Shared wallet Solidity smart contract

Phemex Trading

Build a shared wallet Solidity smart contract. The owner of this contract can add and remove other owners and temporarily disable owners. Anyone can deposit ETH into the contract however to withdraw ETH more then one owner needs to approve the transaction.

Experiment with the contract below to learn the basics of mappings, function modifiers and events. Try to add or enhance the smart contract code. Deploy it to the test network using Remix. Keep in mind:

  • Saving a state variable to the blockchain uses gas
  • Viewing state variables from the blockchain does not use gas

pragma solidity ^0.5.17;

 
contract sharedWallet {

    address private _owner;

    //create a mapping so other addresses can interact with this wallet.  Uint8 is used to determine is the address enabled of disabled
    mapping(address => uint8) private _owners;

    //in order to interact with the wallet you need to be the owner so added a require statement then execute the function _;
    modifier isOwner() {
        require(msg.sender == _owner);
        _;
    }

    
    //Require the msg.sender/the owner OR || Or an owner with a 1 which means enabled owner
    modifier validOwner() {
        require(msg.sender == _owner || _owners[msg.sender] == 1);
        _;
    }

    
    event DepositFunds(address from, uint amount);
    event WithdrawFunds(address from, uint amount);
    event TransferFunds(address from, address to, uint amount);


    //the creator is the owner of the wallet
    constructor() 
        public {
        _owner = msg.sender;
    }

    
    //this function is used to add owners of the wallet.  Only the isOwner can add addresses.  1 means enabled
    function addOwner(address owner) 
        isOwner 
        public {
        _owners[owner] = 1;
    }

    
    //remove an owner from the wallet.  0 means disabled
    function removeOwner(address owner)
        isOwner
        public {
        _owners[owner] = 0;   
    }

    
    //Anyone can deposit funds into the wallet and emit an event called depositfunds
    function ()
        external
        payable {
        emit DepositFunds(msg.sender, msg.value);
    }

    
    //to withdraw you need to be an owner, the amount needs to be >= balance of acct.  then transfer and emit an event
    function withdraw (uint amount)
        validOwner
        public {
        require(address(this).balance >= amount);
        msg.sender.transfer(amount);
        emit WithdrawFunds(msg.sender, amount);
    }

    
    function transferTo(address payable to, uint amount) 
        validOwner
        public {
        require(address(this).balance >= amount);
        to.transfer(amount);
        emit TransferFunds(msg.sender, to, amount);
    }
}

Try it in Remix

A shared wallet Solidity smart contract is not a multi signature wallet Solidity smart contract. Click here to learn more about multi signature wallets.

This code is for learning and entertainment purposes only. The code has not been audited. Use at your own risk. Remember smart contracts are experimental and could contain bugs.

Click here for more information about how to use the Ethereum test network and how to obtain test ETH.

Next Review – Create a trustless token swap smart contract in Solidity

Ledger Nano X - The secure hardware wallet

Leave a Reply