1 files changed, 55 insertions, 0 deletions
diff --git a/custodia/store/encgen.py b/custodia/store/encgen.py
new file mode 100644
index 0000000..671f152
--- /dev/null
+++ b/custodia/store/encgen.py
@@ -0,0 +1,55 @@
+# Copyright (C) 2015  Custodia Project Contributors - see LICENSE file
+
+from jwcrypto.common import json_decode, json_encode
+from jwcrypto.jwe import JWE
+from jwcrypto.jwk import JWK
+
+from custodia.store.interface import CSStore, CSStoreError
+
+
+class EncryptedOverlay(CSStore):
+
+    def __init__(self, config):
+        super(EncryptedOverlay, self).__init__(config)
+
+        if 'backing_store' not in config:
+            raise ValueError('Missing "backing_store" for Encrypted Store')
+        self.store_name = config['backing_store']
+        self.store = None
+
+        if 'master_key' not in config:
+            raise ValueError('Missing "master_key" for Encrypted Store')
+
+        with open(config['master_key']) as f:
+            data = f.read()
+            key = json_decode(data)
+            self.mkey = JWK(**key)
+
+        self.enc = config.get('master_enctype', 'A256CBC_HS512')
+
+    def get(self, key):
+        value = self.store.get(key)
+        if value is None:
+            return None
+        try:
+            jwe = JWE()
+            jwe.deserialize(value, self.mkey)
+            return jwe.payload.decode('utf-8')
+        except Exception as err:
+            self.logger.error("Error parsing key %s: [%r]" % (key, repr(err)))
+            raise CSStoreError('Error occurred while trying to parse key')
+
+    def set(self, key, value, replace=False):
+        jwe = JWE(value, json_encode({'alg': 'dir', 'enc': self.enc}))
+        jwe.add_recipient(self.mkey)
+        cvalue = jwe.serialize(compact=True)
+        return self.store.set(key, cvalue, replace)
+
+    def span(self, key):
+        return self.store.span(key)
+
+    def list(self, keyfilter=''):
+        return self.store.list(keyfilter)
+
+    def cut(self, key):
+        return self.store.cut(key)