Encrypted appservices can't decrypt event: decryption failed because the room key is missing

[Half-Shot]

For whatever reason, the bridge never seems to sort out it's room keys.

INFO 22:21:24:094 [Appservice] Processing event of type m.room.encrypted
WARN 22:21:24:095 [Appservice] Bot client was not able to decrypt !YFBJGTnYoiyRzBXhlm:beefy $lSrPWwC3ZtgLbF13Bi7aCpzulOQyFJsriQ470USSdi4 - trying other intents
DEBUG 22:21:24:095 [MatrixHttpClient] (REQ-123) GET http://localhost:8008/_matrix/client/r0/rooms/!YFBJGTnYoiyRzBXhlm%3Abeefy/joined_members
ERROR 22:21:24:105 [Appservice] Decryption error on !YFBJGTnYoiyRzBXhlm:beefy $lSrPWwC3ZtgLbF13Bi7aCpzulOQyFJsriQ470USSdi4 Error: Decryption failed: decryption failed because the room key is missing
    at OlmMachine.decryptRoomEvent (/home/will/git/matrix-hookshot/node_modules/@turt2live/matrix-sdk-crypto-nodejs/src/ts/OlmMachine.ts:305:37)
    at CryptoClient.<anonymous> (/home/will/git/matrix-hookshot/node_modules/matrix-bot-sdk/lib/e2ee/CryptoClient.js:157:50)
    at Generator.next (<anonymous>)
    at /home/will/git/matrix-hookshot/node_modules/matrix-bot-sdk/lib/e2ee/CryptoClient.js:17:71
    at new Promise (<anonymous>)
    at __awaiter (/home/will/git/matrix-hookshot/node_modules/matrix-bot-sdk/lib/e2ee/CryptoClient.js:13:12)
    at CryptoClient.decryptRoomEvent (/home/will/git/matrix-hookshot/node_modules/matrix-bot-sdk/lib/e2ee/CryptoClient.js:156:16)
    at CryptoClient.descriptor.value (/home/will/git/matrix-hookshot/node_modules/matrix-bot-sdk/lib/e2ee/decorators.js:33:35)
    at Appservice.<anonymous> (/home/will/git/matrix-hookshot/node_modules/matrix-bot-sdk/lib/appservice/Appservice.js:540:83)
    at Generator.next (<anonymous>)
    at fulfilled (/home/will/git/matrix-hookshot/node_modules/matrix-bot-sdk/lib/appservice/Appservice.js:5:58)
    at processTicksAndRejections (node:internal/process/task_queues:96:5) {
  code: 'GenericFailure'
}

The appservice is configured to use crypto: https://github.com/matrix-org/matrix-hookshot/blob/ac761ba771fa4016882a1fc471f6eb0c20d8d661/src/appservice.ts#L5-L29

(have checked that the storage backend is indeed working)

The registration file has:

de.sorunome.msc2409.push_ephemeral: true
org.matrix.msc3202: true

Synapse has:

experimental_features:
  msc3202_device_masquerading: true
  msc3202_transaction_extensions: true
  msc2409_to_device_messages_enabled: true

[turt2live]

is it possible that the room key was sent before synapse's support was enabled?

[Half-Shot]

Definitely not in this case. I created fresh rooms and accounts after enabling support.

[turt2live]

I think this might be caused by the crypto stack assuming client.on(...) will work, but it won't. Will need to figure this out.

[turt2live]

Blocked on #236