PubSub Security Key Services: add a callback SK builder for SKS push model

Description

PubSub Security Key Service push model requires to be notified when keys are updated in order to push the security keys to a server with a SetSecurityKeys method call. It requires additional utility SK builder module to be able to trigger this method call.

Detailed description

In order to be able to trigger a SetSecurityKeys method call using the already defined utility SK modules (in Common/sks), it is necessary to define a builder that will trigger a callback after keys update on the random keys provider side. Thus the application will be in charge to implement the expected method call depending on its configuration.

Code version identification

caa7b19b

Security impact

No security impact

Implementation

Implement new builder instance:

SOPC_SKBuilder* SOPC_SKBuilder_Callback_Create(SOPC_SKBuilder* skb,
                                               SOPC_SKBuilder_Callback_Func callback,
                                               uintptr_t userParam);

This builder take an inner builder as parameter that will be called first during an update and then it will call the provided callback with user defined parameter.

Note: the different use cases for the SK modules will be added in a dedicated S2OPC wiki page.

Known limitations

No particular limitation identified.