gh-94172: Remove keyfile, certfile and check_hostname parameters (#94173)

Remove the keyfile, certfile and check_hostname parameters,
deprecated since Python 3.6, in modules: ftplib, http.client,
imaplib, poplib and smtplib. Use the context parameter (ssl_context
in imaplib) instead.

Parameters following the removed parameters become keyword-only
parameters.

ftplib: Remove the FTP_TLS.ssl_version class attribute: use the
context parameter instead.

Author: vstinner

Doc/whatsnew/3.12.rst

@@ -540,6 +540,16 @@ Removed
   <https://github.com/sphinx-contrib/sphinx-lint>`_.
   (Contributed by Julien Palard in :gh:`98179`.)
 
+* Remove the *keyfile*, *certfile* and *check_hostname* parameters, deprecated
+  since Python 3.6, in modules: :mod:`ftplib`, :mod:`http.client`,
+  :mod:`imaplib`, :mod:`poplib` and :mod:`smtplib`. Use the *context* parameter
+  (*ssl_context* in :mod:`imaplib`) instead.
+  (Contributed by Victor Stinner in :gh:`94172`.)
+
+* :mod:`ftplib`: Remove the ``FTP_TLS.ssl_version`` class attribute: use the
+  *context* parameter instead.
+  (Contributed by Victor Stinner in :gh:`94172`.)
+
 
 Porting to Python 3.12
 ======================

Lib/ftplib.py

@@ -713,28 +713,12 @@ class FTP_TLS(FTP):
         '221 Goodbye.'
         >>>
         '''
-        ssl_version = ssl.PROTOCOL_TLS_CLIENT
 
         def __init__(self, host='', user='', passwd='', acct='',
-                     keyfile=None, certfile=None, context=None,
-                     timeout=_GLOBAL_DEFAULT_TIMEOUT, source_address=None, *,
-                     encoding='utf-8'):
-            if context is not None and keyfile is not None:
-                raise ValueError("context and keyfile arguments are mutually "
-                                 "exclusive")
-            if context is not None and certfile is not None:
-                raise ValueError("context and certfile arguments are mutually "
-                                 "exclusive")
-            if keyfile is not None or certfile is not None:
-                import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a "
-                              "custom context instead", DeprecationWarning, 2)
-            self.keyfile = keyfile
-            self.certfile = certfile
+                     *, context=None, timeout=_GLOBAL_DEFAULT_TIMEOUT,
+                     source_address=None, encoding='utf-8'):
             if context is None:
-                context = ssl._create_stdlib_context(self.ssl_version,
-                                                     certfile=certfile,
-                                                     keyfile=keyfile)
+                context = ssl._create_stdlib_context()
             self.context = context
             self._prot_p = False
             super().__init__(host, user, passwd, acct,
@@ -749,7 +733,7 @@ def auth(self):
             '''Set up secure control connection by using TLS/SSL.'''
             if isinstance(self.sock, ssl.SSLSocket):
                 raise ValueError("Already using TLS")
-            if self.ssl_version >= ssl.PROTOCOL_TLS:
+            if self.context.protocol >= ssl.PROTOCOL_TLS:
                 resp = self.voidcmd('AUTH TLS')
             else:
                 resp = self.voidcmd('AUTH SSL')

Lib/http/client.py

@@ -1414,33 +1414,14 @@ class HTTPSConnection(HTTPConnection):
 
         default_port = HTTPS_PORT
 
-        # XXX Should key_file and cert_file be deprecated in favour of context?
-
-        def __init__(self, host, port=None, key_file=None, cert_file=None,
-                     timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
-                     source_address=None, *, context=None,
-                     check_hostname=None, blocksize=8192):
+        def __init__(self, host, port=None,
+                     *, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+                     source_address=None, context=None, blocksize=8192):
             super(HTTPSConnection, self).__init__(host, port, timeout,
                                                   source_address,
                                                   blocksize=blocksize)
-            if (key_file is not None or cert_file is not None or
-                        check_hostname is not None):
-                import warnings
-                warnings.warn("key_file, cert_file and check_hostname are "
-                              "deprecated, use a custom context instead.",
-                              DeprecationWarning, 2)
-            self.key_file = key_file
-            self.cert_file = cert_file
             if context is None:
                 context = _create_https_context(self._http_vsn)
-            if check_hostname is not None:
-                context.check_hostname = check_hostname
-            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
 
         def connect(self):

