Element-R: Exceptions when setting up backup/cross-signing/etc on existing account with no 4S

[richvdh]

STR:

1. Create a new account outside Element Web (eg, via another client which doesn't automatically configure secret-storage, or via API)
2. Log in on ER
3. Settings -> Security & Privacy -> Set up backup
4. Enter recovery passphrase, continue

In logs:

11:38:42.322
Uncaught (in promise) Error: No keys specified and no default key present
    store secret-storage.ts:498
    exportCrossSigningKeysToStorage CrossSigningIdentity.ts:145
    bootstrapCrossSigning CrossSigningIdentity.ts:72
    bootstrapCrossSigning rust-crypto.ts:624
    CreateSecretStorageDialog CreateSecretStorageDialog.tsx:383
    CreateSecretStorageDialog CreateSecretStorageDialog.tsx:459
    React 14
    unstable_runWithPriority scheduler.development.js:468
    React 4
[secret-storage.ts:498:22](webpack:///matrix-js-sdk/src/secret-storage.ts)
11:38:42.322
Uncaught (in promise) Error: No keys specified and no default key present
    store secret-storage.ts:498
    exportCrossSigningKeysToStorage CrossSigningIdentity.ts:150
    bootstrapCrossSigning CrossSigningIdentity.ts:72
    bootstrapCrossSigning rust-crypto.ts:624
    CreateSecretStorageDialog CreateSecretStorageDialog.tsx:383
    CreateSecretStorageDialog CreateSecretStorageDialog.tsx:459
    React 14
    unstable_runWithPriority scheduler.development.js:468
    React 4
[secret-storage.ts:498:22](webpack:///matrix-js-sdk/src/secret-storage.ts)
11:38:42.322
Uncaught (in promise) Error: No keys specified and no default key present
    store secret-storage.ts:498
    exportCrossSigningKeysToStorage CrossSigningIdentity.ts:155
    bootstrapCrossSigning CrossSigningIdentity.ts:72
    bootstrapCrossSigning rust-crypto.ts:624
    CreateSecretStorageDialog CreateSecretStorageDialog.tsx:383
    CreateSecretStorageDialog CreateSecretStorageDialog.tsx:459
    React 14
    unstable_runWithPriority scheduler.development.js:468
    React 4
        runWithPriority$1
        discreteUpdates$1
        discreteUpdates
        dispatchDiscreteEvent
[secret-storage.ts:498:22](webpack:///matrix-js-sdk/src/secret-storage.ts)

I think it works despite the errors, but the log spam is problematic and prevents the Cypress tests working correctly.

[richvdh]

So the problem here is that bootstrapCrossSigning is being called before bootstrapSecretStorage here and bootstrapCrossSigning doesn't handle that situation well.

(It is unclear to me why the react SDK makes the calls in that order, but since the documented API of bootstrapCrossSigning includes handling that case gracefully, we should do so.)

[richvdh]

Oh, also: bootstrapCrossSigning is actually being called twice: once at startup (from MatrixChat with this.state.view === Views.E2E_SETUP, via CreateCrossSigningDialog, because there are no published public cross-signing keys), and once when we actually try to set up key backup, from CreateSecretStorageDialog). Which explains why the js-sdk integ tests didn't find this code path