Support for CDS/CDNSKEY/CSYNC updates

Relevant IETF Documents

• https://datatracker.ietf.org/doc/html/rfc7344
• https://datatracker.ietf.org/doc/html/rfc8078
• https://datatracker.ietf.org/doc/html/rfc9615

Support in domain registries

Registry	CDS	CDNSKEY	Delete	Bootstrap from insecure	Bootstrap via _dsboot	CSYNC	Notes
.ch	Yes	No	Yes	72 hours TCP-only	Yes	No	guidelines
.cr	No	Yes	Yes	7 days TCP-only		No	No documentation found; FRED is used
.cz	No	Yes	Yes	7 days TCP-only		No	FRED is used
.fo	Yes	No	Yes	72 hours		No	guidelines
.li	Yes	No	Yes	72 hours TCP-only	Yes	No	guidelines
.nu	Yes	No	Yes	72 hours TCP-only		Yes	Policy and Guidelines
.se	Yes	No	Yes	72 hours TCP-only		Yes	Policy and Guidelines
.sk	Yes	No	Yes	72 hours		No	No clear information about using TCP for bootstrapping
.alt.za, .edu.za	Yes	No	Yes	72 hours	No	No
RIPE NCC	Yes	No	Yes	No		No

Support in domain registrars

Registrar	CDS	CDNSKEY	Delete	Bootstrap from insecure	Bootstrap via _dsboot	CSYNC	Notes
Glauca	Yes	Yes	Yes	All name servers must respond the same, TCP-only	Yes	?	Docs
Domainnameshop	Yes	Yes	Yes	All name servers must respond the same, TCP-only	Possible future	No

Support in DNS providers

Provider	CDS	CDNSKEY	Delete	Publishes _dsboot	Notes
Cloudflare	Yes	Yes	Yes	Yes
deSEC	Yes	Yes	Yes	Yes	docs
DNSimple	Yes	Yes			blog post
Glauca HexDNS	Yes	Yes	Yes	Yes
GoDaddy	Yes	Yes			presentation at ICANN 68
RcodeZero DNS	Yes	Yes	No	No

Parent-side software

dnssec-cds(8)

• part of BIND 9
• can use both CDS and CDNSKEY
• can produce DSset file or script for nsupdate
• no support for bootstrapping from insecure
• no support for DNSSEC delete

cdnskey-scanner

• part of FRED
• only CDNSKEY records
• supports bootstrapping from insecure
• almost zero documentation :(

akm-multi-scanner

• rewritten cdnskey-scanner part of FRED
• supports scanning from multiple locations
• source code location unknown :(
• there is diploma thesis and presentation in Czech

rcdss (RIPE NCC CDS Scanner)

• written in Python using dnspython
• reads RIPE Database objects
• produces RPSL-like diff objects
• multithreaded scanning
• no support for bootstrapping from insecure

Child-side software

Knot

• publishes both CDS and CDNSKEY records
• automated KSK rollover based on feedback from the parent
• controlled by cds-cdnskey-publish config option
• can also submit DS change directly using DDNS

BIND9

• publishes both CDS and CDNSKEY records
• requires rndc dnssec -checkds published to advance the KSK rollover

PowerDNS

• publishes both CDS and CDNSKEY records
• controlled by pdnsutil set-publish-cds
• requires manual KSK rollover
• synthesis of _dsboot record via LUA records: Setup LUA records; LUA module; pdns config

Other links

• https://archive.fosdem.org/2019/schedule/event/dns_dnssec_security_without_maintenance/
• https://jpmens.net/2017/09/21/parents-children-cds-cdnskey-records-and-dnssec-cds/