[Python-checkins] bpo-32947: Fixes for TLS 1.3 and OpenSSL 1.1.1 (GH-8761)
Christian Heimes
webhook-mailer at python.org
Tue Aug 14 10:56:35 EDT 2018
https://github.com/python/cpython/commit/2a4ee8aa01d61b6a9c8e9c65c211e61bdb471826
commit: 2a4ee8aa01d61b6a9c8e9c65c211e61bdb471826
branch: 3.6
author: Christian Heimes <christian at python.org>
committer: GitHub <noreply at github.com>
date: 2018-08-14T16:56:32+02:00
summary:
bpo-32947: Fixes for TLS 1.3 and OpenSSL 1.1.1 (GH-8761)
Backport of TLS 1.3 related fixes from 3.7.
Misc fixes and workarounds for compatibility with OpenSSL 1.1.1 from git
master and TLS 1.3 support. With OpenSSL 1.1.1, Python negotiates TLS 1.3 by
default. Some test cases only apply to TLS 1.2.
OpenSSL 1.1.1 has added a new option OP_ENABLE_MIDDLEBOX_COMPAT for TLS
1.3. The feature is enabled by default for maximum compatibility with
broken middle boxes. Users should be able to disable the hack and CPython's test suite needs
it to verify default options
Signed-off-by: Christian Heimes <christian at python.org>
files:
A Misc/NEWS.d/next/Library/2018-08-14-08-57-01.bpo-32947.mqStVW.rst
M Doc/library/ssl.rst
M Lib/test/test_asyncio/test_events.py
M Lib/test/test_ssl.py
M Modules/_ssl.c
diff --git a/Doc/library/ssl.rst b/Doc/library/ssl.rst
index 25ecfaec2565..e12cfc6af0ef 100644
--- a/Doc/library/ssl.rst
+++ b/Doc/library/ssl.rst
@@ -821,6 +821,15 @@ Constants
.. versionadded:: 3.3
+.. data:: OP_ENABLE_MIDDLEBOX_COMPAT
+
+ Send dummy Change Cipher Spec (CCS) messages in TLS 1.3 handshake to make
+ a TLS 1.3 connection look more like a TLS 1.2 connection.
+
+ This option is only available with OpenSSL 1.1.1 and later.
+
+ .. versionadded:: 3.6.7
+
.. data:: OP_NO_COMPRESSION
Disable compression on the SSL channel. This is useful if the application
diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py
index 548a4610f772..bd62897b6a57 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -1187,7 +1187,11 @@ def test_create_server_ssl_match_failed(self):
self.loop.run_until_complete(f_c)
# close connection
- proto.transport.close()
+ # transport may be None with TLS 1.3, because connection is
+ # interrupted, server is unable to send session tickets, and
+ # transport is closed.
+ if proto.transport is not None:
+ proto.transport.close()
server.close()
def test_legacy_create_server_ssl_match_failed(self):
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index 9785a59a7e49..6b3cd5b6e376 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -89,6 +89,7 @@ def data_file(*name):
OP_SINGLE_DH_USE = getattr(ssl, "OP_SINGLE_DH_USE", 0)
OP_SINGLE_ECDH_USE = getattr(ssl, "OP_SINGLE_ECDH_USE", 0)
OP_CIPHER_SERVER_PREFERENCE = getattr(ssl, "OP_CIPHER_SERVER_PREFERENCE", 0)
+OP_ENABLE_MIDDLEBOX_COMPAT = getattr(ssl, "OP_ENABLE_MIDDLEBOX_COMPAT", 0)
def handle_error(prefix):
@@ -181,8 +182,8 @@ def test_constants(self):
ssl.OP_NO_TLSv1
ssl.OP_NO_TLSv1_3
if ssl.OPENSSL_VERSION_INFO >= (1, 0, 1):
- ssl.OP_NO_TLSv1_1
- ssl.OP_NO_TLSv1_2
+ ssl.OP_NO_TLSv1_1
+ ssl.OP_NO_TLSv1_2
def test_str_for_enums(self):
