Allow simulating unsigned transactions

[kristovatlas]

Description

We have a UX challenge currently in which a user must sign a transaction using a key with funds in order to estimate gas for the transaction.

The proposed solution from today's Contributor call was to modify gnokey logic as follows:

• If the user signed -> verify with their address / sig
• If the user didn't sign -> use real simulate mode, no real verifications

[kristovatlas]

@zivkovicmilos

[kristovatlas]

@jefft0

[moul]

Is that really what we said? I think we said we just want to expect a valid signature, nope?

[jefft0]

Is that really what we said? I think we said we just want to expect a valid signature, nope?

I thought we said that the Signature should have the correct PubKey (to simulate as the correct user) but that the signature bytes won't be checked.

[jefft0]

Good news. It's already the case that the GnoVM only verifies the transaction signature if not simulating. To estimate gas, the transaction only needs the public key, not the signature bytes. No need to get permission unlock the private key and sign. We did a PR to take advantage of this in Gno Native Kit (used by Gnokey Mobile).

If this makes sense, I think we can close this issue as resolved.

[zivkovicmilos]

@jefft0
Let's keep this issue open 🙏

This is not really the UX we want, or expect.

The ideal flow is, when simulating:

• user signed a transaction -> use the signature and the user's account (for funds)
• user didn't sign a transaction -> consider execution is funded, skip signature verification