WebR full support for dehydrated device v2

element-hq / element-meta

Shared/meta documentation and project artefacts for Element clients

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WebR full support for dehydrated device v2 #2278

Closed pmaier1 closed 2 months ago

pmaier1 commented 5 months ago

### Tasks
- [x] wasm bindings
- [x] create and rehydrate device in js-sdk
- [x] create and rehydrate device in react-sk
- [x] add `dehydrated` flag in Rust
- [x] don't show dehydrated devices as normal devices
- [x] periodically recreate dehydrated device
- [ ] update MSC

BillCarsonFr commented 4 months ago

Adding the dehydrated flag on the device keys payload will break SQL lite store https://github.com/matrix-org/matrix-rust-sdk/issues/3132

=> We have to release EAR and EIR with a new sdk version before starting creating web dehydrated device

uhoreg commented 3 months ago

Current status:

dehydration only enabled by setting well-known (or if dehydration key is in SSSS)
dehydrated device is displayed differently in device lists (if the user only has one device marked as dehydrated) -- as a localizable string in device list, and hidden in session manager but shown as an enabled feature in encryption settings
only enabled when unlocking SSSS by passphrase/key (not enabled when verifying with another device)
creates new dehydrated device once a week, but only if Element is not restarted/reloaded (dehydration key only stored in memory)

Work for future phases

persist dehydration key, so that dehydrated devices can be recreated even after restarts
add UI to enable dehydration (don't require enabling in well-known)
gossip dehydration key?
look into possibility of not encrypting to dehydrated device if recipient has enough other devices available

uhoreg commented 3 months ago

Relevant PRs:

https://github.com/matrix-org/matrix-rust-sdk/pull/3164 ETA Mar 18
https://github.com/matrix-org/matrix-rust-sdk-crypto-wasm/pull/104 ETA Mar 19
https://github.com/matrix-org/matrix-js-sdk/pull/4062 ETA Mar 21
https://github.com/matrix-org/matrix-react-sdk/pull/12316 ETA Mar 25

uhoreg commented 3 months ago

Screenshots:

Dehydrated device is removed from list of devices in Sessions tab.

Presence of dehydrated device is indicated in Security & Privacy tab (called "Offline device" for now)

In user info sidebar, dehydrated device is shown as "Offline device" (maybe we want to add some help text somehow?)

pmaier1 commented 3 months ago

Thanks! I think we can find a better design for this but it's good enough for now. We should think about improvements once we plan delabsing it.

uhoreg commented 2 months ago

I've documented what's left to be done for phase 2 at https://github.com/element-hq/element-web/issues/27336