Authentication Methods

Uyuni supports several different authentication methods. This section discusses pluggable authentication modules (PAM) and single sign-on (SSO).

Authenticate with PAM

Uyuni supports network-based authentication systems using pluggable authentication modules (PAM). PAM is a suite of libraries that allows you to integrate Uyuni with a centralized authentication mechanism, eliminating the need to remember multiple passwords. Uyuni supports LDAP, Kerberos, and other network-based authentication systems using PAM.

Procedure: Enabling PAM

Create a PAM service file at /etc/pam.d/susemanager. A standard /etc/pam.d/susemanager file should look like this. It configures Uyuni to use the system wide PAM configuration:
```
#%PAM-1.0
auth     include        common-auth
account  include        common-account
password include        common-password
session  include        common-session
```
Enforce the use of the service file by adding this line to /etc/rhn/rhn.conf:
```
pam_auth_service = susemanager
```
In this example, the PAM service file is called susemanager.
Restart the Uyuni services after a configuration change.
In the Uyuni Web UI, navigate to Create User and enable a new or existing user to authenticate with PAM.
Check the Pluggable Authentication Modules (PAM) checkbox. It is below the password and password confirmation fields.

Changing the password in the Uyuni Web UI changes only the local password on the Uyuni Server. If PAM is enabled for that user, the local password might not be used at all. In the above example, for instance, the Kerberos password will not be changed. Use the password change mechanism of your network service to change the password for these users.

To configure system-wide authentication you can use YaST. You will need to install the yast2-ldap-client and yast2-kerberos-client packages.

For more information about configuring PAM, the SUSE Linux Enterprise Server Security Guide contains a generic example that will also work for other network-based authentication methods. It also describes how to configure an Active Directory Service. For more information, see https://documentation.suse.com/sles/15-SP1/html/SLES-all/part-auth.html.

Authenticate with Single Sign-On (SSO)

This feature is provided as a technical preview. It is not supported for use in production environments.

Uyuni supports single sign-on (SSO) by implementing the Security Assertion Markup Language (SAML) 2 protocol.

Single sign-on is an authentication process that allows a user to access multiple applications with one set of credentials. SAML is an XML-based standard for exchanging authentication and authorization data. A SAML identity service provider (IdP) provides authentication and authorization services to service providers (SP), such as Uyuni. Uyuni exposes three endpoints which must be enabled for single sign-on.

SSO in Uyuni supports:

Log in with SSO.
Log out with service provider-initiated single logout (SLO), and Identity service provider single logout service (SLS).
Assertion and nameId encryption.
Assertion signatures.
Message signatures with AuthNRequest, LogoutRequest, and LogoutResponses.
Enable an Assertion consumer service endpoint.
Enable a single logout service endpoint.
Publish the SP metadata (which can be signed).

SSO in Uyuni does not support:

Product choosing and implementation for the Identity Service Provider (IdP).
SAML support for other products (check with the respective product documentation).

Prerequisites

Before you begin, you will need to have configured an external Identity Service Provider with these parameters. Check your IdP documentation for instructions.

You will need these endpoints:

Assertion Consumer Service (or ACS): an endpoint to accept SAML messages to establish a session into the Service Provider. The endpoint for ACS in Uyuni is: https://example.com/rhn/manager/sso/acs
Single Logout Service (or SLS): an endpoint to initiate a logout request from the IdP. The endpoint for SLS in Uyuni is: https://example.com/rhn/manager/sso/sls
Metadata: an endpoint to retrieve Uyuni metadata for SAML. The endpoint for Metadata in Uyuni is: https://example.com/rhn/manager/sso/metadata

Your IdP must have a SAML:Attribute containing the username of the IdP user domain, called uid. The uid attribute passed in the SAML:Attribute must be created in the Uyuni user base before you activate single sign-on.

After the authentication with the IdP using the user orgadmin is successful, you will be logged in into Uyuni as the orgadmin user, provided that the orgadmin user exists in Uyuni.

Enable SSO

Using SSO is mutually exclusive with other types of authentication: it is either enabled or disabled. SSO is disabled by default.

Procedure: Enabling SSO

If your users do not yet exist in Uyuni, create them first.
Edit /etc/rhn/rhn.conf and add this line at the end of the file:
```
java.sso = true
```
Find the parameters you want to customize in /usr/share/rhn/config-defaults/rhn_java_sso.conf. Insert the parameters you want to customize into /etc/rhn/rhn.conf and prefix them with java.sso..

For example, in /usr/share/rhn/config-defaults/rhn_java_sso.conf find:
```
onelogin.saml2.sp.assertion_consumer_service.url = https://YOUR-PRODUCT-HOSTNAME-OR-IP/rhn/manager/sso/acs
```
In order to customize it, create the corresponding option in /etc/rhn/rhn.conf by prefixing the option name with java.sso.:
```
java.sso.onelogin.saml2.sp.assertion_consumer_service.url = https://YOUR-PRODUCT-HOSTNAME-OR-IP/rhn/manager/sso/acs
```
To find all the occurrences you need to change, search in the file for the placeholders YOUR-PRODUCT and `YOUR-IDP-ENTITY. Every parameter comes with a brief explanation of what it is meant for.
Restart the spacewalk service to pick up the changes:
```
spacewalk-service restart
```

When you visit the Uyuni URL, you will be redirected to the IdP for SSO where you will be requested to authenticate. Upon successful authentication, you will be redirected to the Uyuni Web UI, logged in as the authenticated user. If you encounter problems with logging in using SSO, check the Uyuni logs for more information.