Lib/imaplib.py

@@ -1285,40 +1285,23 @@ class IMAP4_SSL(IMAP4):
 
         """IMAP4 client class over SSL connection
 
-        Instantiate with: IMAP4_SSL([host[, port[, keyfile[, certfile[, ssl_context[, timeout=None]]]]]])
+        Instantiate with: IMAP4_SSL([host[, port[, ssl_context[, timeout=None]]]])
 
                 host - host's name (default: localhost);
                 port - port number (default: standard IMAP4 SSL port);
-                keyfile - PEM formatted file that contains your private key (default: None);
-                certfile - PEM formatted certificate chain file (default: None);
                 ssl_context - a SSLContext object that contains your certificate chain
                               and private key (default: None)
-                Note: if ssl_context is provided, then parameters keyfile or
-                certfile should not be set otherwise ValueError is raised.
                 timeout - socket timeout (default: None) If timeout is not given or is None,
                           the global default socket timeout is used
 
         for more documentation see the docstring of the parent class IMAP4.
         """
 
 
-        def __init__(self, host='', port=IMAP4_SSL_PORT, keyfile=None,
-                     certfile=None, ssl_context=None, timeout=None):
-            if ssl_context is not None and keyfile is not None:
-                raise ValueError("ssl_context and keyfile arguments are mutually "
-                                 "exclusive")
-            if ssl_context is not None and certfile is not None:
-                raise ValueError("ssl_context and certfile arguments are mutually "
-                                 "exclusive")
-            if keyfile is not None or certfile is not None:
-                import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a "
-                              "custom ssl_context instead", DeprecationWarning, 2)
-            self.keyfile = keyfile
-            self.certfile = certfile
+        def __init__(self, host='', port=IMAP4_SSL_PORT,
+                     *, ssl_context=None, timeout=None):
             if ssl_context is None:
-                ssl_context = ssl._create_stdlib_context(certfile=certfile,
-                                                         keyfile=keyfile)
+                ssl_context = ssl._create_stdlib_context()
             self.ssl_context = ssl_context
             IMAP4.__init__(self, host, port, timeout)
 

Lib/poplib.py

@@ -419,35 +419,19 @@ def stls(self, context=None):
     class POP3_SSL(POP3):
         """POP3 client class over SSL connection
 
-        Instantiate with: POP3_SSL(hostname, port=995, keyfile=None, certfile=None,
-                                   context=None)
+        Instantiate with: POP3_SSL(hostname, port=995, context=None)
 
                hostname - the hostname of the pop3 over ssl server
                port - port number
-               keyfile - PEM formatted file that contains your private key
-               certfile - PEM formatted certificate chain file
                context - a ssl.SSLContext
 
         See the methods of the parent class POP3 for more documentation.
         """
 
-        def __init__(self, host, port=POP3_SSL_PORT, keyfile=None, certfile=None,
-                     timeout=socket._GLOBAL_DEFAULT_TIMEOUT, context=None):
-            if context is not None and keyfile is not None:
-                raise ValueError("context and keyfile arguments are mutually "
-                                 "exclusive")
-            if context is not None and certfile is not None:
-                raise ValueError("context and certfile arguments are mutually "
-                                 "exclusive")
-            if keyfile is not None or certfile is not None:
-                import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a "
-                              "custom context instead", DeprecationWarning, 2)
-            self.keyfile = keyfile
-            self.certfile = certfile
+        def __init__(self, host, port=POP3_SSL_PORT,
+                     *, timeout=socket._GLOBAL_DEFAULT_TIMEOUT, context=None):
             if context is None:
-                context = ssl._create_stdlib_context(certfile=certfile,
-                                                     keyfile=keyfile)
+                context = ssl._create_stdlib_context()
             self.context = context
             POP3.__init__(self, host, port, timeout)
 
@@ -457,7 +441,7 @@ def _create_socket(self, timeout):
                                             server_hostname=self.host)
             return sock
 
-        def stls(self, keyfile=None, certfile=None, context=None):
+        def stls(self, context=None):
             """The method unconditionally raises an exception since the
             STLS command doesn't make any sense on an already established
             SSL/TLS session.

Lib/smtplib.py

@@ -749,14 +749,14 @@ def login(self, user, password, *, initial_response_ok=True):
         # We could not login successfully.  Return result of last attempt.
         raise last_exception
 
-    def starttls(self, keyfile=None, certfile=None, context=None):
+    def starttls(self, *, context=None):
         """Puts the connection to the SMTP server into TLS mode.
 
