Help debug bad session errors by logging some envelope info about the
message we are about to decrypt. With this, if there is a decryption
error (e.g., bad mac or no session) it is clear from the logs what
number and device message sent the bad message.
Also log when we send and receive end session messages and when we close
sessions for certain devices.
// FREEBIE
Previously, libtextsecure would send a sync message automatically
when appropriate. This fails if any recipient has a key conflict
or if our network connection fails mid-send.
Instead, when appropriate, return a the DataMessage encoded as an array
buffer for later syncing. This lets the application choose when to send
it, which we now do after any successful send to a recipient, rather
than after all recipients are successfully sent to.
Eventually we should move the DataMessage protobuf construction and
group sending logic to the application layer entirely, in which case
we wouldn't need libtextsecure to construct the sync message either.
Fixes#408
encryptMessageFor now requires an array buffer instead of a protobuf.
By converting the message to an array buffer outside the Promise.all, we
avoid allocating a new copy for each device.
// FREEBIE
If you're the last member of the group, it doesn't make sense to send
messages to it. Previously, we would wait forever for a callback,
causing a stuck pending state indicator.
// FREEBIE
This function dynamically declares a bunch of functions which bind to
its input arguments. Instead, use a new prototypal class to define
these functions within the context of a particular message.
// FREEBIE
Add a pendingMessages object to MessageSender. This object holds
one promise per recipient number. We init this promise with
Promise.resolve(), and chain on promises for message sending, replacing
the previous promise with the newly chained promise each time. If the
current promise resolves and finds that it is still the last promise
in the chain, it removes itself.
Split into separate encrypt and transmit functions. Let the encryption
function also handle all wire formatting (ie, jsonification and base64
encoding), which simplifes TextSecureServer.sendMessages, removes a
TODO, and lets us save fewer params to make network errors replayable.
// FREEBIE
`tryMessageAgain` is the routine called when re-trying a message that
failed to decrypt due to an IncomingIdentityKeyError. This handling
needs to move to MessageReceiver because it depends on
`processDecrypted` to handle incoming message protos, which depends
on a server instance in order to download attachments.
// FREEBIE
textsecure.MessageSender takes server url and credentials and returns
a message sending interface configured for that server.
Used a wrapper function to insert a TextSecureServer instance into
sendmessage.js code at runtime. This will result in function duplication
between different MessageSender objects, pending further refactoring to
use prototypal inheritence.
// FREEBIE
Fix inconsistency in error format, where we sometimes get an unexpected
Error object and sometimes get a wrapper object containing an Error.
Also start saving network errors.
// FREEBIE
1. This is nonstandard behavior, not supported by any other clients. It
may help sometimes but will also cause bugs (see 2)
2. iOS doesn't handle group updates with missing fields. all fields must
be populated, and libtextsecure doesn't have any knowledge of the group
name or avatar, so these updates will clobber group state on iOS.
// FREEBIE
Start by requesting keys for only the master device, then handle 410 as
needed. Single-device users are the more common case and this strategy
lets us avoid requesting/expending one of our own device keys when
establishing a session with sibling devices.
// FREEBIE
saveKeysToDeviceObject is the detector of outgoing identity key errors.
Catch these key errors closer to the source by pulling the
getKeysForNumber into the context of sendMessageToDevices, which lets
it access registerError and the message protobuf.
Previously identity key errors would be uncaught if all existing
sessions with a recipient were closed/deleted, since we would
preemptively fetch the new identity key. The old error handling only
kicked in after a 409/410 response from the server when posting a
message encrypted for a stale session.
// FREEBIE
The following are equivalent, except that the first is longer and
invokes an extra function call.
```
return new Promise(function(resolve, reject) {
reject(new Error("Unknown Group"));
});
return Promise.reject(new Error("Unknown Group"));
```
Protocol and handling is all analogous to contact sync: Multiple
GroupDetails structs are packed into a single attachment blob and parsed
on our end. We don't display the synced groups in the conversation list
until a new message is sent to one of them.
// FREEBIE
Update protobuf definitions and refactor message receive and decrypt
codepath to support new protocol, including various flavors of sync
messages (sent messages, contacts, and groups).
Also cleans up background.js and lets libtextsecure internalize
textsecure.processDecrypted and ensure that it is called before handing
DataMessages off to the application.
The Envelope structure now has a generic content field and a
legacyMessage field for backwards compatibility. We'll send outgoing
messages as legacy messages, and sync messages as "content" while
continuing to support both legacy and non-legacy messages on the receive
side until old clients have a chance to transition.
