Specifies whether Kasmvnc supports 16-bit color depth

[CourageKang]

kasmvnc works with a default color depth of 24 bits, but an error occurs when a color depth of 16 bits is set

2024-03-11 21:38:41,723 [INF0] sConnection: client requests security type VncAuth(2)
(EE)
(EE)Backtrace:
(EE)0:/usr/b1n/xvnc(xorg backtrace+ux4d) lvx5e/1/d]
(EE)1:/usr/bin/Xvnc(0x400000+0xleaaf9)[0x5eaaf9]
(EE)2: /lib/x86 64-linux-gnu/libpthread.so.0(0x7f02a4513000+0x12980)[0x7f02a4525980]
(EE)3:/usr/bin/Xvnc(XXH64+0x80)[0x56c330]
(EE)4:/usr/bin/xvnc( ZN7network14GetAPIMessagerl6mainUpdatescreenEPN3rfb11PixelBufferE+0x138[0x
(EE)5:/usr/bin/Xvnc(23rfb11VNcServerST11writeUpdateEv+0x3d5)[0x567205]
(EE)6:/usr/bin/Xvnc(2N3rfb16VNcsConnectionST1lauthSuccessEv+0x39)[0x57e8c9]
(EE)7:./usr/bin/Xvnc(ZN3rfb16VNCSConnectionST15queryConnectionEPKc+0x6d)[0x57b7ed1
(EE)8:/usr/bin/Xvnc(2N3rfb11sConnection18processSecurityMsgEv+0x61)[0x5736b1]
(EE)9:/usr/bin/Xvnc( ZN3rfb16VNcSConnectionST15processMessagesEy+0x7f) [@x57fa5fl
(EE)10: /usr/bin/Xvnc ( ZN14xserverDesktop17handleSocketEventEiPN7network12socketServerEbb+0x11e) [8
(EE)11:/usr/bin/xvnc(ZN14XserverDesktop17handleSocketEventEibb+0x87)[0x52are7]
(EE)12:/usr/bin/Xvnc(ospoll wait+0x81)0x5eb5f113:/usr/bin/Xvnc:(WaitForSomething+0x1c3)0x5e50b314:/usr/bin/Xvnc(Dispatch+0xa7)[0x5998a7]
(EE)15:/usr/bin/Xvnc(dix main+0x36e)[0x59da9e]
(EE)16:/lib/x86_64-linux-gnu/libc,so.6 ( libc_start_main+0xe7)[0x7f02a1810c87]
(EE)17:/usr/bin/xvnc(_start+0x2a)[0x45f71a]
(EE)
(EE)Segmentation fault at address 0x7f029e7b9000
(EE)
Fatal server error:
(EE)Caught signal 11(Segmentation fault), Server aborting

[mmcclaskey]

Are using the builtin web client or connecting using a VNC client?

KasmVNC only supports our built-in web client and we have broken the RFB (VNC) specification in order to move things forward. That being said, the web client only supports 24bit, so a setting of 16bit is not valid. However, we also shouldn't exception and instead should send an error to the client or reject the connection. @clbr any additional thoughts and did I get that all right?

[clbr]

Since the only supported client only uses 24-bit, there are no checks currently to reject other bitdepths. Could certainly be added.