Fix pywin32.CredEnumerate implementation for ctypes backend (#117)

* Fix pywin32.CredEnumerate implementation for ctypes backend
* Do not show traceback when an access violation is expected
* Use more recent action steps
* Fix github workflow lint step
* Fix cffi backend on 32bit
* build and upload html report

Author: itziakos

.github/workflows/test.yml

@@ -31,7 +31,7 @@ jobs:
           coverage run -m haas -v win32ctypes
           pip install --upgrade cffi
           coverage run -m haas -v win32ctypes
-      env: 
+      env:
           PYTHONFAULTHANDLER: 1
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v4
@@ -48,18 +48,22 @@ jobs:
           coverage run -p -m haas -v win32ctypes
           pip install --upgrade cffi
           coverage run -p -m haas -v win32ctypes
-      env: 
+      env:
           PYTHONFAULTHANDLER: 1
-    - uses: actions/upload-artifact@v2
+    - name: Generate coverage report
+      run: |
+          coverage combine
+          coverage html
+    - uses: actions/upload-artifact@v3
       with:
         name: Upload Coverage info
-        path: .coverage*
+        path: htmlcov/*
   code-lint:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Python 3.8
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v4
       with:
         python-version: 3.8
     - name: Install flake8

win32ctypes/core/ctypes/_authentication.py

@@ -95,11 +95,6 @@ def credential2dict(creds):
     return credential
 
 
-def _CredEnumerate(Filter, Flags, Count, pppCredential):
-    filter_ = LPCWSTR(Filter)
-    _BaseCredEnumerate(filter_, Flags, Count, pppCredential)
-
-
 _CredWrite = function_factory(
     dlls.advapi32.CredWriteW,
     [PCREDENTIAL, DWORD],
@@ -118,7 +113,7 @@ def _CredEnumerate(Filter, Flags, Count, pppCredential):
     BOOL,
     check_false_factory("CredDelete"))
 
-_BaseCredEnumerate = function_factory(
+_CredEnumerate = function_factory(
     dlls.advapi32.CredEnumerateW,
     [LPCWSTR, DWORD, POINTER(DWORD), PPPCREDENTIAL],
     BOOL,

win32ctypes/pywin32/win32cred.py

@@ -114,25 +114,32 @@ def CredEnumerate(Filter=None, Flags=0):
     with _pywin32error():
         if _backend == 'cffi':
             pcount = _common.PDWORD()
-            pppcreds = _authentication.PPPCREDENTIAL()
-            _authentication._CredEnumerate(Filter, Flags, pcount, pppcreds)
+            pppcredential = _authentication.PPPCREDENTIAL()
+            _authentication._CredEnumerate(
+                Filter, Flags, pcount, pppcredential)
             count = pcount[0]
-            pcreds = _common.dereference(
-                _common.ffi.cast(f"PCREDENTIAL*[{count}]", pppcreds))
+            data = _common.dereference(
+                _common.ffi.cast(f"PCREDENTIAL*[{count}]", pppcredential))
+            memory = _common.dereference(pppcredential)
         else:
             import ctypes
             count = _authentication.DWORD()
-            # Create a mutable pointer variable
-            mem = ctypes.create_string_buffer(1)
-            pppcreds = _common.cast(
-                mem, _authentication.PPPCREDENTIAL)
+            pcredential = _authentication.PCREDENTIAL()
+            ppcredential = ctypes.pointer(pcredential)
+            pppcredential = ctypes.pointer(ppcredential)
             _authentication._CredEnumerate(
-                Filter, Flags, _common.byreference(count), pppcreds)
+                Filter, Flags, _common.byreference(count), pppcredential)
             count = count.value
-            pcreds = _common.dereference(_common.dereference(pppcreds))
+            data = _common.dereference(
+                _common.cast(
+                    ppcredential,
+                    _common.POINTER(_authentication.PCREDENTIAL*count)))
+            memory = pcredential
     try:
-        return [
-            _authentication.credential2dict(pcreds[i])
-            for i in range(count)]
+        result = []
+        for i in range(count):
+            credential = _common.dereference(data[i])
+            result.append(_authentication.credential2dict(credential))
+        return result
     finally:
-        _authentication._CredFree(pcreds)
+        _authentication._CredFree(memory)

win32ctypes/tests/test_win32api.py

@@ -11,9 +11,11 @@
 import contextlib
 import tempfile
 import shutil
+import faulthandler
 
 import win32api
 
+
 from win32ctypes import pywin32
 from win32ctypes.pywin32.pywintypes import error
 
@@ -49,6 +51,22 @@ def resource_update(self, module, library=sys.executable):
         finally:
             module.EndUpdateResource(handle, False)
 
+    @contextlib.contextmanager
+    def nofaulthandler(self):
+        """ Disable the faulthander
+
+            Use this function to avoid poluting the output with errors
+            When it is known that an access violation is expected.
+
+        """
+        enabled = faulthandler.is_enabled()
+        faulthandler.disable()
+        try:
+            yield
+        finally:
+            if enabled:
+                faulthandler.enable()
+
     def test_load_library_ex(self):
         with self.load_library(win32api) as expected:
             with self.load_library(self.module) as handle:
@@ -63,7 +81,8 @@ def test_free_library(self):
             self.assertNotEqual(self.module.FreeLibrary(handle), 0)
 
         with self.assertRaises(error):
-            self.module.FreeLibrary(-3)
+            with self.nofaulthandler():
+                self.module.FreeLibrary(-3)
 
     def test_enum_resource_types(self):
         with self.load_library(win32api, u'shell32.dll') as handle:
@@ -75,7 +94,8 @@ def test_enum_resource_types(self):
         self.assertEqual(resource_types, expected)
 
         with self.assertRaises(error):
-            self.module.EnumResourceTypes(-3)
+            with self.nofaulthandler():
+                self.module.EnumResourceTypes(-3)
 
     def test_enum_resource_names(self):
         with self.load_library(win32api, u'shell32.dll') as handle:
@@ -138,8 +158,9 @@ def test_load_resource(self):
                         self.assertEqual(resource, expected)
 
         with self.assertRaises(error):
-            self.module.LoadResource(
-                handle, resource_type, resource_name, 12435)
+            with self.nofaulthandler():
+                self.module.LoadResource(
+                    handle, resource_type, resource_name, 12435)
 
     def test_get_tick_count(self):
         self.assertGreater(self.module.GetTickCount(), 0.0)