* normal session where both introducees accept
* normal session where the first introducee declines
* normal session where the second introducee declines
* one session where a contact is introduced to herself
* one session where two identities of the same contact
are introduced to each other
This introduces a new IntroductionAbortedEvent to signal when the
protocol was aborted. It is not yet used in the UI.
It closes#276
* force decline when two of our own identities are introduced to each
other
* throw away introduction requests to the same identity
(impossible to trigger from UI)
Closes#284
When devices' clocks are out of sync, it is possible that a response is
shown before the request. This commit makes sure that the timestamp of
responses is always later than the last message in the conversation.
Some wording could be misunderstood to thing introductions were
successful even though they were not. That has been clarified.
A new database transaction was created when getting contacts and local
transport properties. This has been changed to re-use the existing
transaction.
Also addresses minor issues found in review.
The code made the assumption that a session state can be identified by
the unique session ID. However, when multiple identities from the same
device are involved, there are two sessions with the same ID running on
the device.
Hence, a second identifying criteria has to be used to uniquely identify
the correct session. Here, the ID of the group was chosen.
Unfortunately, the session state can not be cached easily anymore
leading to a small performance penalty when getting all messages for the
UI.
Contact Introduction Backend
This MR allows you to introduce two of your contacts to each other. They both will receive an introduction with an optional message and then can accept or refuse the introduction which is presented as a notification.
When reviewing, I propose to review the individual commits separately as I took great care to split functional independent parts into separate commits. You might also want to have a look at the [Introduction Client Wiki page](https://code.briarproject.org/akwizgran/briar/wikis/IntroductionClient) to better understand what is going on before looking into the actual code.
Protocol sessions and states are not yet deleted and the UI is still missing (#253). In order to practically test this feature, the UI from !122 is needed.
See merge request !116
BQP with QR codes
This MR implements BQP for key agreement over short-range transports. It also implements the Android UI for using BQP with QR codes.
Closes#117.
See merge request !84
This Introduction BSP Client uses its own group to communicate with
existing contacts. It uses four types of messages to facilitate
introductions: the introduction, the response, the ack and the abort.
The protocol logic is encapsulated in two protocol engines, one for the
introducer and one for the introducee. The introduction client keeps the
local state for each engine, hands messages over to the engines and
processes the result and state changes they return.
This requires exposing the `containsContact()` method to the `DatabaseComponent`
and is needed for finding out efficiently whether a contact already exists.
Message queues. #266
A message queue is a group shared by two devices that delivers messages from each device to the other in order. The first 64 bits of the message body contain a sequence number that's incremented for each message sent in a given direction. The incoming and outgoing sequence numbers and information about any messages received out of order and waiting to be delivered are stored in the group metadata.
See merge request !121
Fix race condition when closing redundant Bluetooth sockets
The Bluetooth invitation code has a race condition: if Alice and Bob connect to each other at roughly the same time, they each consider their outgoing socket to be redundant and close it, resulting in both sockets being closed. This can be triggered pretty reliably by using two phones of the same model and pressing 'Continue' at the same time on both phones.
When more than one invitation socket is opened, Alice should pick which one to use and Bob should use whichever one Alice picks, which Bob can detect by trying to read from both sockets.
Hopefully the Bluetooth invitation code will be retired when #117 is merged, but I'm putting this up for review in case we need to keep Bluetooth as a fallback method.
See merge request !120
When more than one invitation socket is opened, Alice should pick which one to use and Bob should use whichever one Alice picks. This fixes a race condition where each party picked a different socket and closed the other.
