Hi Simon, thanks for your mail. On 11/01/2024 13.39, Holger Weiß wrote:
* Simon Josefsson <simon@josefsson.org> [2024-01-11 13:10]:
I believe tls-server-end-point is generally best left unimplemented to guide efforts towards supporting the stronger tls-exporter.
One use case I see for tls-server-end-point is that it allows for supporting channel binding by setups where TLS is terminated by some reverse proxy, thereby protecting against _some_ but not all attack vectors that tls-exporter protects against.
Additionally, implementing tls-server-end-point demands minimal effort since it is just based on the hash of the certificate. I believe that not making it mandatory won't deter anyone who is inclined to implement it, as it is a low hanging fruit. Furthermore, we hope to achieve a high success rate by making it mandatory to implement for servers. You are correct, one should aim for better altnatives than tls-server-end-point when implementing XEP-0440, and this should be explicitly mentioned in the XEP. As it stands, the XEP does not clearly convey this. I intend to propose a revision to rectify this in the near future. - Flow