AuthenticationLookup.java

/*
************************************************************************
*******************  CANADIAN ASTRONOMY DATA CENTRE  *******************
**************  CENTRE CANADIEN DE DONNÉES ASTRONOMIQUES  **************
*
*  (c) 2010.                            (c) 2010.
*  Government of Canada                 Gouvernement du Canada
*  National Research Council            Conseil national de recherches
*  Ottawa, Canada, K1A 0R6              Ottawa, Canada, K1A 0R6
*  All rights reserved                  Tous droits réservés
*
*  NRC disclaims any warranties,        Le CNRC dénie toute garantie
*  expressed, implied, or               énoncée, implicite ou légale,
*  statutory, of any kind with          de quelque nature que ce
*  respect to the software,             soit, concernant le logiciel,
*  including without limitation         y compris sans restriction
*  any warranty of merchantability      toute garantie de valeur
*  or fitness for a particular          marchande ou de pertinence
*  purpose. NRC shall not be            pour un usage particulier.
*  liable in any event for any          Le CNRC ne pourra en aucun cas
*  damages, whether direct or           être tenu responsable de tout
*  indirect, special or general,        dommage, direct ou indirect,
*  consequential or incidental,         particulier ou général,
*  arising from the use of the          accessoire ou fortuit, résultant
*  software.  Neither the name          de l'utilisation du logiciel. Ni
*  of the National Research             le nom du Conseil National de
*  Council of Canada nor the            Recherches du Canada ni les noms
*  names of its contributors may        de ses  participants ne peuvent
*  be used to endorse or promote        être utilisés pour approuver ou
*  products derived from this           promouvoir les produits dérivés
*  software without specific prior      de ce logiciel sans autorisation
*  written permission.                  préalable et particulière
*                                       par écrit.
*
*  This file is part of the             Ce fichier fait partie du projet
*  OpenCADC project.                    OpenCADC.
*
*  OpenCADC is free software:           OpenCADC est un logiciel libre ;
*  you can redistribute it and/or       vous pouvez le redistribuer ou le
*  modify it under the terms of         modifier suivant les termes de
*  the GNU Affero General Public        la “GNU Affero General Public
*  License as published by the          License” telle que publiée
*  Free Software Foundation,            par la Free Software Foundation
*  either version 3 of the              : soit la version 3 de cette
*  License, or (at your option)         licence, soit (à votre gré)
*  any later version.                   toute version ultérieure.
*
*  OpenCADC is distributed in the       OpenCADC est distribué
*  hope that it will be useful,         dans l’espoir qu’il vous
*  but WITHOUT ANY WARRANTY;            sera utile, mais SANS AUCUNE
*  without even the implied             GARANTIE : sans même la garantie
*  warranty of MERCHANTABILITY          implicite de COMMERCIALISABILITÉ
*  or FITNESS FOR A PARTICULAR          ni d’ADÉQUATION À UN OBJECTIF
*  PURPOSE.  See the GNU Affero         PARTICULIER. Consultez la Licence
*  General Public License for           Générale Publique GNU Affero
*  more details.                        pour plus de détails.
*
*  You should have received             Vous devriez avoir reçu une
*  a copy of the GNU Affero             copie de la Licence Générale
*  General Public License along         Publique GNU Affero avec
*  with OpenCADC.  If not, see          OpenCADC ; si ce n’est
*  <http://www.gnu.org/licenses/>.      pas le cas, consultez :
*                                       <http://www.gnu.org/licenses/>.
*
*  $Revision: 5 $
*
************************************************************************
*/

package ca.nrc.cadc.tomcat;

import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.UnknownHostException;

import org.apache.log4j.Logger;


/**
 * A very simple caching IVOA Registry client. All the lookups done by this client use a properties
 * file named RegistryClient.properties found via the classpath.
 * <p><p>
 * Note for developers: You can set a system property to force this class to replace the hostname
 * in the resuting URL with the canonical hostname of the local host. This is useful for testing:
 * <p>
 * <pre>
 * ca.nrc.cadc.reg.client.RegistryClient.local=true
 * </pre>
 * <p><p>
 * Note for developers: You can set a system property to force this class to replace the hostname
 * in the resuting URL with an arbitrary hostname. This is useful for testing a specific remote server:
 * <p>
 * <pre>
 * ca.nrc.cadc.reg.client.RegistryClient.host=www.example.com
 * </pre>
 * <p>
 * This class is a forked and trimmed version of ca.nrc.cadc.reg.client.RegistryClient.  It was forked
 * to allow the realm implementation to be deployed without library dependencies.
 *
 * @author pdowler
 */
public class AuthenticationLookup
{
    private static Logger log = Logger.getLogger(AuthenticationLookup.class);

    private static final String LOCAL_PROPERTY = "ca.nrc.cadc.reg.client.RegistryClient.local";
    private static final String HOST_PROPERTY = "ca.nrc.cadc.reg.client.RegistryClient.host";
    private static final String SHORT_HOST_PROPERTY = "ca.nrc.cadc.reg.client.RegistryClient.shortHostname";

    private String hostname;
    private String shortHostname;


    private void init()
    {
        try
        {
            String localP = System.getProperty(LOCAL_PROPERTY);
            String hostP = System.getProperty(HOST_PROPERTY);
            String shortHostP = System.getProperty(SHORT_HOST_PROPERTY);

            log.debug("    local: " + localP);
            log.debug("     host: " + hostP);
            log.debug("shortHost: " + shortHostP);
            if ("true".equals(localP))
            {
                log.debug(LOCAL_PROPERTY
                          + " is set, assuming localhost runs the service");
                this.hostname = InetAddress.getLocalHost()
                        .getCanonicalHostName();
            }

            if (shortHostP != null)
            {
                shortHostP = shortHostP.trim();
                if (shortHostP.length() > 0)
                {
                    this.shortHostname = shortHostP;
                }
            }

            if (hostP != null && this.hostname == null)
            {
                hostP = hostP.trim();
                if (hostP.length() > 0)
                {
                    this.hostname = hostP;
                }
            }
        }
        catch (UnknownHostException ex)
        {
            log.warn("failed to find localhost name via name resolution ("
                     + ex.toString() + "): using localhost");
            this.hostname = "localhost";
        }
    }

    public URL configureAuthenticationServiceURL(URL serviceURL)
            throws MalformedURLException
    {
        init();
        log.debug("configureAuthenticationServiceURL: " + serviceURL + ","
                  + serviceURL.getProtocol() + "," + serviceURL.getPath());

        final StringBuilder sb = new StringBuilder();

        if (hostname != null || shortHostname != null)
        {
            sb.append(serviceURL.getProtocol());
            sb.append("://");
            if (shortHostname != null)
            {
                String hname = shortHostname;
                String fqhn = serviceURL.getHost();
                int i = fqhn.indexOf('.');
                if (i > 0)
                {
                    String domain = fqhn.substring(i);
                    hname += domain;
                }
                sb.append(hname);
            }
            else
            {
                sb.append(hostname);
            }
            int p = serviceURL.getPort();
            if (p > 0 && p != serviceURL.getDefaultPort())
            {
                sb.append(":");
                sb.append(p);
            }
            sb.append(serviceURL.getPath());
        }
        else
        {
            sb.append(serviceURL);
        }

        return new URL(sb.toString());
    }
}