Config File Users

New in version v0.9.0.


By setting auth_type = "config-file" in krill.conf you can configure Krill to require users to enter a username and password in the web user interface when logging in, rather than the secret token that is usually required:

Config file login screen

Using config file user credentials to login to Krill


It is important to realize that Krill is not a complete user management system and that Config File Users therefore have some limitations.

While Config File Users are useful as a quick way to test named user support in Krill and may suffice for simple situations, in larger more critical settings you are strongly advised to consider using OpenID Connect Users instead.

How does it work?

To add a user to the krill.conf file an administrator uses the krillc command to compute a password hash for the user and then adds an entry to the [auth_users] section including their username, password hash, salt and any attributes that are relevant for that user.

When a user enters their username and password into the web user interface a hash of the password is computed and sent with the username to the Krill server.

The Krill server will verify that the user logging in provided a correct password and has the LOGIN permission. On success Krill will respond with a token which the web user interface should send on subsequent requests to authenticate itself with Krill. The web user interface will keep a copy of this token in browser local storage until the user logs out or is timed out due to inactivity.


The actual user password is NEVER stored on either the Krill server nor the client browser and is NEVER sent by the client browser to the Krill server. Only password hashes are stored and transmitted.


Do NOT serve the Krill web user interface over unencrypted HTTP. While the password is never transmitted, the authentication token that the user is subsequently issued is subject to interception by malicious parties if sent unencrypted from the Krill server to the web user interface. Note that this is equally true when using any credential to authenticate with Krill, whether secret token or password hash or when Krill is configured to interact with an OpenID Connect provider.

Known limitations

Config File Users are easy to define and give you complete control over who has access to your Krill instance and what level of access is granted. However, Krill is not a complete user management system and so there are some things to remember when using Config File Users:

  • Krill has no feature for requiring a user to change their password on first login. As such, by issuing users with passwords you become responsible for delivering the new password to them securely.

  • OpenID Connect providers often have support for one-time passwords (OTP) or other secondary lines of defence to protect an account than just a username and password. Krill does not have this capability.

  • Krill has no feature for generating cryptographically strong passwords. You are responsible for choosing sufficiently strong passwords for your users.

  • Usernames, password hashes and user attributes are sensitive information. By adding them to your krill.conf file you become responsible for protecting them.

  • If you lose your krill.conf file you will also lose the password hashes and will have to reset your users passwords unless you have a (secure) copy elsewhere.

  • If a user forgets their password you will need to issue them with a new one. Krill does not offer a forgotten password or password reset feature.

  • Adding or changing users requires a restart of Krill. There is no support in Krill at present for reloading the user details while Krill is running. While Krill is restarting the web user interface will be unavailable for your users.

Setting it up

The following steps are required to use Config File Users in your Krill setup.

1. Decide on the settings to be configured.

Decide which usernames you are going to configure, and what role and password they should have. For this example let’s assume we want to configure the following users:












2. Configure Krill

For each user generate a password hash and salt using the following command:

$ krillc config user --id
Enter the password to hash: ********

"" = { password_hash="521e....0529", salt="d539....115e" }

Then add the auth_type, [auth_users] and individual user lines to krill.conf. The end result should look something like this:

auth_type = "config-file"

""  = { attributes={ role="admin" },     password_hash="521e....0529", salt="d539....115e" }
"sally"            = { attributes={ role="readonly" },  password_hash="...", salt="..." }
"dave_the_octopus" = { attributes={ role="readwrite" }, password_hash="...", salt="..." }

3. Go!

Restart Krill and deliver the chosen passwords to the respective users to whom they belong. The users should now be able to login to your Krill instance.


Take whatever steps you think are necessary to ensure that the passwords are delivered securely to your users.

Advanced configuration

The information above gives you the basic structure for the configuration file syntax needed to configure local users in Krill.

See Permissions, Roles & Attributes for information about other user attributes and configuration settings that you might want to use.

See Custom Authorization Policies for information about customizing the configuration even further.

Below is a slightly modified version of the example above that also uses the inc_cas, exc_cas and auth_private_attributes features and adds a user that has custom team attributes as well. Notice how the team user does NOT have a role attribute!

auth_type = "config-file"
auth_private_attributes = [ "exc_cas" ]

""   = { attributes={ role="admin" }, password_hash="f45d...b25f", salt="..." }
"sally"             = { attributes={ role="readonly", inc_cas="ca1,ca3" },  password_hash="...", salt="..." }
"dave_the_octopus"  = { attributes={ role="readwrite" }, exc_cas="some_private_ca" }, password_hash="...", salt="..." }
"rob_from_team_one" = { attributes={ team="t1", teamrole="readwrite" }, password_hash="...", salt="..." }

Additional sources of information

The krill.conf file is the definitive guide to the possible values that can be used in the Krill configuration file. If in doubt, consult the krill.conf file that came with your copy of Krill.

Login related events will be reported in the Krill logs:

  • Login failures are reported at error level.

  • Login successes are reported at info level.

  • Additional diagnostics may be reported at debug or trace level.