Hello Nagesh,
This should be possible, this section of the KB article should be of
interest to you:
https://kb.isc.org/docs/dnssec-key-and-signing-policy#importing-dnssec-keys
The takeaway is that you should not set timing metadata in the key files
(other than Created). Keys without timing metadata are considered
pregenerated keys and are eligible candidates to become successor keys.
Also don't set "Predecessor"/"Successor" metadata, dnssec-policy will
set those when selecting a successor key.
Furthermore, depending on what 9.18 version you are running, there may
be bugs in older versions that cause existing keys to retire too soon.
On 3/17/26 06:02, Nagesh Thati wrote:
Hello BIND Community,
I am working on a solution that integrates with BIND 9.18 for DNSSEC key
management. I would like to share a behavior I have observed and seek
guidance from the community on the best approach.
Background
==========
Our architecture is as follows:
- My solution is responsible for generating DNSSEC keys (KSK and ZSK)
using dnssec-keygen.
- The generated keys are copied to the BIND key directory configured via
the key-directory directive.
- BIND is configured with dnssec-policy to handle automatic zone signing
and re-signing.
- My solution monitors key Inactive times and generates new replacement
keys ahead of rollover, copying them to the key directory when rollover
time approaches.
- We then run 'rndc loadkeys <zone>' to signal BIND to pick up the new keys.
Our dnssec-policy configuration is as follows:
dnssec-policy "managed-keys" {
keys {
ksk lifetime P365D algorithm ecdsap256sha256;
zsk lifetime P30D algorithm ecdsap256sha256;
};
};
zone "dnssectest.com <http://dnssectest.com>" IN {
type master;
file "/var/named/zones/db.dnssectest.com <http://
db.dnssectest.com>";
key-directory "/var/named/keys";
inline-signing yes;
dnssec-policy "managed-keys";
};
Observed Issue
==============
When testing our key rollover logic, we simulate an approaching expiry
by manually changing the Inactive time of the current ZSK or KSK to 2-3
days from now. We then generate a new replacement key and copy it to the
key directory, followed by running 'rndc loadkeys'.
The observed behavior is:
1. For ZSK rollover: BIND's KASP engine detects the newly copied ZSK in
the key directory and automatically retires it, instead of treating it
as the incoming replacement key.
2. For KSK rollover: The same behavior is observed — the newly copied
KSK is auto-retired by KASP shortly after being picked up.
This appears to happen because BIND's KASP engine takes ownership of all
keys present in the key directory and manages their lifecycle
independently, overriding the timing metadata we have set on the newly
copied keys.
Questions
=========
1. Is there a supported way to use dnssec-policy while having an
external application manage key generation and rollover, with BIND only
responsible for signing and re-signing?
No. BIND can do DNSSEC maintenance for you, or you have to do key and
signature maintenance manually with dnssec-signzone.
Your best choice is to set key lifetimes to unlimited, and when there is
a new key rollover, drop the key files into the configured key-directory
and issue a 'rndc dnssec -rollover' command.
2. Is there a mechanism to signal to BIND's KASP engine that a newly
copied key should be treated as a pre-publication replacement key for an
upcoming rollover, rather than a new independent key?
As you have experienced, excess keys with key timing metadata will be
retired. Try copying the key files of the successor key without setting
timing metadata.
3. Does BIND 9.18's KASP engine honor the Publish, Activate, Inactive,
and Delete timing metadata set on externally generated keys when they
are copied to the key directory, or does it always recalculate and
override these values based on the active dnssec-policy?
Nope. BIND will set those timing metadata given the dnssec-policy. It is
merely used to inform the user when it can expect a key to become
published, active, inactive and removed from the zone.
4. Is the 'auto-dnssec maintain' directive (without dnssec-policy) still
a viable option for this use case in BIND 9.18, given that it is
deprecated? Are there plans to remove it in an upcoming release?
It is already removed in 9.20, so I wouldn't consider it viable.
5. Are there any plans in future BIND versions to support an "external
key provider" interface or a "bring your own key" (BYOK) model within
the KASP framework?
It should work as I described above.
If not, feel free to create an issue in our GitLab:
https://gitlab.isc.org/isc-projects/bind9/-/issues/new
Best regards,
Matthijs
What We Have Tried
==================
- Using 'lifetime unlimited' in dnssec-policy to prevent BIND from auto-
generating replacement keys. However, BIND still auto-retires newly
copied keys when it detects them in the key directory.
- Using 'auto-dnssec maintain' with 'inline-signing yes' without dnssec-
policy. This works correctly and respects our key timing metadata, but
we are concerned about relying on a deprecated directive for a
production system.
- Manually editing the .private file and running 'rndc loadkeys'. BIND
picks up the timing changes but KASP still overrides the lifecycle
management of newly added keys.
Environment
===========
- BIND Version: 9.18.x
- OS: Alma Linux
- Key Algorithm: ECDSAP256SHA256
- ZSK Lifetime: 30 days
- KSK Lifetime: 365 days
Any guidance, suggestions, or pointers to relevant documentation or
discussions would be greatly appreciated. We want to ensure our
implementation is aligned with BIND's intended design and is forward-
compatible with future releases.
Thank you for your time and assistance.
Best regards
Nagesh
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