Raise RSCPKeyError if invalid RSCP key given (#60)

* directly raising RSCPAuthenticationError if empty data received

* add RSCPKeyError exception

---------

Co-authored-by: Christopher Banck <vchrisb@users.noreply.github.com>

Author: mdhom

e3dc/__init__.py

@@ -6,7 +6,7 @@
 """
 
 from ._e3dc import E3DC, AuthenticationError, PollError
-from ._e3dc_rscp_local import CommunicationError, RSCPAuthenticationError
+from ._e3dc_rscp_local import CommunicationError, RSCPAuthenticationError, RSCPKeyError
 from ._e3dc_rscp_web import RequestTimeoutError, SocketNotReady
 from ._rscpLib import FrameError
 from ._rscpLib import set_debug as set_rscp_debug
@@ -17,6 +17,7 @@
     "PollError",
     "CommunicationError",
     "RSCPAuthenticationError",
+    "RSCPKeyError",
     "RequestTimeoutError",
     "SocketNotReady",
     "FrameError",

e3dc/_e3dc.py

@@ -17,6 +17,7 @@
 from ._e3dc_rscp_local import (
     E3DC_RSCP_local,
     RSCPAuthenticationError,
+    RSCPKeyError,
     RSCPNotAvailableError,
 )
 from ._e3dc_rscp_web import E3DC_RSCP_web
@@ -524,6 +525,8 @@ def sendRequest(self, request, retries=3, keepAlive=False):
                 raise AuthenticationError()
             except RSCPNotAvailableError:
                 raise NotAvailableError()
+            except RSCPKeyError:
+                raise
             except Exception:
                 retry += 1
                 if retry > retries:

e3dc/_e3dc_rscp_local.py

@@ -25,6 +25,12 @@ class RSCPNotAvailableError(Exception):
     pass
 
 
+class RSCPKeyError(Exception):
+    """Class for RSCP Encryption Key Error Exception."""
+
+    pass
+
+
 class CommunicationError(Exception):
     """Class for Communication Error Exception."""
 
@@ -58,6 +64,8 @@ def _send(self, plainMsg):
 
     def _receive(self):
         data = self.socket.recv(BUFFER_SIZE)
+        if len(data) == 0:
+            return None
         decData = rscpDecode(self.encdec.decrypt(data))[0]
         return decData
 
@@ -85,6 +93,9 @@ def sendRequest(self, plainMsg):
             self.disconnect()
             raise CommunicationError
 
+        if receive is None:
+            raise RSCPKeyError
+
         if receive[1] == "Error":
             self.disconnect()
             if receive[2] == "RSCP_ERR_ACCESS_DENIED":