Python 3.12 compatibility - closes #1057

There are two Python 3.12 changes that affect the pyVmomi client
- Python 3.12 removes ssl.wrap_socket(), deprecated in Python 3.7. ssl.SSLContext.wrap_socket() should be used instead. Ref. https://docs.python.org/3/whatsnew/3.12.html#ssl
- key_file, cert_file are removed from http.client.HTTPSConnection. Ref. https://docs.python.org/3/whatsnew/3.12.html#others

This change:
- The connection logic is refactored to comply with the new Python rules. Python now forces users to generate the SSL context on their own. However, the SoapStubAdapter still has to accept the cert and key pair and SSL context at the same time to keep backwards compatibility for all existing tests and clients.
To do that, instead of relying on the http module to generate the SSL context if none is provided, the SoapStubAdapter now handles that generation by mirroring the http module code before the Python 3.12 changes. Because the SSL context generation is pulled to be executed as early as possible there is no need to figure out what parameters are acceptable to pass to the Python http module because the context is already generated. Therefore, the HTTP connection wrappers can be removed - _HTTPConnection and _HTTPSConnection.

- ssl.create_default_context() is replaced with SSL._create_default_https_context() to mirror the HTTP module logic.
	This change is propagated to the sso.py module to keep the behavior consistent.

Additional changes:
Breaking change:
- SSLTunnelConnection is trimmed down to handle only tunnel connections. The code that handles remote proxy doubles the HTTPProxyConnection logic and therefore is removed.
  This is a breaking change for consumers that wrongly set "sslProxyPath" instead of "httpProxyHost" when they want to go through a remote proxy but I consider this a necessary change because allowing this behavior is a bug and shouldn't have been available at first place.

Non-breaking changes:
- SSLTunnelConnection now inherits HTTPProxyConnection and overwrites the call method because the constructor is the same. Keep in mind that it's deprecated. Hopefully it will be removed sooner rather than later.

- _CheckIPv4(), _CheckIPv6() and _CheckHostname() are removed because it's not necessary to make those verifications when SSLTunnelConnection does not support remote proxies.

- Small changes to variable names and imports

pyVim/sso.py

@@ -1,11 +1,13 @@
 #############################################################
-# Copyright (c) 2012-2024 VMware, Inc.
+# Copyright (c) 2012-2024 Broadcom. All Rights Reserved.
+# The term "Broadcom" refers to Broadcom Inc.
+# and/or its subsidiaries.
 # A python helper module to do SSO related operations.
 #############################################################
 __author__ = 'VMware, Inc.'
 
 #Standard library imports.
-import six.moves.http_client
+from six.moves.http_client import HTTPConnection, HTTPSConnection
 import re
 from six import PY3
 if PY3:
@@ -101,30 +103,11 @@ def __str__(self):
                 "faultxml: %(_soap_msg)s" % self.__dict__)
 
 
-class SSOHTTPConnection(six.moves.http_client.HTTPConnection):
-    """
-    A class that establishes HTTP Connection.
-    Only intened to be used for calls routing through
-    a local sidecar proxy (localhost:1080).
-    """
-    def __init__(self, *args, **kwargs):
-        """
-        Initializer.  See httplib.HTTPConnection for other arguments
-        """
-        tmpKwargs = {}
-        httpConn = six.moves.http_client.HTTPConnection
-        for key in httpConn.__init__.__code__.co_varnames:
-            if key in kwargs and key != 'self':
-                tmpKwargs[key] = kwargs[key]
-        self.host = kwargs.pop('host')
-        six.moves.http_client.HTTPConnection.__init__(self, *args, **tmpKwargs)
-
-
-class SSOHTTPSConnection(six.moves.http_client.HTTPSConnection):
+class _SSOHTTPSConnection(HTTPSConnection):
     """
     An HTTPS class that verifies server's certificate on connect.
     """
-    def __init__(self, *args, **kwargs):
+    def __init__(self, host, context, thumbprint=None, server_cert=None):
         """
         Initializer.  See httplib.HTTPSConnection for other arguments
         than thumbprint and server_cert.
@@ -140,18 +123,18 @@ def __init__(self, *args, **kwargs):
         @param         server_cert: File with expected server certificate.
                                     May be None.
         """
-        self.server_thumbprint = kwargs.pop('thumbprint')
+        self.server_thumbprint = thumbprint
         if self.server_thumbprint is not None:
             self.server_thumbprint = re.sub(':', '',
                                             self.server_thumbprint.lower())
-        server_cert_path = kwargs.pop('server_cert')
+        server_cert_path = server_cert
         if server_cert_path is not None:
             with open(server_cert_path, 'rb') as f:
                 server_cert = f.read().decode(UTF_8)
             self.server_cert = _extract_certificate(server_cert)
         else:
             self.server_cert = None
-        six.moves.http_client.HTTPSConnection.__init__(self, *args, **kwargs)
+        HTTPSConnection.__init__(self, host=host, context=context)
 
     def _check_cert(self, peerCert):
         """
@@ -182,7 +165,7 @@ def connect(self):
         Throws an exception when something is wrong.  See
         httplib.HTTPSConnection.connect() for details.
         """
-        six.moves.http_client.HTTPSConnection.connect(self)
+        HTTPSConnection.connect(self)
 
         self._check_cert(self.sock.getpeercert(True))
 
@@ -240,7 +223,6 @@ def perform_request(self,
                                  user registered with SSO, in PEM format.
         @type       ssl_context: C{ssl.SSLContext}
         @param      ssl_context: SSL context describing the various SSL options.
-                                 It is only supported in Python 2.7.9 or higher.
         @rtype: C{str}
         @return: Response received from the STS after the HoK request.
         """
@@ -249,29 +231,25 @@ def perform_request(self,
         scheme = parsed.scheme
         encoded_message = soap_message.encode(UTF_8)
 
+        if ssl_context is not None:
+            sslContext = ssl_context
+        else:
+            sslContext = ssl._create_default_https_context()
+        if public_key and private_key:
+            sslContext.load_cert_chain(public_key, private_key)
+
         """
         Allow creation of HTTPConnection, only for calls routing
         through local sidecar (localhost:1080)
         """
         if is_sidecar_request(scheme, host):
-            webservice = SSOHTTPConnection(host=host)
-        elif hasattr(ssl, '_create_unverified_context'):
-            # Python 2.7.9 has stronger SSL certificate validation, so we need
-            # to pass in a context when dealing with self-signed certificates.
-            webservice = SSOHTTPSConnection(host=host,
-                                            key_file=private_key,
-                                            cert_file=public_key,
+            webservice = HTTPConnection(host=host)
+        else:
+            webservice = _SSOHTTPSConnection(host=host,
                                             server_cert=self._sts_cert,
                                             thumbprint=self._sts_thumbprint,
                                             context=ssl_context)
-        else:
-            # Versions of Python before 2.7.9 don't support
-            # the context parameter, so don't pass it on.
-            webservice = SSOHTTPSConnection(host=host,
-                                            key_file=private_key,
-                                            cert_file=public_key,
-                                            server_cert=self._sts_cert,
-                                            thumbprint=self._sts_thumbprint)
+
 
         webservice.putrequest("POST", parsed.path, skip_host=True)  # pylint: disable=E1101
         webservice.putheader("Host", host)
@@ -342,7 +320,6 @@ def get_bearer_saml_assertion(self,
                                  The default value is False
         @type       ssl_context: C{ssl.SSLContext}
         @param      ssl_context: SSL context describing the various SSL options.
-                                 It is only supported in Python 2.7.9 or higher.
         @rtype: C{str}
         @return: The SAML assertion in Unicode.
         """
@@ -398,7 +375,6 @@ def get_hok_saml_assertion(self,
                                  The default value is False
         @type       ssl_context: C{ssl.SSLContext}
         @param      ssl_context: SSL context describing the various SSL options.
-                                 It is only supported in Python 2.7.9 or higher.
         @rtype: C{str}
         @return: The SAML assertion in Unicode.
         """
@@ -449,7 +425,6 @@ def get_token_by_token(self,
                                  The default value is False
         @type       ssl_context: C{ssl.SSLContext}
         @param      ssl_context: SSL context describing the various SSL options.
-                                 It is only supported in Python 2.7.9 or higher.
         @rtype: C{str}
         @return: The Hok SAML assertion in Unicode.
         """