Packages and Binaries:
tightvncpasswd
VNC stands for Virtual Network Computing. It is, in essence, a remote display system which allows you to view a computing `desktop’ environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
This package provides the vncpasswd tool mandatory for the tightvncserver and optional for the xtightvncviewer.
Installed size: 69 KB
How to install: sudo apt install tightvncpasswd
Dependencies:
- libc6
tightvncpasswd
Set passwords for VNC server
root@kali:~# man tightvncpasswd
vncpasswd(1) TightVNC vncpasswd(1)
NAME
vncpasswd - set passwords for VNC server
SYNOPSIS
vncpasswd [file]
vncpasswd -t
vncpasswd -f
DESCRIPTION
The vncpasswd utility should be used to create and change passwords for
the TightVNC server authentication. Xvnc uses such passwords when
started with the -rfbauth command-line option (or when started from the
vncserver script).
vncpasswd allows one to enter either one or two passwords. The first
password is the primary one, the second password can be used for view-
only authentication. Xvnc will restrict mouse and keyboard input from
clients who authenticated with the view-only password. The vncpasswd
utility asks interactively if it should set the second password.
The password file name defaults to $HOME/.vnc/passwd unless the -t com-
mand-line option was used (see the OPTIONS section below). The
$HOME/.vnc/ directory will be created if it does not exist.
Each password has to be longer than five characters (unless the -f com-
mand-line option was used, see its description below). Only the first
eight characters are significant. If the primary password is too short,
the program will abort. If the view-only password is too short, then
only the primary password will be saved.
Unless a file name was provided in the command-line explicitly, this
utility may perform certain sanity checks to prevent writing a password
file into some hazardous place.
If at least one password was saved successfully, vncpasswd will exit
with status code 0. Otherwise the returned status code will be set to 1.
OPTIONS
-t Write passwords into /tmp/$USER-vnc/passwd, creating the
/tmp/$USER-vnc/ directory if it does not exist, and checking the
permissions on that directory (the mode must be 700). This option
can help to improve security when your home partition may be
shared via network (e.g. when using NFS).
-f Filter mode. Read plain-text passwords from stdin, write en-
crypted versions to stdout. One or two passwords (full-control
and view-only) can be supplied in the input stream, newline ter-
minates a password. Note that in the filter mode, short or even
empty passwords will be silently accepted.
SEE ALSO
vncserver(1), Xvnc(1), vncviewer(1), vncconnect(1)
AUTHORS
Original VNC was developed in AT&T Laboratories Cambridge. TightVNC ad-
ditions were implemented by Constantin Kaplinsky. Many other people par-
ticipated in development, testing and support.
Man page authors:
Marcus Brinkmann <[email protected]>,
Tim Waugh <[email protected]>,
Constantin Kaplinsky <[email protected]>
August 2006 vncpasswd(1)
tightvncserver
VNC stands for Virtual Network Computing. It is, in essence, a remote display system which allows you to view a computing `desktop’ environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
This package provides a server to which X clients can connect and the server generates a display that can be viewed with a vncviewer.
The difference between the tightvncserver and the normal vncserver is the data encoding, optimized for low bandwidth connections. If the client do not support jpeg or zlib encoding it can use the default one. Later versions of vncserver (> 3.3.3r2) support a new automatic encoding that should be equally good as the tightvnc encoding.
Note: This server does not support or need a display. You need a vncviewer to see something. However, this viewer may also be on a computer running other operating systems in the local net.
