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SmartWalletChecker

The SmartWalletChecker is an external contract that checks if certain smart contracts are approved to lock CRV tokens into the VotingEscrow. Permission can be granted via the approveWallet and revoked via revokeWallet methods.

Contract Source & Deployment

SmartWalletChecker contract is deployed to the Ethereum mainnet at: 0xca719728Ef172d0961768581fdF35CB116e0B7a4.

This contract can be replaced in its entirety with a new SmartWalletChecker through the VotingEscrow's commit_smart_wallet_checker function.

Once this happens, the previously approved smart contracts will not be able to create a new lock, extend the lock duration, or add more CRV to the already existing lock if the new SmartWalletChecker does not approve them again. This is because all those methods (create_lock, increase_unlock_time, and increase_amount) check if the caller is approved via the internal assert_not_contract function.

VotingEscrow: Internal assert_not_contract function 
@internal
def assert_not_contract(addr: address):
    """
    @notice Check if the call is from a whitelisted smart contract, revert if not
    @param addr Address to be checked
    """
    if addr != tx.origin:
        checker: address = self.smart_wallet_checker
        if checker != ZERO_ADDRESS:
            if SmartWalletChecker(checker).check(addr):
                return
        raise "Smart contract depositors not allowed"

Approve/Revoke SmartContracts

approveWallet

SmartWalletChecker.approveWallet(address _wallet) public

Guarded Method

This function is only callable by the dao, which is the CurveOwnershipAdmin.

Function to approve a smart contract to lock CRV.

Emits: ApproveWallet

Input Type Description
_wallet address smart contract to approve
Source code 
event ApproveWallet(address)

function approveWallet(address _wallet) public {
    require(msg.sender == dao, "!dao");
    wallets[_wallet] = true;

    emit ApproveWallet(_wallet);
}

>>> SmartWalletChecker.approveWallet("smart contract address")

revokeWallet

SmartWalletChecker.revokeWallet(address _wallet) external

Guarded Method

This function is only callable by the dao, which is the CurveOwnershipAdmin.

Function to revoke the allowance of a smart contract to lock CRV.

Emits: RevokeWallet

Input Type Description
_wallet address smart contract to revoke
Source code 
event RevokeWallet(address)

function revokeWallet(address _wallet) external {
    require(msg.sender == dao, "!dao");
    wallets[_wallet] = false;

    emit RevokeWallet(_wallet);
}

>>> SmartWalletChecker.revokeWallet("0x52f541764E6e90eeBc5c21Ff570De0e2D63766B6")

Contract Info Methods

check

SmartWalletChecker.check(address _wallet) external view returns (bool)

Function to check if a wallet has been approved.

Returns: True or False (bool).

Input Type Description
_wallet address smart contract address
Source code 
function check(address _wallet) external view returns (bool) {
    bool _check = wallets[_wallet];
    if (_check) {
        return _check;
    } else {
        if (checker != address(0)) {
            return SmartWalletChecker(checker).check(_wallet);
        }
    }
    return false;
}

>>> SmartWalletChecker.check("0x989AEb4d175e16225E39E87d0D97A3360524AD80")
'true'

dao

SmartWalletChecker.commit_smart_wallet_checker(addr: address):

Getter for the dao of the contract. dao in this context is pretty much the admin/owner of the contract.

Returns: CurveOwnershipAgent (address).

Source code 
address public dao

constructor(address _dao) public {
    dao = _dao;
    wallets[0xF147b8125d2ef93FB6965Db97D6746952a133934] = true;
    emit ApproveWallet(0xF147b8125d2ef93FB6965Db97D6746952a133934);
}

>>> SmartWalletChecker.dao()
'0x40907540d8a6C65c637785e8f8B742ae6b0b9968'