[Opendnssec-user] Problems when a change in delegation cause A RRs to become glue RRs

Göran Bengtson goeran at chalmers.se
Fri Jun 15 05:43:05 UTC 2012

I noticed what I believe is a problem with OpenDNSSEC when a change in
delegation of subdomains cause normal A-RRs to become glue A-RRs.
(Running the 1.3-branch, rev. 6352 on a RHEL 5.8 32bit system).

Before the delegation is changed, the A-RRs should be (and are)
signed, but when the A-RRs becomes glue they should not.

I recreated the problem in a test zone. I've saved the
unsigned and signed zone-files for the different phases in
the test case and can send them if so requested (or open
a case if that is preferred).

I don't know exactly when the RRSIG for the A-RRs in question
(that transitioned from normal A-RRs to glue RRs) should be removed,
but I assume it should be done immediately after the change.

In any case, ODS seems to:

1	Keep the signatures after the change.
2	Not process them (e.g. update them if they should
 	be recalculated).
3	Cause NSEC3 issues.

In my case (the "live one", not the test) the (partial) auditor complained
Jun 13 19:16:39 ns-test ods-auditor[17437]: chalmers.se : Signature expiration (1339853028) for green.net.chalmers.se., A should be later than (the refresh period (259200) - the resign period (3600)) from now (1339607799)

I think this is because the signature was to be recalculated
at the next run, but then the delegation was changed so the
A RR was glue and ODS didn't process the RRSIG at all (2 above).

I'm also surprised that the auditor didn't complain over
the fact that the glue A-RRs were signed. If I remember correct
it used to do that, but maybe only i full mode?

In the test-case, a full audit after the delegation was changed
and the zone resigned gave the following output:
[root at ns-test unsigned]# ods-auditor -f -z test.eu
Auditor started
Auditor starting on test.eu
6: test.eu : SOA differs : from 1 to 2012061403
6: test.eu : Auditing test.eu zone : NSEC3 SIGNED
3: test.eu : Found RRs for ns3.dom.test.eu (f6arn3nl2f2tog71r9jegncjiaid1ts0.test.eu) which was not covered by an NSEC3 record
3: test.eu : Found RRs for ns1.dom.test.eu (gip7rppf16ufvqmlbq537gk6ni77ma9s.test.eu) which was not covered by an NSEC3 record
3: test.eu : Found RRs for ns2.dom.test.eu (sphlgq22pk3uga2t1f3tccbqf4hfu0p9.test.eu) which was not covered by an NSEC3 record
6: test.eu : Finished auditing test.eu zone
Auditor found errors - check log for details

Indicate that the RRSIGs shouldn't be there.

Manually removing the RRSIGs for the glue A RRs from
the zone made the auditor run without complains,
so maybe the root of these problems is that the
RRSIGs for the A-RRs that became glue are left
in the signed zone?

Also - ODS does not generate RRSIG for glue-RRs
in general. Removing one of the glue-RRs in the
test case, resign, add it again, a resign does
not recreate a RRSIG for the glue RR. This too
indicate that the problem is that the RRSIGs are
"left" in the signed zone when the delegation is changed.


 			/ GÖran Bengtson
 			  Chalmers Univ. of Technology

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