/** verify that a DS RR hashes to a key and that key signs the set */
static enum sec_status
verify_dnskeys_with_ds_rr(struct module_env* env, struct val_env* ve,
struct ub_packed_rrset_key* dnskey_rrset,
struct ub_packed_rrset_key* ds_rrset, size_t ds_idx, char** reason)
{
enum sec_status sec = sec_status_bogus;
size_t i, num, numchecked = 0, numhashok = 0;
num = rrset_get_count(dnskey_rrset);
for(i=0; i<num; i++) {
/* Skip DNSKEYs that don't match the basic criteria. */
if(ds_get_key_algo(ds_rrset, ds_idx)
!= dnskey_get_algo(dnskey_rrset, i)
|| dnskey_calc_keytag(dnskey_rrset, i)
!= ds_get_keytag(ds_rrset, ds_idx)) {
continue;
}
numchecked++;
verbose(VERB_ALGO, "attempt DS match algo %d keytag %d",
ds_get_key_algo(ds_rrset, ds_idx),
ds_get_keytag(ds_rrset, ds_idx));
/* Convert the candidate DNSKEY into a hash using the
* same DS hash algorithm. */
if(!ds_digest_match_dnskey(env, dnskey_rrset, i, ds_rrset,
ds_idx)) {
verbose(VERB_ALGO, "DS match attempt failed");
continue;
}
numhashok++;
verbose(VERB_ALGO, "DS match digest ok, trying signature");
/* Otherwise, we have a match! Make sure that the DNSKEY
* verifies *with this key* */
sec = dnskey_verify_rrset(env, ve, dnskey_rrset,
dnskey_rrset, i, reason);
if(sec == sec_status_secure) {
return sec;
}
/* If it didn't validate with the DNSKEY, try the next one! */
}
if(numchecked == 0)
algo_needs_reason(env, ds_get_key_algo(ds_rrset, ds_idx),
reason, "no keys have a DS");
else if(numhashok == 0)
*reason = "DS hash mismatches key";
else if(!*reason)
*reason = "keyset not secured by DNSKEY that matches DS";
return sec_status_bogus;
}
size_t
anchor_list_keytags(struct trust_anchor* ta, uint16_t* list, size_t num)
{
size_t i, ret = 0;
if(ta->numDS == 0 && ta->numDNSKEY == 0)
return 0; /* insecure point */
if(ta->numDS != 0 && ta->ds_rrset) {
struct packed_rrset_data* d=(struct packed_rrset_data*)
ta->ds_rrset->entry.data;
for(i=0; i<d->count; i++) {
if(ret == num) continue;
list[ret++] = ds_get_keytag(ta->ds_rrset, i);
}
}
if(ta->numDNSKEY != 0 && ta->dnskey_rrset) {
struct packed_rrset_data* d=(struct packed_rrset_data*)
ta->dnskey_rrset->entry.data;
for(i=0; i<d->count; i++) {
if(ret == num) continue;
list[ret++] = dnskey_calc_keytag(ta->dnskey_rrset, i);
}
}
qsort(list, ret, sizeof(*list), keytag_compare);
return ret;
}
