LdapUserDAO.java

/*
 ************************************************************************
 *******************  CANADIAN ASTRONOMY DATA CENTRE  *******************
 **************  CENTRE CANADIEN DE DONNÉES ASTRONOMIQUES  **************
 *
 *  (c) 2014.                            (c) 2014.
 *  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
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 *
 *  OpenCADC is distributed in the       OpenCADC est distribué
 *  hope that it will be useful,         dans l’espoir qu’il vous
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 *  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
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 *  <http://www.gnu.org/licenses/>.      pas le cas, consultez :
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 *
 *  $Revision: 4 $
 *
 ************************************************************************
 */
package ca.nrc.cadc.ac.server.ldap;

import ca.nrc.cadc.ac.PersonalDetails;
import ca.nrc.cadc.ac.PosixDetails;
import ca.nrc.cadc.ac.User;
import ca.nrc.cadc.ac.UserAlreadyExistsException;
import ca.nrc.cadc.ac.UserDetails;
import ca.nrc.cadc.ac.UserNotFoundException;
import ca.nrc.cadc.ac.UserRequest;
import ca.nrc.cadc.auth.AuthenticationUtil;
import ca.nrc.cadc.auth.HttpPrincipal;
import ca.nrc.cadc.net.TransientException;
import com.unboundid.ldap.sdk.AddRequest;
import com.unboundid.ldap.sdk.Attribute;
import com.unboundid.ldap.sdk.BindRequest;
import com.unboundid.ldap.sdk.BindResult;
import com.unboundid.ldap.sdk.Control;
import com.unboundid.ldap.sdk.DN;
import com.unboundid.ldap.sdk.Filter;
import com.unboundid.ldap.sdk.LDAPException;
import com.unboundid.ldap.sdk.LDAPResult;
import com.unboundid.ldap.sdk.LDAPSearchException;
import com.unboundid.ldap.sdk.Modification;
import com.unboundid.ldap.sdk.ModificationType;
import com.unboundid.ldap.sdk.ModifyRequest;
import com.unboundid.ldap.sdk.ResultCode;
import com.unboundid.ldap.sdk.SearchRequest;
import com.unboundid.ldap.sdk.SearchResult;
import com.unboundid.ldap.sdk.SearchResultEntry;
import com.unboundid.ldap.sdk.SearchScope;
import com.unboundid.ldap.sdk.SimpleBindRequest;
import com.unboundid.ldap.sdk.controls.ProxiedAuthorizationV2RequestControl;
import com.unboundid.ldap.sdk.extensions.PasswordModifyExtendedRequest;
import com.unboundid.ldap.sdk.extensions.PasswordModifyExtendedResult;
import org.apache.log4j.Logger;

import javax.security.auth.x500.X500Principal;
import java.security.AccessControlException;
import java.security.Principal;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;


public class LdapUserDAO<T extends Principal> extends LdapDAO
{
    private static final Logger logger = Logger.getLogger(LdapUserDAO.class);

    // Map of identity type to LDAP attribute
    private final Map<Class<?>, String> userLdapAttrib = new HashMap<Class<?>, String>();

    // Returned User attributes
    protected static final String LDAP_OBJECT_CLASS = "objectClass";
    protected static final String LDAP_INET_ORG_PERSON = "inetOrgPerson";
    protected static final String LDAP_CADC_ACCOUNT = "cadcaccount";
    protected static final String LDAP_NSACCOUNTLOCK = "nsaccountlock";
    protected static final String LDAP_MEMBEROF = "memberOf";
    protected static final String LDAP_ENTRYDN = "entrydn";
    protected static final String LDAP_COMMON_NAME = "cn";
    protected static final String LDAP_DISTINGUISHED_NAME = "distinguishedName";
    protected static final String LADP_USER_PASSWORD = "userPassword";
    protected static final String LDAP_FIRST_NAME = "givenName";
    protected static final String LDAP_LAST_NAME = "sn";
    protected static final String LDAP_ADDRESS = "address";
    protected static final String LDAP_CITY = "city";
    protected static final String LDAP_COUNTRY = "country";
    protected static final String LDAP_EMAIL = "email";
    protected static final String LDAP_INSTITUTE = "institute";
    protected static final String LDAP_UID = "uid";

    private String[] userAttribs = new String[]
            {
                    LDAP_FIRST_NAME, LDAP_LAST_NAME, LDAP_ADDRESS, LDAP_CITY,
                    LDAP_COUNTRY,
                    LDAP_EMAIL, LDAP_INSTITUTE, LDAP_UID
            };
    private String[] memberAttribs = new String[]
            {
                    LDAP_FIRST_NAME, LDAP_LAST_NAME
            };

    public LdapUserDAO(LdapConfig config)
    {
        super(config);
        this.userLdapAttrib.put(HttpPrincipal.class, LDAP_UID);
        this.userLdapAttrib.put(X500Principal.class, LDAP_DISTINGUISHED_NAME);

