search

PowerDNS / pdns

PowerDNS Authoritative, PowerDNS Recursor, dnsdist
https://www.powerdns.com/
GNU General Public License v2.0
3.69k stars 907 forks source link

Reconsider RSA defaults #2095

Closed Habbie closed 8 years ago

Habbie commented 9 years ago

pdnssec secure-zone currently defaults to algo 8 with a 2048 bit KSK and a 1024 bit ZSK. The way PowerDNS currently works and is deployed by most people, the KSK/ZSK split makes no sense, other than slightly reducing load on validators (which does not strike me as an important argument).

Suggestions:

  1. drop the 1024 bit ZSK (thus increasing overall security and reducing DNSKEY RRset size)
  2. increase the ZSK to 2048 (similarly increasing security; increasing DNSKEY RRset size; less (or posisbly just different) confusion about the lack of key split)
X-Cli commented 8 years ago

I completely subscribe to your security analysis: current deployments do not benefit from KSK/ZSK splitting. I also confirm that several information security gov agencies publicly document that RSA 1024 should not be used. Therefore, I, hat-off, would recommend to use a RSA 2048 CSK by default.

Habbie commented 8 years ago

Follow up question for anybody reading this - CSK with or without SEP set?

jpmens commented 8 years ago

CSK as 257; I think that would make things clearer for people who've read that SEP bit is the trust anchor for the zone. (Though I know it's not required, e.g. dig co.uk dnskey :-)

Habbie commented 8 years ago

Yes, 257 is clearer but it's good to know validators won't choke on it, given that co.uk runs with 256 :)

Habbie commented 8 years ago

@ahupowerdns has just made the executive decision to go ECDSA, which to me means that most split-key arguments are falling away as well.

jpmens commented 8 years ago

Executive Decision? You asked for votes! ;-)

Habbie commented 8 years ago

Pondering 13 vs. 14. Key flags probably 256. Should fix #3068 to go with this.

Habbie commented 8 years ago

13 (ecdsa256), key flags 256, one key. Now on master.