加密与解密md5 3des

/// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static string MD5Encrypt(string s)
        {
            string strResult = "";
            System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create();
            byte[] bytResult = md5.ComputeHash(System.Text.Encoding.UTF8.GetBytes(s));
            for (int i = ; i < bytResult.Length; i++)
            {
                strResult = strResult + bytResult[i].ToString("x").PadLeft(,'');
            }
            return strResult;
        }

        /// <summary>
        /// 与PHP兼容的MD5加密
        /// </summary>
        /// <param name="password"></param>
        /// <returns></returns>
        public static string MD5(string password)
        {

            byte[] textBytes = System.Text.Encoding.UTF8.GetBytes(password);
            try
            {
                System.Security.Cryptography.MD5CryptoServiceProvider cryptHandler;
                cryptHandler = new System.Security.Cryptography.MD5CryptoServiceProvider();
                byte[] hash = cryptHandler.ComputeHash(textBytes);
                string ret = "";
                foreach (byte a in hash)
                {
                    if (a < )
                        ret += "" + a.ToString("x");
                    else
                        ret += a.ToString("x");
                }
                return ret;
            }
            catch
            {
                throw;
            }

        }

        /// <summary>
        /// 16位md5加密，小写
        /// </summary>
        /// <param name="password"></param>
        /// <returns></returns>
        public static string MD5_16(string password) {
            return MD5(password).ToLower().Substring(, );
        }

private static string KEY = "";
        private static string IV = "";

        /// <summary>
        /// 3DES解密
        /// </summary>
        /// <param name="strText"></param>
        /// <param name="key"></param>
        /// <param name="iv"></param>
        /// <returns></returns>
        public static String DESDecrypt(String strText, string key, string iv)
        {
            System.Security.Cryptography.TripleDESCryptoServiceProvider des3 = new System.Security.Cryptography.TripleDESCryptoServiceProvider();
            des3.Key = Convert.FromBase64String(key);
            des3.IV = Convert.FromBase64String(iv);

            string result = string.Empty;
            try
            {
                byte[] buffer = Convert.FromBase64String(strText);
                buffer = des3.CreateDecryptor().TransformFinalBlock(buffer, , buffer.Length);
                result = System.Text.Encoding.UTF8.GetString(buffer);
            }
            catch
            {

            }
            return result;
        }

        /// <summary>
        /// 3DES加密
        /// </summary>
        /// <param name="strText">待加密文字</param>
        /// <param name="key">KEY</param>
        /// <param name="iv">向量</param>
        /// <returns></returns>
        public static string DESEncrypt(string strText, string key, string iv)
        {
            System.Security.Cryptography.TripleDESCryptoServiceProvider des3 = new System.Security.Cryptography.TripleDESCryptoServiceProvider();
            des3.Key = Convert.FromBase64String(key);
            des3.IV = Convert.FromBase64String(iv);

            string result = string.Empty;
            try
            {
                byte[] buffer = System.Text.Encoding.UTF8.GetBytes(strText);
                buffer = des3.CreateEncryptor().TransformFinalBlock(buffer, , buffer.Length);
                result = Convert.ToBase64String(buffer);
            }
            catch
            {

            }
            return result;
        }