OIDs: Add dotted_form and byte_form properties

This introduces two new properties, dotted_form, for querying
the dotted form of the OID, and byte_form, for querying the
raw OID encoding. By making __bytes__ and __hash__ rely on byte_form,
infinite recursion is prevented when deriving a subclass that
overrides __bytes__.

Signed-off-by: Alexander Scheel <[email protected]>

Author: cipherboy

gssapi/raw/oids.pyx

@@ -129,11 +129,15 @@ cdef class OID:
         if self._free_on_dealloc:
             free(self.raw_oid.elements)
 
-    def __bytes__(self):
+    @property
+    def byte_form(self):
         return (<char*>self.raw_oid.elements)[:self.raw_oid.length]
 
+    def __bytes__(self):
+        return self.byte_form
+
     def _decode_asn1ber(self):
-        ber_encoding = self.__bytes__()
+        ber_encoding = self.byte_form
         # NB(directxman12): indexing a byte string yields an int in Python 3,
         #                   but yields a substring in Python 2
         if six.PY2:
@@ -156,12 +160,15 @@ cdef class OID:
             pos += 1
         return decoded
 
+    @property
+    def dotted_form(self):
+        return '.'.join(str(x) for x in self._decode_asn1ber())
+
     def __repr__(self):
-        dotted_oid = '.'.join(str(x) for x in self._decode_asn1ber())
-        return "<OID {0}>".format(dotted_oid)
+        return "<OID {0}>".format(self.dotted_form)
 
     def __hash__(self):
-        return hash(self.__bytes__())
+        return hash(self.byte_form)
 
     def __richcmp__(OID self, OID other, op):
         if op == 2 or op == 3:  # ==