Not working with 'Remote Management' on macOS as VNC server

[freebrowser1]

Describe the bug
When running my Mac with Remote Management on, it acts as a VNC server and can be accessed from any VNC client within the same network.
But when starting the browser (on the same machine) it issues a message with a red bar and cross:
"New connection has been rejected with reason: Incompatible Version."
From another computer the same.

To Reproduce
Start from terminal within the novnc folder:
./utils/launch.sh --vnc 127.0.0.1:5900
which works.

http://localhost:6080/vnc.html
or
http://localhost:6080/vnc.html?host=localhost&port=6080

both do the same issue.

From another computer as well, where I obviously replace 'localhost' by the IP address of my Mac.

Using a different VNC server does not show this issue.

Expected behavior
Seeing the screen of the server.

Screenshots
If applicable, add screenshots to help explain your problem.

Client (please complete the following information):

• OS: macOS 11.0 or Android 10
• Browser: Firefox in both cases
• Browser version: 85

Server (please complete the following information):

• noVNC version: 1.2.0
• VNC server: macOS Big Sur builtin Remote Management or Screen sharing
• WebSocket proxy: builtin by novnc (websockify ?)

[samhed]

Like the error message says, the Remote Management in macOS Big Sur isn't compatible with the protocol version that noVNC sends. We attempt to send a version that corresponds to what the server wants to use, but it seems something has changed here.

Could you check the browser console? You should find more details in there.

[freebrowser1]

This is what the console says:

./utils/launch.sh --vnc localhost:5900
readlink: illegal option -- f
usage: readlink [-n] [file ...]
Warning: could not find self.pem
Using local websockify at /Users/me/webroot/novnc/websockify/run
Starting webserver and WebSockets proxy on port 6080
/Users/me/Documents/webroot/novnc/websockify/websockify/websocket.py:31: UserWarning: no 'numpy' module, HyBi protocol will be slower
warnings.warn("no 'numpy' module, HyBi protocol will be slower")
WebSocket server settings:

• Listen on :6080
• Web server. Web root: /Users/me/webroot/novnc
• No SSL/TLS support (no cert file)
• proxying from :6080 to localhost:5900

Navigate to this URL:

http://mepc:6080/vnc.html?host=mepc&port=6080

Press Ctrl-C to exit

[CendioOssman]

Your web browser also has a console where error messages are shown. On Firefox it's available under the "Web developer" menu.

[freebrowser1]

The console shows:

Failed when connecting: Security negotiation failed on authentication scheme (reason: Incompatible Version.) (rfb.js:808)

Is there a way to bypass this ?

[CendioOssman]

No, I'm afraid not. macOS simply requires some non-standard VNC client. We have no way of knowing what they need unless they publish some specifications.

So unfortunately what macOS includes is no longer VNC, so it's not something noVNC can connect to. You can check if there are some settings to enable proper VNC on the server, but it's not something we're familiar with.

[crystall1nedev]

@CendioOssman I know this is an old issue, but I was able to get noVNC to work with the builtin VNC server by enabling Allow VNC users to connect with password in Remote Management settings, on macOS Monterey 12.0 beta 9. The only issues that I can see is that the server isn't sending the entire screen, and most of the screen is gray until you move the cursor over these spots.

I'll see if I can find out more about this problem later.

[pawansingh00]

Hi
@doregon Were you able to solve this problem?

[crystall1nedev]

Sadly I could not figure out what the issue was, and that Hackintosh died a few weeks ago. I can try on my current MacBook Pro.

[crystall1nedev]

Same problem as before with a Metal-capable GPU.

[pawansingh00]

@doregon Thanks for checking and updating.
Appreciate it.

[Daddoon]

@crystall1nedev Thanks for the tips ! At least i can access te login screen now (even if bugged) and login from it, then switching back to the regular MeshAgent RDP !

[pawansingh00]

FYI: I started using, guacamole works like a Charm.

[CendioOssman]

In case anyone stumbles on to this issue again, the current development version of noVNC should work better with Apple's server.

[crystall1nedev]

In case anyone stumbles on to this issue again, the current development version of noVNC should work better with Apple's server.

Yep! Just tried using my Apple Silicon Mac mini and it works perfectly.

[011V32]

What was the beta-Version which worked?
(Is it already released?)