Just re-reading the text on PSK, I noticed a few things. The text in Section 2.1.2 talks about PSK, the session ticket, and a "key_share" extension. The accompanying diagram doesn't include any of those. I suggest updating the diagram to include them.
As a related note, if the PSK *is* in the resumption cache, but the key is wrong, the cache entry should not be discarded. Otherwise an attacker can disable caching for *all* users. This issue could be clearer in this document. Perhaps it would be useful to add a short note in Section 5 about security of resumption. It should reference RFC 8446 Section 8.1, and 8.2, which discuss this issue. Also, Section 4.2.11 of that document has an "Implementor's note:" which is important. Alan DeKok. _______________________________________________ Emu mailing list Emu@ietf.org https://www.ietf.org/mailman/listinfo/emu