How to encode/decode product id in path in ASP.NET

Question

ASP.NET/Mono MVC4 shopping cart application users product codes as url names for awstats analytics like:

http://myshop.com/Store/Details/PRODUCT1

with default routing and controller

    public class StoreController : MyApp.ControllerBase
    {

        public ActionResult Details(string id)
        {
  ....

PRODUCT1 is product code. If product code contains / and other non-allowed characters in directory name, web server throws error.

Product code should be human readable since analytics shows urls. How to encode product code to passed as directory name and decode it back in controller ? Product code should remain unique after encoding.

Is there some built-in function in ASP.NET or some source code which implements this ?

jquery, jquery ui, razor view engine is used.

Update

I tried recommendatiod in comment by creating Razor helper

@helper Details(string toode)
{
    @Url.Action("Details", new { id = HttpUtility.UrlEncode(toode) });
}

and then using

<a href="@Details(someproduct)">

This causes error:

A potentially dangerous Request.Path value was detected from the client (%). GET /Store/Details/S%c3%9c%c3%9cTAJA HTTP/1.0

% chareter is not allowed in url paths. So UrlEncode cannot used. How to encode/decode?

Answer 1

You can use encryption and decryption algorithm (cryptography) to achieve your goal like this...

 public class CryptoEngine
    {

        private static CryptoEngine _instance;
        private CryptoEngine() { }
        public static CryptoEngine Instance
        {
            get
            {
                if (_instance == null)
                    _instance = new CryptoEngine();

                return _instance;
            }
        }

        static readonly string PasswordHash = "@dM!nCo$";
        static readonly string SaltKey = "AdMinCos";
        static readonly string VIKey = "Polar!s@dM!nCoN$";

        public string Encrypt(string plainText)
        {
            byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);

            byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
            var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.Zeros };
            var encryptor = symmetricKey.CreateEncryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));

            byte[] cipherTextBytes;

            using (var memoryStream = new MemoryStream())
            {
                using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
                {
                    cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
                    cryptoStream.FlushFinalBlock();
                    cipherTextBytes = memoryStream.ToArray();
                    cryptoStream.Close();
                }
                memoryStream.Close();
            }
            return Convert.ToBase64String(cipherTextBytes);
        }

        public string Decrypt(string encryptedText)
        {
            encryptedText = encryptedText.Trim();
            if (encryptedText.Contains(" "))
            {
                encryptedText = encryptedText.Replace(" ", "+");
            }

            byte[] cipherTextBytes = Convert.FromBase64String(encryptedText);
            byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
            var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.None };

            var decryptor = symmetricKey.CreateDecryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
            var memoryStream = new MemoryStream(cipherTextBytes);
            var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
            byte[] plainTextBytes = new byte[cipherTextBytes.Length];

            int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
            memoryStream.Close();
            cryptoStream.Close();
            return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount).TrimEnd("\0".ToCharArray());
        }
    }

and use it like this...

"/Store/Details?id="+CryptoEngine.Instance.Encrypt(toode))

and in your action you can decrypt it as like this...

public ActionResult Details(string id)
{
   string _id = CryptoEngine.Instance.Decrypt(id);
   .......

You can set your PasswordHash, SaltKey and VIKey i think this is what you want.

You can check more about cryptography Reference