[#10631] - Restrict creating user in token based Authentication

Dear Team,
We need your help to figure out below authentication scenario.

1. User logs in into our own web application.
2. We create token based on the user's credentials to connect to Jasper Report Server through visualize.js.
3. We are planning to use token based authentication with encryption and expiry time.
4. In token based Authentication, if a well formatted token is supplied, then it will create the user if it does not exists on jasperserver and also it
synchronizes the roles as well.

Now our question is -
1. We are planning to create all our users/roles in Jasper Report server through a utility with the help of rest APIs.

2. So, now our aim is extract the user name from the token, check if the user exists in the Jasper Server internal database, if it exists then pass the
authentication else fail it. Also, do not synchronize the roles. We do not want to create User in case it does not exist in Jasper Report Server.

Can we achieve this with token based Authentication? If yes, then can you please guide us how to achieve this. Also, If any other Authentication mechanism is to be used then can you please give some sample snippets for this.

Any help in this regard will be greatly appreciated.

Thank you.