Administrator's Guide
2.2.1 Explanation of the Login Process
The following steps describe the login process. This information shows how important it
is to create unique user names and to maintain a password security policy. For more
information, refer to login(1).
1. After the system is installed, the desktop Login Manager displays a login screen.
The Common Desktop Environment (CDE) displays a CDE login screen if it is installed.
2. The init program spawns a getty process, which prompts you for a user name.
You enter your user name. The getty program passes the user name to the login
program.
3. The login program searches/etc/passwd for the user name.
• If the user name exists, login goes to step 4 .
• If the user name does not exist, then login does the following checks:
— Prompts for a password (Password: ).
— If an invalid password is entered, the system displays the Invalid login
error message.
— Updates the /var/adm/btmp file if it exists. The /var/adm/btmp file
keeps track of invalid login attempts. See Section 2.2.2 for more information.
— Exits after three consecutive invalid login attempts.
4. The login process verifies the /etc/passwd file.
• If the password field is set, login prompts for a password and goes to step
5.
• If the password field is not set, the user does not need a password and login
goes to step 6 .
5. The login process compares the password to the encrypted password in
/etc/passwd.
• If the password matches, login goes to step 6.
• If the password does not match, login displays Invalid login. The login
process allows three consecutive login attempts. After the user's third invalid
login attempt, login exits.
6. The login process updates the /var/adm/wtmp file, which keeps track of valid
logins. See Section 2.2.2 for more information.
After a successful login, the user and group IDs, group access list, and working
directory are initialized.
7. The login process then runs the command in the command field of the
/etc/passwd file. Typically, the command field is the path name of a shell, such
32 Administering User and System Security