chrp_checksum
header->chrp_header.chrp_checksum = chrp_checksum(header->chrp_header.signature,
if (header->chrp_header.chrp_checksum !=
chrp_checksum(header->chrp_header.signature,
static int chrp_checksum(int sum, uint8_t *, uint8_t *);
uint8_t chrp_checksum;