opennebula extend(expending) auth module ldap

LDAP Authentication addon permits users to have the same credentials as in LDAP, so effectively centralizing authentication

 let any correctly authenticated LDAP user to use OpenNebula

1,prerequistries

Addon requires the 'net/ldap' ruby library provided by the 'net-ldap' gem

Addon will not install any Ldap server or configure it in any way. It will not create, delete or modify any entry in the Ldap server it connects to. The only requirement is the ability to connect to an already running Ldap server and being able to perform a successful ldapbind operation and have a user able to perform searches of users, therefore no special attributes or values are required in the LDIF entry of the user authenticating.

2,Considerations & Limitations

Transport Layer Security(TLS) as on so做ssl for apache httpd https

LDAP auth driver has a bug that does not let it connect to TLS LDAP instances

3,configuration

Configuration file for auth module is located at /etc/one/auth/ldap_auth.conf. This is the default configuration

:user_field

Field in ldap that holds the user name

To enable ldap authentication the described parameters should be configured. OpenNebula must be also configured to enable external authentication. Uncomment these lines in /etc/one/oned.conf and add ldap and default (more on this later) as an enabled authentication method.

AUTH_MAD = [
    executable = "one_auth_mad",
    authn = "ssh,x509,ldap,server_cipher,server_x509"
]

To be able to use this driver for users that are still not in the user database you must set it to the default driver. To do this go to the auth drivers directory and copy the directory ldap to default. In system-wide installations you can do this using this command:

 

$ cp -R /var/lib/one/remotes/auth/ldap /var/lib/one/remotes/auth/default

User Management

Using LDAP authentication module the administrator doesn't need to create users with oneuser command as this will be automatically done. The user should add its credentials to $ONE_AUTH file (usually $HOME/.one/one_auth) in this fashion:

<user_dn>:ldap_password

where

• <user_dn> the DN of the user in the LDAP service
• ldap_password is the password of the user in the LDAP service

DN's With Special Characters

When the user dn or password contains blank spaces the LDAP driver will escape them so they can be used to create OpenNebula users. Therefore, users needs to set up their $ONE_AUTH file accordingly.

Users can easily create escaped $ONE_AUTH tokens with the command oneuser encode <user> [<password>], as an example:

$ oneuser encode 'cn=First Name,dc=institution,dc=country' 'pass word'
cn=First%20Name,dc=institution,dc=country:pass%20word

The output of this command should be put in the $ONE_AUTH file.

Active Directory

LDAP Auth drivers are able to connect to Active Directory. You will need:

• Active Directory server with support for simple user/password authentication.
• User with read permissions in the Active Directory user's tree.

You will need to change the following values in the configuration file (/etc/one/auth/ldap_auth.conf):

• :user: the Active Directory user with read permissions in the user's tree plus the domain. For example for user Administrator at domain win.opennebula.org you specify it as Administrator@win.opennebula.org
• :password: password of this user
• :host: hostname or IP of the Domain Controller
• :base: base DN to search for users. You need to decompose the full domain name and use each part as DN component. Example, for win.opennebula.org you will get te base DN: DN=win,DN=opennebula,DN=org
• :user_field: set it to sAMAccountName

:group parameter is still not supported for Active Directory, leave it commented.

Enabling LDAP auth in Sunstone

Update the /etc/one/sunstone-server.conf :auth parameter to use the opennebula:

    :auth: opennebula

Using this method the credentials provided in the login screen will be sent to the OpenNebula core and the authentication will be delegated to the OpenNebula auth system, using the specified driver for that user. Therefore any OpenNebula auth driver can be used through this method to authenticate the user (i.e: LDAP).

To automatically encode credentials as explained in DN's with special characters section also add this parameter to sunstone configuration:

    :encode_user_password: true