static const knot_dname_t *signature_authority(knot_pkt_t *pkt)
{
for (knot_section_t i = KNOT_ANSWER; i <= KNOT_AUTHORITY; ++i) {
const knot_pktsection_t *sec = knot_pkt_section(pkt, i);
for (unsigned k = 0; k < sec->count; ++k) {
const knot_rrset_t *rr = knot_pkt_rr(sec, k);
if (rr->type == KNOT_RRTYPE_RRSIG) {
return knot_rrsig_signer_name(&rr->rrs, 0);
}
}
}
return NULL;
}
/**
* Check the RRSIG RR validity according to RFC4035 5.3.1 .
* @param flags The flags are going to be set according to validation result.
* @param cov_labels Covered RRSet owner label count.
* @param rrsigs RRSet containing the signatures.
* @param sig_pos Specifies the signature within the RRSIG RRSet.
* @param keys Associated DNSKEY RRSet.
* @param key_pos Specifies the key within the DNSKEY RRSet,
* @param keytag Used key tag.
* @param zone_name The name of the zone cut.
* @param timestamp Validation time.
*/
static int validate_rrsig_rr(int *flags, int cov_labels,
const knot_rrset_t *rrsigs, size_t sig_pos,
const knot_rrset_t *keys, size_t key_pos, uint16_t keytag,
const knot_dname_t *zone_name, uint32_t timestamp)
{
if (!flags || !rrsigs || !keys || !zone_name) {
return kr_error(EINVAL);
}
/* bullet 5 */
if (knot_rrsig_sig_expiration(&rrsigs->rrs, sig_pos) < timestamp) {
return kr_error(EINVAL);
}
/* bullet 6 */
if (knot_rrsig_sig_inception(&rrsigs->rrs, sig_pos) > timestamp) {
return kr_error(EINVAL);
}
/* bullet 2 */
const knot_dname_t *signer_name = knot_rrsig_signer_name(&rrsigs->rrs, sig_pos);
if (!signer_name || !knot_dname_is_equal(signer_name, zone_name)) {
return kr_error(EINVAL);
}
/* bullet 4 */
{
int rrsig_labels = knot_rrsig_labels(&rrsigs->rrs, sig_pos);
if (rrsig_labels > cov_labels) {
return kr_error(EINVAL);
}
if (rrsig_labels < cov_labels) {
*flags |= FLG_WILDCARD_EXPANSION;
}
}
/* bullet 7 */
if ((!knot_dname_is_equal(keys->owner, signer_name)) ||
(knot_dnskey_alg(&keys->rrs, key_pos) != knot_rrsig_algorithm(&rrsigs->rrs, sig_pos)) ||
(keytag != knot_rrsig_key_tag(&rrsigs->rrs, sig_pos))) {
return kr_error(EINVAL);
}
/* bullet 8 */
/* Checked somewhere else. */
/* bullet 9 and 10 */
/* One of the requirements should be always fulfilled. */
return kr_ok();
}