Re: [Doh] How to start HTTP/2?

Daniel Stenberg <daniel@haxx.se> Tue, 16 January 2018 15:31 UTC

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From: Daniel Stenberg <daniel@haxx.se>
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To: Stephane Bortzmeyer <bortzmeyer@nic.fr>
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Subject: Re: [Doh] How to start HTTP/2?
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On Tue, 16 Jan 2018, Stephane Bortzmeyer wrote:

> OK, but could it be better to say explicitely "Servers and clients MUST 
> start HTTP/2 using the ALPN extension of TLS, as specified in RFC 7540, 
> section 3.3"?

It probably could, but as that's exactly what doing HTTP/2 over HTTPS means I 
considered that implied.

> (Then, what a server should do if the client did not use ALPN? Start HTTP/2 
> anyway, because of the robustness principle?)

If you want HTTP/2 over HTTPS, you need to use ALPN. An HTTPS server that 
doesn't do ALPN can't speak HTTP/2 as defined in RFC7540.

-- 

  / daniel.haxx.se