Fake64

openencryptedpackage.js

function openencryptedpackage(encryptedpackage) {
  function e2c(e) {encryptedpackage
    return Array.from(e).map(function (c) {
      return c === 'a' ? 'A': c === 'g' ? 'E': c === '1' ? 'I': c === '0' ? 'O': c === '7' ? 'U': c === 'p' ? 'P': c === 'w' ? 'W': c === 'e' ? 'H': c === '5' ? 'S': c === 'A' ? 'a': c === 'H' ? 'e': c === 'E' ? 'i': c === 'v' ? 'o': c === 'o' ? 'u': c === 'u' ? 'v': c === 'i' ? 'g': c === 'P' ? 'p': c === 'W' ? 'w': c === 'O' ? '0': c === 'I' ? '1': c === 'S' ? '5': c === 'U' ? '7': c;
    }).join('');
  }

  function c2a(e) {
    return Array.from(e).map(function (c) {
      return c === 'x' ? '%' : c === '1' ? '2' : c === '%' ? 'x' : c === '2' ? '1' : c;
    }).join('');
  }

  const info = JSON.parse(window.decodeURIComponent(c2a(window.atob(e2c(encryptedpackage)))));
  [...]
}

ViewFunctions.cshtml

@functions {

  public static string MakeFake64(string b64)
  {
    var f64 = new System.Text.StringBuilder();
    var vistor = b64.GetEnumerator();
    while (vistor.MoveNext())
    {
      switch (vistor.Current)
      {
        case 'A': f64.Append('a'); break;
        case 'E': f64.Append('g'); break;
        case 'I': f64.Append('1'); break;
        case 'O': f64.Append('0'); break;
        case 'U': f64.Append('7'); break;
        case 'P': f64.Append('p'); break;
        case 'W': f64.Append('w'); break;
        case 'H': f64.Append('e'); break;
        case 'S': f64.Append('5'); break;
        case 'a': f64.Append('A'); break;
        case 'e': f64.Append('H'); break;
        case 'i': f64.Append('E'); break;
        case 'o': f64.Append('v'); break;
        case 'u': f64.Append('o'); break;
        case 'v': f64.Append('u'); break;
        case 'g': f64.Append('i'); break;
        case 'p': f64.Append('P'); break;
        case 'w': f64.Append('W'); break;
        case '0': f64.Append('O'); break;
        case '1': f64.Append('I'); break;
        case '5': f64.Append('S'); break;
        case '7': f64.Append('U'); break;
        default: f64.Append(vistor.Current); break;
      }
    }

    return f64.ToString();
  }

  public static string MakeFake3986(string s3968)
  {
    var f3968 = new System.Text.StringBuilder();
    var vistor = s3968.GetEnumerator();
    while (vistor.MoveNext())
    {
      switch (vistor.Current)
      {
        case '%': f3968.Append('x'); break;
        case 'x': f3968.Append('%'); break;
        case '2': f3968.Append('1'); break;
        case '1': f3968.Append('2'); break;
        default: f3968.Append(vistor.Current); break;
      }
    }

    return f3968.ToString();
  }
}

string encryptedpackage = ViewFunctions.MakeFake64(Convert.ToBase64String(System.Text.ASCIIEncoding.ASCII.GetBytes(
      ViewFunctions.MakeFake3986(Uri.EscapeDataString(Newtonsoft.Json.JsonConvert.SerializeObject(info, Newtonsoft.Json.Formatting.None))))));