pam_apparmor
Linux uses PAM (pluggable authentication modules) in the authentication process as a layer that mediates between user and application. PAM modules are available on a system-wide basis, so they can be requested by any application. This chapter describes how the modular authentication mechanism works and how it is configured.
When multiple Unix systems in a network access common resources, it becomes imperative that all user and group identities are the same for all machines in that network. The network should be transparent to users: their environments should not vary, regardless of which machine they are actually using. This can be done by means of NIS and NFS services. NFS distributes file systems over a network and is discussed in Book “Reference”, Chapter 22 “Sharing File Systems with NFS”.
NIS (Network Information Service) can be described as a database-like
service that provides access to the contents of
/etc/passwd
, /etc/shadow
, and
/etc/group
across networks. NIS can also be used
for other purposes (making the contents of files like
/etc/hosts
or /etc/services
available, for example), but this is beyond the scope of this
introduction. People often refer to NIS as YP,
because it works like the network's “yellow pages.”
Whereas Kerberos is used for authentication, LDAP is used for authorization and identification. Both can work together. For more information about LDAP, see Chapter 6, LDAP—A Directory Service, and about Kerberos, see Chapter 7, Network Authentication with Kerberos.
The Lightweight Directory Access Protocol (LDAP) is a protocol designed to access and maintain information directories. LDAP can be used for user and group management, system configuration management, address management, and more. This chapter provides a basic understanding of how LDAP works.
Kerberos is a network authentication protocol which also provides encryption. This chapter describes how to set up Kerberos and integrate services like LDAP and NFS.
Active Directory* (AD) is a directory-service based on LDAP, Kerberos, and other services. It is used by Microsoft* Windows* to manage resources, services, and people. In a Microsoft Windows network, Active Directory provides information about these objects, restricts access to them, and enforces po…
The RADIUS (Remote Authentication Dial-In User Service) protocol has long been a standard service for manage network access. It performs authentication, authorization, and accounting (AAA) protocol for very large businesses such as Internet service providers and cellular network providers, and is al…