Principal Providers

Overview

Fedora Principal Providers allow a Fedora repository to pull in user security and role designations from other sources (e.g. LDAP). They are usually executed after the initial container authentication but before finer-grained authentication (such as role resolution) is applied.

Implementation Details

The repository configuration file (repository.json) contains the class name of an authentication provider (under "providers") as well as the roles to be used when starting the provider module. By default, the org.fcrepo.auth.common.BypassSecurityServletAuthenticationProvider exists in the configuration file, as it doesn't rely on an external PrincipalProvider and offers the simplest authentication model (the module always gives access privileges to the session).

New roles must be specified in web.xml as shown below. The default role is fedoraUser.

web.xml

<auth-constraint>
  <role-name>fedoraUser</role-name>
  <role-name>fedoraAdmin</role-name>
  <role-name>my-new-tomcat-role</role-name>
</auth-constraint>

The Fedora class org.fcrepo.auth.common.ServletContainerAuthenticationProvider contains a list of PrincipalProvider derivative instances that are called for every authentication query. 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.