Element-R: wire up encryptAndSendToDevices

[richvdh]

This is used by element call, which could otherwise be an early adopter of the rustified crypto.

[richvdh]

Looks like we'll have to expose this functionality in the rust matrix-crypto-sdk as well

[richvdh]

Blocked on matrix-org/matrix-rust-sdk#1816

[richvdh]

Given that MatrixClient.encryptAndSendToDevices takes a DeviceInfo, which is part of the legacy crypto stack, we won't be able to implement this directly.

I'd suggest adding a new api encryptToDeviceMessages to CryptoApi, which takes an array of (user_id, device_id) pairs. The application can then call MatrixClient.queueToDeviceon the results.

[hughns]

I'd suggest adding a new api encryptToDeviceMessages to CryptoApi, which takes an array of (user_id, device_id) pairs. The application can then call MatrixClient.queueToDeviceon the results.

This sounds perfect 👍

[hughns]

n.b. matrix-org/matrix-rust-sdk-crypto-wasm#140 is a blocker.

[hughns]

@richvdh I have started an implementation at #4380. On the API shape, might you be able to take a look and see if this is going in the right direction?

The motivation behind leaving a MatrixClient.encryptAndSendToDevices function is that it then works nicely when using the js-sdk as a matryoshka client within the widget API.

[hughns]

Dealing with the breaking changes in matrix-sdk-crypto-wasm is now a blocker: #4396