Appendix D. Using the Fingerprint Reader / D.3. Managing Fingerprints with tf-tool
	D.2. Managing Fingerprints with YaST		D.4. For More Information

Managing Fingerprints with tf-tool

Procedure D.3. Registering a Fingerprint

Open a shell and log in as root.
To register a fingerprint for a certain user, enter
```
tf-tool --add-user login
```
tf-tool prompts the user to swipe his finger until three readable fingerprints have been gathered.
If you also want to use fingerprint authentication for starting YaST or the YaST modules in the GNOME Control Center, you need to register a fingerprint for root, too.

As soon as the user's fingerprint has been successfully registered, the user can choose to authenticate with either fingerprint or password for the actions and applications listed in Section D.1, “Supported Applications and Actions ”.

Procedure D.4. Verifying or Removing a Fingerprint

Open a shell and log in as root.
To verify an existing fingerprint for a certain user, run the following command:
```
tf-tool --verify-user login
```
Let the user swipe his finger. tf-tool compares the fingerprint to the print stored for this user and provides a message if the fingerprints match.
To remove a user's fingerprint, delete the appropriate fingerprint file for this user with the following command:
```
shred /etc/pam_thinkfinger/login.bir
```

With tf-tool --acquire you can do a test run with tf-tool. The fingerprint is stored as /tmp/test.bir and can be verified with tf-tool --verify.