Check signature scheme, fixes #390

ipython-kernel/src/IHaskell/IPython/Types.hs

@@ -70,7 +70,10 @@ data Profile = Profile { ip :: IP                     -- ^ The IP on which to li
 
 -- Convert the kernel profile to and from JSON.
 instance FromJSON Profile where
-  parseJSON (Object v) =
+  parseJSON (Object v) = do
+    signatureScheme <- v .: "signature_scheme"
+    case signatureScheme of
+      "hmac-sha256" ->
         Profile <$> v .: "ip"
                 <*> v .: "transport"
                 <*> v .: "stdin_port"
@@ -79,6 +82,7 @@ instance FromJSON Profile where
                 <*> v .: "shell_port"
                 <*> v .: "iopub_port"
                 <*> (Text.encodeUtf8 <$> v .: "key")
+      sig -> error $ "Unexpected signature scheme: " ++ sig
   parseJSON _ = fail "Expecting JSON object."
 
 instance ToJSON Profile where