1 files changed, 77 insertions, 0 deletions
diff --git a/macaroonbakery/store.py b/macaroonbakery/store.py
new file mode 100644
index 0000000..ae5f7a7
--- /dev/null
+++ b/macaroonbakery/store.py
@@ -0,0 +1,77 @@
+# Copyright 2017 Canonical Ltd.
+# Licensed under the LGPLv3, see LICENCE file for details.
+import abc
+import os
+
+
+class MemoryOpsStore:
+    ''' A multi-op store that stores the operations in memory.
+    '''
+    def __init__(self):
+        self._store = {}
+
+    def put_ops(self, key, time, ops):
+        ''' Put an ops only if not already there, otherwise it's a no op.
+        '''
+        if self._store.get(key) is None:
+            self._store[key] = ops
+
+    def get_ops(self, key):
+        ''' Returns ops from the key if found otherwise raises a KeyError.
+        '''
+        ops = self._store.get(key)
+        if ops is None:
+            raise KeyError(
+                'cannot get operations for {}'.format(key))
+        return ops
+
+
+class RootKeyStore(object):
+    ''' Defines a store for macaroon root keys.
+    '''
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractmethod
+    def get(self, id):
+        ''' Returns the root key for the given id.
+        If the item is not there, it returns None.
+        @param id: bytes
+        @return: bytes
+        '''
+        raise NotImplementedError('get method must be defined in '
+                                  'subclass')
+
+    @abc.abstractmethod
+    def root_key(self):
+        ''' Returns the root key to be used for making a new macaroon, and an
+        id that can be used to look it up later with the get method.
+        Note that the root keys should remain available for as long as the
+        macaroons using them are valid.
+        Note that there is no need for it to return a new root key for every
+        call - keys may be reused, although some key cycling is over time is
+        advisable.
+        @return: bytes
+        '''
+
+
+class MemoryKeyStore(RootKeyStore):
+    ''' MemoryKeyStore returns an implementation of
+    Store that generates a single key and always
+    returns that from root_key. The same id ("0") is always
+    used.
+    '''
+    def __init__(self, key=None):
+        ''' If the key is not specified a random key will be generated.
+        @param key: bytes
+        '''
+        if key is None:
+            key = os.urandom(24)
+        self._key = key
+
+    def get(self, id):
+        if id != b'0':
+            return None
+        return self._key
+
+    def root_key(self):
+        return self._key, b'0'