bpo-37440: Enable TLS 1.3 post-handshake auth in http.client (GH-14448)
Post-handshake authentication is required for conditional client cert authentication with TLS 1.3.
https://bugs.python.org/issue37440
diff --git a/Lib/http/client.py b/Lib/http/client.py
index 82908eb..f61267e 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -1358,6 +1358,9 @@
self.cert_file = cert_file
if context is None:
context = ssl._create_default_https_context()
+ # enable PHA for TLS 1.3 connections if available
+ if context.post_handshake_auth is not None:
+ context.post_handshake_auth = True
will_verify = context.verify_mode != ssl.CERT_NONE
if check_hostname is None:
check_hostname = context.check_hostname
@@ -1366,6 +1369,10 @@
"either CERT_OPTIONAL or CERT_REQUIRED")
if key_file or cert_file:
context.load_cert_chain(cert_file, key_file)
+ # cert and key file means the user wants to authenticate.
+ # enable TLS 1.3 PHA implicitly even for custom contexts.
+ if context.post_handshake_auth is not None:
+ context.post_handshake_auth = True
self._context = context
if check_hostname is not None:
self._context.check_hostname = check_hostname
diff --git a/Lib/test/test_httplib.py b/Lib/test/test_httplib.py
index 968cbd8..9148169 100644
--- a/Lib/test/test_httplib.py
+++ b/Lib/test/test_httplib.py
@@ -1745,6 +1745,24 @@
self.assertEqual(h, c.host)
self.assertEqual(p, c.port)
+ def test_tls13_pha(self):
+ import ssl
+ if not ssl.HAS_TLSv1_3:
+ self.skipTest('TLS 1.3 support required')
+ # just check status of PHA flag
+ h = client.HTTPSConnection('localhost', 443)
+ self.assertTrue(h._context.post_handshake_auth)
+
+ context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+ self.assertFalse(context.post_handshake_auth)
+ h = client.HTTPSConnection('localhost', 443, context=context)
+ self.assertIs(h._context, context)
+ self.assertFalse(h._context.post_handshake_auth)
+
+ h = client.HTTPSConnection('localhost', 443, context=context,
+ cert_file=CERT_localhost)
+ self.assertTrue(h._context.post_handshake_auth)
+
class RequestBodyTest(TestCase):
"""Test cases where a request includes a message body."""