         If there has been no previous EHLO or HELO command this session, this
         method tries ESMTP EHLO first.
 
         If the server supports TLS, this will encrypt the rest of the SMTP
-        session. If you provide the keyfile and certfile parameters,
+        session. If you provide the context parameter,
         the identity of the SMTP server and client can be checked. This,
         however, depends on whether the socket module really checks the
         certificates.
@@ -774,19 +774,8 @@ def starttls(self, keyfile=None, certfile=None, context=None):
         if resp == 220:
             if not _have_ssl:
                 raise RuntimeError("No SSL support included in this Python")
-            if context is not None and keyfile is not None:
-                raise ValueError("context and keyfile arguments are mutually "
-                                 "exclusive")
-            if context is not None and certfile is not None:
-                raise ValueError("context and certfile arguments are mutually "
-                                 "exclusive")
-            if keyfile is not None or certfile is not None:
-                import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a "
-                              "custom context instead", DeprecationWarning, 2)
             if context is None:
-                context = ssl._create_stdlib_context(certfile=certfile,
-                                                     keyfile=keyfile)
+                context = ssl._create_stdlib_context()
             self.sock = context.wrap_socket(self.sock,
                                             server_hostname=self._host)
             self.file = None
@@ -1017,35 +1006,18 @@ class SMTP_SSL(SMTP):
         compiled with SSL support). If host is not specified, '' (the local
         host) is used. If port is omitted, the standard SMTP-over-SSL port
         (465) is used.  local_hostname and source_address have the same meaning
-        as they do in the SMTP class.  keyfile and certfile are also optional -
-        they can contain a PEM formatted private key and certificate chain file
-        for the SSL connection. context also optional, can contain a
-        SSLContext, and is an alternative to keyfile and certfile; If it is
-        specified both keyfile and certfile must be None.
+        as they do in the SMTP class.  context also optional, can contain a
+        SSLContext.
 
         """
 
         default_port = SMTP_SSL_PORT
 
         def __init__(self, host='', port=0, local_hostname=None,
-                     keyfile=None, certfile=None,
-                     timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+                     *, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
                      source_address=None, context=None):
-            if context is not None and keyfile is not None:
-                raise ValueError("context and keyfile arguments are mutually "
-                                 "exclusive")
-            if context is not None and certfile is not None:
-                raise ValueError("context and certfile arguments are mutually "
-                                 "exclusive")
-            if keyfile is not None or certfile is not None:
-                import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a "
-                              "custom context instead", DeprecationWarning, 2)
-            self.keyfile = keyfile
-            self.certfile = certfile
             if context is None:
-                context = ssl._create_stdlib_context(certfile=certfile,
-                                                     keyfile=keyfile)
+                context = ssl._create_stdlib_context()
             self.context = context
             SMTP.__init__(self, host, port, local_hostname, timeout,
                           source_address)

Lib/test/test_ftplib.py

@@ -984,11 +984,11 @@ def test_context(self):
         ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
         ctx.check_hostname = False
         ctx.verify_mode = ssl.CERT_NONE
-        self.assertRaises(ValueError, ftplib.FTP_TLS, keyfile=CERTFILE,
+        self.assertRaises(TypeError, ftplib.FTP_TLS, keyfile=CERTFILE,
                           context=ctx)
-        self.assertRaises(ValueError, ftplib.FTP_TLS, certfile=CERTFILE,
+        self.assertRaises(TypeError, ftplib.FTP_TLS, certfile=CERTFILE,
                           context=ctx)
-        self.assertRaises(ValueError, ftplib.FTP_TLS, certfile=CERTFILE,
+        self.assertRaises(TypeError, ftplib.FTP_TLS, certfile=CERTFILE,
                           keyfile=CERTFILE, context=ctx)
 
         self.client = ftplib.FTP_TLS(context=ctx, timeout=TIMEOUT)

