bind9 is compiled without support for EdDSA DNSSEC keys

[Teemu Torma]

[Impact]
Bind9, either when acting as a resolver, or a master for a zone, does not have support for EdDSA algorithms like ED25519 or ED448. This is a regression from the package in Cosmic: this support was disabled by mistake in Disco.

[Test Case]
* Install the packages that will be tested:
sudo apt install dnsutils bind9utils bind9

* Offline test. Without EDDSA support, this command will fail:
$ dnssec-keygen -a ED25519 example.com
dnssec-keygen: fatal: unsupported algorithm: 15

* With EDDSA support, the command will succeed:
$ dnssec-keygen -a ED25519 example.com
Generating key pair.
Kexample.com.+015+02524

* Online test. Without EDDSA support, the command below will return "unsigned answer" and "no valid signature found":
$ delv +dnssec +multiline @127.0.0.1 ed25519.nl
;; validating ed25519.nl/A: no valid signature found
; unsigned answer
ed25519.nl. 3589 IN A 77.72.150.82
ed25519.nl. 3200171710 IN RRSIG A 15 2 3600 (
    20190502000000 20190411000000 27662 ed25519.nl.
    f7HjJcbvekrmuLtXDzjddWJZzZAAFO6fV+NoMCg+UiIl
    nQjUxNcCvDWuR38XAJuHrctvQOlAg1JmIGwYyKM2DQ== )

* With EDDSA support, it will return "fully validated":
$ delv +dnssec +multiline @127.0.0.1 ed25519.nl
; fully validated
ed25519.nl. 3600 IN A 77.72.150.82
ed25519.nl. 3600 IN RRSIG A 15 2 3600 (
    20190502000000 20190411000000 27662 ed25519.nl.
    f7HjJcbvekrmuLtXDzjddWJZzZAAFO6fV+NoMCg+UiIl
    nQjUxNcCvDWuR38XAJuHrctvQOlAg1JmIGwYyKM2DQ== )

[Regression Potential]
This change is fixing a regression already. It's adding support for a crypto algorithm used with DNSSEC which was enabled before.

[Other Info]
EdDSA requires openssl 1.1.1, so this change will also update the dependency chain to require libssl1.1 >= 1.1.1, as opposed to just 1.1.0 as is the case in Disco at the moment (this happens automatically during build). This is also true for the udebs that are built from this package.

[Original Description]
In Ubuntu Disco Dingo, bind9_9.11.5.P1+dfsg-1ubuntu2 is built --with-eddsa=no, thus breaking DNSSEC zones using Ed25519 keys. This used to work fine in Cosmic Cattlefish.

[Andreas Hasenack (ahasenack)]

Thanks for filing this bug in Ubuntu.

You are right, this should have been enabled back.

[Andreas Hasenack (ahasenack)]

Do you have an example at hand of such a breakage? It will make the testing and SRU easier. Something like using dig with @localhost and asking for info for such a public zone.

[Andreas Hasenack (ahasenack)]

Maybe this test is good.

With current disco packages:
$ delv +dnssec +multiline @127.0.0.1 ed25519.nl
;; validating ed25519.nl/A: no valid signature found
; unsigned answer
ed25519.nl. 3591 IN A 77.72.150.82
ed25519.nl. 3200171710 IN RRSIG A 15 2 3600 (
                                20190502000000 20190411000000 27662 ed25519.nl.
                                f7HjJcbvekrmuLtXDzjddWJZzZAAFO6fV+NoMCg+UiIl
                                nQjUxNcCvDWuR38XAJuHrctvQOlAg1JmIGwYyKM2DQ== )

With a new build, that does have eddsa support:
$ delv +dnssec +multiline @127.0.0.1 ed25519.nl
; fully validated
ed25519.nl. 3600 IN A 77.72.150.82
ed25519.nl. 3600 IN RRSIG A 15 2 3600 (
                                20190502000000 20190411000000 27662 ed25519.nl.
                                f7HjJcbvekrmuLtXDzjddWJZzZAAFO6fV+NoMCg+UiIl
                                nQjUxNcCvDWuR38XAJuHrctvQOlAg1JmIGwYyKM2DQ== )

[Teemu Torma (teemu-torma)]

I don't have simple test case, I use unbound as resolver. I noticed the problem with my authoritative bind9 server failing to sign zones using Ed25519 keys with "unsupported algorithm" or similar error. I just had to rebuild bind9 with eddsa support (and add the symbol) to keep on going.

But I guess testing ed25519.nl is good test that it is enabled.

[Andreas Hasenack (ahasenack)]

This is also a good test, and doesn't require networking:

dnssec-keygen -a ED25519 example.com

[Launchpad Janitor (janitor)]

This bug was fixed in the package bind9 - 1:9.11.5.P1+dfsg-1ubuntu4

---------------
bind9 (1:9.11.5.P1+dfsg-1ubuntu4) eoan; urgency=medium

  * d/rules: add back EdDSA support (LP: #1825712)

 -- Andreas Hasenack <email address hidden> Fri, 26 Apr 2019 14:04:37 +0000

[Brian Murray (brian-murray)]

Hello Teemu, or anyone else affected,

Accepted bind9 into disco-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/bind9/1:9.11.5.P1+dfsg-1ubuntu2.4 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-disco to verification-done-disco. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-disco. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Teemu Torma (teemu-torma)]

This fixes the ed25519 zone signing for me.

