e65760ca85
This commit adds basic syncing capabilities with peers if they are both online. It updates the work done on MVDS, but I decided to create the code in status-go instead, since it's very tight to the application (similarly the code that was the inspiration for mvds, bramble, is all tight together at the database level). I reused parts of the protobufs. The flow is: 1) An OFFER message is sent periodically with a bunch of message-ids and group-ids. 2) Anyone can REQUEST some of those messages if not present in their database. 3) The peer will then send over those messages. It's disabled by default, but I am planning to add a way to set up the flags.
protocol/encryption package
Hash ratchet encryption
encryptor.GenerateHashRatchetKey() generates a hash ratchet key and stores it in in the DB.
There, 2 new tables are created: hash_ratchet_encryption and hash_ratchet_encryption_cache.
Each hash ratchet key is uniquely identified by the (groupId, keyId) pair, where keyId is derived from a clock value.
protocol.BuildHashRatchetKeyExchangeMessage builds an 1-on-1 message containing the hash ratchet key, given it's ID.
protocol.BuildHashRatchetMessage builds a hash ratchet message with arbitrary payload, given groupId. It will use the latest hash ratchet key available. encryptor.encryptWithHR encrypts the payload using Hash Ratchet algorithms. Intermediate hashes are stored in hash_ratchet_encryption_cache table.
protocol.HandleMessage uses encryptor.decryptWithHR fn for decryption.