Encryption policies

[llbartekll]

To make our jsonrpc serialization more future proof it would be better to create typed envelopes thus making all topics encrypted but only Invite topic would have an envelope that is prefixed with a public key

The typed envelope would allow us to upgrade envelopes in the future as well if needed without breaking existing implementation

Type 0 envelope would use our current serialization and simply prefix it with the type byte

Type 1 envelope would have type byte of 1 and add a public key

So here is the proposed specification that we discussed:

tp = type byte (1 byte)
pk = public key (32 bytes)
iv = initialization vector (12 bytes)
ct = ciphertext (N bytes)

type 0 = tp + iv + ct
type 1 = tp + pk + iv + ct

[chadyj]

From the meeting:

From SDK meeting:

Right now the encrypted message has the format of [ (nonce/iv) + encrypted message + tag ]. This is not possible in the Chat SDK method wc_chatInvite and we have to use the format of [publicKey + (nonce/iv) + encrypted message + tag]. To differentiate them easily we should add envelope type to message payload. For example, in Sign we would have [ 0 + (nonce/iv) + encrypted message ], and for Chat [ 1 +publicKey + (nonce/iv) + encrypted message]