Overview

Fedora Principal Provider Extensions allow a Fedora repository to pull in user security and role designations from other sources,  LDAP being a common source. They are usually executed after the initial container authentication but before finer-grained authentication such as role resolution. There are several PrincipalProvider modules available, this wiki page documents just some of them.

Operation

The repository.json file contains the class name of authentication provider (under "providers") as well as the roles to be used when starting the provider module (the roles which a query is checked against). By default the org.fcrepo.auth.common.BypassSecurityServletAuthenticationProvider is used for this layer of security, as it doesn't rely on an external PrincipalProviders and provides the simplest authentication model (The module always authenticates and gives access privileges to the session).

The Fedora class org.fcrepo.auth.common.ServletContainerAuthenticationProvider (configured from repository.json) contains a list of PrincipalProvider derivative instances that are called for every authentication query ( ServletContainerAuthenticationProvider.authenticate() ). The union of the authentication traits of the PrincipalProvider instances will be assigned to the FEDORA_ALL_PRINCIPALS session attribute. In the case that the user is has the fedoraAdmin role, a FedoraAdminSecurityContext is provided as the users SecurityContext. If the user does not have the fedoraAdmin role, an ExecutionContext is provided as the users SecurityContext.

Different derivatives of the Principal Provider class can initialize in different ways, either through the repository.json file, other credential files, from information sent via HTTP header or by connecting to external information sources such as LDAP.

PrincipalProvider

The interface that the providers must implement.

Container Roles Principal Provider

ContainerRolesPrincipalProvider is a PrincpalProivder that obtains its set of principals from repo.xml. 

HTTP Header Principal Provider

HttpHeaderPrincipalProvider is an example Principal Provider that obtains its initial set of principals from HTTP header requests instead of from the repo.xml file.