I am working with activiti engine using REST api to integrate with my struts 2 application. I have a requirement to add custom roles like editor, approver, user. These roles can have different permissions like read only, read write, etc. I would like to know how can activiti allow me through REST to add roles, assign permissions, and assign users to those roles. Please help me so that I can test it out. I am very hopeful about making this solution work but so far this is a hurdle in me using activiti. Thanks.