Added pillarsdk.utils.is_valid_id(some_id) function.

This allows Pillar-Web to check for ID validity before sending IDs
from the URL to Pillar.

pillarsdk/utils.py

@@ -161,3 +161,19 @@ def sanitize_filename(file_name):
     safe_name = ''.join(c for c in file_name
                         if ord(c) > 31 and c not in badchars)
     return safe_name.strip(' .')
+
+
+def is_valid_id(some_id, _valid_id_chars=frozenset(b'0123456789abcdef')):
+    """Returns True iff the ID has a valid form."""
+
+    if isinstance(some_id, text_type):
+        try:
+            some_id = some_id.encode('ascii')
+        except UnicodeEncodeError:
+            return False
+
+    if len(some_id) != 24:
+        return False
+
+    return all(char in _valid_id_chars
+               for char in some_id)

tests/test_utils.py

@@ -77,3 +77,17 @@ class PillarUtilsTests(unittest.TestCase):
         self.assertEqual('abc......def', utils.sanitize_filename('././abc../..///..def'))
         self.assertEqual('Pad Thai is ผัดไทย', utils.sanitize_filename('Pad Thai is ผัดไทย'))
         self.assertEqual(u'Pad Thai is ผัดไทย', utils.sanitize_filename(u'Pad Thai is ผัดไทย'))
+
+    def test_is_valid_id(self):
+        self.assertTrue(utils.is_valid_id(24 * 'a'))
+        self.assertTrue(utils.is_valid_id('55f35f7e2beb3300960bb074'))
+        self.assertTrue(utils.is_valid_id(u'55f35f7e2beb3300960bb074'))
+
+        self.assertFalse(utils.is_valid_id(u'555f35f7e2beb3300960bb074'))
+        self.assertFalse(utils.is_valid_id(u'%2355f35f7e2beb3300960bb074'))
+        self.assertFalse(utils.is_valid_id(u'#55f35f7e2beb3300960bb074'))
+        self.assertFalse(utils.is_valid_id(u'a55f-35f7-e2be-b330-0960-bb07'))
+        self.assertFalse(utils.is_valid_id(u'a55f-35f7-e2be-b330-0960-bb07'[:24]))
+
+        self.assertFalse(utils.is_valid_id(u'55f…'))
+        self.assertFalse(utils.is_valid_id(u'ประเทศไทย'))