> On 26 Mar 2019, at 14:45, Hubert Kario <hka...@redhat.com> wrote: > > On Monday, 25 March 2019 22:09:35 CET Yoav Nir wrote: >> Hi. Today at the TLS meeting, there was a discussion at the mic about 1-bit >> extensions that only serve to indicate support for an optional feature. EKR >> commented that such extensions take 4 bytes each and that maybe we need to >> replace them with a flags extension. >> >> So I threw together a quick -00 draft with an extension that does just that >> [1]. >> >> Comments are welcome. > > I don't think that "penny-pinching" the 4 bytes necessary to send a flag is > worth the interoperability problems, and increased complexing of parsing > Client Hello. Especially if we go the route of actual bit flags.
Right. Which is why I went with a 1-byte encoding rather than a bitstring. > I think the likelihood of bugs in that code over the possible bytes saved > makes it a net negative. I don’t think so. My encoding is not all that complex. > yes, TLS is quite chatty protocol, it could encode values much more tightly, > but I think we all remember the bugs related to ASN.1 parsing from inside of > PKCS#1 v1.5 signatures Complexity is on a spectrum. DER encoding is pretty far on this spectrum. A list of 1-octet identifiers is on the other end. A bitstring is more complex than the identifier list, but not anywhere near DER. I don’t think we should project the failings of DER parsing to the parsing of much simpler structures. Yoav _______________________________________________ TLS mailing list TLS@ietf.org https://www.ietf.org/mailman/listinfo/tls
