1 files changed, 75 insertions, 0 deletions
diff --git a/macaroonbakery/json_serializer.py b/macaroonbakery/json_serializer.py
new file mode 100644
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+++ b/macaroonbakery/json_serializer.py
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+# Copyright 2017 Canonical Ltd.
+# Licensed under the LGPLv3, see LICENCE file for details.
+
+import base64
+import json
+
+from pymacaroons.macaroon import Macaroon
+from pymacaroons.caveat import Caveat
+
+
+class JsonSerializer(object):
+    '''Serializer used to produce JSON macaroon format v1.
+    '''
+    def serialize(self, macaroon):
+        '''Serialize the macaroon in JSON format v1.
+
+        @param macaroon the macaroon to serialize.
+        @return JSON macaroon.
+        '''
+        serialized = {
+            'identifier': macaroon.identifier,
+            'signature': macaroon.signature
+        }
+        if macaroon.location:
+            serialized['location'] = macaroon.location
+        if macaroon.caveats:
+            serialized['caveats'] = [
+                caveat_v1_to_dict(caveat) for caveat in macaroon.caveats
+            ]
+        return json.dumps(serialized)
+
+    def deserialize(self, serialized):
+        '''Deserialize a JSON macaroon v1.
+
+        @param serialized the macaroon in JSON format v1.
+        @return the macaroon object.
+        '''
+        from macaroonbakery import utils
+        caveats = []
+        deserialized = json.loads(serialized)
+
+        for c in deserialized['caveats']:
+            caveat = Caveat(
+                caveat_id=c['cid'],
+                verification_key_id=(
+                    utils.raw_urlsafe_b64decode(c['vid']) if c.get('vid')
+                    else None
+                ),
+                location=(
+                    c['cl'] if c.get('cl') else None
+                )
+            )
+            caveats.append(caveat)
+
+        return Macaroon(
+            location=deserialized['location'],
+            identifier=deserialized['identifier'],
+            caveats=caveats,
+            signature=deserialized['signature']
+        )
+
+
+def caveat_v1_to_dict(c):
+    ''' Return a caveat as a dictionary for export as the JSON
+    macaroon v1 format
+    '''
+    serialized = {}
+    if len(c.caveat_id) > 0:
+        serialized['cid'] = c.caveat_id
+    if c.verification_key_id:
+        serialized['vid'] = base64.urlsafe_b64encode(
+            c.verification_key_id).decode('ascii')
+    if c.location:
+        serialized['cl'] = c.location
+    return serialized