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resolved: don't insist on finding DNSKEYs for RRsets of zones with DNSSEC off

This commit is contained in:
Lennart Poettering 2015-12-22 18:21:25 +01:00
parent d1c4ee3248
commit 94aa707129
1 changed files with 87 additions and 0 deletions
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87
src/resolve/resolved-dns-transaction.c
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@ -1855,6 +1855,71 @@ static int dns_transaction_requires_nsec(DnsTransaction *t) {
return true;
}
static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) {
DnsResourceRecord *rrsig;
bool found = false;
int r;
/* Checks whether any of the DNSKEYs used for the RRSIGs for
* the specified RRset is authenticated (i.e. has a matching
* DS RR). */
DNS_ANSWER_FOREACH(rrsig, t->answer) {
DnsTransaction *dt;
Iterator i;
r = dnssec_key_match_rrsig(rr->key, rrsig);
if (r < 0)
return r;
if (r == 0)
continue;
SET_FOREACH(dt, t->dnssec_transactions, i) {
if (dt->key->class != rr->key->class)
continue;
if (dt->key->type == DNS_TYPE_DNSKEY) {
r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer);
if (r < 0)
return r;
if (r == 0)
continue;
/* OK, we found an auxiliary DNSKEY
* lookup. If that lookup is
* authenticated, report this. */
if (dt->answer_authenticated)
return true;
found = true;
} else if (dt->key->type == DNS_TYPE_DS) {
r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer);
if (r < 0)
return r;
if (r == 0)
continue;
/* OK, we found an auxiliary DS
* lookup. If that lookup is
* authenticated and non-zero, we
* won! */
if (!dt->answer_authenticated)
return false;
return dns_answer_match_key(dt->answer, dt->key, NULL);
}
}
}
return found ? false : -ENXIO;
}
int dns_transaction_validate_dnssec(DnsTransaction *t) {
_cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL;
bool dnskeys_finalized = false;
@ -1936,6 +2001,7 @@ int dns_transaction_validate_dnssec(DnsTransaction *t) {
break;
} else if (dnskeys_finalized) {
/* If we haven't read all DNSKEYs yet
* a negative result of the validation
* is irrelevant, as there might be
@ -1957,6 +2023,27 @@ int dns_transaction_validate_dnssec(DnsTransaction *t) {
}
}
if (IN_SET(result,
DNSSEC_MISSING_KEY,
DNSSEC_SIGNATURE_EXPIRED,
DNSSEC_UNSUPPORTED_ALGORITHM)) {
r = dns_transaction_dnskey_authenticated(t, rr);
if (r < 0 && r != -ENXIO)
return r;
if (r == 0) {
/* The DNSKEY transaction was not authenticated, this means there's
* no DS for this, which means it's OK if no keys are found for this signature. */
r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0);
if (r < 0)
return r;
changed = true;
break;
}
}
r = dns_transaction_is_primary_response(t, rr);
if (r < 0)
return r;