Setting up a pam_userdb.so based authentication

(Version française)

The pam_userdb.so authentication module uses a Berkeley format DB to hold passwords associated with user names.

To create this DB, you need to install the libdb3-util package, which includes the necessary tools.

Here is how you can setup the pam_userdb.so based authentication:

1. Create a text file with the username and password pairs: This file will list all username and password pairs, each username being on a first line, with the associated password on the following line. For example:

   user_1
   password_of_user_1
   user_2
   password_of_user_2
   ...

2. Convert this text file to a Berkeley DB:

   db3_load -T -f users_and_passwords_text_file.txt -t hash userpass.db

   This will create a Berkeley DB called "userpass.db" which we can use for PAM authentication.
3. Make sure that only root can read and change this file:

   chown root.root userpass.db
   chmod 0600 userpass.db

4. Add the call to the PAM module in the appropriate file in /etc/pam.d/:

   auth   required    pam_userdb.so    db=/full/path/to/userpass

   Please note that the ".db" extension is omitted in the parameter given to the PAM module.