Submission Details
Severity:
Gaz optimization: Replacing `require` statements
Summary
Currently, some of the functions in ScrvusdVerifierV2.sol and ScrvusdVerifierV1.sol use require statements for validation checks. Each require statement consumes additional gas due to the storage of revert reasons in memory. Replacing require statements with if conditions followed by revert with custom errors reduces gas usage by minimizing string memory allocation.
Vulnerability Details
For example:
function verifyPeriodByBlockHash(
bytes memory _block_header_rlp,
bytes memory _proof_rlp
) external returns (bool) {
Verifier.BlockHeader memory block_header = Verifier.parseBlockHeader(_block_header_rlp);
require(block_header.hash != bytes32(0), "Invalid blockhash"); // Replacing with `if` statement and custom error
require(
block_header.hash == IBlockHashOracle(ScrvusdVerifierV1.BLOCK_HASH_ORACLE).get_block_hash(block_header.number),
"Blockhash mismatch" // Also replacing with `if` statement followed by custom error
);
uint256 period = _extractPeriodFromProof(block_header.stateRootHash, _proof_rlp);
return IScrvusdOracleV2(SCRVUSD_ORACLE).update_profit_max_unlock_time(period, block_header.number);
}
/// @param _block_number Number of the block to use state root hash
/// @param _proof_rlp The state proof of the period
Impact
Using custom errors than require statement is more gas efficient and without requiring additional memory allocation.
Tools Used
Recommendations
Use of custom errors:
error InvalidBlockHash();
error BlockhashMismatch();
function verifyPeriodByBlockHash(
bytes memory _block_header_rlp,
bytes memory _proof_rlp
) external returns (bool) {
Verifier.BlockHeader memory block_header = Verifier.parseBlockHeader(_block_header_rlp);
if (block_header.hash == bytes32(0)) {
revert InvalidBlockHash(); // gas efficient
}
if (block_header.hash != IBlockHashOracle(ScrvusdVerifierV1.BLOCK_HASH_ORACLE).get_block_hash(block_header.number)) {
revert BlockhashMismatch(); // gas efficient
}
uint256 period = _extractPeriodFromProof(block_header.stateRootHash, _proof_rlp);
return IScrvusdOracleV2(SCRVUSD_ORACLE).update_profit_max_unlock_time(period, block_header.number);
}
Prize pool breakdown
Total prize
14,723 OP
Eagles
1,472 OP
nSLOC
39437 OP / LOC
12,700
551
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