test_hmac.py 文件源码

def test_legacy_block_size_warnings(self):
        class MockCrazyHash(object):
            """Ain't no block_size attribute here."""
            def __init__(self, *args):
                self._x = hashlib.sha1(*args)
                self.digest_size = self._x.digest_size
            def update(self, v):
                self._x.update(v)
            def digest(self):
                return self._x.digest()

        with warnings.catch_warnings():
            warnings.simplefilter('error', RuntimeWarning)
            with self.assertRaises(RuntimeWarning):
                hmac.HMAC('a', 'b', digestmod=MockCrazyHash)
                self.fail('Expected warning about missing block_size')

            MockCrazyHash.block_size = 1
            with self.assertRaises(RuntimeWarning):
                hmac.HMAC('a', 'b', digestmod=MockCrazyHash)
                self.fail('Expected warning about small block_size')