Newly created user accounts will not work immediately after they have been created and a user-certificate link has been established. In the examples in Registering a user-certificate link you might have noticed that the "Activated" column for the example users was not set. To make these accounts work, they must be activated, which is done through the users command in eurephiadm. Again, it is a pretty straight forward process. In the example below, the three user accounts created through the earlier examples will be activated.

user@host:~ $ eurephiadm users --activate --username norma.jones
User account is activated
user@host:~ $ eurephiadm users --activate --username jane.doe
User account is activated
user@host:~ $ eurephiadm users --activate --username bill.doe
User account is activated
user@host:~ $

Now these accounts will be able to login, given that they use the proper certificate, the correct user name and password. If you for some reason want to disable their access, you can do the same command above, just replacing --activate with --deactivate. Since Jane Doe is using the same certificate as Norma Jones, lets disable that account.

user@host:~ $ eurephiadm users --deactivate --username jane.doe
User account is deactivated
user@host:~ $