Fix ssl protocol

config

@@ -28,7 +28,7 @@ key = /etc/apache2/ssl/server.key
 # SSL Protocol used. See python's ssl module for available values
 protocol = PROTOCOL_SSLv23
 # Ciphers available. See python's ssl module for available ciphers
-ciphers = None
+ciphers =
 # Reverse DNS to resolve client address in logs
 dns_lookup = True
 # Root URL of Radicale (starting and ending with a slash)

radicale/__init__.py

@@ -100,7 +100,7 @@ class HTTPSServer(HTTPServer):
             keyfile=config.get("server", "key"),
             ssl_version=getattr(ssl, config.get("server", "protocol"),
                                 ssl.PROTOCOL_SSLv23),
-            ciphers=config.get("server", "ciphers"))
+            ciphers=config.get("server", "ciphers") or None)
 
         self.server_bind()
         self.server_activate()

radicale/config.py

@@ -46,7 +46,7 @@ INITIAL_CONFIG = {
         "certificate": "/etc/apache2/ssl/server.crt",
         "key": "/etc/apache2/ssl/server.key",
         "protocol": "PROTOCOL_SSLv23",
-        "ciphers": None,
+        "ciphers": "",
         "dns_lookup": "True",
         "base_prefix": "/",
         "realm": "Radicale - Password Required"},