Add test to verify mar signatures

tests/test.pubkey

@@ -0,0 +1,9 @@
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAvH4r94FpQ0gvr1hhTfV9
+NUeWPJ5CN6TZRq7v/Dc4nkJ1J4IP1B3UEii34tcNKpy1nKupiZuTT6T1zQYT+z5x
+3UkDF9qQboQ8RNb/BEz/cN3on/LTEnZ7YSraRL11M6cEB8mvmJxddCEquwqccRbs
+Usp8WUB7uRv1w6Anley7N9F/LE1iLPwJasZypRnzWb3aYsJy0cMFOYy+OXVdpktn
+qYqlNIjnt84u4Nil6UXnBbIJNUVOCY8wOFClNvVpubjPkWK1gtdWy3x/hJU5RpAO
+K9cnHxq4M/I4SUWTWO3r7yweQiHG4Jyoc7sP1jkwjBkSG93sDEycfwOdOoZft3wN
+sQIDAQAB
+-----END PUBLIC KEY-----

tests/test_signing.py

@@ -0,0 +1,19 @@
+from unittest import TestCase
+import os
+
+from mardor.marfile import MarFile
+
+TEST_MAR = os.path.join(os.path.dirname(__file__), 'test.mar')
+
+# This was extracted via:
+# curl
+# https://hg.mozilla.org/mozilla-central/raw-file/58e4264903ba/toolkit/mozapps/update/updater/release_primary.der
+# | openssl x509 -inform DER -pubkey -noout
+TEST_KEY = os.path.join(os.path.dirname(__file__), 'test.pubkey')
+
+
+class TestMarSignatures(TestCase):
+    def test_verify(self):
+        """Check that our test mar is signed correctly"""
+        marfile = MarFile(TEST_MAR, signature_versions=[(1, TEST_KEY)])
+        marfile.verify_signatures()

tox.ini

@@ -8,6 +8,7 @@ setenv =
 deps = 
     nose
     coverage
+    cryptography
 
 commands =
     coverage run -a --branch --source=mardor {envbindir}/nosetests