User Authentication

Version 98.2 by Thomas Mortagne on 2018/02/09

XWiki supports several different authentication mechanisms for authenticating users.

XWiki currently allows only one method of authentication to be enabled at a time. This will probably be improved in the future.

Also note that XWiki requires cookies to be enable in order to track your session and to keep you logged in between pages.

Form Authentication

Form authentication is the default way to get authenticated within a Wiki. It requires a user and a password.

Basic Authentication

XWiki supports basic access authentication, a method designed to allow a web browser or other client programs to provide credentials - in the form of a user name and password - when making a request. You can get authenticated against an XWiki server with the basic authentication protocol using the following URL scheme:

http://username:password@mywiki.xwiki.com/xwiki/bin/view/Main/WebHome?basicauth=1

Be careful that if you use the HTTP protocol your password will be sent in clear over the network and is thus very unsafe. When using basic authentication you should make sure your wiki is configured to use HTTPS.

Container Authentication

Delegates authentication to the Servlet Container. If it fails it falls back to the standard XWiki authentication.

To configure XWiki to use it, specify:

xwiki.authentication.authclass=com.xpn.xwiki.user.impl.xwiki.AppServerTrustedAuthServiceImpl

For users to be actually created and not just set as context user you must set in xwiki.cfg configuration file (if the property does not already exist, create it):

xwiki.authentication.createuser=empty

Social Login

See the Social Login Application.

Active Directory

If you're looking to connect XWiki to an Active Directory server, you currently have 2 options:

LDAP

Use the LDAP Authenticator extension.

The deprecated LDAP core authenticator (for XWiki < 7.4) can be found on OldLDAPAuthenticator.

Custom Authentication

This allows plugging to any existing authentication mechanism such as SiteMinder, etc. To configure a custom authentication do the following:

  1. Implement the XWikiAuthService interface.
  2. Edit the WEB-INF/xwiki.cfg file and add a xwiki.authentication.authclass property pointing to your class. For example:
xwiki.authentication.authclass = com.acme.MyCustomAuthenticationService

You can find various authenticators examples in sandbox or extensions.

Here's a tutorial on implementing a custom authentication class for authenticating against Oracle's SSO.

Note that it's also possible to customize the right management system, see Security Module for more details.

Custom Authentication using a Groovy script in a wiki page

Start by specifying you want to use the Groovy Authenticator:

xwiki.authentication.authclass = com.xpn.xwiki.user.impl.xwiki.GroovyAuthServiceImpl

Then add another configuration parameter to specify in which wiki page the authenticator is:

xwiki.authentication.groovy.pagename = MySpace.MyPage

Then put some Groovy code in a wiki page that returns a XWikiAuthService object.

Authentication parameters

You can set each of these parameters by setting:

xwiki.authentication.<param_name>=<param_value>
NameOptionalAllowed valuesDefault valueDescription
encryptionKeyNo(1)?n/aSet the Encryption Key used to create a secret key, the secret key is passed to the Cipher object to be used during encryption and decryption of cookie values.
validationKeyNo(2)?n/aSet the Validation Key used to generate hash value; the hash value is stored with the cookie and used to verify that the cookie has not been tampered with.
cookiedomainsYesStringServer host nameWhich host(s) should your cookies be sent to; use only if you want to share cookies across domains, otherwise should be commented out
cookielifeYesNumber14Number of days cookies take to expire
cookiepathYesString/The webapp path that XWiki cookies should be sent to; if you have anything else running on your web server, this should be set to /xwiki
default_pageYesString/bin/view/ Main/WebHomePage to redirect to if xredirect parameter is not set
encryptionalgorithmYes??Set the Encryption Algorithm used to encrypt and decrypt cookies
encryptionmodeYes??Set the Encryption Mode used to encrypt and decrypt cookies
encryptionpaddingYes??Set the Encryption Padding used to encrypt and decrypt cookies
errorpageYesString/bin/loginerror/ XWiki/XWikiLoginPage to redirect to if there is an error logging in
loginpageYesString/bin/login/ XWiki/XWikiLoginPage to redirect to when not logged in
loginsubmitpageYesString/loginsubmit/ XWiki/XWikiLoginThe URL where the username and password are posted to when logging in.
logoutpageYesString/bin/logout/ XWiki/XWikiLogoutPage to redirect to after logged out
realmnameYesStringXWikiSets the realm name
protectionYesall, validation, encryption, noneallProtection level for the "remember me" cookie functionality
unauthorized_codeYesNumber401The HTTP status code to return when the login has failed.
useipYestrue / falsetrueSpecify to use the IP address when encrypting the cookie data; if IP address changes will need to re-login.
  1. Only required if protection = encryption or all (default)
  2. Only required if protection = validation or all (default)

