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P10CR renewal and KUR roadmap

cmp-issuer implements enrollment through P10CR and renews the same way, by sending a fresh P10CR. It implements no CMP Key Update Request, so cert-manager renewal and KUR stay distinct concepts here.

cert-manager renewal

When a Certificate nears expiry cert-manager may create a new CertificateRequest for the same identity. cmp-issuer sends another P10CR with a fresh CSR.

Whether that succeeds depends entirely on the CMP server profile:

Server behavior Outcome
Allows repeat P10CR for the same identity Renewal succeeds
One-time enrollment code (EJBCA client mode) Fails until the end entity is reset
Requires KUR with proof of possession Unsupported today

cmp-issuer does not implement KUR. Repeat P10CR is not KUR even when it works.

Both private key rotation policies work where the server allows re-enrollment

Renewal was exercised against Nokia NCM 26.7 through cert-manager, with cmctl renew, for both values of privateKey.rotationPolicy:

rotationPolicy What the renewal sends Result
Always A new key, so a new public key in the CSR New certificate, new serial
Never The existing key, so the same public key in the CSR New certificate, new serial

Each renewal is a new CMP transaction with a fresh identifier, not a repeat of the earlier one, which is why it does not draw the transactionIdInUse refusal that an actual retransmission gets. See transaction recovery for that distinction.

The controller reads no private key in either case. Under Never cert-manager reuses the key it already holds and signs the new CSR itself, exactly as it does for the first enrollment.

A server whose profile authorizes enrollment once per identity refuses the second request. That is a property of the profile, not of cmp-issuer, and the failure is reported as a CMP rejection with the server's own failInfo.

Nokia NCM REST renewal

Some Nokia deployments expose certificate renewal through NCM REST APIs. That path is unrelated to CMP KUR and is Unsupported by cmp-issuer.

Planned: true KUR

A future release may implement CMPv2 KUR with CRMF proof of possession. That requires reading the workload private key under strict authorization rules described in Private-key handling.

Planned: IR and CRMF

Initial Registration with CRMF (IR) is also planned and shares the private-key access design.

Support matrix

Operation Status
P10CR initial enrollment Implemented
P10CR repeat enrollment Server dependent, not KUR. Verified against NCM 26.7 for both rotation policies
KUR Planned
IR (CRMF) Planned
Nokia NCM REST renewal Unsupported

See Support matrix.