nicjes

function crc16(crc, buffer) {
    for (let byte of buffer) {
        crc ^= BigInt(byte) << BigInt(8);
        for (let i = 0; i < 8; i++) {
            if (crc & BigInt(0x8000)) {
                crc = (crc << BigInt(1)) ^ BigInt(0x1021);
            } else {
                crc <<= BigInt(1);
            }
            crc &= BigInt(0xFFFF);