Implement AA mechanism in core

[b1m0n]

Introduction

We are heading to implement a more generic and flexible account abstraction scheme. Accounts in U2U will be able to initiate transactions, like an EOA, but can also have arbitrary logic implemented in them, like a smart contract. The simple AA implementation at PR #64 and #66 is kinda simple, subjects to be spammed because this implementation doesn't have a selective mechanism for paying gas. The arbitrarity in AA logic and other DoS protection can be achieve via this new transaction type and how we treat the execution/gas estimation flow.

References:

• https://docs.zksync.io/build/developer-reference/account-abstraction.html
• https://github.com/matter-labs/zksync-era/blob/main/docs/specs/zk_evm/account_abstraction.md

Checklist

• Define a new transaction type EIP712TxType = 0x71 to implement Transaction interface: Define a new transaction type EIP712TxType = 0x71 to implement Transaction interface #91
• TransactionHelper, IAccount, IPaymaster smart contract interfaces and simple implementations for testing purposes: Implement the paymaster flow #94
• Implement the paymaster flow first to serve AA gas sponsoring in the future: Implement the paymaster flow #94
• Apply the EIP712TxType execution and gas estimation flow
  • Account versioning to allow breaking changes in the future
  • Nonce ordering to signal to the operator which nonce ordering it should expect
  • Extending EIP-4337 to provide DoS protection for the operator by imposing several restrictions on the validation step of the account
• Documentation

[khoau2u]

• Implement the alternative account flow