The forum client is a BSP client that synchronises forum posts among groups of devices. It is used in conjunction with the forum sharing client.
Any user who subscribes to a forum can post messages. Posts are signed by their authors.
Identifier
The client's identifier is org.briarproject.briar.forum. The major version is 0.
Groups
Each forum is represented by a separate BSP group. The group descriptor is a BDF list with two elements: name (string) and salt (raw). The salt is 32 random bytes, to prevent collisions between forums with the same name.
Message types
POST - The message body is a BDF list with four elements: parentId (unique ID or null), author (list), text (string), and signature (raw).
parentId is the optional ID of a post in the same forum to which this post replies. author is a list with three elements: formatVersion (int), nickname (string), and publicKey (raw). This identifies the author of the post.
The signature covers a BDF list with five elements: groupId (unique ID), timestamp (int), parentId (unique ID or null), author (list), and text (string). The group ID and timestamp are taken from the message header. The public key from author is used to verify the signature. The signature label is org.briarproject.briar.forum/POST.
Validity policy
- A post is valid if it is well-formed, has a valid signature, and its parent (if any) is valid.
Storage policy
- All messages are stored.
Sharing policy
- All messages are shared.