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Re: are ALPN values desirable command line options?

From: Daniel Stenberg via curl-library <>
Date: Mon, 23 Oct 2023 08:51:58 +0200 (CEST)

On Sun, 22 Oct 2023, Stephen Farrell via curl-library wrote:

> So, finally getting to the question, for a ZF to use curl to check if a
> requested ALPN works or not, (in conjunction with the relevant
> ECHConfigList), there'd have to be a new way to pass in ALPN values from the
> command line. As of now, IIUC there's no way to do that, but should there
> be?
> If the answer's "yes," then we can play about with doing that as part of our
> ECH PR. [2] That could later be separated out into a different PR I guess if
> that's better.
> If the answer's "no," I'd love to understand why it's a bad plan for curl to
> accept a command line argument for setting ALPN values.

Are there actually cases where sending in a custom ALPN is likely to be the
right thing for a user to get a transfer going? I have not heard of any such
cases before.

If not, then setting a custom ALPN is likely to just cause the transfer to
fail since curl does not just negotaite an ALPN and then says "yes it worked",

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Received on 2023-10-23