Red Hat Training

A Red Hat training course is available for Red Hat Virtualization

15.4. Configuring LDAP and Kerberos for Single Sign-on

Single sign-on allows users to log in to the VM Portal or the Administration Portal without re-typing their passwords. Authentication credentials are obtained from the Kerberos server. To configure single sign-on to the Administration Portal and the VM Portal, you need to configure two extensions: ovirt-engine-extension-aaa-misc and ovirt-engine-extension-aaa-ldap; and two Apache modules: mod_auth_gssapi and mod_session. You can configure single sign-on that does not involve Kerberos, however this is outside the scope of this documentation.

Note

If single sign-on to the VM Portal is enabled, single sign-on to virtual machines will not be possible. With single sign-on to the VM Portal enabled, the VM Portal does not need to accept a password, thus the password cannot be delegated to sign in to virtual machines.

This example assumes the following:

  • The existing Key Distribution Center (KDC) server uses the MIT version of Kerberos 5.
  • You have administrative rights to the KDC server.
  • The Kerberos client is installed on the Red Hat Virtualization Manager and user machines.
  • The kadmin utility is used to create Kerberos service principals and keytab files.

This procedure involves the following components:

On the KDC server

  • Create a service principal and a keytab file for the Apache service on the Red Hat Virtualization Manager.

On the Red Hat Virtualization Manager

  • Install the authentication and authorization extension packages and the Apache Kerberos authentication module.
  • Configure the extension files.

Configuring Kerberos for the Apache Service

  1. On the KDC server, use the kadmin utility to create a service principal for the Apache service on the Red Hat Virtualization Manager. The service principal is a reference ID to the KDC for the Apache service. 

    # kadmin
kadmin> addprinc -randkey HTTP/fqdn-of-rhevm@REALM.COM

  2. Generate a keytab file for the Apache service. The keytab file stores the shared secret key. 

    kadmin> ktadd -k /tmp/http.keytab HTTP/fqdn-of-rhevm@REALM.COM
kadmin> quit

  3. Copy the keytab file from the KDC server to the Red Hat Virtualization Manager: 

    # scp /tmp/http.keytab root@rhevm.example.com:/etc/httpd

Configuring Single Sign-on to the VM Portal or Administration Portal

  1. On the Red Hat Virtualization Manager, ensure that the ownership and permissions for the keytab are appropriate: 

    # chown apache /etc/httpd/http.keytab
# chmod 400 /etc/httpd/http.keytab

  2. Install the authentication extension package, LDAP extension package, and the mod_auth_gssapi and mod_session Apache modules: 

    # yum install ovirt-engine-extension-aaa-misc ovirt-engine-extension-aaa-ldap mod_auth_gssapi mod_session

  3. Copy the SSO configuration template file into the /etc/ovirt-engine directory. Template files are available for Active Directory (ad-sso) and other directory types (simple-sso). This example uses the simple SSO configuration template. 

    # cp -r /usr/share/ovirt-engine-extension-aaa-ldap/examples/simple-sso/. /etc/ovirt-engine

  4. Move ovirt-sso.conf into the Apache configuration directory: 

    # mv /etc/ovirt-engine/aaa/ovirt-sso.conf /etc/httpd/conf.d

  5. Review the authentication method file. You do not need to edit this file, as the realm is automatically fetched from the keytab file. 

    # vi /etc/httpd/conf.d/ovirt-sso.conf

    Example 15.5. Example authentication method file

    <LocationMatch ^/ovirt-engine/sso/(interactive-login-negotiate|oauth/token-http-auth)|^/ovirt-engine/api>
  <If "req('Authorization') !~ /^(Bearer|Basic)/i">
    RewriteEngine on
    RewriteCond %{LA-U:REMOTE_USER} ^(.*)$
    RewriteRule ^(.*)$ - [L,NS,P,E=REMOTE_USER:%1]
    RequestHeader set X-Remote-User %{REMOTE_USER}s

    AuthType GSSAPI
    AuthName "Kerberos Login"

    # Modify to match installation
    GssapiCredStore keytab:/etc/httpd/http.keytab
    GssapiUseSessions On
    Session On
    SessionCookieName ovirt_gssapi_session path=/private;httponly;secure;

    Require valid-user
    ErrorDocument 401 "<html><meta http-equiv=\"refresh\" content=\"0; url=/ovirt-engine/sso/login-unauthorized\"/><body><a href=\"/ovirt-engine/sso/login-unauthorized\">Here</a></body></html>"
  </If>
</LocationMatch>

  6. Rename the configuration files to match the profile name you want visible to users on the Administration Portal and the VM Portal login pages: 

    # mv /etc/ovirt-engine/aaa/profile1.properties /etc/ovirt-engine/aaa/example.properties
    # mv /etc/ovirt-engine/extensions.d/profile1-http-authn.properties /etc/ovirt-engine/extensions.d/example-http-authn.properties
    # mv /etc/ovirt-engine/extensions.d/profile1-http-mapping.properties /etc/ovirt-engine/extensions.d/example-http-mapping.properties
    # mv /etc/ovirt-engine/extensions.d/profile1-authz.properties /etc/ovirt-engine/extensions.d/example-authz.properties

  7. Edit the LDAP property configuration file by uncommenting an LDAP server type and updating the domain and passwords fields: 