Installed size: 1.72 MB
How to install: sudo apt install tightvncserver
Dependencies:
- libc6
- libjpeg62-turbo
- libx11-6
- perl
- tightvncpasswd
- x11-common | xserver-common
- x11-utils
- xauth
- zlib1g
Xtightvnc
An X server providing VNC connectivity
root@kali:~# Xtightvnc -h
Unrecognized option: -h
use: X [:<display>] [option]
-a # mouse acceleration (pixels)
-ac disable access control restrictions
-audit int set audit trail level
-auth file select authorization file
bc enable bug compatibility
-bs disable any backing store support
-c turns off key-click
c # key-click volume (0-100)
-cc int default color visual class
-co file color database file
-core generate core dump on fatal error
-dpi int screen resolution in dots per inch
-deferglyphs [none|all|16] defer loading of [no|all|16-bit] glyphs
-f # bell base (0-100)
-fc string cursor font
-fn string default font name
-fp string default font path
-help prints message with these options
-I ignore all remaining arguments
-ld int limit data space to N Kb
-lf int limit number of open files to N
-ls int limit stack space to N Kb
-nolock disable the locking mechanism
-logo enable logo in screen saver
nologo disable logo in screen saver
-nolisten string don't listen on protocol
-p # screen-saver pattern duration (minutes)
-pn accept failure to listen on all ports
-nopn reject failure to listen on all ports
-r turns off auto-repeat
r turns on auto-repeat
-s # screen-saver timeout (minutes)
-su disable any save under support
-t # mouse threshold (pixels)
-terminate terminate at server reset
-to # connection time out
-tst disable testing extensions
ttyxx server started from init on /dev/ttyxx
v video blanking for screen-saver
-v screen-saver without video blanking
-wm WhenMapped default backing-store
-x string loads named extension at init time
-query host-name contact named host for XDMCP
-broadcast broadcast for XDMCP
-indirect host-name contact named host for indirect XDMCP
-port port-num UDP port number to send messages to
-once Terminate server after one session
-class display-class specify display class to send in manage
-cookie xdm-auth-bits specify the magic cookie for XDMCP
-displayID display-id manufacturer display ID for request
-geometry WxH set framebuffer width & height
-depth D set framebuffer depth
-pixelformat format set pixel format (BGRnnn or RGBnnn)
-udpinputport port UDP port for keyboard/pointer data
-rfbport port TCP port for RFB protocol
-rfbwait time max time in ms to wait for RFB client
-nocursor don't put up a cursor
-rfbauth passwd-file use authentication on RFB protocol
-httpd dir serve files via HTTP from here
-httpport port port for HTTP
-deferupdate time time in ms to defer updates (default 40)
-economictranslate less memory-hungry translation
-lazytight disable "gradient" filter in tight encoding
-desktop name VNC desktop name (default x11)
-alwaysshared always treat new clients as shared
-nevershared never treat new clients as shared
-dontdisconnect don't disconnect existing clients when a new non-shared
connection comes in (refuse new connection instead)
-viewonly let clients only to view the desktop
-localhost only allow connections from localhost
-interface ipaddr only bind to specified interface address
-inetd Xvnc is launched by inetd
-compatiblekbd set META key = ALT key as in the original VNC
-version report Xvnc version on stderr
tightvncconnect
Connect a VNC server to a VNC viewer
root@kali:~# tightvncconnect -h
usage: tightvncconnect [-display Xvnc-display] host[:port]
Tells Xvnc to connect to a listening VNC viewer on the given host and port
tightvncserver
A wrapper to launch an X server for VNC.
root@kali:~# tightvncserver -h
TightVNC Server version 1.3.10
Usage: tightvncserver [<OPTIONS>] [:<DISPLAY#>]
tightvncserver -kill :<DISPLAY#>
<OPTIONS> are Xtightvnc options, or:
-name <DESKTOP-NAME>
-depth <DEPTH>
-geometry <WIDTH>x<HEIGHT>
-httpport number
-basehttpport number
-alwaysshared
-nevershared
-pixelformat rgb<NNN>
-pixelformat bgr<NNN>
See vncserver and Xtightvnc manual pages for more information.
xtightvncviewer
VNC stands for Virtual Network Computing. It is, in essence, a remote display system which allows you to view a computing `desktop’ environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
It is implemented in a client/server model. This package provides a client for X, with this you can connect to a vncserver somewhere in the network and display its content in a window. There are vncserver available for other operating systems.
The difference between the xtightvncviewer and the normal vncviewer is the data encoding, optimized for low bandwidth connections. If the client do not support jpeg or zlib encoding it can use the default one. Later versions of xvncviewer (> 3.3.3r2) support a new automatic encoding that should be equally good as the tightvnc encoding.
