From d424da2ae0860268ab863ce8945a425aa79e3826 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 7 Jan 2016 17:03:31 +0100 Subject: resolved: rework trust anchor revoke checking Instead of first iterating through all DNSKEYs in the DnsAnswer in dns_transaction_check_revoked_trust_anchors(), and then doing that a second time in dns_trust_anchor_check_revoked(), do so only once in the former, and pass the dnskey we found directly to the latter. --- src/resolve/resolved-dns-transaction.c | 5 +-- src/resolve/resolved-dns-trust-anchor.c | 72 ++++++++++++++++----------------- src/resolve/resolved-dns-trust-anchor.h | 2 +- 3 files changed, 36 insertions(+), 43 deletions(-) diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index b393c5238a..62075f2ef3 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -2239,10 +2239,7 @@ static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { * sufficient if it is self-signed. */ DNS_ANSWER_FOREACH(rr, t->answer) { - if (rr->key->type != DNS_TYPE_DNSKEY) - continue; - - r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, t->answer, rr->key); + r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); if (r < 0) return r; } diff --git a/src/resolve/resolved-dns-trust-anchor.c b/src/resolve/resolved-dns-trust-anchor.c index 9f8b76ebe2..d2a9c3635b 100644 --- a/src/resolve/resolved-dns-trust-anchor.c +++ b/src/resolve/resolved-dns-trust-anchor.c @@ -643,61 +643,57 @@ static int dns_trust_anchor_check_revoked_one(DnsTrustAnchor *d, DnsResourceReco return 0; } -int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsAnswer *rrs, const DnsResourceKey *key) { - DnsResourceRecord *dnskey; +int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs) { + DnsResourceRecord *rrsig; int r; assert(d); - assert(key); + assert(dnskey); + + /* Looks if "dnskey" is a self-signed RR that has been revoked + * and matches one of our trust anchor entries. If so, removes + * it from the trust anchor and returns > 0. */ - /* Looks for self-signed DNSKEY RRs in "rrs" that have been revoked. */ + if (dnskey->key->type != DNS_TYPE_DNSKEY) + return 0; - if (key->type != DNS_TYPE_DNSKEY) + /* Is this DNSKEY revoked? */ + if ((dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE) == 0) return 0; - DNS_ANSWER_FOREACH(dnskey, rrs) { - DnsResourceRecord *rrsig; + /* Could this be interesting to us at all? If not, + * there's no point in looking for and verifying a + * self-signed RRSIG. */ + if (!dns_trust_anchor_knows_domain_positive(d, DNS_RESOURCE_KEY_NAME(dnskey->key))) + return 0; + + /* Look for a self-signed RRSIG in the other rrs belonging to this DNSKEY */ + DNS_ANSWER_FOREACH(rrsig, rrs) { DnssecResult result; - r = dns_resource_key_equal(key, dnskey->key); + if (rrsig->key->type != DNS_TYPE_RRSIG) + continue; + + r = dnssec_rrsig_match_dnskey(rrsig, dnskey, true); if (r < 0) return r; if (r == 0) continue; - /* Is this DNSKEY revoked? */ - if ((dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE) == 0) - continue; - - /* Could this be interesting to us at all? If not, - * there's no point in looking for and verifying a - * self-signed RRSIG. */ - if (!dns_trust_anchor_knows_domain_positive(d, DNS_RESOURCE_KEY_NAME(dnskey->key))) + r = dnssec_verify_rrset(rrs, dnskey->key, rrsig, dnskey, USEC_INFINITY, &result); + if (r < 0) + return r; + if (result != DNSSEC_VALIDATED) continue; - /* Look for a self-signed RRSIG */ - DNS_ANSWER_FOREACH(rrsig, rrs) { - - if (rrsig->key->type != DNS_TYPE_RRSIG) - continue; - - r = dnssec_rrsig_match_dnskey(rrsig, dnskey, true); - if (r < 0) - return r; - if (r == 0) - continue; - - r = dnssec_verify_rrset(rrs, key, rrsig, dnskey, USEC_INFINITY, &result); - if (r < 0) - return r; - if (result != DNSSEC_VALIDATED) - continue; + /* Bingo! This is a revoked self-signed DNSKEY. Let's + * see if this precise one exists in our trust anchor + * database, too. */ + r = dns_trust_anchor_check_revoked_one(d, dnskey); + if (r < 0) + return r; - /* Bingo! Now, act! */ - r = dns_trust_anchor_check_revoked_one(d, dnskey); - if (r < 0) - return r; - } + return 1; } return 0; diff --git a/src/resolve/resolved-dns-trust-anchor.h b/src/resolve/resolved-dns-trust-anchor.h index 303c4088d1..054c98da70 100644 --- a/src/resolve/resolved-dns-trust-anchor.h +++ b/src/resolve/resolved-dns-trust-anchor.h @@ -40,4 +40,4 @@ void dns_trust_anchor_flush(DnsTrustAnchor *d); int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey* key, DnsAnswer **answer); int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name); -int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsAnswer *rrs, const DnsResourceKey *key); +int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs); -- cgit v1.2.3-54-g00ecf