# Make sure that the PROTOCOL_* constants have enum-like string
@@ -899,12 +900,13 @@ def test_get_ciphers(self):
@skip_if_broken_ubuntu_ssl
def test_options(self):
- ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+ ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
# OP_ALL | OP_NO_SSLv2 | OP_NO_SSLv3 is the default value
default = (ssl.OP_ALL | ssl.OP_NO_SSLv2 | ssl.OP_NO_SSLv3)
# SSLContext also enables these by default
default |= (OP_NO_COMPRESSION | OP_CIPHER_SERVER_PREFERENCE |
- OP_SINGLE_DH_USE | OP_SINGLE_ECDH_USE)
+ OP_SINGLE_DH_USE | OP_SINGLE_ECDH_USE |
+ OP_ENABLE_MIDDLEBOX_COMPAT)
self.assertEqual(default, ctx.options)
ctx.options |= ssl.OP_NO_TLSv1
self.assertEqual(default | ssl.OP_NO_TLSv1, ctx.options)
@@ -1857,11 +1859,23 @@ def wrap_conn(self):
self.sock, server_side=True)
self.server.selected_npn_protocols.append(self.sslconn.selected_npn_protocol())
self.server.selected_alpn_protocols.append(self.sslconn.selected_alpn_protocol())
- except (ssl.SSLError, ConnectionResetError, OSError) as e:
+ except (ConnectionResetError, BrokenPipeError) as e:
# We treat ConnectionResetError as though it were an
# SSLError - OpenSSL on Ubuntu abruptly closes the
# connection when asked to use an unsupported protocol.
#
+ # BrokenPipeError is raised in TLS 1.3 mode, when OpenSSL
+ # tries to send session tickets after handshake.
+ # https://github.com/openssl/openssl/issues/6342
+ self.server.conn_errors.append(str(e))
+ if self.server.chatty:
+ handle_error(
+ "\n server: bad connection attempt from " + repr(
+ self.addr) + ":\n")
+ self.running = False
+ self.close()
+ return False
+ except (ssl.SSLError, OSError) as e:
# OSError may occur with wrong protocols, e.g. both
# sides use PROTOCOL_TLS_SERVER.
#
@@ -3042,7 +3056,7 @@ def serve():
# Block on the accept and wait on the connection to close.
evt.set()
remote, peer = server.accept()
- remote.recv(1)
+ remote.send(remote.recv(4))
t = threading.Thread(target=serve)
t.start()
@@ -3050,6 +3064,8 @@ def serve():
evt.wait()
client = context.wrap_socket(socket.socket())
client.connect((host, port))
+ client.send(b'data')
+ client.recv()
client_addr = client.getsockname()
client.close()
t.join()
diff --git a/Misc/NEWS.d/next/Library/2018-08-14-08-57-01.bpo-32947.mqStVW.rst b/Misc/NEWS.d/next/Library/2018-08-14-08-57-01.bpo-32947.mqStVW.rst
new file mode 100644
index 000000000000..28de360c3671
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-08-14-08-57-01.bpo-32947.mqStVW.rst
@@ -0,0 +1,2 @@
+Add OP_ENABLE_MIDDLEBOX_COMPAT and test workaround for TLSv1.3 for future
+compatibility with OpenSSL 1.1.1.
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index 5e007da858bd..e0c7dfbdaacb 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -5486,6 +5486,10 @@ PyInit__ssl(void)
PyModule_AddIntConstant(m, "OP_NO_COMPRESSION",
SSL_OP_NO_COMPRESSION);
#endif
+#ifdef SSL_OP_ENABLE_MIDDLEBOX_COMPAT
+ PyModule_AddIntConstant(m, "OP_ENABLE_MIDDLEBOX_COMPAT",
+ SSL_OP_ENABLE_MIDDLEBOX_COMPAT);
+#endif
#if HAVE_SNI
r = Py_True;
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