managed();
            byte[] byte1;
            byte1 = s256.ComputeHash(Encoding.Default.GetBytes(str));
            s256.Clear();
            return Convert.ToBase64String(byte1);
        }

        /// <summary>
        /// SHA384加密，不可逆转
      /// </summary>
        /// <param name="str">string str:被加密的字符串</param>
        /// <returns>返回加密后的字符串</returns>
        private string SHA384Encrypt(string str)
        {
            System.Security.Cryptography.SHA384 s384 = new System.Security.Cryptography.SHA384Managed();
            byte[] byte1;
            byte1 = s384.ComputeHash(Encoding.Default.GetBytes(str));
            s384.Clear();
            return Convert.ToBase64String(byte1);
        }



        /// <summary>
        /// SHA512加密，不可逆转
        /// </summary>
        /// <param name="str">string str:被加密的字符串</param>
        /// <returns>返回加密后的字符串</returns>
        private string SHA512Encrypt(string str)
        {
            System.Security.Cryptography.SHA512 s512 = new System.Security.Cryptography.SHA512Managed();
            byte[] byte1;
            byte1 = s512.ComputeHash(Encoding.Default.GetBytes(str));
            s512.Clear();
            return Convert.ToBase64String(byte1);
        }






        //默认密钥向量
      private byte[] Keys = { 0xEF, 0xAB, 0x56, 0x78, 0x90, 0x34, 0xCD, 0x12 };
        /// <summary>
        /// DES加密字符串
        /// </summary>
        /// <param name="encryptString">待加密的字符串</param>
        /// <param name="encryptKey">加密密钥,要求为8位</param>
        /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>
        public string EncryptDES(string encryptString, string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }

        /// <summary>
        /// DES解密字符串
        /// </summary>
        /// <param name="decryptString">待解密的字符串</param>
        /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>
        /// <returns>解密成功返回解密后的字符串，失败返源串</returns>
        public string DecryptDES(string decryptString, string decryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return decryptString;
            }
        }