"Unable to restore session" on 2024040401 nightly

[clokep]

Steps to reproduce

I restarted to update to today's nightly and am greeted with a page saying "Unable to restore session".

I've sent a rageshake already, although was unable to actually click on either of the buttons and had to use the keyboard.

Outcome

I was expecting a usable application. 😄

Operating system

macOS

Application version

2024040401 nightly

How did you install the app?

Unsure

Homeserver

matrix.org

Will you send logs?

Yes

[clokep]

Maybe fallout from enabling Rust crypto? #1518? It somewhat sounds like element-hq/element-web#27196 but I'm connected to the Internet and my homeserver is up.

[t3chguy]

Will you send logs?
Yes

Not seeing any logs from you @clokep

[richvdh]

@t3chguy I linked this issue from the rageshakes; you should see the reverse links above.

[t3chguy]

Ah yes, thanks, my browser was showing me a stale view as I had opened this tab 4 days ago

[BillCarsonFr]

It's different than element-hq/element-web#27196

Something with getAndDecryptCachedSecretKey

024-04-04T13:25:29.211Z E Unable to load session The first argument must be one of type string, Buffer, ArrayBuffer, Array, or Array-like Object. Received type undefined
TypeError: The first argument must be one of type string, Buffer, ArrayBuffer, Array, or Array-like Object. Received type undefined
    at from (vector://vector/webapp/bundles/1d2e934471ebcb41f3e7/bundle.js:295302:11)
    at Buffer.from (vector://vector/webapp/bundles/1d2e934471ebcb41f3e7/bundle.js:295353:10)
    at decodeBase64 (vector://vector/webapp/bundles/1d2e934471ebcb41f3e7/bundle.js:108039:19)
    at decryptAES (vector://vector/webapp/bundles/1d2e934471ebcb41f3e7/bundle.js:119820:85)
    at async getAndDecryptCachedSecretKey (vector://vector/webapp/bundles/1d2e934471ebcb41f3e7/865.js:4549:44)
    at async migrateBaseData (vector://vector/webapp/bundles/1d2e934471ebcb41f3e7/865.js:4395:53)
    ```

[clokep]

Please reach out if there's anything I can do to help debug!

[andybalaam]

We are treating this as a blocker for rolling out further migration to Rust crypto.

[BillCarsonFr]

After investigation, the secret stored in this session are mixed encrypted / not encrypted.
I.e ssss_cache:megolm_backup.v1 is in the form {ciphertext, iv, mac}
But ssss_cache:self_signing is a row UInt8Array

So libolm_migration#getAndDecryptCachedSecretKey is failing to get a key not encrypted and will error because ciphertext is undefined.
The CrossSigning.ts code support retrieving both encrypted or not encrypted

[clokep]

Just to confirm matrix-org/matrix-js-sdk#4168 did fix this issue for me. 🎉 Thanks!