commit f97406be4c0a02c1501c7ab8bc8ef3850eddb962
author Christian Heimes <christian@python.org> Fri Nov 13 16:37:52 2020 +0100
committer GitHub <noreply@github.com> Fri Nov 13 16:37:52 2020 +0100
tree 9fe83b52d120269d64fec6e877bb9576124bbd57
parent 09490a109faaee9cc393b52742a8575c116c56ba

bpo-40968: Send http/1.1 ALPN extension (#20959)

Signed-off-by: Christian Heimes <christian@python.org>

Lib/http/client.py

diff --git a/Lib/http/client.py b/Lib/http/client.py
index 15abcfe..a54679c 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -1407,6 +1407,9 @@ def __init__(self, host, port=None, key_file=None, cert_file=None,
             self.cert_file = cert_file
             if context is None:
                 context = ssl._create_default_https_context()
+                # send ALPN extension to indicate HTTP/1.1 protocol
+                if self._http_vsn == 11:
+                    context.set_alpn_protocols(['http/1.1'])
                 # enable PHA for TLS 1.3 connections if available
                 if context.post_handshake_auth is not None:
                     context.post_handshake_auth = True