Merge pull request #1422 from alex/multi-fernet

Fixes #1327 -- adds multifernet

1 files changed, 21 insertions, 0 deletions

diff --git a/cryptography/fernet.py b/cryptography/fernet.py
index a8e0330e..4f98feec 100644
--- a/cryptography/fernet.py
+++ b/cryptography/fernet.py
@@ -127,3 +127,24 @@ class Fernet(object):
         except ValueError:
             raise InvalidToken
         return unpadded
+
+
+class MultiFernet(object):
+    def __init__(self, fernets):
+        fernets = list(fernets)
+        if not fernets:
+            raise ValueError(
+                "MultiFernet requires at least one Fernet instance"
+            )
+        self._fernets = fernets
+
+    def encrypt(self, msg):
+        return self._fernets[0].encrypt(msg)
+
+    def decrypt(self, msg, ttl=None):
+        for f in self._fernets:
+            try:
+                return f.decrypt(msg, ttl)
+            except InvalidToken:
+                pass
+        raise InvalidToken