Authentication Configuration

If you select Authentication Configuration you will be taken to a menu where you will be able to select a password server. In order to setup NIS, LDAP, or Hesiod you will need to have at least one of those servers running. Later in this book we will talk about setting up an NIS server. If you would like to learn more skip ahead to Chapter 14.

After selecting Next you will be taken to a menu where you can decide if you want to use Shadow passwords, MD5 passwords, LDAP Authentication, or Kerberos 5.

Shadow passwords only means that the passwords will be stored in the /etc/shadow file instead of the /etc/passwd file. This is good because password crackers will have a slightly more difficult time getting the passwords to run a cracking program against.

MD5 passwords are longer. Usually you can only have 8 characters in a password, but with MD5 the passwords can be up to 256 chatacters long. With out MD5 these passwords would all be the same:

abcdefgh1
abcdefghijklmn
abcdefgh987654321
abcdefghABCDEFGH

LDAP and Kerberos are both server related options. LDAP servers provide passwords and directory space. Kerberos servers give tickets that allow you to authenticate once to a server, then continue logging into other Kerberos machines without reauthenticating.

The authentication menu can also be started by running authconfig from the shell.