Encryption plugin help

Here you will find help for frequently asked questions as well as for your specific question.

Encryption plugin help

Postby cultclassic » 2018-03-23 23:23


I have ultravnc server on a Win 7 machine. I also
installed and configured the encryption plugin,
and generated the public and private keys.
Are there any more steps to get encryption to
work? Because when I try to connect from another
windows or linux mint machines, I get the warning the
that the connection is not secure.
A client on ubuntu gave me this error:
"unknown authentication scheme from vnc server 17 151 153"
Am I missing some steps?

Posts: 1
Joined: 2018-03-23 23:14

Re: Encryption plugin help

Postby Rudi De Vos » 2018-03-24 13:53

encryption plugin
**you need a server and viewer that support the plugins

**Simple mode,
Nothing to confgure, just select use [v]


If you configure the plugin
1) You can set a longer password ( Passphrase)
This way, the encryption plugin encrypt the data and authenticate with a stronger key

2) You can generate a server and viewer key
*server key stay on the server in the same folder as the plugin and winvnc
*viewer key is copied to the same folder as the viewer and plugin
This way, the key act as authentication and encryption. Only the viewer with the key can connect.

I don't know if someone has implemented the plugins for unix else you are restricted to the version that support it
Rudi De Vos
Admin & Developer
Admin & Developer
Posts: 5871
Joined: 2004-04-23 10:21

Re: Encryption plugin help

Postby mhertz » 2018-03-24 21:41

For linux, the only viewer i'm aware of supporting ultravnc encryption(+ ultravnc chat, file-transfer, repeater and mslogon) is ssvncviewer, an enhanced and patched tightvnc v1.3.9 viewer, provided in the ssvnc package from Karl Runge. I'm not fully sure if it supports also the securevncplugin.dsm, or only the older msrc4plugin.dsm. It's rather old though, not updated since 2011, but works fine. Additionally, it's the only linux vncviewer I could get to connect to an ultravnc SC server, as ultravnc SC reports supporting RFB3.16, and all the viewers don't get that and uses 3.8 which isn't compatible. It works in RFB3.3 mode, which ssvncviewer uses automatically when connecting to ultravnc SC servers. Btw, you can also install cygwin/openssh(or on win10 possibly opt for the native openssh-beta, or the linux-subsystem/openssh) and simply encrypt using ssh-tunnel with any vncviewer, which is what I do currently(I use the vncviewer from tigervnc which is currently updated and slightly faster).

Ohh, I forgot, in the ssvnc package, there's also a standalone command-line tool ultravnc_dsm_plugin, which you can use with any vncviewer. Too bad development has ceased with these great tools, though atleast we still have them available and many things(all?) works as promised - Karl Runge rocks! He's also the one behind the nice x11vnc which adds winvnc functionality to *nix i.e. connect to real X display instead of dynamic one.

Posts: 36
Joined: 2018-02-27 20:19

Return to General help

Who is online

Users browsing this forum: Bing [Bot], Google [Bot] and 6 guests