[B46-01C] Significantly Outdated Base64 Implementation

[chasebrownn]

B46-01C: Significantly Outdated Base64 Implementation

Type	Severity	Location
Gas Optimization		Base64.sol:L12-L71

Description:

The Base64 implementation ported to the codebase represents a significantly outdated variant of the same library that OpenZeppelin contains.

Example:

/// @notice Encodes some bytes to the base64 representation
function encode(bytes memory data) internal pure returns (string memory) {
    uint256 len = data.length;
    if (len == 0) return "";

    // multiply by 4/3 rounded up
    uint256 encodedLen = 4 * ((len + 2) / 3);

    // Add some extra buffer at the end
    bytes memory result = new bytes(encodedLen + 32);

    bytes memory table = TABLE;

    assembly {
        let tablePtr := add(table, 1)
        let resultPtr := add(result, 32)

        for {
            let i := 0
        } lt(i, len) {

        } {
            i := add(i, 3)
            let input := and(mload(add(data, i)), 0xffffff)

            let out := mload(add(tablePtr, and(shr(18, input), 0x3F)))
            out := shl(8, out)
            out := add(
                out,
                and(mload(add(tablePtr, and(shr(12, input), 0x3F))), 0xFF)
            )
            out := shl(8, out)
            out := add(
                out,
                and(mload(add(tablePtr, and(shr(6, input), 0x3F))), 0xFF)
            )
            out := shl(8, out)
            out := add(
                out,
                and(mload(add(tablePtr, and(input, 0x3F))), 0xFF)
            )
            out := shl(224, out)

            mstore(resultPtr, out)

            resultPtr := add(resultPtr, 4)
        }

        switch mod(len, 3)
        case 1 {
            mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
        }
        case 2 {
            mstore(sub(resultPtr, 1), shl(248, 0x3d))
        }

        mstore(result, encodedLen)
    }

    return string(result);
}

Recommendation:

We advise the v5.0.0 OpenZeppelin variant to be ported to the codebase or directly utilized, optimizing the code's gas cost significantly.

[chasebrownn]

Only passiveIncomeNFT uses this. So not a relevant finding