This change updates the CSR API to add a new, optional field called
expirationSeconds. This field is a request to the signer for the
maximum duration the client wishes the cert to have. The signer is
free to ignore this request based on its own internal policy. The
signers built-in to KCM will honor this field if it is not set to a
value greater than --cluster-signing-duration. The minimum allowed
value for this field is 600 seconds (ten minutes).
This change will help enforce safer durations for certificates in
the Kube ecosystem and will help related projects such as
cert-manager with their migration to the Kube CSR API.
Future enhancements may update the Kubelet to take advantage of this
field when it is configured in a way that can tolerate shorter
certificate lifespans with regular rotation.
Signed-off-by: Monis Khan <mok@vmware.com>
This change updates the backdating logic to only be applied to the
NotBefore date and not the NotAfter date when the certificate is
short lived. Thus when such a certificate is issued, it will not be
immediately expired. Long lived certificates continue to have the
same lifetime as before.
Consolidated all certificate lifetime logic into the
PermissiveSigningPolicy.policy method.
Signed-off-by: Monis Khan <mok@vmware.com>
