VNC
What the VNC client speaks and what it does not.
A remote-desktop host opens as a tab that shows a picture instead of a terminal.
Supported
- RFB 3.3, 3.7 and 3.8
- Security types None and VNC Authentication
- Encodings Raw, CopyRect, RRE, Hextile and ZRLE
- Desktop resize
- Pointer, keyboard and text clipboard
Connect through SSH
VNC Authentication is weak: DES with at most eight password characters and a challenge that crosses the network in the clear. The tab says "Not encrypted".
Use Connect through SSH. The host's address is then the SSH server. Motty uses
the saved SSH host with the same address and account (its port, algorithms and jump
route), or plain SSH on port 22, asks the SSH questions first, and opens
127.0.0.1:<port> from the SSH server through a direct-tcpip channel.
In the tab
- Fit-to-window or 100% scaling; at 100% a larger picture pans with the pointer.
- While the picture has focus, Motty's shortcuts do not run and keys go to the remote. Ctrl+Alt+G releases the keyboard and takes it again.
- The status line shows the remote size, scale, "Through SSH" or "Not encrypted", clipboard sharing and the escape chord.
- A lost connection keeps the last picture, dimmed, with a Reconnect button.
Clipboard
Per host, off by default, text only. RFB carries Latin-1, so other characters are
sent as ?.
Not supported
VeNCrypt/TLS, Apple Remote Desktop authentication (macOS Screen Sharing needs "VNC viewers may control screen with password"), Tight/JPEG, extended clipboard, images in the clipboard, audio, file transfer, changing the remote resolution and multiple screens. KasmVNC cannot be driven because it reads pointer events in a non-standard format; TigerVNC and any server that follows RFC 6143 work.
What was verified
KasmVNC Xvnc on a Linux machine and TigerVNC in Docker, including through an SSH
tunnel. Not exercised: a real window, physical keyboards, input-method composition,
hidden or covered windows, macOS Screen Sharing and a Windows VNC server.