The Remote Framebuffer Protocol
RFC 6143

Internet Engineering Task Force (IETF)                     T. Richardson
Request for Comments: 6143                                     J. Levine
Category: Informational                                     RealVNC Ltd.
ISSN: 2070-1721                                               March 2011

                    The Remote Framebuffer Protocol

Abstract

   RFB ("remote framebuffer") is a simple protocol for remote access to
   graphical user interfaces that allows a client to view and control a
   window system on another computer.  Because it works at the
   framebuffer level, RFB is applicable to all windowing systems and
   applications.  This document describes the protocol used to
   communicate between an RFB client and RFB server.  RFB is the
   protocol used in VNC.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6143.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Richardson & Levine           Informational                     [Page 1]
RFC 6143             The Remote Framebuffer Protocol          March 2011

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Initial Connection . . . . . . . . . . . . . . . . . . . . . .  4
   3.  Display Protocol . . . . . . . . . . . . . . . . . . . . . . .  4
   4.  Input Protocol . . . . . . . . . . . . . . . . . . . . . . . .  5
   5.  Representation of Pixel Data . . . . . . . . . . . . . . . . .  5
   6.  Protocol Versions and Extensions . . . . . . . . . . . . . . .  6
   7.  Protocol Messages  . . . . . . . . . . . . . . . . . . . . . .  7
     7.1.  Handshake Messages . . . . . . . . . . . . . . . . . . . .  8
       7.1.1.  ProtocolVersion Handshake  . . . . . . . . . . . . . .  8
       7.1.2.  Security Handshake . . . . . . . . . . . . . . . . . .  8
       7.1.3.  SecurityResult Handshake . . . . . . . . . . . . . . . 10
     7.2.  Security Types . . . . . . . . . . . . . . . . . . . . . . 10
       7.2.1.  None . . . . . . . . . . . . . . . . . . . . . . . . . 10
       7.2.2.  VNC Authentication . . . . . . . . . . . . . . . . . . 10
     7.3.  Initialization Messages  . . . . . . . . . . . . . . . . . 11
       7.3.1.  ClientInit . . . . . . . . . . . . . . . . . . . . . . 11
       7.3.2.  ServerInit . . . . . . . . . . . . . . . . . . . . . . 11
     7.4.  Pixel Format Data Structure  . . . . . . . . . . . . . . . 12
     7.5.  Client-to-Server Messages  . . . . . . . . . . . . . . . . 13
       7.5.1.  SetPixelFormat . . . . . . . . . . . . . . . . . . . . 13
       7.5.2.  SetEncodings . . . . . . . . . . . . . . . . . . . . . 14
       7.5.3.  FramebufferUpdateRequest . . . . . . . . . . . . . . . 15
       7.5.4.  KeyEvent . . . . . . . . . . . . . . . . . . . . . . . 16
       7.5.5.  PointerEvent . . . . . . . . . . . . . . . . . . . . . 19
       7.5.6.  ClientCutText  . . . . . . . . . . . . . . . . . . . . 19
     7.6.  Server-to-Client Messages  . . . . . . . . . . . . . . . . 20
       7.6.1.  FramebufferUpdate  . . . . . . . . . . . . . . . . . . 20
       7.6.2.  SetColorMapEntries . . . . . . . . . . . . . . . . . . 21
       7.6.3.  Bell . . . . . . . . . . . . . . . . . . . . . . . . . 22
       7.6.4.  ServerCutText  . . . . . . . . . . . . . . . . . . . . 22
     7.7.  Encodings  . . . . . . . . . . . . . . . . . . . . . . . . 22
       7.7.1.  Raw Encoding . . . . . . . . . . . . . . . . . . . . . 23
       7.7.2.  CopyRect Encoding  . . . . . . . . . . . . . . . . . . 23
       7.7.3.  RRE Encoding . . . . . . . . . . . . . . . . . . . . . 23
       7.7.4.  Hextile Encoding . . . . . . . . . . . . . . . . . . . 24