- The certificate signer no longer accepts ca.key passwords via the `CFSSL_CA_PK_PASSWORD` environment variable. This capability was not prompted by user request, never advertised, and recommended against in the security audit. ([#84677](https://github.com/kubernetes/kub...

- kube-apiserver: `--service-account-max-token-expiration` can now be used in combination with an external token signer `--service-account-signing-endpoint`, as long as the `--service-account-max-token-expiration` is not longer than the external token signer's max expiration. ([#129816](https://github.com/kubernetes/kubernetes/pull/129816), [@sambdavidson](https://github.com/sambdavidson)) [SIG API Machinery and Auth]

- Updated the control plane's trust anchor publisher to create and manage a new ClusterTrustBundle object, associated with the `kubernetes.io/kube-apiserver-serving` X.509 certificate signer. This ClusterTrustBundle contains a PEM bundle in its payload that you can use to verify kube-apiserver serving certificates. ([#127326](https://github.com/kubernetes/kubernetes/pull/127326), [@stlaz](https://github.com/stlaz)) [SIG API Machinery,...

- Migrated the bootstrap signer controller and the token cleaner controller (within `kube-controller-manager`) to use [contextual logging](https://k8s.io/docs/concepts/cluster-administration/system-logs/#contextual-logging). ([#113464](https://github.com/kubernetes/kubernetes/pull/113464),...

## Changelog since v1.22.14

## Changes by Kind

### Bug or Regression

- Kube-apiserver: gzip compression switched from level 4 to level 1 to improve large list call latencies in exchange for higher network bandwidth usage (10-50% higher). This increases the headroom before very large unpaged list calls exceed request timeout limits. ([#112401](https://github.com/kubernetes/kubernetes/pull/112401), [@shyamjvs](https://github.com/shyamjvs)) [SIG API Machinery]

- consumers of the 'certificatesigningrequests/approval' API must now have permission to 'approve' CSRs for the specific signer requested by the CSR. More information on the new signerName field and the required authorization can be found at https://kubernetes.io/docs/reference/access-authn-authz/certificate-signing-requests#authorization ([#88246](https://github.com/kube...

- The kube-controller-manager managed signers can now have distinct signing certificates and keys.  See the help about `--cluster-signing-[signer-name]-{cert,key}-file`.  `--cluster-signing-{cert,key}-file` is still the default. ([#90822](https://github.com/kubernetes/kubernetes/pull/90822), [@deads2k](https://github.com/deads2k)) [SIG API Machinery,...

### Signing Release Artifacts

Release artifacts are [signed](https://github.com/kubernetes/enhancements/issues/3031) using [cosign](https://github.com/sigstore/cosign)
signatures
and there is experimental support for [verifying image signatures](https://kubernetes.io/docs/tasks/administer-cluster/verify-signed-images/).

* Allow kubernetes components to react to SIGTERM signal and shutdown gracefully. ([#57756](https://github.com/kubernetes/kubernetes/pull/57756), [@mborsz](https://github.com/mborsz))

- `kubeadm alpha certs renew` and `kubeadm upgrade` now supports renewal of certificates embedded in KubeConfig files managed by kubeadm; this does not apply to certificates signed by external CAs.  ([#77180](https://github.com/kubernetes/kubernetes/pull/77180), [@fabriziopandini](https://github.com/fabriziopandini))