Fix RustCrypto.resetEncryption failure

[florianduros]

Regression due to #4742

When RustCrypto.resetEncryption is called, CrossSigningIdentity.resetCrossSigning raises this error:

Uncaught (in promise) Error: No keys specified and no default key present
    store secret-storage.ts:525
    exportCrossSigningKeysToStorage CrossSigningIdentity.ts:184
    resetCrossSigning CrossSigningIdentity.ts:154
    bootstrapCrossSigning CrossSigningIdentity.ts:46
    resetEncryption rust-crypto.ts:1473
    onClick ResetIdentityPanel.tsx:92
    React 23
    getOrCreateStaticRoot Modal.tsx:109
    reRender Modal.tsx:415
    createDialog Modal.tsx:316
    MatrixChat MatrixChat.tsx:781
    invokeCallback dispatcher.ts:115
secret-storage.ts:525:22

The 4S is not completely deleted and we try to export keys that has been deleted. Due to of missing await on this.deleteSecretStorage() in

matrix-js-sdk/src/rust-crypto/rust-crypto.ts

Lines 1458 to 1480 in 3657eb6

	public async resetEncryption(authUploadDeviceSigningKeys: UIAuthCallback<void>): Promise<void> {
	this.logger.debug("resetEncryption: resetting encryption");
	// Delete the dehydrated device, since any existing one will be signed
	// by the wrong cross-signing key
	this.dehydratedDeviceManager.delete();
	// Disable backup, and delete all the backups from the server
	await this.backupManager.deleteAllKeyBackupVersions();
	this.deleteSecretStorage();
	// Reset the cross-signing keys
	await this.crossSigningIdentity.bootstrapCrossSigning({
	setupNewCrossSigning: true,
	authUploadDeviceSigningKeys,
	});
	// Create a new key backup
	await this.resetKeyBackup();
	this.logger.debug("resetEncryption: ended");
	}

The secretStorage object is mocked in the test, the mock making it synchronous so the test didn't catch the race.

[andybalaam]

Good catch, one request 👍

[andybalaam]

Can you update the test so this would be caught by it please?

[florianduros]

This is difficult because we are using a mocked SecretStorage which is way faster than the real execution. Meaning that even by adding jest.fn().mockResolvedValue(undefined) to store or setDefaultKeyId, the test passes. Also I don't think that adding manual latency is a good thing neither.

[andybalaam]

OK, I'd prefer the change to mockResolvedValue for async methods, even if it doesn't make the test fail. Personally I would add a small delay that makes the test fail but I definitely won't insist on that.

I'll tick the PR and you can use your judgement. Thank you!

[richvdh]

@florianduros: Why do we need to do this.deleteSecretStorage() and await this.deleteSecretStorage(); ?

[florianduros]

Oh, an error during the rebase. Good spot, I'll fix it tomorrow

[florianduros]

Removed in #4789