[fpc-pascal] fcl-web websocket

[Andrew Haines]

On 12/26/22 8:48 AM, Michael Van Canneyt via fpc-pascal wrote:
>
>
> Please make a version of your program that does not use the LCL.
> Then I'll test that too.
>
> 2 reasons for this request: - I don't have a working version of 
> Lazarus with FPC trunk.
> - I want to exclude the problems of dealing with the main application 
> message loop.
>
>
I attached a console version. It uses threads. If this is useful at all 
please feel free to add it to the examples and modify it however you want.

I found the problem. First was the problem of no data being read, which 
you fixed by changing the inheritance. But the second problem is that 
the OutgoingFrameMask value was not being used. In the rfc section 5.2 
it states in the Mask bit explanation that all frames sent from a client 
must be masked. Unfortunately the echo server was not giving a close 
frame with a protocol error which would have been useful.

In the attached patch there are 3 hunks that include the 
OutgoingFrameMask with the payload. The rest of the patch is about 
handling a connection that encounters an error sending data. I added an 
exception and also a flag that ignores the exception and tries to close 
gracefully.

You can compile the console client I sent without applying the patch to 
see how it was failing before. There are default servers to choose from.

Maybe in the client, the constructor should pick a mask at random by 
default since all frames from the client are supposed to be masked 
anyway. Section 5.3 has some strong language about the random mask 
having a strong entropy source. It actually says each frame should have 
a new unique mask so I'm not sure the OutgoingFrameMask property really 
makes sense since the mask is given to the connection only once when the 
connection is created. I doubt most server implementations care about this.

Regards,

Andrew


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