- For #1483: The failure reason when an NSEC NXDOMAIN is

  encountered when looking for an insecure delegation, is
  fixed to mention the NSEC records, instead of nonexistent
  NSEC3 records, that it attempted.

diff --git a/doc/Changelog b/doc/Changelog
index 9bd4356f9d1d6584dc9868010c34440e96923523..32e525e3b54aac1c6a293b27bd725abbe52943d3 100644 (file)
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,9 @@
+31 July 2026: Wouter
+       - For #1483: The failure reason when an NSEC NXDOMAIN is
+         encountered when looking for an insecure delegation, is
+         fixed to mention the NSEC records, instead of nonexistent
+         NSEC3 records, that it attempted.
+

 30 July 2026: Wouter
        - Fix #1482: DNS-over-QUIC doesn't work with simple config.
          That fixes interface-automatic for use with doq service.
 30 July 2026: Wouter
        - Fix #1482: DNS-over-QUIC doesn't work with simple config.
          That fixes interface-automatic for use with doq service.

diff --git a/testdata/val_nx_uns_resp.rpl b/testdata/val_nx_uns_resp.rpl
new file mode 100644 (file)
index 0000000..88dc955
--- /dev/null
+++ b/testdata/val_nx_uns_resp.rpl
@@ -0,0 +1,82 @@
+; config options
+server:
+       ; This is the test key 29332 in the testdata.
+       trust-anchor: ". 3600 IN DS 29332 8 2 b75e26316631b6e37cbc977323a08769f86e36a10fee888676d35f61e2ff4181"
+       val-override-date: "20201020135527"
+       target-fetch-policy: "0 0 0 0 0"
+       qname-minimisation: no
+       fake-sha1: yes
+       trust-anchor-signaling: no
+       minimal-responses: no
+       log-servfail: yes
+
+forward-zone:
+       name: "."
+       forward-addr: 10.5.5.5
+CONFIG_END
+
+SCENARIO_BEGIN Test nxdomain that gets unsigned response
+; and the DS lookup that it makes gets an NSEC NXDOMAIN response.
+
+; 10.5.5.5 forwarder
+RANGE_BEGIN 0 100
+       ADDRESS 10.5.5.5
+
+; unsigned NXDOMAIN response, from the first forwarder, here it is served
+; from the upstream.
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NXDOMAIN
+SECTION QUESTION
+example.veryinvalid. IN TXT
+SECTION AUTHORITY
+. 3600 IN SOA ns.root. host.root. 1 3600 3600 3600 3600
+ENTRY_END
+
+; DNSKEY answer, using CSK for test simplicity.
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+. IN DNSKEY
+SECTION ANSWER
+.       IN      DNSKEY  257 3 8 AwEAAb4WMOTBLTFvmBra5m6SK4VfViOzmvyUAU0qv861ZQXeEFvwlndqNU9rwRsMxrSWAYs5nHErKDn49usC/HyxxW1477iGFHhfgL4mjNreJm9zft2QFB1VLbRbEPYdDMLCn4co0qnG7/KG8W2i8Pym1L7f+aREwbLo+/716AS2PbaKMhfWLKLiq5wnBcUClQMNzCiwhqxDJp1oePqfkVdeUgXOtgi0dYRIKyQFhJ5VWJ22npoi/Gif0XLCADAlAwRLKc8o/yJkCxskzgpHpw5Cki1lclg0aq4ssOuPRQ+ne6IHYCz9D2mwzulblhLFamKdq7aHzNt4NlyxhpANVFiKLD8= ;{id = 29332 (ksk), size = 2048b}
