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Disallow HTTP/0.9 ?

From: Daniel Stenberg via curl-library <>
Date: Mon, 17 Dec 2018 16:00:27 +0100 (CET)


I've just submitted a PR [1] that introduces a command line option and
curl_easy_setopt() option for *allowing* HTTP/0.9 reseponses.

A HTTP/0.9 response is a response that is entirely without headers and just a
body with a terminating connection close to signal the end of the data.

You can basically tell curl to connect to any random TCP service that outputs
data and unless it responses as a correct HTTP server, curl will silently
consider it to be HTTP/0.9 and get that data and wait for server close.

I believe this is not what most users would expect and that's why I propose
that we modify this behavior and let users opt-in to that treatment with the
help of these new options.

A more conservative route would be to take the DEPRECATE route and mark this
to happen in 6 months and until then we keep the previous behavior.

Thoughts? Any users of HTTP/0.9 or perhaps someone who is surprised that curl
so willingly accept 0.9 this way?

[1] =

Received on 2018-12-17