Following the setup i can upload a reader extension PFX file to AEM ( https://helpx.adobe.com/aem-forms/6-2/configuring-document-services.html. )
What i try to do in a servlet is to create a resource for the a services user "resolverFactory.SUBSERVICE". Use the keystore of the services account to retrieve the RE key for my document.
Question, can a keystore for a services account be used to store the readerExtension key? When i want to retrieve the keystore i got an error: "The provided userId does not identify an existing user." for "com.adobe.granite.keystore.internal.KeyStoreServiceImpl.retrieveUser(KeyStoreServiceImpl.java:638)"
Did you attached the extension to a services account or a “normal” user account such as admin.?
(btw: every session has a user attached to it; Session.getUserID() will return you the String value)