This adds a first chunk of bootstrapping Secure Secret Storage by creating
cross-signing keys and supporting interactive auth to upload them.
Part of https://github.com/vector-im/riot-web/issues/11212
We can't mark a cross-signing key as blocked/unblocked, known/unknown
or unverified, so throw an exception instead of doing nothing.
Also comment what's going on in this function.
Use options.cryptoCallbacks for things that require information
from the app rather than events, since events can have zero, one
or many listeners and the emitter doesn't know how many, so if
nobody's listening then we would have just waited forever for a
response.
Also a collection of other changes like renaming 'fu' to 'firstUse'
For https://github.com/vector-im/riot-web/issues/10263
Starting/scheduling the backup won't help us because the token would be invalid from a server perspective. Instead, we should update what needs to be done and return a count.
Fixes https://github.com/vector-im/riot-web/issues/10083
Fixes https://github.com/vector-im/riot-web/issues/9197
Fixes https://github.com/vector-im/riot-web/issues/8629
The issue is partially fixed by https://github.com/matrix-org/matrix-react-sdk/pull/3123 in that users would no longer see "Incoming request", but would launch their client to a bunch of "key verification cancelled" dialogs. To work around this, we just don't handle key verification requests which we know are cancelled.
The changes are a bit awkward (flagging the event as cancelled instead of filtering it) because:
* We probably don't want to prevent events getting sent over the EventEmitter because applications may still rely on them.
* The cypto side only has visibility of 1 event at a time, so it needs to have some kind of flag to rely on.
An attempt has been made to generalize the new event flag for possible future cases.
- fix requestVerification in MatrixClient to match the function in crypto
- reorder the arguments so that the arguments actually do what they say they
do
- pass through the third argument, which was accidentally omitted
- ignore verification requests from ourselves
- also fix a comment
