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| author | Daniel Stenberg <daniel@haxx.se> | 2022-09-01 09:23:22 +0200 |
|---|---|---|
| committer | Daniel Stenberg <daniel@haxx.se> | 2022-09-05 07:39:02 +0200 |
| commit | 472f1cbe7e65a8807878e6309926ddb67c0770ff (patch) | |
| tree | 6c3c233908b3c5454105a40a02591650f78c72b1 /docs/DEPRECATE.md | |
| parent | e08c82f0465acfdde88240d660ce426e31095d7c (diff) | |
| download | curl-472f1cbe7e65a8807878e6309926ddb67c0770ff.tar.gz | |
NPN: remove support for and use of
Next Protocol Negotiation is a TLS extension that was created and used
for agreeing to use the SPDY protocol (the precursor to HTTP/2) for
HTTPS. In the early days of HTTP/2, before the spec was finalized and
shipped, the protocol could be enabled using this extension with some
servers.
curl supports the NPN extension with some TLS backends since then, with
a command line option `--npn` and in libcurl with
`CURLOPT_SSL_ENABLE_NPN`.
HTTP/2 proper is made to use the ALPN (Application-Layer Protocol
Negotiation) extension and the NPN extension has no purposes
anymore. The HTTP/2 spec was published in May 2015.
Today, use of NPN in the wild should be extremely rare and most likely
totally extinct. Chrome removed NPN support in Chrome 51, shipped in
June 2016. Removed in Firefox 53, April 2017.
Closes #9307
Diffstat (limited to 'docs/DEPRECATE.md')
| -rw-r--r-- | docs/DEPRECATE.md | 21 |
1 files changed, 1 insertions, 20 deletions
diff --git a/docs/DEPRECATE.md b/docs/DEPRECATE.md index b40142485..a90c60b8f 100644 --- a/docs/DEPRECATE.md +++ b/docs/DEPRECATE.md @@ -19,28 +19,9 @@ We remove support for building curl with the NSS TLS library in August 2023. Starting in 7.82.0, building curl to use NSS configure requires the additional flag --with-nss-deprecated in an attempt to highlight these plans. -## NPN - -We make selecting NPN a no-op starting in August 2022. - -**Next Protocol Negotiation** is a TLS extension that was created and used for -agreeing to use the SPDY protocol (the precursor to HTTP/2) for HTTPS. In the -early days of HTTP/2, before the spec was finalized and shipped, the protocol -could be enabled using this extension with some servers. - -curl supports the NPN extension with some TLS backends since then, with a -command line option `--npn` and in libcurl with `CURLOPT_SSL_ENABLE_NPN`. - -HTTP/2 proper is made to use the ALPN (Application-Layer Protocol Negotiation) -extension and the NPN extension has no purposes anymore. The HTTP/2 spec was -published in May 2015. - -Today, use of NPN in the wild should be extremely rare and most likely totally -extinct. Chrome removed NPN support in Chrome 51, shipped in -June 2016. Removed in Firefox 53, April 2017. - ## past removals - Pipelining - axTLS - PolarSSL + - NPN |