+.      3600    IN      RRSIG   DNSKEY 8 0 3600 20201116135527 20201019135527 29332 . ToK8hJrGa+kNu6y8FpRwZq2FjDPBAk5Ctchia3Vu9yTth2dR7BhK2ALTWVBwAQGwiwxXKoVK9QCxdQM0ti7CVb9x75bejkd2E6UGWVmqyTRPpn3D43qYARm87y3ZVKG7LlWHp8UOf21XLp1H7R+wuipIvBJ1XA+QGXThPdbV9EEz1kKGdprBfdpFkQdcAiuYYrOTa5cJ11z32mGiQ12fWjpb4UUbfcoDD9YOoa/S5a6h7jYBOfm75ZB8UCW3Z/SlsN8KIfYZsg5CZphpf38XH5uNLMmzpaWYhfamJZJve9Isx4eILNmdMLK4E8ESwDFCVNzMIqdf20VRg6Lh7nwQeA==
+ENTRY_END
+
+; answer for DS, from another forwarder, here returned from the test upstream.
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NXDOMAIN
+SECTION QUESTION
+veryinvalid. IN DS
+SECTION AUTHORITY
+versicherung.  3600    IN      NSEC    vet. NS DS RRSIG NSEC
+versicherung.  3600    IN      RRSIG   NSEC 8 1 3600 20201116135527 20201019135527 29332 . AVAON9Y7AVwX9YWQK8JPcB6Wk/tEfQT7JrLiCRlBBQA0+mpVYYYtMyrm4aMjkhusqYcnpIZoLGOI/dxJjIwDgnMkd4EqY2oICea3I260f8z2v9e7zNobyUTjkoWsmLPc7VRLtEGKu1XyVpt7DX6ElGoSUhU4JsTx7wkkXU0SGAakL0bhK8K68B92NEVwgKX4D7+kVfpjc0aHaB3rAkhQCM/G0jEFp0RuhTX1aru6IuYrZmjW0dvQ2niec6NaYzvuGnbhMLlFLuXqSmI2B7uIFx894usd1cVWnSRg49bAkuiEv5q04ltRel1huJBGGiZlLEwanS5g53C5DHfq10OUrw==
+.      3600    IN      NSEC    aaa. NS SOA RRSIG NSEC DNSKEY ZONEMD
+.      3600    IN      RRSIG   NSEC 8 0 3600 20201116135527 20201019135527 29332 . E8r6rpFgFBUda2GnFSMzHZLtjy1dT+ZS0wPRE12RNwVK547bo2vByv9EFhOHS6sEIFqX+AmIJotuiEPKnCFUTr6FKscaxtw38dJRZ3wldqV6dmqUiRmz91crDCV5nSL45FIbkWKk1Q+tnXie3sZ4zwBc12kGg2BttMAQ0i4sbMbf6EUNYZGwYzSB0/VhXVJcl8gl+5lfpiVqfWNZI7vTEaHqrC2gBC3UK1cQE9lQOqhJ6H5ThA1FR9j/mZFM9sG5vQ2Mqlzl2iiN2Y6mCptDY1vwfff6AnT0YeDwJ/XwGisMZrSvTCYaiRndb8CUUmCr23AFy5OER1rmeFGkHX5+WQ==
+.      3600    IN      SOA     ns.root. host.root. 1 3600 3600 3600 3600
+.      3600    IN      RRSIG   SOA 8 0 3600 20201116135527 20201019135527 29332 . tVeReLMXPnl6rk4QX94xy9lCodQ+xc39lokbNkvbXnTURNCOAwtNiMMPlAAJ3/HTpIxo175gPfupACIveBtgajdp85jUIvLMOM5B6lX80+dUPBGZ4gHVjf+8EGnr7q2wnW2+KcJu0OhN2g+YqCV6aPi8pzuAp+AMsBYcMfXqEQq9Lxqv6TL50MUCJN3GPCyBIdjbs/A+ZB7D1EOO1YgdbsMHK/pWKYt4UfBFfekoA6joIGf4vBKKRTWnoo0BcrFob3AW1SyJkoxoqEsN3YAVL9jNkJCkU0/adLypHgDNayLgsWI5/o4Ng8LxN6tNxAilkMhcGY80T5g0uo+ukY7McA==
+ENTRY_END
+RANGE_END
+
+STEP 1 QUERY
+ENTRY_BEGIN
+REPLY RD DO
+SECTION QUESTION
+example.veryinvalid. IN TXT
+ENTRY_END
+
+STEP 10 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH all
+REPLY QR RD RA DO SERVFAIL
+SECTION QUESTION
+example.veryinvalid. IN TXT
+SECTION ANSWER
+ENTRY_END
+
+SCENARIO_END

diff --git a/validator/val_utils.c b/validator/val_utils.c
index e77f93f5ae8e1f86626b2e46a3e1f16f11a5f585..bfff19126ea2960760e67875d466de49a8ba892d 100644 (file)
--- a/validator/val_utils.c
+++ b/validator/val_utils.c
@@ -1323,6 +1323,20 @@ int val_has_signed_nsecs(struct reply_info* rep, char** reason)
        return 0;
 }
 
