1 files changed, 49 insertions, 0 deletions
diff --git a/custodia/message/formats.py b/custodia/message/formats.py
new file mode 100644
index 0000000..f8ddc69
--- /dev/null
+++ b/custodia/message/formats.py
@@ -0,0 +1,49 @@
+# Copyright (C) 2015  Custodia Project Contributors - see LICENSE file
+
+from custodia.message.common import InvalidMessage
+from custodia.message.common import UnknownMessageType
+from custodia.message.common import UnallowedMessage
+from custodia.message.simple import SimpleKey
+
+
+default_types = ['simple']
+
+key_types = {'simple': SimpleKey}
+
+
+class Validator(object):
+    """Validates incoming messages."""
+
+    def __init__(self, allowed=None):
+        """Creates a Validator object.
+
+        :param allowed: list of allowed message types (optional)
+        """
+        self.allowed = allowed or default_types
+        self.types = dict()
+        for t in self.allowed:
+            self.types[t] = key_types[t]
+
+    def add_types(self, types):
+        self.types.update(types)
+
+    def parse(self, request, msg):
+        if not isinstance(msg, dict):
+            raise InvalidMessage('The message must be a dict')
+
+        if 'type' not in msg:
+            raise InvalidMessage('The type is missing')
+
+        if 'value' not in msg:
+            raise InvalidMessage('The value is missing')
+
+        if msg['type'] not in list(self.types.keys()):
+            raise UnknownMessageType("Type '%s' is unknown" % msg['type'])
+
+        if msg['type'] not in self.allowed:
+            raise UnallowedMessage("Message type '%s' not allowed" % (
+                                   msg['type'],))
+
+        handler = self.types[msg['type']](request)
+        handler.parse(msg['value'])
+        return handler