Installed size: 182 KB
How to install: sudo apt install xtightvncviewer
Dependencies:
- libc6
- libjpeg62-turbo
- libx11-6
- libxaw7
- libxext6
- libxmu6
- libxt6t64
- zlib1g
xtightvncviewer
An X viewer client for VNC
root@kali:~# man xtightvncviewer
vncviewer(1) TightVNC vncviewer(1)
NAME
vncviewer - an X viewer client for VNC
SYNOPSIS
vncviewer [options] [host][:display]
vncviewer [options] [host][::port]
vncviewer [options] -listen [display]
vncviewer -help
DESCRIPTION
vncviewer is an Xt-based client application for the VNC (Virtual Network
Computing) system. It can connect to any VNC-compatible server such as
Xvnc or WinVNC, allowing you to control desktop environment of a differ-
ent machine.
You can use F8 to display a pop-up utility menu. Press F8 twice to pass
single F8 to the remote side.
OPTIONS
-help Prints a short usage notice to stderr.
-listen
Make the viewer listen on port 5500+display for reverse connec-
tions from a server. WinVNC supports reverse connections using
the "Add New Client" menu option, or the -connect command line
option. Xvnc requires the use of the helper program vncconnect.
-via gateway
Automatically create encrypted TCP tunnel to the gateway machine
before connection, connect to the host through that tunnel
(TightVNC-specific). By default, this option invokes SSH local
port forwarding, assuming that SSH client binary can be accessed
as /usr/bin/ssh. Note that when using the -via option, the host
machine name should be specified as known to the gateway machine,
e.g. "localhost" denotes the gateway, not the machine where
vncviewer was launched. See the ENVIRONMENT section below for the
information on configuring the -via option.
-shared
When connecting, specify that a shared connection is requested.
In TightVNC, this is the default mode, allowing you to share the
desktop with other clients already using it.
-noshared
When connecting, specify that the session may not be shared. This
would either disconnect other connected clients or refuse your
connection, depending on the server configuration.
-viewonly
Disable transfer of mouse and keyboard events from the client to
the server.
-fullscreen
Start in full-screen mode. Please be aware that operating in
full-screen mode may confuse X window managers. Typically, such
conflicts cause incorrect handling of input focus or make the
viewer window disappear mysteriously. See the grabKeyboard set-
ting in the RESOURCES section below for a method to solve input
focus problem.
-noraiseonbeep
By default, the viewer shows and raises its window on remote beep
(bell) event. This option disables such behaviour (TightVNC-spe-
cific).
-passwd passwd-file
File from which to get the password (as generated by the vnc-
passwd(1) program). This option affects only the standard VNC au-
thentication.
-encodings encoding-list
TightVNC supports several different compression methods to encode
screen updates; this option specifies a set of them to use in or-
der of preference. Encodings are specified separated with spaces,
and must thus be enclosed in quotes if more than one is speci-
fied. Available encodings, in default order for a remote connec-
tion, are "copyrect tight hextile zlib corre rre raw". For a lo-
cal connection (to the same machine), the default order to try is
"raw copyrect tight hextile zlib corre rre". Raw encoding is al-
ways assumed as a last option if no other encoding can be used
for some reason. For more information on encodings, see the sec-
tion ENCODINGS below.
-bgr233
Always use the BGR233 format to encode pixel data. This reduces
network traffic, but colors may be represented inaccurately. The
bgr233 format is an 8-bit "true color" format, with 2 bits blue,
3 bits green, and 3 bits red.
-owncmap
Try to use a PseudoColor visual and a private colormap. This al-
lows the VNC server to control the colormap.
-truecolour, -truecolor
Try to use a TrueColor visual.
-depth depth
On an X server which supports multiple TrueColor visuals of dif-
ferent depths, attempt to use the specified one (in bits per
pixel); if successful, this depth will be requested from the VNC
server.
