trusted_tpm1.c

/*
 * Lock a trusted key, by extending a selected PCR.
 *
 * Prevents a trusted key that is sealed to PCRs from being accessed.
 * This uses the tpm driver's extend function.
 */
static int pcrlock(const int pcrnum)
{
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
}