This was a holdover from Signal's origins as a pure SMS app.
It causes problems, depends on undefined device specific behavior,
and should no longer be necessary now that we have all the
information we need to E164 all numbers.
// FREEBIE
1) Prefetch identity keys when possible
2) Always accept prefetched keys or keys from incoming messages
3) Block sending only if it's a recent change, or if always
block is enabled
// FREEBIE
1) Switch to new TextSecureAddress addressing, rather than mixing
long-based recipient IDs into libtextsecure.
2) Get rid of RecipientFormattingException throws in calls to
RecipientFactory.
Closes#2570
1) When registering with server, indicate that the server should
store messages and send notifications.
2) Process notification GCM messages, and connect to the server
to retrieve actual message content.
1) Use the new /v2/keys API for storing/retrieving prekey bundles.
2) For sessions built with PreKeyBundle and PreKeyWhisperMessage,
use a v3 ratcheting session when available.
1) Add plain two-way key exchange support libaxolotl by moving
all the KeyExchangeMessage code there.
2) Move the bulk of KeyExchangeProcessor code to libaxolotl
for setting up sessions based on retrieved prekeys, received
prekeybundles, or exchanged key exchange messages.
1) Break the core cryptography functions out into libaxolotol.
2) The objective for this code is a Java library that isn't
dependent on any Android functions. However, while the
code has been separated from any Android functionality,
it is still an 'android library project' because of the
JNI.
1) At registration time, a client generates a random ID and
transmits to the the server.
2) The server provides that registration ID to any client
that requests a prekey.
3) Clients include that registration ID in any
PreKeyWhisperMessage.
4) Clients include that registration ID in their sendMessage
API call to the server.
5) The server verifies that the registration ID included in
an API call is the same as the current registration ID
for the destination device. Otherwise, it notifies the
sender that their session is stale.
