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Mailbox Properties Client

Daniel Lublin edited this page 2022-05-16 09:46:55 +02:00

Table of Contents

• Identifier
• Groups
• Message types
• Validity policy
• Storage policy
• Sharing policy

The mailbox properties (or updates) client is a BSP client that synchronises mailbox properties and supported mailbox api versions between pairs of devices. The properties describe how to connect to a mailbox associated with a device.

Identifier

The client's identifier is org.briarproject.bramble.mailbox.properties. The major version is 1.

Groups

The client uses a separate BSP group for communicating with each contact. The group descriptor is a BDF list containing the unique IDs of the contacts' identities, sorted in ascending order as byte strings.

Message types

UPDATE - The message body is a BDF list with 4 elements: version (int), clientSupports (list), and serverSupports (list), properties (dictionary).

version is incremented with each new update message.

clientSupports is a non-empty list of Mailbox API versions that the sender's Briar instance can talk to as a client. Each element (a version) is a list with 2 elements: major (int), minor (int).

serverSupports is a list of Mailbox API versions that the sender's Mailbox supports. The list must be empty if properties is empty (there is no mailbox), otherwise it must be non-empty. Each element (a version) is a list with 2 elements: maj (int), min (int).

The keys of the properties dictionary are strings. The dictionary of a well-formed update contains either no (0) entries, which means for the receiver that there is no mailbox available. Or, it contains all of the following entries:

• "onion" : String -- Onion of the mailbox (56 lower-case base32 chars, derived from the v3 Onion Service public key)
• "authToken" : byte[32] -- token used for authenticating with the mailbox
• "inboxId" : byte[32] -- folder id used when receiving data from the mailbox
• "outboxId" : byte[32] -- folder id used when delivering data to the mailbox

Validity policy

• An update is valid if it is well-formed.

Storage policy

• In the groups shared with contacts:
  • The local message with the highest version is stored.
  • The remote message with the highest version is stored.

Sharing policy

• In the groups shared with contacts, all local messages are shared.