C#簡單的對稱加解密

這是參考自Jeff隨手記。我將他稍作修改可以讓Key與initial vector可以直接吃字串。解密失敗時會產生exception，可以作為檢測該密碼是否合法。

        public string EncodeString(string EnString){
            byte[] Key = Encoding.UTF8.GetBytes("xxxxxxxx");
            byte[] IV = Encoding.UTF8.GetBytes("yyyyyyyy");
            byte[] b = Encoding.UTF8.GetBytes(EnString);   DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            ICryptoTransform ict = des.CreateEncryptor(Key, IV);
            byte[] outData = ict.TransformFinalBlock(b, 0, b.Length);
            return Convert.ToBase64String(outData); 
        }

        public string DecodeString(string DeString){   byte[] Key = Encoding.UTF8.GetBytes("xxxxxxxx");
            byte[] IV = Encoding.UTF8.GetBytes("yyyyyyyy");
            byte[] b = Convert.FromBase64String(DeString);
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            ICryptoTransform ict = des.CreateDecryptor(Key, IV);
            byte[] outData = ict.TransformFinalBlock(b, 0, b.Length);
            return Encoding.UTF8.GetString(outData);
        }

資料來源：
[1] 對稱式加解密 C#