Algorithm roll-over, unexpected content in dsset-file

Sun Aug 11 17:32:09 UTC 2019

When there’s no DNSSEC KEY with SEP bit set, the Algo-13 “chain” has single entry point, e.g. Single-Type Signing Scheme (Combined Signing Key), see https://tools.ietf.org/html/rfc6781#section-3.1 and https://tools.ietf.org/html/rfc8499#section-10

I don’t know exactly know what are you trying achieve, but adding only ZSK with new algorithm serves no purpose.

Ondřej
--
Ondřej Surý — ISC

> On 11 Aug 2019, at 12:59, Mark Elkins <mje at posix.co.za> wrote:
> 
> Hi, Running BIND 9.14.4 on Gentoo.
> 
> I've been running BIND and DNSSEC for a long time. Years ago - I changed from Algorithm 5 to 8 and am now changing from 8 to 13.
> 
> My ZSK's have a lifetime of 34 days and my KSK a lifetime of 370 days. I've chosen to create a new ZSK every 17 days and KSK every 185 days - so usually have two of each per domain. I've 1532 domains in my system, 74 are NSEC and 54 are NSEC3 - the rest are unsigned. Currently - resigning happens randomly over the year - which keeps loads (and changes) scattered over the year. Some parents - I manage via EPP, others have various other methods of updating - so having the best part of six month to do a key-rollover has its advantages.
> 
> I've just started allowing the system to add Algo-13 Keys... and this is what I see:
> 
> 1 - Created a test zone file: contains enough to be legal.
> 
> 2 - Created some old keys, one ZSK and one KSK - Signed the domain and looked inside the "dsset-" file....
>   # vi db.foo.com
>   # dnssec-keygen -a RSASHA256 foo.com
>   # dnssec-keygen -a RSASHA256 -f KSK foo.com
>   # cat Kfoo.com.*.key >> db.foo.com
>   # dnssec-signzone -a -o foo.com db.foo.com
>   # cat dsset-foo.com.
> foo.com.        IN DS 62014 8 1 6CFC9114C7D0954195C01B488C3B8D6E1BD0F220
> foo.com.        IN DS 62014 8 2 74112FE6AE6E9DFB5A00EB3C26397E92CAA27038FA176A9B4B67D9FE 4E0154FE
> (perfect!)
> 
> 3 - created one additional ZSK - Algo 13, add that to the zone and resigned.
> 
>  # dnssec-keygen -a ECDSAP256SHA256 foo.com
>  # cat Kfoo.com.+013+34805.key >> db.foo.com
> 
>  # dnssec-signzone -a -o foo.com db.foo.com
> Verifying the zone using the following algorithms: RSASHA256.
> Missing self-signed KSK for algorithm ECDSAP256SHA256
> The zone is not fully signed for the following algorithms: ECDSAP256SHA256.
> DNSSEC completeness test failed.
> Zone verification failed (failure)
> 
> I don't mind the failure - after all there is no complete Algo-13 chain - but the existing Algo-8 chain is complete. Interestingly, the signed zone contains no mention of the Algo-13 ZSK. No problem.
> 
> However - WTF is a ZSK doing in the dsset file??? Is this a bug?
> 
> # cat dsset-foo.com.
> foo.com.        IN DS 34805 13 1 A040C7BC6C03778B20AD4A3AEE3BC0648CE8AC23
> foo.com.        IN DS 34805 13 2 340DC924A523CAD49E5C22357BBFECC07A2944D7723AD8F44DCE5332 FACD3AB2
> foo.com.        IN DS 62014 8 1 6CFC9114C7D0954195C01B488C3B8D6E1BD0F220
> foo.com.        IN DS 62014 8 2 74112FE6AE6E9DFB5A00EB3C26397E92CAA27038FA176A9B4B67D9FE 4E0154FE
> 
> 4 - If I then add an algo-13 KSK, add it to the Zone and run signzone - everything looks good again...
> 
> (New KSK) foo.com. IN DNSKEY 257 3 13 pD6yMHdPCKmLj0hY8oiLA1F2Vdb8a1LgpzU8XiO2c6eIh16n1Dv2Vogc 9WylTUjOLTZlhRXPDmAcIUTyBUuC2Q==
> # dnssec-signzone -a -o foo.com db.foo.com
> Verifying the zone using the following algorithms: RSASHA256 ECDSAP256SHA256.
> Zone fully signed:
> Algorithm: RSASHA256: KSKs: 1 active, 0 stand-by, 0 revoked
>                       ZSKs: 1 active, 0 stand-by, 0 revoked
> Algorithm: ECDSAP256SHA256: KSKs: 1 active, 0 stand-by, 0 revoked
>                             ZSKs: 1 active, 0 stand-by, 0 revoked
> db.foo.com.signed
> # cat dsset-foo.com.
> foo.com.        IN DS 23294 13 1 AADE5856B8EB3BB946DAAD2804A735816B3B3132
> foo.com.        IN DS 23294 13 2 7FD5F02A2E52A1C6E3DEBD54C05A9A974CE88FA78548E3644B36FA2D 27E0F910
> foo.com.        IN DS 62014 8 1 6CFC9114C7D0954195C01B488C3B8D6E1BD0F220
> foo.com.        IN DS 62014 8 2 74112FE6AE6E9DFB5A00EB3C26397E92CAA27038FA176A9B4B67D9FE 4E0154FE
> 
> I really don't like the bad ZSK DS record in dsset because I currently use that info to build CDS records in to my Database - which is used to verify when the DS record is seen in the parent. Anyway - I think this is a bug in the code of dnssec-signzone.
> 
> I'm trying to wait as long as possible before forcibly creating Algo-13 KSK's in the hope that they will be created according to the existing schedule. If the Second Algo-13 ZSK is to be created in under 3 days - then I'll replace the oldest KSK with an Algo-13 KSK.
> 
> -- 
> Mark James ELKINS  -  Posix Systems - (South) Africa
> mje at posix.co.za       Tel: +27.128070590  Cell: +27.826010496
> For fast, reliable, low cost Internet in ZA: https://ftth.posix.co.za
> 
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