Generate key log file

[octaviandumitran]

Can you add functionality to generate a key log file?
This should be something similar to what Python3.8+ does when SSLKEYLOGFILE is defined.

Alternatively, could you explain how I can generate the file myself?
Presumably, I would need to call keyingMaterialExporter, but I do not know exactly how to serialize that.

[tomato42]

I generally don't use it (I simply insert print statements when I need to inspect stuff), but I can clearly see how it would be useful, so I'm fine with having support for it.

generating it is a bit more involved that just using the keyingMaterialExporter as that one is for a different purpose. You need to export the master secret and the client random at a minimum (the available fields are documented in a proposed RFC: https://datatracker.ietf.org/doc/html/draft-ietf-tls-keylogfile-02 ). As to how to create it? likely some code in the tlsconnection or tlsrecordlayer modules that checks for that environment variable and then dumps the relevant key material into the file pointed to by the environment variable.

I've created #523 issue to track it.