Biconomy Hyphen 2.0 contest - Tomio's results

1. The default of uint is already 0

Proof of Concept: https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityFarming.sol#L144 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityFarming.sol#L158 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityFarming.sol#L233 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityFarming.sol#L266 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/WhitelistPeriodManager.sol#L247

Recommended Mitigation Steps: considered remove 0 value can save gas

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2. Avoiding external call can save gas

Proof of Concept: https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityPool.sol#L354

Recommended Mitigation Steps: Change to:

if (denominator != 0) {
            fee = numerator / denominator;
        }
    }

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3. != 0 is a cheaper operation compared to > 0, when dealing with uint

Proof of Concept: https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityFarming.sol#L132 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityFarming.sol#L318 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityProviders.sol#L182 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityProviders.sol#L182 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityProviders.sol#L283 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityProviders.sol#L410

Recommended Mitigation Steps: Replace with: ! =

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4. 10 ** 18 can be changed to 1e18 and save some gas

Proof of Concept: https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityProviders.sol#L27

Recommended Mitigation Steps:

uint256 public constant BASE_DIVISOR = 1e18;

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5. more efficient gas usage by removing && operator

Proof of Concept: https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityPool.sol#L156 https://github.com/code-423n4/2022-03-biconomy/blob/main/contracts/hyphen/LiquidityPool.sol#L247

Recommended Mitigation Steps: Example:

require( tokenManager.getDepositConfig(toChainId, tokenAddress).min <= amount,"Deposit amount not in Cap limit");
require( tokenManager.getDepositConfig(toChainId, tokenAddress).max >= amount, "Deposit amount not in Cap limit");
``

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