Kerberos SSO Authentication

This implementation of SSO is currently under review see: https://jira.xwiki.org/browse/XWIKI-2496 . The class which is described in this segment of documentation, AppServerTrustedKerberosAuthServiceImpl, is not part of the default XWiki distribution!

The following is an example of mod_auth_kerb for Apache being used to easily implement XWiki authentication of users via HTTP Negotiate on a linux server. This example assumes you already have a working Apache2 HTTPD and Apache Tomcat setup with mod_jk.

First of all you need to create a principal and keytab for the webserver:

# kadmin
kadmin> addprinc -randkey HTTP/wiki.example.com
kadmin> ktadd -k /etc/apache2/ssl/wiki.keytab HTTP/wiki.example.com
kadmin> quit

Make sure the keytab has the right permissions and ownership:

chown www-data:www-data /etc/apache2/ssl/wiki.keytab
chmod 400 /etc/apache2/ssl/wiki.keytab

Install mod_auth_kerb in your linux installation. On Debian or Ubuntu this would be achieved by running:

aptitude install libapache2-mod-auth-kerb

Of course the installation procedure varies per Linux distribution.

If your xwiki installation is mounted in Apache HTTPD under /xwiki, add the following to the virtual host configuration:

<Location /xwiki/>
  AuthType Kerberos
  AuthName "Kerberos Login"
  KrbAuthRealms EXAMPLE.COM
  Krb5Keytab "/etc/apache2/ssl/wiki.keytab"
  KrbMethodK5Passwd off
  KrbMethodNegotiate on
  KrbSaveCredentials on
  require valid-user
</Location>

Make sure Apache Tomcat uses the authentication performed by Apache HTTPD with the "tomcatAuthentication" property in the connector description (which is in the server.xml file of Apache Tomcat):

<Connector port="8009" address="127.0.0.1" enableLookups="false" tomcatAuthentication="false" redirectPort="8443" protocol="AJP/1.3" />

Place the authkerb.jar jar in the WEB-INF/lib directory of XWiki in Apache Tomcat.

Have Xwiki use the authentication module by changing the "xwiki.authentication.authclass" property in the WEB-INF/lib/xwiki.cfg file.

xwiki.authentication.authclass=com.xpn.xwiki.user.impl.xwiki.AppServerTrustedKerberosAuthServiceImpl

If you use Firefox, do not forget to whitelist the xwiki URL for HTTP Negotiate in about:config with the "network.negotiate-auth.trusted-uris" property. Possible values for this property include: https:// for all secured connections or example.com for all example.com subdomains.

When I used JBoss SPNEGO (Kerberos in combination with LDAP) I changed the code of the XWikiLDAPAuthServiceImpl to be able to detect the sso user. The authenication already happend by using the SPNEGO module (JAAS). After that I'm using the ldap synchronisation feature to make sure that the user is up to date. The combination leads to an automatic login in XWiki and the user rights are controlled in the Active Directory server. I hope you can adopt this code or that you can use it for your own projects.

