I have tested my OPC UA client/Application for secure connection using self signed certificates and it works fine. Now I want to try to establish the secure connection using CA signed certificates for that I need help to get trusted certificate via ACME protocol or some other tool to avail free CA signed certificates. Please share input on this subject.
With OPC UA, you do not generally use global authorities as CA because it is impossible to verify hostnames of devices installed on factory floor with no direct access to the Internet.
It is expected that factory owners will have their own on premise CAs (or at least CAs run by the corporate IT department). The OPC UA specification includes an API designed to allows OPC UA applications to get signed Certificates from the on premise CA. (see https://reference.opcfoundatio.....v105/docs/ )
A sample CertificateManager is here: