Imports System

Imports System.Security.Cryptography

Imports System.Xml

Imports System.IO

Imports System.Web

​

Public Module Module1

​

    Public Function ValidateAuthenticationToken(ByVal authenticationToken As String, ByRef userName As String) As Boolean

        Dim STR_EncryptionKey As String = "a3sEncrypti0nK3yF0rP0rtalW3bsit3"

        Dim STR_IV As String = "ZsGMgXGgxAhritPfSs9jDQ=="

        Dim result As Boolean

​

        Try

            Dim decryptedToken As String = String.Empty

            Console.WriteLine("start")

            Using aesAlg As AesCryptoServiceProvider = New AesCryptoServiceProvider()

                aesAlg.Key = Convert.FromBase64String(STR_EncryptionKey)

                aesAlg.IV = Convert.FromBase64String(STR_IV)

                Dim decryptor As ICryptoTransform = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)

​

                Using msDecrypt As MemoryStream = New MemoryStream(Convert.FromBase64String(authenticationToken))

​

                    Using csDecrypt As CryptoStream = New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)

​

                        Using srDecrypt As StreamReader = New StreamReader(csDecrypt)

                            decryptedToken = srDecrypt.ReadToEnd()

                        End Using

                    End Using

                End Using

            End Using

            Console.WriteLine("start 2")

            Dim xmlDocument As New XmlDocument()

            xmlDocument.LoadXml(decryptedToken)

​

            Dim userNameElement As XmlNode = xmlDocument.SelectNodes("/authenticationToken/userName")(0)

            userName = userNameElement.InnerText

​

            Dim expiresElement As XmlNode = xmlDocument.SelectNodes("/authenticationToken/expires")(0)

            Dim expires As DateTime = DateTime.FromBinary(System.Convert.ToInt64(expiresElement.InnerText))

            Console.WriteLine(expires)

            result = expires > DateTime.Now

​

        Catch ex As Exception

            Console.WriteLine("fail")

            result = False

        End Try

​

        Return result

​

    End Function

​

    Sub Main()

        Dim decodedUrl As String = "Q5lPGZlaI7zbXN3A1D5zVkWFTfVtsU66ZWWhw4b%20YrrTanIG0SkM4YiObYmS8mG3Vhj1dxBejD0v9u/fv46nSKcUhd6daLVeBGTsqgk/Ge8hGGfUREsU1ep%20HuL%20S6zkv5RZWYwCSs56zx/P415VH/8mGDdA4tbqVmwEgOgwGBs="

        Console.WriteLine(HttpUtility.UrlDecode(decodedUrl))

        Console.WriteLine(Convert.FromBase64String(decodedUrl))        

        Dim result as Boolean = ValidateAuthenticationToken(decodedUrl, "")

        Console.WriteLine(result)

    End Sub

End Module