Server Authentication

This page describes:

  1. the status of authentication,
  2. how to bind (authenticate) as the admin superuser after starting the server the first time,
  3. adding non-superusers and binding to the directory as them,
  4. how to protect user passwords,
  5. how to disable anonymous binds,
  6. how to customize the server to use different authentication mechanisms.

Status

Presently the directory server supports only simple authentication and anonymous binds while storing passwords in clear text within userPassword attributes in user entries. Within a short while we'll be able to store passwords using the authPassword property which uses strong one way hashes for authentication such as MD5 and SHA1. These schemes and the schema used are described in detail here in RFC 3112 .

How to bind as the admin superuser after initial startup?

You just downloaded the server and started it up for the first time. Now you're wondering how to bind to the server using an LDAP client like jxplorer, gq, or ldapbrowser. By default the super user or admin account is created when the system partition is created under the 'ou=system' naming context. This occurs when the server is started for the first time. The admin user can be found under the following DN:
          uid=admin,ou=system
The password is initially set to 'secret'. You definately want to change this after starting the server. For the first time you can bind to the server as this user with 'secret' as the password. To change the password for the admin user you'll have to make changes to two places. First you'll have to change the password in the directory for the user. Second you'll have to change the password in the server.xml configuration file for the java.naming.security.credentials property.

If you did not disable anonymous binds by setting the respective property (described below), then you can bind anonymously to the server without any username or password.

Even when anonymous binds are disabled anonymous users can still bind to the RootDSE as required by the protocol to lookup supported SASL mechanisms before attempting a bind. Don't worry the RootDSE is read only.

Adding and authenticating normal users

By default a user in the server can be just about any entry with a userPassword attribute that contains a clear text password. The DN can be anything reachable within one of the directory partitions. So if you add a partition to hang off of 'dc=example,dc=com' then you can add user entries anywhere under this naming context or just add user entries under the 'ou=system' naming context. Below is an LDIF of a user you can add to the directory as a test user.

dn: uid=jdoe,ou=users,ou=system
cn: John Doe
sn: Doe
givenname: John
objectclass: top
objectclass: person
objectclass: organizationalPerson
objectclass: inetOrgPerson
ou: Human Resources
ou: People
l: Las Vegas
uid: jdoe
mail: jdoe@apachecon.comm
telephonenumber: +1 408 555 5555
facsimiletelephonenumber: +1 408 555 5556
roomnumber: 4613
userpassword: test

You can download this newuser.ldif file and use it to add the user. Below we use the ldapadd OpenLDAP client to import the LDIF file presuming the server was started on port 1024 on the localhost:

ldapadd -a -D "uid=admin,ou=system" -f newuser.ldif -h localhost -p 1024 -x -w secret

You can confirm the add/import by performing a search for the user. This time using the OpenLDAP search client you use the following command:

ldapsearch -D "uid=admin,ou=system" -h localhost -p 1024 -x -w secret -s one
    -b "ou=users,ou=system" "(uid=jdoe)"

You can start searching the directory using this new user like so:

ldapsearch -D "uid=jdoe,ou=users,ou=system" -h localhost -p 1024 -x -w test -s one -b "ou=system" "(objectClass=*)"

Protecting user passwords

Without access controls enabled userPasswords and user entries are accessible and alterable by all: even anonymous users. There are however some minimal built-in rules for protecting users and groups within the server without having to turn on the ACI subsystem.

Without ACIs the server automatically protects, hides, the admin user from everyone but the admin user. Users cannot see other user entries under the 'ou=users,ou=system' entry. So placing new users there automatically protects them. Placing new users anywhere else exposes them. Groups defined using groupOfNames or groupOfUniqueNames under the 'ou=groups,ou=system' are also protected from access or alteration by anyone other than the admin user. Again this protection is not allowed anywhere else but under these entries.

For simple configurations this should provide adequate protection but it lacks flexibility. For advanced configurations users should enable the ACI subsystem. This however shuts down access to everything by everyone except the admin user which bypasses the ACI subsystem. Directory administrators should look at the docomentation on how to specify access control information here: Authorization .

Disabling anonymous binds

Anonymous binds come enabled out of the box. So you might want to turn off this feature especially if you're not using a version of ApacheDS that is 0.9.3 or higher with ACI support. To do so you're going to have to restart the server after setting the allowAnonymousAccess property to false in the server.xml configuration file.

Using custom authenticators

Authenticator SPI provides a way to implement your own authentication mechanism, for instance simple mechanism using password encryption such as MD5 or SHA1, or SASL mechanism. See the following example:

import javax.naming.NamingException;

import org.apache.ldap.server.auth.AbstractAuthenticator;
import org.apache.ldap.server.auth.LdapPrincipal;
import org.apache.ldap.server.jndi.ServerContext;
import org.apache.ldap.common.exception.LdapNoPermissionException;
import org.apache.ldap.common.name.LdapName;

public class MyAuthenticator extends AbstractAuthenticator {

    public MyAuthenticator( )
    {
        // create authenticator that will handle "simple" authentication mechanism
        super( "simple" );
    }

    public void init() throws NamingException
    {
        ...
    }

    public LdapPrincipal authenticate( ServerContext ctx ) throws NamingException
    {
        ...

        // return the authorization id
        LdapName principalDn = new LdapName( dn );
        return new LdapPrincipal( principalDn );
    }
}

The authenticator class has to extend the org.apache.ldap.server.auth.AbstractAuthenticator. This class needs to have a no-argument constructor that calls the super() constructor with parameter the authentication mechanism it is going to handle. In the above example, MyAuthenticator class is going to handle the simple authentication mechanism. To implement a SASL mechanism you need to call super() with the name of the SASL mechanism, e.g. super( "DIGEST-MD5" ).

You can optionally implement the init() method to initialize your authenticator class. This will be called when the authenticator is loaded by ApacheDS during start-up.

When a client performs an authentication, ApacheDS will call the authenticate() method. You can get the client authentication info from the server context. After you authenticate the client, you need to return the authorization id. If the authentication fails, you should throw an LdapNoPermissionException.

When there are multiple authenticators registered with the same authentication type, ApacheDS will try to use them in the order it was registered. If one fails it will use the next one, until it finds one that successfully authenticates the client.

To tell ApacheDS to load your custom authenticators, you need to specify it in the server.xml. You can also optionally specify the location of a .properties file containing the initialization parameters. See the following example:

EXAMPLE BELOW IS NO LONGER VALID WITH XML CONFIGURATION

server.authenticators=myauthenticator yourauthenticator

server.authenticator.class.myauthenticator=com.mycompany.MyAuthenticator
server.authenticator.properties.myauthenticator=myauthenticator.properties

server.authenticator.class.yourauthenticator=com.yourcompany.YourAuthenticator
server.authenticator.properties.yourauthenticator=yourauthenticator.properties