--------
bind9 (1:9.11.5.P1+dfsg-1ubuntu2.4) disco; urgency=medium

  * d/rules: add back EdDSA support (LP: #1825712)

 -- Andreas Hasenack <email address hidden> Fri, 26 Apr 2019 14:20:00 +0000

[Andreas Hasenack (ahasenack)]

Disco verification:

First, reproducing the bug:
ubuntu@disco-bind-1825712:~$ apt-cache policy bind9
bind9:
  Installed: 1:9.11.5.P1+dfsg-1ubuntu2.3
  Candidate: 1:9.11.5.P1+dfsg-1ubuntu2.3
  Version table:
 *** 1:9.11.5.P1+dfsg-1ubuntu2.3 500
        500 http://br.archive.ubuntu.com/ubuntu disco-updates/main amd64 Packages

Offline test:
ubuntu@disco-bind-1825712:~$ dnssec-keygen -a ED25519 example.com
dnssec-keygen: fatal: unsupported algorithm: 15

Online test returns "unsigned answer", as expected:
ubuntu@disco-bind-1825712:~$ delv +dnssec +multiline @127.0.0.1 ed25519.nl
;; validating ed25519.nl/A: no valid signature found
; unsigned answer
ed25519.nl. 3600 IN A 77.72.150.82
ed25519.nl. 3200171710 IN RRSIG A 15 2 3600 (
    20190523000000 20190502000000 27662 ed25519.nl.
    3y59a9G5rk/CMh36BPqonn2NjILp12SDmeQGloaUD5go
    e5A+Q6TsD7fDU9Bj3DtP6SqBturCFCxcUDzLeCp4AQ== )

Now with the updated packages:
ubuntu@disco-bind-1825712:~$ apt-cache policy bind9
bind9:
  Installed: 1:9.11.5.P1+dfsg-1ubuntu2.4
  Candidate: 1:9.11.5.P1+dfsg-1ubuntu2.4
  Version table:
 *** 1:9.11.5.P1+dfsg-1ubuntu2.4 500
        500 http://br.archive.ubuntu.com/ubuntu disco-proposed/main amd64 Packages

Offline test succeeds:
ubuntu@disco-bind-1825712:~$ dnssec-keygen -a ED25519 example.com
Generating key pair.
Kexample.com.+015+18445

Online test returns "fully validated":
ubuntu@disco-bind-1825712:~$ delv +dnssec +multiline @127.0.0.1 ed25519.nl
; fully validated
ed25519.nl. 3600 IN A 77.72.150.82
ed25519.nl. 3600 IN RRSIG A 15 2 3600 (
    20190523000000 20190502000000 27662 ed25519.nl.
    3y59a9G5rk/CMh36BPqonn2NjILp12SDmeQGloaUD5go
    e5A+Q6TsD7fDU9Bj3DtP6SqBturCFCxcUDzLeCp4AQ== )

Disco verification succeeded.

[Launchpad Janitor (janitor)]

This bug was fixed in the package bind9 - 1:9.11.5.P1+dfsg-1ubuntu2.4

---------------
bind9 (1:9.11.5.P1+dfsg-1ubuntu2.4) disco; urgency=medium

  * d/rules: add back EdDSA support (LP: #1825712)

 -- Andreas Hasenack <email address hidden> Fri, 26 Apr 2019 14:20:00 +0000

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for bind9 has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Michael Glanznig (nebulon42)]

This is also a problem in bionic. At least with bind9utils. On the system I tested I don't have bind9 available. I wanted to create a Ed25519 ZSK. Could this be backported? I wanted to add an Affects Link, but got an error instead.

[Christian Ehrhardt  (paelzer)]

It was never in Bionic and only added as a feature later.

$ git show pkg/ubuntu/bionic-devel:debian/rules | grep eddsa
                --with-eddsa=no \
                --with-eddsa=no \

I think that would break the SRU rules, but I'll add a bionic task and assign ahasenack to finally decide on that.

[Andreas Hasenack (ahasenack)]

It's a valid request, I'm just not sure if the version of bind in bionic is good enough for this support. I vaguely remember reading somewhere that certain encryption types were not working well in certain versions of bind9 (sorry, very vague, I know). Because of that I'm confirming the bug, but this would have to be investigated.

[Simon Déziel (sdeziel)]

For what it's worth, Bionic's bind9 version should support EdDSA according to https://bind.isc.org/doc/arm/9.11/man.dnssec-keygen.html
I dunno how well it would work on 9.11.3 though.

It would be nice to have EdDSA support enabled in Bionic if that can work reliably. It would help with the adoption of this relatively new algo (RFC8080 was accepted on February 2017).

[Athos Ribeiro (athos-ribeiro)]

Ubuntu 18.04 (bionic) reached end-of-standard-support on May 31, 2023.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases