return nil, status.Error(codes.Unauthenticated, "request impersonation authentication failure")
		}
		// Node is authorized to impersonate; overwrite the SAN to the impersonated identity.
		sans = []string{impersonatedIdentity}
	}
	serverCaLog.Debugf("generating a certificate, sans: %v, requested ttl: %s", sans, time.Duration(request.ValidityDuration*int64(time.Second)))