    #  vi /etc/ovirt-engine/aaa/example.properties

    Example 15.6. Example profile: LDAP server section

    # Select one
include = <openldap.properties>
#include = <389ds.properties>
#include = <rhds.properties>
#include = <ipa.properties>
#include = <iplanet.properties>
#include = <rfc2307-389ds.properties>
#include = <rfc2307-rhds.properties>
#include = <rfc2307-openldap.properties>
#include = <rfc2307-edir.properties>
#include = <rfc2307-generic.properties>

# Server
#
vars.server = ldap1.company.com

# Search user and its password.
#
vars.user = uid=search,cn=users,cn=accounts,dc=company,dc=com
vars.password = 123456

pool.default.serverset.single.server = ${global:vars.server}
pool.default.auth.simple.bindDN = ${global:vars.user}
pool.default.auth.simple.password = ${global:vars.password}

    To use TLS or SSL protocol to interact with the LDAP server, obtain the root CA certificate for the LDAP server and use it to create a public keystore file. Uncomment the following lines and specify the full path to the public keystore file and the password to access the file.

    Note

    For more information on creating a public keystore file, see Section D.2, “Setting Up Encrypted Communication between the Manager and an LDAP Server”.

    Example 15.7. Example profile: keystore section

    # Create keystore, import certificate chain and uncomment
# if using ssl/tls.
pool.default.ssl.startTLS = true
pool.default.ssl.truststore.file = /full/path/to/myrootca.jks
pool.default.ssl.truststore.password = password

  8. Review the authentication configuration file. The profile name visible to users on the Administration Portal and the VM Portal login pages is defined by ovirt.engine.aaa.authn.profile.name. The configuration profile location must match the LDAP configuration file location. All fields can be left as default. 

    # vi /etc/ovirt-engine/extensions.d/example-http-authn.properties

    Example 15.8. Example authentication configuration file

    ovirt.engine.extension.name = example-http-authn
ovirt.engine.extension.bindings.method = jbossmodule
ovirt.engine.extension.binding.jbossmodule.module = org.ovirt.engine-extensions.aaa.misc
ovirt.engine.extension.binding.jbossmodule.class = org.ovirt.engineextensions.aaa.misc.http.AuthnExtension
ovirt.engine.extension.provides = org.ovirt.engine.api.extensions.aaa.Authn
ovirt.engine.aaa.authn.profile.name = example-http
ovirt.engine.aaa.authn.authz.plugin = example-authz
ovirt.engine.aaa.authn.mapping.plugin = example-http-mapping
config.artifact.name = HEADER
config.artifact.arg = X-Remote-User

  9. Review the authorization configuration file. The configuration profile location must match the LDAP configuration file location. All fields can be left as default. 

    #  vi /etc/ovirt-engine/extensions.d/example-authz.properties

    Example 15.9. Example authorization configuration file

    ovirt.engine.extension.name = example-authz
ovirt.engine.extension.bindings.method = jbossmodule
ovirt.engine.extension.binding.jbossmodule.module = org.ovirt.engine-extensions.aaa.ldap
ovirt.engine.extension.binding.jbossmodule.class = org.ovirt.engineextensions.aaa.ldap.AuthzExtension
ovirt.engine.extension.provides = org.ovirt.engine.api.extensions.aaa.Authz
config.profile.file.1 = ../aaa/example.properties

  10. Review the authentication mapping configuration file. The configuration profile location must match the LDAP configuration file location. The configuration profile extension name must match the ovirt.engine.aaa.authn.mapping.plugin value in the authentication configuration file. All fields can be left as default. 

    # vi /etc/ovirt-engine/extensions.d/example-http-mapping.properties

    Example 15.10. Example authentication mapping configuration file

    ovirt.engine.extension.name = example-http-mapping
ovirt.engine.extension.bindings.method = jbossmodule
ovirt.engine.extension.binding.jbossmodule.module = org.ovirt.engine-extensions.aaa.misc
ovirt.engine.extension.binding.jbossmodule.class = org.ovirt.engineextensions.aaa.misc.mapping.MappingExtension
ovirt.engine.extension.provides = org.ovirt.engine.api.extensions.aaa.Mapping
config.mapAuthRecord.type = regex
config.mapAuthRecord.regex.mustMatch = true
config.mapAuthRecord.regex.pattern = ^(?<user>.?)((\\\\(?<at>@)(?<suffix>.?)@.)|(?<realm>@.))$
config.mapAuthRecord.regex.replacement = ${user}${at}${suffix}

  11. Ensure that the ownership and permissions of the configuration files are appropriate: 

    # chown ovirt:ovirt /etc/ovirt-engine/aaa/example.properties
    # chown ovirt:ovirt /etc/ovirt-engine/extensions.d/example-http-authn.properties
    # chown ovirt:ovirt /etc/ovirt-engine/extensions.d/example-http-mapping.properties
    # chown ovirt:ovirt /etc/ovirt-engine/extensions.d/example-authz.properties
    # chmod 600 /etc/ovirt-engine/aaa/example.properties
    # chmod 640 /etc/ovirt-engine/extensions.d/example-http-authn.properties
    # chmod 640 /etc/ovirt-engine/extensions.d/example-http-mapping.properties
    # chmod 640 /etc/ovirt-engine/extensions.d/example-authz.properties

  12. Restart the Apache service and the ovirt-engine service: 

    # systemctl restart httpd.service
# systemctl restart ovirt-engine.service