-compresslevel level
Use specified compression level (0..9) for "tight" and "zlib" en-
codings (TightVNC-specific). Level 1 uses minimum of CPU time and
achieves weak compression ratios, while level 9 offers best com-
pression but is slow in terms of CPU time consumption on the
server side. Use high levels with very slow network connections,
and low levels when working over high-speed LANs. It's not recom-
mended to use compression level 0, reasonable choices start from
the level 1.
-quality level
Use the specified JPEG quality level (0..9) for the "tight" en-
coding (TightVNC-specific). Quality level 0 denotes bad image
quality but very impressive compression ratios, while level 9 of-
fers very good image quality at lower compression ratios. Note
that the "tight" encoder uses JPEG to encode only those screen
areas that look suitable for lossy compression, so quality level
0 does not always mean unacceptable image quality.
-nojpeg
Disable lossy JPEG compression in Tight encoding (TightVNC-spe-
cific). Disabling JPEG compression is not a good idea in typical
cases, as that makes the Tight encoder less efficient. You might
want to use this option if it's absolutely necessary to achieve
perfect image quality (see also the -quality option).
-nocursorshape
Disable cursor shape updates, protocol extensions used to handle
remote cursor movements locally on the client side (TightVNC-spe-
cific). Using cursor shape updates decreases delays with remote
cursor movements, and can improve bandwidth usage dramatically.
-x11cursor
Use a real X11 cursor with X-style cursor shape updates, instead
of drawing the remote cursor on the framebuffer. This option also
disables the dot cursor, and disables cursor position updates in
non-fullscreen mode.
-autopass
Read a plain-text password from stdin. This option affects only
the standard VNC authentication.
ENCODINGS
The server supplies information in whatever format is desired by the
client, in order to make the client as easy as possible to implement.
If the client represents itself as able to use multiple formats, the
server will choose one.
Pixel format refers to the representation of an individual pixel. The
most common formats are 24 and 16 bit "true-color" values, and 8-bit
"color map" representations, where an arbitrary map converts the color
number to RGB values.
Encoding refers to how a rectangle of pixels are sent (all pixel infor-
mation in VNC is sent as rectangles). All rectangles come with a header
giving the location and size of the rectangle and an encoding type used
by the data which follows. These types are listed below.
Raw The raw encoding simply sends width*height pixel values. All
clients are required to support this encoding type. Raw is also
the fastest when the server and viewer are on the same machine,
as the connection speed is essentially infinite and raw encoding
minimizes processing time.
CopyRect
The Copy Rectangle encoding is efficient when something is being
moved; the only data sent is the location of a rectangle from
which data should be copied to the current location. Copyrect
could also be used to efficiently transmit a repeated pattern.
RRE The Rise-and-Run-length-Encoding is basically a 2D version of
run-length encoding (RLE). In this encoding, a sequence of iden-
tical pixels are compressed to a single value and repeat count.
In VNC, this is implemented with a background color, and then
specifications of an arbitrary number of subrectangles and color
for each. This is an efficient encoding for large blocks of con-
stant color.
CoRRE This is a minor variation on RRE, using a maximum of 255x255
pixel rectangles. This allows for single-byte values to be used,
reducing packet size. This is in general more efficient, because
the savings from sending 1-byte values generally outweighs the
losses from the (relatively rare) cases where very large regions
are painted the same color.
Hextile
Here, rectangles are split up in to 16x16 tiles, which are sent
in a predetermined order. The data within the tiles is sent ei-
ther raw or as a variant on RRE. Hextile encoding is usually the
best choice for using in high-speed network environments (e.g.
Ethernet local-area networks).
Zlib Zlib is a very simple encoding that uses zlib library to compress
raw pixel data. This encoding achieves good compression, but con-
sumes a lot of CPU time. Support for this encoding is provided
for compatibility with VNC servers that might not understand
Tight encoding which is more efficient than Zlib in nearly all
real-life situations.
Tight Like Zlib encoding, Tight encoding uses zlib library to compress
the pixel data, but it pre-processes data to maximize compression
ratios, and to minimize CPU usage on compression. Also, JPEG com-
pression may be used to encode color-rich screen areas (see the
description of -quality and -nojpeg options above). Tight encod-
ing is usually the best choice for low-bandwidth network environ-
ments (e.g. slow modem connections).
