david-iov / rif-relay

Meta-transaction support for RSKJ

RIF Enveloping - V2

A secure transaction relay system to enable users to pay fees using ERC-20 tokens.

Description

RIF Enveloping takes its inspiration from the Gas Station Network (GSN) project. GSN is a decentralized system that improves dApp usability without sacrificing security. In a nutshell, GSN abstracts away gas (used to pay transaction fees) to minimize onboarding and UX friction for dApps. With GSN, "gasless clients" can interact with smart contracts paying for gas with tokens instead of native-currency.

RIF Enveloping V1 started as a fork of GSN with two goals in mind:

• Be compatible with existing and future smart contracts without requiring such contracts to be adapted to work with RIF Enveloping.
• Be as cost effective as possible.

RIF Enveloping V2 is a redesign of GSN, it reduces gas costs and simplifies the interaction between the different contracts that are part of the system. It achieves this by:

• Securely deploying counterfactual Smart Wallet proxies for each user account: this eliminates the need for relying on _msgSender() and _msgData() functions, making existing and future contracts compatible with RIF Enveloping without any modification.
• Allowing relayers to receive tokens in a worker address under their control and decide what to do with funds later on.
• Reducing gas costs by optimizing the GSN architecture.

Our main objective is to provide the RSK ecosystem with the means to enable blockchain applications and end-users (wallet-apps) to pay for transaction fees using tokens (e.g. RIF tokens), and thereby remove the need to acquire RBTC in advance.

It is important to recall that - as a security measure - the version 1 contracts deployed on Mainnet have limits on the staked amounts to operate, these limits were removed in version 2.

Technical Documentation

The following technical content is available:

• Architecture docs/enveloping_architecture
• Installing requirements docs/basic_requirements
• Launching RIF Enveloping docs/launching_enveloping
• Development guide docs/development_guide
• Integration guide docs/integration_guide
• Gas costs docs/overhead_tx_costs

Testnet Contracts - V2

Primary contracts

Contract	Address
Penalizer	0x5FdeE07Fa5Fed81bd82e3C067e322B44589362d9
RelayHub	0xe90592939fE8bb6017A8a533264a5894B41aF7d5
SmartWallet	0x27646c85F9Ad255989797DB0d99bC4a9DF2EdA68
SmartWalletFactory	0xEbb8AA43CA09fD39FC712eb57F47A9534F251996
DeployVerifier	0x345799D90aF318fd2d8CbA87cAD4894feF2f3518
RelayVerifier	0xDe988dB9a901C29A9f04050eB7ab08f71868a8fc

For CustomSmartWallet support

Contract	Address
CustomSmartWallet	0xB8dB52615B1a94a03C2251fD417cA4d945484530
CustomSmartWalletFactory	0xA756bD95D8647be254de40B842297c945D8bB9a5
CustomSmartWalletDeployVerifier	0x3c26685CE3ac89F755D68A81175655b4bBE54AE0
CustomSmartWalletRelayVerifier	0xBcCA9B8faA9cee911849bFF83B869d230f83f945

For Testing purposes

Contract	Address
SampleRecipient	0x4De3eB249409e8E40a99e3264a379BCfa10634F5
TestToken	0x77740cE4d7897430E74D5E06540A9Eac2C2Dee70

Changelog

V2

• RelayHub contract doesn't receive payments, the payment for the service (in tokens) is sent directly to the worker relaying the transaction on behalf of the user.
• RelayHub contract now handles relay manager staking.
• Gas estimation improvements:
  • GasOverhead removed from RelayHub, there are no more validations against hardcoded values
  • Now the gas and tokenGas fields from the request can be left undefined, and in that case they will be automatically estimated by the RelayClient.
  • The maximum gas estimation in the RelayServer is more precise now
  • A new utility function is available to estimate the maximum gas a relay transaction would consume, based in a linear fit estimation. This can be used in applications that don't want to sign a payload each time they need an approximation of the cost of relaying the transaction
• Paymaster verifications are done off-chain to optimize gas costs, thus the paymasters are now called Verifiers and they are not part of the on-chain relay flow nor they handle payments at all.
• Big gas cost optimization.
• Security issues fixed.