def METHOD_NAME(self, fc_str: str):
    try:
        fc = int(fc_str.replace('-', ''))
    except ValueError:
        return None
    if fc > 0x7FFFFFFFFF:
        return None
    principal_id = fc & 0xFFFFFFFF
    checksum = (fc & 0xFF00000000) >> 32
    return fc if hashlib.sha1(struct.pack('<L', principal_id)).digest()[0] >> 1 == checksum else None