Re: Binary HTTP [RFC 9292] header name behavior

Thanks Tommy.

Given that we have a widely deployed implementation that's not forcing a
downcase, I think we might be stuck in the "tolerate non-compliance"
equilibrium [1]. I'd suggest we write an errata saying that BHTTP encoders
MUST downcase and BHTTP decoders MUST downcase to tolerate implementations
from before the errata.

David

[1] https://www.rfc-editor.org/rfc/rfc9413#section-4.2

On Fri, Aug 15, 2025 at 4:42 PM Tommy Pauly <tpauly@apple.com> wrote:

> The Binary HTTP implementation on iOS/macOS clients don’t force downcase
> field names currently, although all of the applications that run with it
> use lower-case field names, as far as I’m aware.
>
> I’d be OK with downcasing going forward if that was the consensus of the
> group.
>
> Tommy
>
> On Aug 12, 2025, at 4:54 PM, David Schinazi <dschinazi.ietf@gmail.com>
> wrote:
>
> I guess it comes down to what deployed implementations are doing in
> production. Google's implementation currently downcases on both encode and
> decode. If everyone does it on encode, we'd be happy to shift to rejecting
> on decode to be more in line with RFC 9413.
>
> David
>
> On Tue, Aug 12, 2025 at 3:22 PM Martin Thomson <mt@lowentropy.net> wrote:
>
>> On Wed, Aug 13, 2025, at 06:25, Ricky Perez wrote:
>> > Thank you for the context Martin! So just to clarify, should downcasing
>> > happen at the encoding path, at the decoding path, or at both paths?
>>
>> Encoding.  The decoder would validate that the name was lowercase and
>> reject.
>>
>> > I'm happy to assist with filing the erratum, though let me know if you
>> > prefer I hold that off in favor of following some other process.
>>
>> I'm going to wait for others to weigh in.  I don't entirely trust my
>> instincts on this one.
>>
>>
>