VB VNC Server

Simple VNC Server in VB6 using DXGI Desktop Duplication

Description

• Supports password based authentication
  • Plain, VNC and Tight security types (DES in ECB mode)
  • UltraVNC and UltraVNC_MsLogonIIAuth (Diffie-Hellman KX for the shared key and DES in CBC mode)
• Supports Raw, CopyRect, Zlib and Tight encodings
  • Windows Imaging Component (WIC) for fast JPEG compression in Tight encoding
• Uses Desktop Duplication from DirectX 11 for incremental screen updates
  • Chunks output in 256x256 tiles
  • Multiple clients per desktop duplication source
• Supports cursor pseudo-encodings
  • Including cursor with alpha
• Supports file transfer protocol extensions
  • UltraVNC (including ZIP compression on folder downloads)
  • TightVNC (latest version of protocol extension only)
• Single-thread asynchronous implementation
• Conditional compilation to reduce footprint on final executable
  • Optional ZLib support
  • Optional histograms for JPEG quality estimation

How to use

Copy VBD3D11.tlb type library from lib\VBD3D11\typelib to your local disk and register it before adding a project reference to this newly registered "DirectX 11 for VB6 1.0" from Project->References menu in VB IDE.

Add cVncServer.cls, cAsyncSocket.cls (from lib\VbAsyncSocket\src) and cZipArchive.cls (from lib\ZipArchive\src) to your project and use cVncServer.Init method to start a new VNC server like this:

Option Explicit

Private m_oServer As cVncServer

Private Sub Form_Load()
    Dim lPort           As Long
    
    lPort = Val(Environ$("MYLOBAPP_VNC_PORT"))
    If lPort <> 0 Then
        Set m_oServer = New cVncServer
        m_oServer.Init "0.0.0.0", lPort, Environ$("MYLOBAPP_VNC_PASSWORD")
    End If
End Sub

The snippet above allows optionally starting the built-in in your LOB application VNC server by configuring a listening port through the MYLOBAPP_VNC_PORT environment variable and optionally securing it with a password through the MYLOBAPP_VNC_PASSWORD environment variable.

Please when copy/pasting the sample code use common sense and change the prefix of these environment variables to include your LOB application name.

To reduce footprint on final executable you can optionally exclude cZipArchive.cls from your project by using VNC_NOZLIB = 1 in conditional compilation settings which will remove (or reduce) some of the server functionalities.