/** see if the reply has signed NSEC records and return the signer */
static uint8_t* reply_nsec_signer(struct reply_info* rep, size_t* signer_len,
uint16_t* dclass)
{
size_t i;
struct packed_rrset_data* d;
uint8_t* s;
for(i=rep->an_numrrsets; i< rep->an_numrrsets+rep->ns_numrrsets; i++){
if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC ||
ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC3) {
d = (struct packed_rrset_data*)rep->rrsets[i]->
entry.data;
/* return first signer name of first NSEC */
if(d->rrsig_count != 0) {
val_find_rrset_signer(rep->rrsets[i],
&s, signer_len);
if(s && *signer_len) {
*dclass = ntohs(rep->rrsets[i]->
rk.rrset_class);
return s;
}
}
}
}
return 0;
}
int
iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp)
{
/* if for query example.com, there is example.com SOA or a subdomain
* of example.com, then we are too low and need to fetch NS. */
size_t i;
/* if we have a DNAME or CNAME we are probably wrong */
/* if we have a qtype DS in the answer section, its fine */
for(i=0; i < msg->rep->an_numrrsets; i++) {
struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME ||
ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
/* not the right answer, maybe too low, check the
* RRSIG signer name (if there is any) for a hint
* that it is from the dp zone anyway */
uint8_t* sname;
size_t slen;
val_find_rrset_signer(s, &sname, &slen);
if(sname && query_dname_compare(dp->name, sname)==0)
return 0; /* it is fine, from the right dp */
return 1;
}
if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS)
return 0; /* fine, we have a DS record */
}
for(i=msg->rep->an_numrrsets;
i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) {
struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) {
if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname))
return 1; /* point is too low */
if(query_dname_compare(s->rk.dname, dp->name)==0)
return 0; /* right dp */
}
if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC ||
ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
uint8_t* sname;
size_t slen;
val_find_rrset_signer(s, &sname, &slen);
if(sname && query_dname_compare(dp->name, sname)==0)
return 0; /* it is fine, from the right dp */
return 1;
}
}
/* we do not know */
return 1;
}
void
val_find_signer(enum val_classification subtype, struct query_info* qinf,
struct reply_info* rep, size_t skip, uint8_t** signer_name,
size_t* signer_len)
{
size_t i;
if(subtype == VAL_CLASS_POSITIVE || subtype == VAL_CLASS_ANY) {
/* check for the answer rrset */
for(i=skip; i<rep->an_numrrsets; i++) {
if(query_dname_compare(qinf->qname,
rep->rrsets[i]->rk.dname) == 0) {
val_find_rrset_signer(rep->rrsets[i],
signer_name, signer_len);
return;
}
}
*signer_name = NULL;
*signer_len = 0;
} else if(subtype == VAL_CLASS_CNAME) {
/* check for the first signed cname/dname rrset */
for(i=skip; i<rep->an_numrrsets; i++) {
val_find_rrset_signer(rep->rrsets[i],
signer_name, signer_len);
if(*signer_name)
return;
if(ntohs(rep->rrsets[i]->rk.type) != LDNS_RR_TYPE_DNAME)
break; /* only check CNAME after a DNAME */
}
*signer_name = NULL;
*signer_len = 0;
} else if(subtype == VAL_CLASS_NAMEERROR
|| subtype == VAL_CLASS_NODATA) {
/*Check to see if the AUTH section NSEC record(s) have rrsigs*/
for(i=rep->an_numrrsets; i<
rep->an_numrrsets+rep->ns_numrrsets; i++) {
if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC
|| ntohs(rep->rrsets[i]->rk.type) ==
LDNS_RR_TYPE_NSEC3) {
val_find_rrset_signer(rep->rrsets[i],
signer_name, signer_len);
return;
}
}
} else if(subtype == VAL_CLASS_CNAMENOANSWER) {
/* find closest superdomain signer name in authority section
* NSEC and NSEC3s */
int matchcount = 0;
*signer_name = NULL;
*signer_len = 0;
for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->
ns_numrrsets; i++) {
if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC
|| ntohs(rep->rrsets[i]->rk.type) ==
LDNS_RR_TYPE_NSEC3) {
val_find_best_signer(rep->rrsets[i], qinf,
signer_name, signer_len, &matchcount);
}
}
} else if(subtype == VAL_CLASS_REFERRAL) {
/* find keys for the item at skip */
if(skip < rep->rrset_count) {
val_find_rrset_signer(rep->rrsets[skip],
signer_name, signer_len);
return;
}
*signer_name = NULL;
*signer_len = 0;
} else {
verbose(VERB_QUERY, "find_signer: could not find signer name"
" for unknown type response");
*signer_name = NULL;
*signer_len = 0;
}
}