Import Upstream version 4.12.4

ipaserver/custodia/message/formats.py

@@ -0,0 +1,64 @@
+# Copyright (C) 2015  Custodia Project Contributors - see LICENSE file
+from __future__ import absolute_import
+
+from ipaserver.custodia.message.common import InvalidMessage
+from ipaserver.custodia.message.common import UnallowedMessage
+from ipaserver.custodia.message.common import UnknownMessageType
+from ipaserver.custodia.message.kem import KEMHandler
+from ipaserver.custodia.message.simple import SimpleKey
+
+
+default_types = ['simple', 'kem']
+
+key_types = {'simple': SimpleKey,
+             'kem': KEMHandler}
+
+
+class Validator:
+    """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 = key_types.copy()
+
+    def add_types(self, types):
+        self.types.update(types)
+
+    def parse(self, request, msg, name):
+        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 isinstance(msg['type'], list):
+            if len(msg['type']) != 1:
+                raise InvalidMessage('Type is multivalued: %s' % msg['type'])
+            msg_type = msg['type'][0]
+        else:
+            msg_type = msg['type']
+
+        if 'value' not in msg:
+            raise InvalidMessage('The value is missing')
+
+        if isinstance(msg['value'], list):
+            if len(msg['value']) != 1:
+                raise InvalidMessage('Value is multivalued: %s' % msg['value'])
+            msg_value = msg['value'][0]
+        else:
+            msg_value = msg['value']
+
+        if msg_type not in self.types:
+            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, name)
+        return handler