Encode transport properties more compactly in QR codes
The [original BQP spec](https://code.briarproject.org/akwizgran/briar/wikis/BQP) described a compact encoding for transport properties, with the goal of making the QR code as small as possible. At some point during the implementation, I asked @str4d to use TransportIds and TransportProperties instead, as described in the [current spec](https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BQP.md). That was a mistake.
Using the original format reduces the payload from 60 to 34 bytes (43% smaller) for Bluetooth only, and from 96 to 49 bytes (49% smaller) for Bluetooth and LAN. This makes it easier to scan codes from low-resolution screens using fixed-focus and/or low-resolution cameras. Using this branch I can exchange codes between the Sony Xperia Tipo (320x480 screen, fixed focus, 640x480 preview size) and the Huawei Ascend Y300 (480x800 screen, infinity focus, 1280x720 preview size).
This also removes an obstacle to implementing #558, as TransportIds are no longer included in QR codes.
Closes#346.
See merge request !394
Forum controller thread safety and tree safety
This branch solves the concurrent forum issues by code restructure and refactoring.
Closes#556Closes#552
See merge request !262
Like other recursive operations on the dependency graph, this is
not done in a single transaction to prevent an attacker from creating
arbitrary large transactions.
So at startup, the `ValidationManager` finds and resumes any
unfinished operations, by looking for shared messages with unshared
dependencies.
Check whether File#listFiles() returns null
The docs say this can happen if there's an I/O error. Also fixed a throw-in-finally-block warning and renamed an IoUtils method to make its contract clearer.
See merge request !328
Add support for comments and reblogging to Blog Client
Comments and reblogs need to depend on the post they refer to.
Since message dependencies are limited to one group,
the post and also the comments need to be wrapped
when commented on or reblogged to another blog (and group).
For this reason, in addition to comments, two new wrapping message types
are introduced. They retain all data of the original messages and allow
for reconstruction and signature verification.
This MR breaks backwards compatibility with old blog posts.
It removes the content type, title and parent ID from the post.
Furthermore, it includes one commit that replaces the `Message` in `MessageSharedEvent` with a `MessageId`.
Closes#494
See merge request !285
Before the introducee sends her ACK,
she derives a master key from the ephemeral shared secret as before.
Two nonces and a MAC key are then derived from the master key.
The local introducee signs one of the nonces and calculates a MAC
over her own identity public key, ephemeral public key,
transport properties and timestamp.
The local introducee includes the signature and MAC in her ACK.
On receiving the remote introducee's ACK,
the local introducee verifies the signature and MAC.
Should the verification fail, an ABORT is sent to the introducer and
the remote introducee that was added as inactive is deleted again.
Comments and reblogs need to depend on the post they refer to.
Since message dependencies are limited to one group,
the post and also the comments need to be wrapped
when commented on or reblogged to another blog.
For this reason, in addition to comments, two new wrapping message types
are introduced. They retain all data of the original messages and allow
for reconstruction and signature verification.
This commit breaks backwards compatibility with old blog posts.
It removes the content type, title and parent ID from the post
message structure.
