iOS Question AES Encryption problem

 Dim AES As New System.Security.Cryptography.RijndaelManaged

    Public Function Codifica(ByVal stringToEncrypt As String, Optional ByVal key() As Byte = Nothing) As String

        Dim encrypted As String = ""

        Try
            If key IsNot Nothing Then AES.Key = key
            AES.KeySize = 128
            AES.BlockSize = 128
            AES.Padding = Security.Cryptography.PaddingMode.Zeros
            AES.Mode = Security.Cryptography.CipherMode.CBC

            If AES.Key.Length > 0 Then
                Dim DESEncrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateEncryptor
                Dim Buffer As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(stringToEncrypt)
                encrypted = Convert.ToBase64String(DESEncrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
                'For temp2 As Byte = 0 To Buffer.Length - 1
                '    Debug.Print(String.Format("{0} - {1}", Buffer(temp2), Hex(Buffer(temp2))))
                'Next

            End If

        Catch ex As Exception
            Debug.Print(ex.Message)
        End Try

        Return encrypted

    End Function

Private Sub GetXpKeys()

    Dim bytes2Crypt() As Byte = Array As Byte(TCPIP_KEY_REQUEST)
    Dim msg2Send() As Byte = iAes.Encrypt2(bytes2Crypt, pKeys, "AES", Null, iAes.OPTION_PKCS7Padding)

    SendMessage(msg2Send)
   
End Sub