Aml-vnc and "No matching security types" for certain clients

Help and Support Vero V
1

Hello,

is there a known incompatibility (and ideally a workaround) between aml-vnc used by Vero V and TigerVNC? It does connect to the server but then it reports an error:

CConnection: No matching security types
CConn:       No matching security types

Test results with all VNC viewers I have installed

Client Version Result
AVNC (Android) 2.6.1 OK
gtk-vnc 1.3.1 OK
RealVNC viewer 7.8.0 OK
Remmina 1.4.36 ERROR (No details)
TigerVNC 1.14.0 ERROR (No matching security types)
TigerVNC - Java viewer 1.14.0 OK
TightVNC - Java viewer 2.8.3 OK

Thanks, j

2

It works with Remmina 1.4.25

3

Until you start a video. I get a blank screen when playing 1080p, interface crashes on starting 4k.

Is it supposed to forward video to the client?

4

No Video is ā€œprotectedā€ by the hardware decoder and not shared via VNC. So the black screen is normal. While it should not crash.

5

Works with version 1.12.0 with a warning about insecure connection.

6

VNC is used for remote administration and setup but isnā€™t suitable for video playback. If you want video playback on other devices you could use DLNA which is built in to share your media library with other devices

Sam

7

Interesting, I downgraded to 1.12.0 (and even 1.9.0), but still getting the same error.

TigerVNC Viewer 64-bit v1.12.0
Built on: 2022-03-14 12:48
..
..
 DecodeManager: Creating 4 decoder thread(s)
 CConn:       connected to host XXX port 5900
 CConnection: Server supports RFB protocol version 3.8
 CConnection: Using RFB protocol version 3.8
 CConnection: No matching security types
 CConn:       No matching security types

What is your distro? Mine is Arch-rolling. Might be a matter of using the correct compilation options (?)

8

I suggest to open a new thread with regards to this particular problem - will share my test results too.

9

Linux Mint 21.3 Cinnamon. Just using the distro versions of VNC clients.

I canā€™t see those messages you post but I guess itā€™s the same behaviour here. A message comes up in the window ā€˜This connection is not secureā€™ but I can connect (?insecurely) via password. It must have exhausted all these options:

SecurityTypes  - Specify which security scheme to use (None, VncAuth, Plain,
                   TLSNone, TLSVnc, TLSPlain, X509None, X509Vnc, X509Plain)
                   (default=X509Plain,TLSPlain,X509Vnc,TLSVnc,X509None,TLSNone,VncAuth,None)

Found it! I see this

Thu Oct 31 09:42:33 2024
 DecodeManager: Detected 6 CPU core(s)
 DecodeManager: Creating 4 decoder thread(s)
 CConn:       Connected to host 192.168.1.55 port 5900
 CConnection: Server supports RFB protocol version 3.8
 CConnection: Using RFB protocol version 3.8
 CConnection: Choosing security type VncAuth(2)
10

Just installed TigerVNC 1.14.1 from staging and it fixed the problem! Release notes of the version list

Default installation of native viewer can once again handle VncAuth

which could explain the behaviour.

Remmina shows

(org.remmina.Remmina:308321): remmina-DEBUG: 12:08:09.441: (remmina_plugin_vnc_rfb_output) - VNC returned: ConnectClientToTcpAddr6: connect
(org.remmina.Remmina:308321): remmina-DEBUG: 12:08:09.441: (remmina_plugin_vnc_rfb_output) - VNC returned: Unable to connect to VNC server

which does not make much sense because the IP is IPv4, but it works if provided on commandline using the protocol syntax:

remmina -c vnc://host:0

Thanks everyone for your help.

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