Identity/AttachedServices/StorageServerProtocol: Difference between revisions

Identity/AttachedServices/StorageServerProtocol (view source)

Revision as of 03:22, 16 May 2013

763 bytes added , 16 May 2013

→‎Delta-Sync Data Model

Rfkelly

Confirmed users

358

edits

@@ Line 5: / Line 5: @@
 == Delta-Sync Data Model ==
-The storage server hosts a number of independent named '''collections''' for each user.  Each collection is a key-value store whose contents can be atomically modified by the client.  Each modification of a collection creates a new '''version''' with corresponding version identifier, which is a signed hash of the contents of the collection at that version.
+The storage server hosts a number of independent named '''collections''' for each user.  Each collection is a key-value store whose contents can be atomically modified by the client.
+Each modification of a collection creates a new '''version''' with corresponding version identifier, which is a signed hash of the contents of the collection at that version.  Version identifiers are of the form <seqnum>:<contents-hash>:<mac> and are provided by the client during write.  The server ensures that the version sequences numbers of monotonically increasing.
+Each collection has a '''keyid''' which identifies the encryption key used on its contents.  This is of the form <seqnum>:<bytes> is would typically be derived from the master encryption key using HKDF.  The server ensures that keyid updates are given monotonically increasing sequence numbers, so that out-of-date clients can't accidentally roll back a key to a previous version.
+Each collection has also have a '''details''' field, a JSON blob that the client can use to store arbitrary metadata on the collection.  If not set by the client, it defaults to null.
 More details at [[Identity/CryptoIdeas/04-Delta-Sync]].