WFIL

Wrapped Filecoin, ERC20 Wrapper over Filecoin

WFIL is the first ERC20 wrapper over Filecoin backed by Filecoin deposits on a custodian wallet (1:1 ratio).

WFIL is implemented using OpenZeppelin ERC20 module and controlled by a Factory contract, set as minter by a DAO multisig contract (Gnosis Safe), to allow merchants and custodians to add mint/burn requests via ad-hoc APIs that interact with OpenZeppelin Defender Relay.

Merchants and Custodians are approved by DAO members via Multisignatures.

Future Developments & Features:

We plan to develop a non-custodian version where by leveraging Filecoin smart contracts we'd be able to implement a fully decentralized application.

Applications:

• Lending Platforms (MakerDAO, Compound, Aave)
• Liquidity Pools (Curve, Balancer)
• Uniswap
• De-Fi
• Access to Filecoin Storage Deals to Ethereum Users
• ...

Sections

• Building Blocks
• Setup
• Audit
• About

Building Blocks

WFIL

Implements an ERC20 token by leveraging on OpenZeppelin Library.

It allows the owner of the contract, a multisig contract (Gnosis Safe) to add/remeove a Minter (Factory contract) via addMinter, removeMinter functions by leveraging on AccessControl module by OpenZeppelin.

The contract implements the wrap function to mint WFIL by passing the recepient address and the amount of Filecoin to wrap as parameters and emitting an event, Wrapped.

The contract also implements the unwrapFrom function to allow the Factory contract to burn the WFIL by passing the holder address and the amount of WFIL to burn as parameters and emitting an event, Unwrapped. In order to mitigate Allowance Double-Spend Exploit we recommend merchants to use increaseAllowance and decreaseAllowance functions.

The contract inherits OpenZeppelin AccessControl module to set the Pauser role to the owner of the contract that can call the pause, unpause functions in case of emergency (Circuit Breaker Design Pattern).

Once the owner call the pause function, thanks to the _beforeTokenTransfer() hook, _mint(), _burn() and _transfer() internal functions, will revert.
To avoid users from sending WFIL to the contract address, _beforeTokenTransfer() checks the recipient address to make sure it does not correspond to the contract address, and revert if it does on _mint and _transfer functions.

A Gnosis Safe Multisig is set as owner during deployment (dao_) to allow DAO members to grant the Minter Role to the Factory contract and future versions.

Setup

Clone this GitHub repository.

Steps to compile and test

• Local dependencies:
  • Truffle
  • Ganache CLI
  • OpenZeppelin Contracts v3.1.0
  • Truffle HD Wallet Provider
  • Truffle-Flattener
  • Truffle-Plugin-Verify
  • Solhint

  $ npm i

• Global dependencies:
  • Truffle (recommended):

  $ npm install -g truffle

  • Ganache CLI (recommended):

  $ npm install -g ganache-cli

  • Slither (optional):

  $ git clone https://github.com/crytic/slither.git && cd slither
  $ sudo python3 setup.py install

  • MythX CLI (optional):

  $ git clone git://github.com/dmuhs/mythx-cli && cd mythx-cli
  $ sudo python setup.py install

Running the project with local test network (ganache-cli)

• Start ganache-cli with the following command (global dependency):

  $ ganache-cli

• Compile the smart contract using Truffle with the following command (global dependency):

  $ truffle compile

• Deploy the smart contracts using Truffle & Ganache with the following command (global dependency):

  $ truffle migrate

• Test the smart contracts using Mocha & OpenZeppelin Test Environment with the following command:

  $ npm test

• Analyze the smart contracts using Slither with the following command (optional):

  $ slither .

• Analyze the smart contracts using MythX CLI with the following command (optional):

  $ mythx analyze

Development deployment

WFIL 0.7.0 (Rinkeby): 0xf33b9e9cc559329e25ca76e338e21e8e24e14c24

Current Mainnet Contracts (3/12/2020)

• WFIL DAO: 0x44443407e196298a0aD68207Aa93eA919df53961
• WFIL: 0xd187C6C8C6aeE0F021F92cB02887A21D529e26cb

Audit

• Quantstamp

About

Inspiration & References

Authors

Project created by Nazzareno Massari and Cristiam Da Silva.
Logo by Cristiam Da Silva.