Content Comparison

Solution Repository Objects

Once you have a container for an ACL, how is it associated with objects in the solution repository? That is where the interface IAclSolutionFile comes in. This interface extends IAclHolder and is implemented by com.pentaho.repository.dbbased.solution.RepositoryFile. RepositoryFile also implements AclObjectIdentity. So not only does a RepositoryFile store an ACL (since it implements IAclHolder), it also is a securable object (since it implements AclObjectIdentity).

Persistence

The Pentaho BI Platform uses Hibernate for reading and writing to the db-based repository. The PRO_FILES table contains solution repository objects while the PRO_ACLS_LIST table contains ACL entries associated with those objects. Below are (incomplete) listings of the columns of each of these tables.

PRO_FILES Table

FILE_ID is the primary key. PARENT is a reference (by file id) to the object's parent. DIRECTORY is a boolean that is true if this object is a directory and false if this object is a file.

PRO_ACLS_LIST Table

Technically, rows in this table represent ACL entries, not ACLs. An ACL for an object can be created by querying for all rows sharing the same ACL_ID. ACL_ID is a foreign key that references PRO_FILES.FILE_ID. ACL_MASK is the decimal representation of the bit mask that represents the permissions in this ACL entry. And RECIPIENT is the username or granted authority that is the recipient of this ACL entry.

Voters

For every domain object, there is exactly one access control list. Add to that a user that wants to perform some operation on that object and that adds up to three inputs: a recipient, an operation, and an ACL. But what makes the "access granted" or "access denied" decision given these three pieces of information? The answer to that question is an IAclVoter. An instance of IAclVoter contains an all-important hasAccess method. It takes the three aforementioned inputs and returns a boolean result: true meaning access granted and false meaning access denied. An ACL voter is a singleton; there is only one instance per Java virtual machine. It is specified in pentaho.xml.

One might ask: How many ways can a voter arrive at a decision? Assume that user sally has the following granted authorities: ROLE_DEV and ROLE_MGR. Also assume that the ACL for a particular object contains the following entries: (sally, read), (ROLE_DEV, readwrite). Both ACL entries are applicable to sally since the first specifies sally (and she is sally) and the second specifies ROLE_DEV (and she has been granted the ROLE_DEV authority). Should the voter grant or deny a request to write to the object associated with this ACL? This is where extensibility of the voting system comes in. The Pentaho BI Platform provides multiple implementations of IAclVoter that each make different decisions in this situation! As the user of the platform, you decide how access decisions are made through your choice of IAclVoter. For more information about IAclVoter implementations, see 12. IAclVoter Node.