I’ve been searching through the API documentation all day, but haven’t been able to find anything that gives access to information contained in the SSL/TLS handshake (such as the modulus value provided by the server). Everything I can see is for accessing the HTTP headers after the handshake is already completed.
Is this possible to do with add-ons in Firefox? I realize I can get the modulus prime value by querying the server with OpenSSL in a separate request, but I want to see which prime value the Firefox HTTPS requests are receiving each time requests are made.