Exchange TLS symmetric keys via RSA instead of DH to debug/inspect PEAP and EAP-TTLS tunnels

[carlospolop]

During an assessment I had problems within a PEAP communication, but as the TLS tunnel was created using DH to share keys I wasn't able to decrypt the tunnel.
Anyway, I finally discovered that if in hostapd-wpe you comment the line where the DH file is indicated (the dh_file=/path/to/dh_params line) the TLS tunnel is created sharing keys via RSA and you can easily decrypt that tunnel with Wireshark using the servers private key.

Describe the solution you'd like
I would like that eaphammer implement this behaviour by default (if the author considers that this won't suppose any security issue).

Describe alternatives you've considered

• Create an eaphammer parameter to indicate when you want this behaviour
• Add this behaviour to --debug

Additional context
I suppose that this would also be useful to decrypt EAP-TTLS tunnels, but I haven't tried it yet.

Thank you very much for the tool and for your time.

[s0lst1c3]

This is awesome and will definitely be added in the future. Thanks for figuring this out!