[bpo-28414] Make all hostnames in SSL module IDN A-labels (GH-5128) (GH-5843)
Previously, the ssl module stored international domain names (IDNs)
as U-labels. This is problematic for a number of reasons -- for
example, it made it impossible for users to use a different version
of IDNA than the one built into Python.
After this change, we always convert to A-labels as soon as possible,
and use them for all internal processing. In particular, server_hostname
attribute is now an A-label, and on the server side there's a new
sni_callback that receives the SNI servername as an A-label rather than
a U-label.
(cherry picked from commit 11a1493bc4198f1def5e572049485779cf54dc57)
Co-authored-by: Christian Heimes <christian@python.org>
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index a253f51..a48eb89 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -1528,16 +1528,6 @@
# For compatibility
self.assertEqual(cm.exception.errno, ssl.SSL_ERROR_WANT_READ)
- def test_bad_idna_in_server_hostname(self):
- # Note: this test is testing some code that probably shouldn't exist
- # in the first place, so if it starts failing at some point because
- # you made the ssl module stop doing IDNA decoding then please feel
- # free to remove it. The test was mainly added because this case used
- # to cause memory corruption (see bpo-30594).
- ctx = ssl.create_default_context()
- with self.assertRaises(UnicodeError):
- ctx.wrap_bio(ssl.MemoryBIO(), ssl.MemoryBIO(),
- server_hostname="xn--.com")
def test_bad_server_hostname(self):
ctx = ssl.create_default_context()
@@ -2634,10 +2624,10 @@
if support.verbose:
sys.stdout.write("\n")
- server_context = ssl.SSLContext(ssl.PROTOCOL_TLS)
+ server_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
server_context.load_cert_chain(IDNSANSFILE)
- context = ssl.SSLContext(ssl.PROTOCOL_TLS)
+ context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
context.verify_mode = ssl.CERT_REQUIRED
context.check_hostname = True
context.load_verify_locations(SIGNING_CA)
@@ -2646,18 +2636,26 @@
# different ways
idn_hostnames = [
('könig.idn.pythontest.net',
- 'könig.idn.pythontest.net',),
+ 'xn--knig-5qa.idn.pythontest.net'),
('xn--knig-5qa.idn.pythontest.net',
'xn--knig-5qa.idn.pythontest.net'),
(b'xn--knig-5qa.idn.pythontest.net',
- b'xn--knig-5qa.idn.pythontest.net'),
+ 'xn--knig-5qa.idn.pythontest.net'),
('königsgäßchen.idna2003.pythontest.net',
- 'königsgäßchen.idna2003.pythontest.net'),
+ 'xn--knigsgsschen-lcb0w.idna2003.pythontest.net'),
('xn--knigsgsschen-lcb0w.idna2003.pythontest.net',
'xn--knigsgsschen-lcb0w.idna2003.pythontest.net'),
(b'xn--knigsgsschen-lcb0w.idna2003.pythontest.net',
- b'xn--knigsgsschen-lcb0w.idna2003.pythontest.net'),
+ 'xn--knigsgsschen-lcb0w.idna2003.pythontest.net'),
+
+ # ('königsgäßchen.idna2008.pythontest.net',
+ # 'xn--knigsgchen-b4a3dun.idna2008.pythontest.net'),
+ ('xn--knigsgchen-b4a3dun.idna2008.pythontest.net',
+ 'xn--knigsgchen-b4a3dun.idna2008.pythontest.net'),
+ (b'xn--knigsgchen-b4a3dun.idna2008.pythontest.net',
+ 'xn--knigsgchen-b4a3dun.idna2008.pythontest.net'),
+
]
for server_hostname, expected_hostname in idn_hostnames:
server = ThreadedEchoServer(context=server_context, chatty=True)
@@ -2676,16 +2674,6 @@
s.getpeercert()
self.assertEqual(s.server_hostname, expected_hostname)
- # bug https://bugs.python.org/issue28414
- # IDNA 2008 deviations are broken
- idna2008 = 'xn--knigsgchen-b4a3dun.idna2008.pythontest.net'
- server = ThreadedEchoServer(context=server_context, chatty=True)
- with server:
- with self.assertRaises(UnicodeError):
- with context.wrap_socket(socket.socket(),
- server_hostname=idna2008) as s:
- s.connect((HOST, server.port))
-
# incorrect hostname should raise an exception
server = ThreadedEchoServer(context=server_context, chatty=True)
with server: