Escape the password for WinRM certificate XML

This patch escapes the password formatted into a hand-crafted
XML for the WinRM certificate mapping. Without it, using passwords
such as 'P@ssw&d' will make the WinRM certificate auth plugin to
fail with a "The WS-Management service cannot process the request
because the XML is invalid.", which is actually true, since the resulting
XML is not valid, due to the unescaped and sign.

Change-Id: Ia93ab13a4ae5783c1fed5fbb748902bda84e9b65
Closes-Bug: #1441884

cloudbaseinit/tests/utils/windows/test_winrmconfig.py

@@ -14,6 +14,7 @@
 
 import importlib
 import unittest
+from xml.sax import saxutils
 
 try:
     import unittest.mock as mock
@@ -267,10 +268,14 @@ class WinRMConfigTests(unittest.TestCase):
                      'subject': 'subject',
                      'uri': 'fake:\\uri'}
         mock_get_xml_bool.return_value = True
+        fake_password = "Pa&ssw0rd!"
+        fake_username = 'fake user'
+        expected_password = saxutils.escape(fake_password)
+        expected_username = saxutils.escape(fake_username)
 
         self._winrmconfig.create_cert_mapping(
-            issuer='issuer', subject='subject', username='fake user',
-            password='fake password', uri='fake:\\uri', enabled=True)
+            issuer='issuer', subject='subject', username=fake_username,
+            password=fake_password, uri='fake:\\uri', enabled=True)
 
         mock_get_xml_bool.assert_called_once_with(True)
         mock_create_resource.assert_called_once_with(
@@ -281,8 +286,8 @@ class WinRMConfigTests(unittest.TestCase):
             '<p:Password>%(password)s</p:Password>'
             '<p:UserName>%(username)s</p:UserName>'
             '</p:certmapping>' % {'enabled': True,
-                                  'username': 'fake user',
-                                  'password': 'fake password'})
+                                  'username': expected_username,
+                                  'password': expected_password})
 
     @mock.patch('cloudbaseinit.utils.windows.winrmconfig.WinRMConfig.'
                 '_get_resource')

cloudbaseinit/utils/windows/winrmconfig.py

@@ -17,6 +17,7 @@ import re
 
 from win32com import client
 from xml.etree import ElementTree
+from xml.sax import saxutils
 
 
 CBT_HARDENING_LEVEL_NONE = "none"
@@ -127,6 +128,8 @@ class WinRMConfig(object):
         resource_uri = self._SERVICE_CERTMAPPING_URI % {'issuer': issuer,
                                                         'subject': subject,
                                                         'uri': uri}
+        escaped_password = saxutils.escape(password)
+        escaped_username = saxutils.escape(username)
         self._create_resource(
             resource_uri,
             '<p:certmapping xmlns:p="http://schemas.microsoft.com/wbem/wsman/'
@@ -135,8 +138,8 @@ class WinRMConfig(object):
             '<p:Password>%(password)s</p:Password>'
             '<p:UserName>%(username)s</p:UserName>'
             '</p:certmapping>' % {'enabled': self._get_xml_bool(enabled),
-                                  'username': username,
-                                  'password': password})
+                                  'username': escaped_username,
+                                  'password': escaped_password})
 
     def get_listener(self, protocol=LISTENER_PROTOCOL_HTTPS, address="*"):
         resource_uri = self._SERVICE_LISTENER_URI % {'protocol': protocol,