test_ssl.test_options does not correctly account for built-in ctx defaults with openssl 1.1.1

[xnox]

BPO	34834
Nosy	@vstinner, @tiran, @zware, @xnox, @stratakis
PRs	bpo-34834: Fix test_ssl.test_options to account for OP_ENABLE_MIDDLEBOX_COMPAT. #9624

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/tiran'
closed_at = <Date 2020-01-19.18:14:28.478>
created_at = <Date 2018-09-28.16:14:56.954>
labels = ['expert-SSL', 'tests']
title = 'test_ssl.test_options does not correctly account for built-in ctx defaults with openssl 1.1.1'
updated_at = <Date 2020-01-19.18:14:28.264>
user = 'https://github.com/xnox'

bugs.python.org fields:

activity = <Date 2020-01-19.18:14:28.264>
actor = 'zach.ware'
assignee = 'christian.heimes'
closed = True
closed_date = <Date 2020-01-19.18:14:28.478>
closer = 'zach.ware'
components = ['Tests', 'SSL']
creation = <Date 2018-09-28.16:14:56.954>
creator = 'xnox'
dependencies = []
files = []
hgrepos = []
issue_num = 34834
keywords = ['patch']
message_count = 3.0
messages = ['326642', '333976', '360263']
nosy_count = 5.0
nosy_names = ['vstinner', 'christian.heimes', 'zach.ware', 'xnox', 'cstratak']
pr_nums = ['9624']
priority = 'normal'
resolution = 'out of date'
stage = 'resolved'
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue34834'
versions = ['Python 2.7']

[xnox]

self.assertEqual(default, ctx.options) in test_options fails with openssl 1.1.1 as it does not correctly account for OP_ENABLE_MIDDLEBOX_COMPAT. It is not defined by the python2.7 ssl module either.

either ssl.OP_ENABLE_MIDDLEBOX_COMPAT needs to be backported, or the test case should just add that constant in when openssl version is >= 1.1.1

[vstinner]

Python 2.7 doesn't support properly OpenSSL 1.1.1 yet, see:

• PR 10607
• PR 10608

I would prefer to have _ssl.OP_ENABLE_MIDDLEBOX_COMPAT rather than have an hardcoded constant in test_ssl. In master, test_ssl has been fixed and the constant has been added by:

commit 05d9fe3
Author: Christian Heimes <christian@python.org>
Date: Tue Feb 27 08:55:39 2018 +0100

bpo-32947: OpenSSL 1.1.1-pre1 / TLS 1.3 fixes (bpo-5663)

* bpo-32947: OpenSSL 1.1.1-pre1 / TLS 1.3 fixes

Misc fixes and workarounds for compatibility with OpenSSL 1.1.1-pre1 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. Other tests currently
fail because the threaded or async test servers stop after failure.

I'm going to address these issues when OpenSSL 1.1.1 reaches beta.

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@python.org>

diff --git a/Doc/library/ssl.rst b/Doc/library/ssl.rst
index 7371024dce..5d5232eda3 100644
--- a/Doc/library/ssl.rst
+++ b/Doc/library/ssl.rst
@@ -831,6 +831,15 @@ 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:: 3.8
+
 .. data:: OP_NO_COMPRESSION
 
    Disable compression on the SSL channel.  This is useful if the application
(...)

[zware]

As this issue appears to only affect 2.7 which recently reached end-of-life status, I'm going to go ahead and close it.