This removes our support for the New Key/DEFAULT case, which iOS will
sync to us. Why? Because it ensures that in out of date scenarios, we
don't lose the higher-security state we were in previously.
FREEBIE
Sessions established with the previous identity should no longer be used for
sending, so we should close them.
Since we've added this call to saveIdentity, we can omit the call to it after
profile fetches.
// FREEBIE
processVerifiedMessage checks the current state of the database against the
identity key from an incoming verification sync message to determine whether or
how to update our local record.
When syncing a DEFAULT status and we have no local record, it's a no-op, but
we'll log it.
When syncing a DEFAULT status and we have non-default record with the same key,
mark it as default.
When syncing a VERIFIED status and either:
1. we have no key on record,
2. we have have a different key on record, or
3. we have the same key on record, but not verified
mark it as verified.
Otherwise do nothing.
References: https://github.com/WhisperSystems/Signal-Android/blob/master/src/org/thoughtcrime/securesms/util/IdentityUtil.java#L129
// FREEBIE
Ensure processVerified resolves
Reduce ambiguity in between the record itself, which now stores other
information besides the public key, and its `publicKey` attribute, which
contains an ArrayBuffer of key material.
This model is internal to SignalProtocolStore.
// FREEBIE
Previously we would only clear the publicKey since that was the only attribute,
but now we should delete the entire record. This method is currently only called
from tests.
// FREEBIE
This will enforce that all identity record attributes are valid and present
before allowing the record to be saved. This is necessary since we will be
exposing a lower-level method to save an identity with explicit values for
firstUse, nonblockingApproval, and verified status.
saveIdentity is now reponsible for determining firstUse, so we must not remove
the existing key before updating it.
Previously, the implementation provided an extra check against overwritting an
existing key, but that should be done via isTrustedIdentity instead.
// FREEBIE
Bind a single listener to keychange events from the storage interface,
which then looks up relevant conversations and adds notices to them,
with tests.
Previously we would need to instantiate a conversation model in order to
start listening to its key change events. In practice this usually
happens at startup but we shouldn't rely on it, and it incurs higher
overhead since it creates a different listener for each conversation.
// FREEBIE
Previously if there was no session to remove, the promise returned from
removeSession would never resolve, potentially blocking sending for that
recipient until restart.
// FREEBIE
