[security] bpo-13617: Reject embedded null characters in wchar* strings. (#2302)

Based on patch by Victor Stinner.

Add private C API function _PyUnicode_AsUnicode() which is similar to
PyUnicode_AsUnicode(), but checks for null characters.

1 files changed, 5 insertions, 0 deletions

diff --git a/Lib/test/test_locale.py b/Lib/test/test_locale.py
index 668f3cb5ca..d93b3ad048 100644
--- a/Lib/test/test_locale.py
+++ b/Lib/test/test_locale.py
@@ -346,9 +346,14 @@ class TestCollation(unittest.TestCase):
         self.assertLess(locale.strcoll('a', 'b'), 0)
         self.assertEqual(locale.strcoll('a', 'a'), 0)
         self.assertGreater(locale.strcoll('b', 'a'), 0)
+        # embedded null character
+        self.assertRaises(ValueError, locale.strcoll, 'a\0', 'a')
+        self.assertRaises(ValueError, locale.strcoll, 'a', 'a\0')
 
     def test_strxfrm(self):
         self.assertLess(locale.strxfrm('a'), locale.strxfrm('b'))
+        # embedded null character
+        self.assertRaises(ValueError, locale.strxfrm, 'a\0')
 
 
 class TestEnUSCollation(BaseLocalizedTest, TestCollation):