Add support for HMAC signatures, fixes #4

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/test_viewstate.py b/tests/test_viewstate.py
index ca20167..9cc9285 100644
--- a/tests/test_viewstate.py
+++ b/tests/test_viewstate.py
@@ -26,3 +26,23 @@ class TestViewState(object):
         with pytest.raises(ViewStateException):
             vs = ViewState(raw=b'\x01\x02')
             vs.decode()
+
+    def test_no_signature(self):
+        vs = ViewState(raw=b'\xff\x01e')
+        vs.decode()
+        assert vs.mac is None
+        assert vs.signature is None
+
+    def test_macs(self):
+        MAC_LENGTHS = {
+            'hmac_sha1': 20,
+            'hmac_sha256': 32,
+            'unknown': 5  # could be any other value
+        }
+
+        for mac, n in MAC_LENGTHS.items():
+            sig = b'\x55' * n  # not a real signature, just testing length
+            vs = ViewState(raw=b'\xff\x01d' + sig)
+            vs.decode()
+            assert vs.mac == mac
+            assert vs.signature == sig