hardhat/src/internal/util/keccak.ts

Hardhat is an extensible developer tool that helps smart contract developers increase productivity by reliably bringing together the tools they want.

import createKeccakHash from "keccak";

export function keccak256(data: Uint8Array): Uint8Array {
  return createKeccakHash("keccak256").update(Buffer.from(data)).digest();
}