eTrust CA-Top Secret Security for z/OS and OS ... - SupportConnect

Chapter2Controlling Access to theHierarchical File SystemThere are two methods a site can use to secure the Hierarchical File System(HFS).■■The first process is internal to UNIX System Services and is based on theUNIX model of security.The second process is external security and uses standard eTrust CA-TopSecret security authorizations to secure HFS.Note: These methods are mutually exclusive, you must select one.Controlling HFS Using the Native UNIX Security ModelThe Hierarchical File System (HFS) is a tree-structured file system consisting ofdirectories and files. It resembles the DOS file system, although the slash (/) isused instead of the backslash (\).Each file and directory is assigned an owning UID and an owning GID. Theassignment is defined and saved in the file system, not in the external securityproduct.Three categories of users can access each directory and file in the HFS:■■■File ownerGroup that owns the fileAll other users defined to UNIX System ServicesDifferent access levels can be set for any of these three categories. For example,permissions can be defined so that the file owner gets READ and WRITE access,a member of the file's group gets only READ access, and all other users haveneither READ nor WRITE access to the file.Controlling Access to the Hierarchical File System 2–1