From 6993d26469ca8deee0eea2b806b3c415deaa2e25 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 15 Feb 2017 20:05:27 +0100 Subject: [PATCH] resolved: try to authenticate SOA on negative replies For caching negative replies we need the SOA TTL information. Hence, let's authenticate all auxiliary SOA RRs through DS requests on all negative requests. --- src/resolve/resolved-dns-transaction.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 532169ff24..ecd7068683 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -2009,8 +2009,18 @@ int dns_transaction_request_dnssec_keys(DnsTransaction *t) { r = dns_resource_key_match_rr(t->key, rr, NULL); if (r < 0) return r; - if (r == 0) - continue; + if (r == 0) { + /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is + * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry? + * If so, we need to validate it, too. */ + + r = dns_answer_match_key(t->answer, t->key, NULL); + if (r < 0) + return r; + if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate + * it. */ + continue; + } r = dnssec_has_rrsig(t->answer, rr->key); if (r < 0)