Who is responsible for providing a new x.509 certificate when a previous one has expired?

The responsibility for providing a new x.509 certificate when a previous one has expired lies with the identity provider. An x.509 certificate is a digital certificate that uses the X.509 public key infrastructure standard to verify that a public key belongs to the user, computer, or service entity. The identity provider is the entity that issues and manages these certificates, ensuring that they are valid and up-to-date.

When a certificate expires, it is crucial to replace it to maintain secure communications and trust between the parties involved. The identity provider has the necessary access and authority to generate and issue a new certificate, ensuring that the new certificate can be trusted in the same way as the previous one.

In the context of the other options, while DocuSign Support may assist in various issues related to account and document management, they do not issue certificates directly. The end-user may utilize these certificates but does not have the infrastructure or authority to issue them. The certificate authority does issue certificates; however, in the context of an identity provider setup, the identity provider typically manages the lifecycle of the certificates, including renewal and replacement. Therefore, the identity provider is the correct choice for this question.