Lib/test/test_httplib.py

@@ -1978,7 +1978,7 @@ def test_local_unknown_cert(self):
         self.assertEqual(exc_info.exception.reason, 'CERTIFICATE_VERIFY_FAILED')
 
     def test_local_good_hostname(self):
-        # The (valid) cert validates the HTTP hostname
+        # The (valid) cert validates the HTTPS hostname
         import ssl
         server = self.make_server(CERT_localhost)
         context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
@@ -1991,46 +1991,29 @@ def test_local_good_hostname(self):
         self.assertEqual(resp.status, 404)
 
     def test_local_bad_hostname(self):
-        # The (valid) cert doesn't validate the HTTP hostname
+        # The (valid) cert doesn't validate the HTTPS hostname
         import ssl
         server = self.make_server(CERT_fakehostname)
         context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
         context.load_verify_locations(CERT_fakehostname)
         h = client.HTTPSConnection('localhost', server.port, context=context)
         with self.assertRaises(ssl.CertificateError):
             h.request('GET', '/')
-        # Same with explicit check_hostname=True
-        with warnings_helper.check_warnings(('', DeprecationWarning)):
-            h = client.HTTPSConnection('localhost', server.port,
-                                       context=context, check_hostname=True)
+
+        # Same with explicit context.check_hostname=True
+        context.check_hostname = True
+        h = client.HTTPSConnection('localhost', server.port, context=context)
         with self.assertRaises(ssl.CertificateError):
             h.request('GET', '/')
-        # With check_hostname=False, the mismatching is ignored
-        context.check_hostname = False
-        with warnings_helper.check_warnings(('', DeprecationWarning)):
-            h = client.HTTPSConnection('localhost', server.port,
-                                       context=context, check_hostname=False)
-        h.request('GET', '/nonexistent')
-        resp = h.getresponse()
-        resp.close()
-        h.close()
-        self.assertEqual(resp.status, 404)
-        # The context's check_hostname setting is used if one isn't passed to
-        # HTTPSConnection.
+
+        # With context.check_hostname=False, the mismatching is ignored
         context.check_hostname = False
         h = client.HTTPSConnection('localhost', server.port, context=context)
         h.request('GET', '/nonexistent')
         resp = h.getresponse()
-        self.assertEqual(resp.status, 404)
         resp.close()
         h.close()
-        # Passing check_hostname to HTTPSConnection should override the
-        # context's setting.
-        with warnings_helper.check_warnings(('', DeprecationWarning)):
-            h = client.HTTPSConnection('localhost', server.port,
-                                       context=context, check_hostname=True)
-        with self.assertRaises(ssl.CertificateError):
-            h.request('GET', '/')
+        self.assertEqual(resp.status, 404)
 
     @unittest.skipIf(not hasattr(client, 'HTTPSConnection'),
                      'http.client.HTTPSConnection not available')
@@ -2066,11 +2049,9 @@ def test_tls13_pha(self):
         self.assertIs(h._context, context)
         self.assertFalse(h._context.post_handshake_auth)
 
-        with warnings.catch_warnings():
-            warnings.filterwarnings('ignore', 'key_file, cert_file and check_hostname are deprecated',
-                                    DeprecationWarning)
-            h = client.HTTPSConnection('localhost', 443, context=context,
-                                       cert_file=CERT_localhost)
+        context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT, cert_file=CERT_localhost)
+        context.post_handshake_auth = True
+        h = client.HTTPSConnection('localhost', 443, context=context)
         self.assertTrue(h._context.post_handshake_auth)
 
 

Lib/test/test_imaplib.py

@@ -573,15 +573,6 @@ def test_ssl_verified(self):
                                  ssl_context=ssl_context)
         client.shutdown()
 
-    # Mock the private method _connect(), so mark the test as specific
-    # to CPython stdlib
-    @cpython_only
-    def test_certfile_arg_warn(self):
-        with warnings_helper.check_warnings(('', DeprecationWarning)):
-            with mock.patch.object(self.imap_class, 'open'):
-                with mock.patch.object(self.imap_class, '_connect'):
-                    self.imap_class('localhost', 143, certfile=CERTFILE)
-
 class ThreadedNetworkedTests(unittest.TestCase):
     server_class = socketserver.TCPServer
     imap_class = imaplib.IMAP4
@@ -1070,18 +1061,6 @@ def test_logout(self):
             rs = _server.logout()
             self.assertEqual(rs[0], 'BYE', rs)
 
-    def test_ssl_context_certfile_exclusive(self):
-        with socket_helper.transient_internet(self.host):
-            self.assertRaises(
-                ValueError, self.imap_class, self.host, self.port,
-                certfile=CERTFILE, ssl_context=self.create_ssl_context())
-
-    def test_ssl_context_keyfile_exclusive(self):
-        with socket_helper.transient_internet(self.host):
-            self.assertRaises(
-                ValueError, self.imap_class, self.host, self.port,
-                keyfile=CERTFILE, ssl_context=self.create_ssl_context())
-
 
 if __name__ == "__main__":
     unittest.main()