session-key-aspect/aspect

Brief Intro

This Aspect will recover the signer address from the transaction signature (r,s,v).

Then, it verifies whether the signer is the session key of the EoA; if so, it will return the EoA address to the base layer.

The base layer retrieves the address and sets it as the sender of this transaction.

Project Layout

.
├── README.md
├── asconfig.json
├── assembly
│   ├── aspect                 <-- aspect code resides here
│   │   └── aspect.ts          <-- entry functions for the aspect
│   └── index.ts
├── test_contracts             <-- smart contracts for testing
├── tests             				 <-- test
├── scripts                    <-- utilitity scripts, including deploying, binding and etc.
│   ├── aspect-deploy.cjs
│   ├── bind.cjs
│   ├── contract-call.cjs
│   └── contract-deploy.cjs
...

Quick start

It's a node.js project, so install the dependency first.

npm install

Build the Aspect and the testing smart contract.

npm run build

Create a testing wallet.

npm run account:create

The private key will be put in the file privateKey.txt.

The wallet address will be printed in the console, copy and require testnet $ART by this faucet guide.

If you want to use your own test net wallet, you can create the file privateKey.txt and paste your private key into it. The private key format is a hex string like this 0xabcd....abcd.

Run the test!!

npm run test

The script will run the test in the folder tests; you can run the specific case like this command node tests/test_tx. js.

Implements Intro

• The function verifyTx implements the session key verification logic.
• The function operation implements the session key management logic. EoA calls this function to register, update, and delete its session keys.

Usage Testnet Session-key Aspect

Session-key Aspect address (testnet)

lastest version: 0x40a908F327B22922983061E9E6a87e785d6401BB

Requirement

The smart contract needs to bind this Aspect to enable the session key feature for its users.

If a smart contract wants to bind any Aspect, it MUST implement the isOwner(address) method. Only the owner wallet can sign the binding transaction for its smart contract.

Bind Aspect

There are two ways to bind Aspects:

• Use Aspect-tool console command
• Use artela-web3.js to call Aspect system contract

Use Aspect-tool

In this way, you can bind Aspect by console command.

Step 1: install aspect-tool

npm install @artela/aspect-tool -g

Step 2: init a empty project

mkdir empty-aspect && cd empty-aspect
aspect-tool init
npm install yargs

Step 3: use the script in this project

  npm run contract:bind -- --pkfile {smart-contract-owner-privateKey-path} --contract {smart-contract-address} --abi {smart-contract-abi-path} --aspectId '0x40a908F327B22922983061E9E6a87e785d6401BB' --gas '800000'

Learn more detailed steps in this guide.

Use artela-web3.js

In this way, you need to write js script. Follow this guide to bind your smart contract to Aspect by using web3.js in js.

Here are brief steps:

1. using your contract address and abi construct a contract object by web3.eth.contract
2. using web3.eth.contract.bind(options, callback) to send tx to bind specific Aspect

Example:

await contract.bind({
        priority: 1,             // <-- Priority of the aspect, int8 number, smaller number has higher priority. Aspect with higher priority will be executed first.
        aspectId: "0xABCD....ABCD", // <-- address of the aspect to bind with the contract, eg. 
        aspectVersion: 1,        // <-- Version of the aspect to bind with the contract
    }).send({ from: accounts[0], nonce, ...sendOptions });

Learn more detailed steps in this guide.