RESOURCES
X resources that vncviewer knows about, aside from the normal Xt re-
sources, are as follows:
shareDesktop
Equivalent of -shared/-noshared options. Default true.
viewOnly
Equivalent of -viewonly option. Default false.
fullScreen
Equivalent of -fullscreen option. Default false.
grabKeyboard
Grab keyboard in full-screen mode. This can help to solve prob-
lems with losing keyboard focus. Default false.
raiseOnBeep
Equivalent of -noraiseonbeep option, when set to false. Default
true.
passwordFile
Equivalent of -passwd option.
passwordDialog
Whether to use a dialog box to get the password (true) or get it
from the tty (false). Irrelevant if passwordFile is set. Default
false.
encodings
Equivalent of -encodings option.
compressLevel
Equivalent of -compresslevel option (TightVNC-specific).
qualityLevel
Equivalent of -quality option (TightVNC-specific).
enableJPEG
Equivalent of -nojpeg option, when set to false. Default true.
useRemoteCursor
Equivalent of -nocursorshape option, when set to false
(TightVNC-specific). Default true.
useBGR233
Equivalent of -bgr233 option. Default false.
nColours
When using BGR233, try to allocate this many "exact" colors from
the BGR233 color cube. When using a shared colormap, setting this
resource lower leaves more colors for other X clients. Irrelevant
when using truecolor. Default is 256 (i.e. all of them).
useSharedColours
If the number of "exact" BGR233 colors successfully allocated is
less than 256 then the rest are filled in using the "nearest"
colors available. This resource says whether to only use the "ex-
act" BGR233 colors for this purpose, or whether to use other
clients' "shared" colors as well. Default true (i.e. use other
clients' colors).
forceOwnCmap
Equivalent of -owncmap option. Default false.
forceTrueColour
Equivalent of -truecolour option. Default false.
requestedDepth
Equivalent of -depth option.
useSharedMemory
Use MIT shared memory extension if on the same machine as the X
server. Default true.
wmDecorationWidth, wmDecorationHeight
The total width and height taken up by window manager decora-
tions. This is used to calculate the maximum size of the VNC
viewer window. Default is width 4, height 24.
bumpScrollTime, bumpScrollPixels
When in full screen mode and the VNC desktop is bigger than the X
display, scrolling happens whenever the mouse hits the edge of
the screen. The maximum speed of scrolling is bumpScrollPixels
pixels every bumpScrollTime milliseconds. The actual speed of
scrolling will be slower than this, of course, depending on how
fast your machine is. Default 20 pixels every 25 milliseconds.
popupButtonCount
The number of buttons in the popup window. See the README file
for more information on how to customize the buttons.
debug For debugging. Default false.
rawDelay, copyRectDelay
For debugging, see the README file for details. Default 0 (off).
ENVIRONMENT
When started with the -via option, vncviewer reads the VNC_VIA_CMD envi-
ronment variable, expands patterns beginning with the "%" character, and
executes result as a command assuming that it would create TCP tunnel
that should be used for VNC connection. If not set, this environment
variable defaults to "/usr/bin/ssh -f -L %L:%H:%R %G sleep 20".
The following patterns are recognized in the VNC_VIA_CMD (note that all
the patterns %G, %H, %L and %R must be present in the command template):
%% A literal "%";
%G gateway host name;
%H remote VNC host name, as known to the gateway;
%L local TCP port number;
%R remote TCP port number.
SEE ALSO
vncserver(1), Xvnc(1), vncpasswd(1), vncconnect(1), ssh(1)
AUTHORS
Original VNC was developed in AT&T Laboratories Cambridge. TightVNC ad-
ditions were implemented by Constantin Kaplinsky. Many other people par-
ticipated in development, testing and support.
Man page authors:
Marcus Brinkmann <[email protected]>,
Terran Melconian <[email protected]>,
Tim Waugh <[email protected]>,
Constantin Kaplinsky <[email protected]>
August 2006 vncviewer(1)
Updated on: 2024-Aug-06