Add message signing and verifying

[brusherru]

It closes #85.

• adds "Sign message" button next to the every local key in the "Manage Keys & Accounts" pane,
• adds "Verify message" button in the settings dropdown.

This PR does not add support of signing messages by Ledger devices, because it requires some tweaks on Ledger App side.

Note for third-party developers:

Signature for the message calculated with a hard-coded prefix Message: which is encoded as Uint8Array [77, 101, 115, 115, 97, 103, 101, 58] to avoid possible vector of attack. So the verify function should add this prefix to the message to be able to validate correct signature.

Example:

// Message: "Hello, world"
// Signed message: "Message:Hellow, world"
// Signature length is 64 bytes

const te = new TextEncoder();
ed25519.verify(signature, te.encode("Hello, world"), pubKey) // invalid
ed25519.verify(signature, te.encode("Message:Hello, world"), pubKey) // valid

[github-actions]

You can preview the changes at : https://fb880be8.smapp-lite-prod.pages.dev

[monikasmolarek]

In general OK but the error/success msgs should be fixed.

The success message once appears, stays sticked forever.

Screen.Recording.2024-09-24.at.14.06.20.mov

In the end of the recording I tried to put different kinds of incorrect signature content and the button [Verify] seemed like doing nothing/not working at all. Checked again with a new obviously incorrect input, and the button doesn’t respond with "check ->throw error", acts as if there was no onClick implemented.

[monikasmolarek]

noticed the typo

[github-actions]

You can preview the changes at : https://43e9f596.smapp-lite-prod.pages.dev

[monikasmolarek]

👌

[github-actions]

You can preview the changes at : https://132177e9.smapp-lite-prod.pages.dev

[github-actions]

You can preview the changes at : https://077f1ca5.smapp-lite-prod.pages.dev