Provides a distributable policy decision point to where authorization requests are sent and policies are evaluated accordingly with the permissions being requested. Part of this also accomplished remotely through the use of the
Being based on {{book.project.name}} Authentication Server, you can obtain attributes from identities and runtime environment during the evaluation of authorization policies.
First, you need to tell to {{book.project.name}} what are you looking to protect, which usually represents a web application or a set of one or more services. See link:../overview/terminology.html[Terminology] for more information about
Resource Servers are managed using the {{book.project.name}} Administration Console. There you can enable any registered client application as a resource server and start managing the resources and scopes you want to protect.
A Resource can be a web page, a RESTFul resource, a file in your filesystem, an EJB, etc. They can represent a group of resources (just like a Class in Java) or they can represent a single and specific resource.
For instance, you may have a _Bank Account_ resource that represents all banking accounts and use it to define the authorization policies that are common to all banking accounts. However,
you may want to define specific policies for _Alice Account_ (a resource instance that belongs to a customer), where only the owner is allowed to access some information or perform an operation.
Resources can be managed using {{book.project.name}} Administration Console or the link:../service/protection-api.html[Protection API]. In the latter case, resource servers are able to
manage their resources remotely.
Scopes usually represent the actions that can be performed on a resource, but they are not limited to that. You can also use scopes to represent a single or multiple attributes belonging to a resource.
Once you have defined your resource server and all the resources you want to protect, you can start working with the fun part: *Permission and Policy Management*.
image:../../images/policy-mgmt-process.png[alt="Permission and Policy Management Overview"]
Policies define the conditions that must be satisfied to access or perform operations on something (resource or scope), but they are not tied with what they are protecting. They are generic and can be reused
For instance, we may want to allow access to a group of resources only for users granted with a role "User Premium". For that, we can just define a simple RBAC (Role-based Access Control).
{{book.project.name}} provides a few built-in policy types(and their respective policy providers) covering the most common access control mechanisms. You can even create policies based on rules written using JavaScript or JBoss Drools.
Once you have your policies defined, you can start defining your permissions. Differently than policies, permissions are tied coupled with the resource they are protecting. Here you specify
what you want to protect (resource or scope) and the policies that must be satisfied in order to _GRANT_ or _DENY_ that permission to someone asking for it.
*Policy Enforcement* involves the necessary steps to actually enforce authorization decisions to a resource server. This is achieved by enabling a *Policy Enforcement Point* or PEP at the
resource server that is capable of communication with the authorization server, ask for authorization data and control access to protected resources based on the decisions and permissions returned
{{book.project.name}} provides some built-in link:../enforcer/overview.html[Policy Enforcers] implementations that you can use to protect your applications depending on the platform they are running on.
The *Protection API* is a https://docs.kantarainitiative.org/uma/rec-uma-core.html[UMA-compliant] endpoint providing a small set of operations
for resource servers in order help them managing their resources and scopes. Only resource servers are allowed to access this API, which also requires a
*uma_protection* scope.
The operations provided by the Protection API can be organized in two main groups:
By default, Remote Resource Management is enabled. You can change that using the {{book.project.name}} Administration Console and only allow resource management through the console.
When using the UMA protocol, the issuance of Permission Tickets by the Protection API is an important part of the whole authorization process. As we'll see later, they represent the permissions
being requested by client and that are sent to the server in order to obtain a final token with all permissions granted during the evaluation of the permissions and policies
associated with the resources and scopes being requested.
For more information, see link:../service/protection-api.html[Protection API].
==== Authorization API
The *Authorization API* is also a https://docs.kantarainitiative.org/uma/rec-uma-core.html[UMA-compliant] endpoint providing a single operation that exchanges an ID Token and _Permission Ticket_
When asking a RPT you can also provide a previously issued RPT. In this case, the resulting RPT will consist of the union of the permissions from the previously RPT and the new ones
The *Entitlement API* provides a 1-legged protocol to issue RPTs. Unlink the_Authorization API, the Entitlement API only expects an ID Token.
From this API you can obtain all the entitlements or permissions for an user (based on the resources managed by a given resource server) or just the entitlements for a set of