        return 0;
 }
 

+void val_has_auth_nsecs(struct reply_info* rep, int* has_nsec, int* has_nsec3)
+{
+       size_t i, num_nsec = 0, num_nsec3 = 0;
+       for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
+               if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NSEC))
+                       num_nsec++;
+               else if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NSEC3))
+                       num_nsec3++;
+               else continue;
+       }
+       *has_nsec = (num_nsec != 0);
+       *has_nsec3 = (num_nsec3 != 0);
+}
+

 struct dns_msg* 
 val_find_DS(struct module_env* env, uint8_t* nm, size_t nmlen, uint16_t c, 
        struct regional* region, uint8_t* topname)
 struct dns_msg* 
 val_find_DS(struct module_env* env, uint8_t* nm, size_t nmlen, uint16_t c, 
        struct regional* region, uint8_t* topname)

diff --git a/validator/val_utils.h b/validator/val_utils.h
index 43386edbf35197260bf969dce7bc350d0ebe0931..f05ff1d94277e3db7abf8fc71ffcafc9cda7652d 100644 (file)
--- a/validator/val_utils.h
+++ b/validator/val_utils.h
@@ -410,6 +410,14 @@ void val_blacklist(struct sock_list** blacklist, struct regional* region,
  */
 int val_has_signed_nsecs(struct reply_info* rep, char** reason);
 
  */
 int val_has_signed_nsecs(struct reply_info* rep, char** reason);
 

+/**
+ * See if there are NSECs, or NSEC3s in the authority section.
+ * @param rep: reply to check
+ * @param has_nsec: returned true if it has nsecs.
+ * @param has_nsec3: returned true if it has nsec3s.
+ */
+void val_has_auth_nsecs(struct reply_info* rep, int* has_nsec, int* has_nsec3);
+

 /**
  * Return algo number for favorite (best) algorithm that we support in DS.
  * @param ds_rrset: the DSes in this rrset are inspected and best algo chosen.
 /**
  * Return algo number for favorite (best) algorithm that we support in DS.
  * @param ds_rrset: the DSes in this rrset are inspected and best algo chosen.

diff --git a/validator/validator.c b/validator/validator.c
index d3ed8be3ed34a800f6262625269857237a0fbcb1..3634e32150834ea8147ddc1a58035a2e921821cb 100644 (file)
--- a/validator/validator.c
+++ b/validator/validator.c
@@ -3116,6 +3116,7 @@ ds_response_to_ke(struct module_qstate* qstate, struct val_qstate* vq,
                        case sec_status_unchecked:
                        default:
                                /* NSEC proof did not work, try next */
                        case sec_status_unchecked:
                        default:
                                /* NSEC proof did not work, try next */

+                               verbose(VERB_ALGO, "NSEC proof did not prove insecure delegation, try NSEC3");

                                break;
                }
 
                                break;
                }
 


@@ -3151,6 +3152,25 @@ ds_response_to_ke(struct module_qstate* qstate, struct val_qstate* vq,
                                *ke = NULL;
                                return 0;
                        case sec_status_bogus:
                                *ke = NULL;
                                return 0;
                        case sec_status_bogus:

+                               /* It could be that the NSEC proof failed,
+                                * and, then tried NSEC3. */
+                               {
+                                       int has_nsec=0, has_nsec3=0;
+                                       val_has_auth_nsecs(msg->rep, &has_nsec,
+                                               &has_nsec3);
+                                       if(!has_nsec3 && has_nsec) {
+                                               /* The NSECs are the cause, mention that in the error message. */
+                                               verbose(VERB_DETAIL, "NSECs for the "
+                                                       "referral did not prove no DS.");
+                                               errinf_ede(qstate, "NSECs for the referral did not prove no DS", LDNS_EDE_DNSSEC_BOGUS);
+                                               goto return_bogus;
+                                       }
+                                       if(!has_nsec3 && !has_nsec) {
+                                               verbose(VERB_DETAIL, "absence of NSECs and NSEC3s when attempting to prove no DS.");
+                                               errinf_ede(qstate, "no NSECs or NSEC3s when attempting to prove no DS", LDNS_EDE_DNSSEC_BOGUS);
+                                               goto return_bogus;
+                                       }
+                               }

                                verbose(VERB_DETAIL, "NSEC3s for the "
                                        "referral did not prove no DS.");
                                errinf_ede(qstate, reason, reason_bogus);
                                verbose(VERB_DETAIL, "NSEC3s for the "
                                        "referral did not prove no DS.");
                                errinf_ede(qstate, reason, reason_bogus);