The configuration of ldap:

xwiki.authentication.authclass=com.wiki.sso.SSOLdapAuthenicationImpl
xwiki.authentication.ldap=1
xwiki.authentication.ldap.server=<ad-server>
xwiki.authentication.ldap.port=389
xwiki.authentication.ldap.base_DN=<OU=Users,...............>
#use a fixed user to attach to the ldap database,
#the password is not provided with the SSOLdapAuthenicationImpl
xwiki.authentication.ldap.bind_DN=<domain>\\<user>
xwiki.authentication.ldap.bind_pass=<password>
#Microsoft AD configuration
xwiki.authentication.ldap.UID_attr=sAMAccountName
xwiki.authentication.ldap.fields_mapping=name=sAMAccountName,last_name=sn,first_name=givenName,fullname=displayName,mail=mail,ldap_dn=dn
xwiki.authentication.ldap.group_memberfields=member,uniqueMember
#LDAP group mapping
xwiki.authentication.ldap.group_mapping=XWiki.XWikiAdminGroup=CN=WIKI_Admin,............|\
                                        XWiki.XWikiAllGroup=CN=WIKI_User,...........

The java code:

package com.wiki.sso;


import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.xpn.xwiki.XWikiContext;
import com.xpn.xwiki.XWikiException;
import com.xpn.xwiki.user.api.XWikiUser;
import com.xpn.xwiki.user.impl.LDAP.XWikiLDAPAuthServiceImpl;

import java.security.Principal;

public class SSOLdapAuthenicationImpl extends XWikiLDAPAuthServiceImpl {
   /**
    * Logging tool.
    */
    private static final Log LOG = LogFactory.getLog(SSOLdapAuthenicationImpl.class);


 public XWikiUser checkAuth(XWikiContext context) throws XWikiException {
  String user = getRemoteUser(context);
 if ((user != null) || !user.equals("")) {
  if (LOG.isInfoEnabled())
    LOG.info("Launching create user for " + user);
  if ( authenticate(user, context) != null ) {
   if (LOG.isInfoEnabled())
     LOG.info("Create user done for " + user);
    user = "XWiki." + user;
    context.setUser(user);
    System.out.println("User is set to:" + user);
   return new XWikiUser(user);
   } else {
    LOG.error( "User " + user + " can't be authenticated against ldap" );
   }
  }
 return super.checkAuth(context);
 }

/**
 * We cannot authenticate locally since we need to trust the app server for
 * authentication
 *
 * @param username
 * @param password
 * @param context
 * @return
 * @throws XWikiException
 */
 public XWikiUser checkAuth(String username, String password,
   String rememberme, XWikiContext context) throws XWikiException {
  String user = getRemoteUser(context);
 if ((user == null) || user.equals("")) {
  return super.checkAuth(username, password, rememberme, context);
  }
 return checkAuth(context);
 }

 private String getRemoteUser(XWikiContext context) {
  String userName = context.getRequest().getHttpServletRequest()
   .getRemoteUser();
 if (userName != null) {
  // only take the front of the username@domain
   String[] elements = userName.split("@", 2);
   userName = elements[0];
  }
 return userName;
 }

    public Principal authenticate(String login, XWikiContext context) throws XWikiException
    {
       if (LOG.isTraceEnabled()) {
            LOG.trace("Starting LDAP authentication");
        }

       /*
        * TODO: Put the next 4 following "if" in common with XWikiAuthService to ensure coherence This method was
        * returning null on failure so I preserved that behaviour, while adding the exact error messages to the context
        * given as argument. However, the right way to do this would probably be to throw XWikiException-s.
        */

       if (login == null) {
           // If we can't find the username field then we are probably on the login screen

           if (LOG.isDebugEnabled()) {
                LOG.debug("The provided user is null."
                   + " We don't try to authenticate, it probably means the user is in non logged mode.");
            }

           return null;
        }

       // Check for empty usernames
       if (login.equals("")) {
            context.put("message", "nousername");

           if (LOG.isDebugEnabled()) {
                LOG.debug("LDAP authentication failed: login empty");
            }

           return null;
        }

       // If we have the context then we are using direct mode
       // then we should specify the database
       // This is needed for virtual mode to work
        Principal principal = null;

       // Try authentication against ldap
        principal = ldapAuthenticate(login, "", context);

       if (LOG.isDebugEnabled()) {
           if (principal != null) {
                LOG.debug("LDAP authentication succeed with principal [" + principal.getName() + "]");
            } else {
                LOG.debug("LDAP authentication failed for user [" + login + "]");
            }
        }

       return principal;
    }
}
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