        // add the id attributes to user and member attributes
        String[] princs = userLdapAttrib.values()
                .toArray(new String[userLdapAttrib.values().size()]);
        String[] tmp = new String[userAttribs.length + princs.length];
        System.arraycopy(princs, 0, tmp, 0, princs.length);
        System.arraycopy(userAttribs, 0, tmp, princs.length,
                         userAttribs.length);
        userAttribs = tmp;

        tmp = new String[memberAttribs.length + princs.length];
        System.arraycopy(princs, 0, tmp, 0, princs.length);
        System.arraycopy(memberAttribs, 0, tmp, princs.length,
                         memberAttribs.length);
        memberAttribs = tmp;
    }

    /**
     * Verifies the username and password for an existing User.
     *
     * @param username username to verify.
     * @param password password to verify.
     * @return Boolean
     * @throws TransientException
     * @throws UserNotFoundException
     */
    public Boolean loginUser(final String username, final String password)
        throws TransientException, UserNotFoundException
    {
        try
        {
            BindRequest bindRequest = new SimpleBindRequest(getUserDN(username), password);
            BindResult bindResult = getConnection().bind(bindRequest);

            if (bindResult != null && bindResult.getResultCode() == ResultCode.SUCCESS)
            {
                return Boolean.TRUE;
            }
            else
            {
                throw new AccessControlException("Invalid username or password");
            }
        }
        catch (LDAPException e)
        {
            logger.debug("loginUser Exception: " + e, e);

            if (e.getResultCode() == ResultCode.INVALID_CREDENTIALS)
            {
                throw new AccessControlException("Invalid password");
            }
            else if (e.getResultCode() == ResultCode.NO_SUCH_OBJECT)
            {
                throw new AccessControlException("Invalid username");
            }

            throw new RuntimeException("Unexpected LDAP exception", e);
        }
    }

    /**
     * @return
     * @throws TransientException
     */
    public Collection<HttpPrincipal> getCadcIDs() throws TransientException
    {
        try
        {
            Filter filter = Filter.createPresenceFilter("uid");
            String[] attributes = new String[]{"uid"};

            SearchRequest searchRequest =
                    new SearchRequest(config.getUsersDN(),
                                      SearchScope.SUB, filter, attributes);

            SearchResult searchResult = null;
            try
            {
                searchResult = getConnection().search(searchRequest);
            }
            catch (LDAPSearchException e)
            {
                if (e.getResultCode() == ResultCode.NO_SUCH_OBJECT)
                {
                    logger.debug("Could not find users root", e);
                    throw new IllegalStateException("Could not find users root");
                }
            }

            LdapDAO.checkLdapResult(searchResult.getResultCode());
            Collection<HttpPrincipal> userIDs = new HashSet<HttpPrincipal>();
            for (SearchResultEntry next : searchResult.getSearchEntries())
            {
                userIDs.add(new HttpPrincipal(next.getAttributeValue("uid")));
            }

            return userIDs;
        }
        catch (LDAPException e)
        {
            logger.error("getCadcIDs Exception: " + e, e);
            LdapDAO.checkLdapResult(e.getResultCode());
            throw new IllegalStateException("Unexpected exception: " +
                                            e.getMatchedDN(), e);
        }
    }

    /**
     * Add the specified user..
     *
     * @param userRequest The user to add.
     * @return User instance.
     * @throws TransientException         If an temporary, unexpected problem occurred.
     * @throws AccessControlException     If the operation is not permitted.
     * @throws UserAlreadyExistsException If the user already exists.
     */
    public User<T> addUser(final UserRequest<T> userRequest)
            throws TransientException, UserAlreadyExistsException
    {
        DN userDN;
        try
        {
            userDN = getUserRequestsDN(userRequest.getUser().getUserID().getName());
            addUser(userRequest, userDN);

            // AD: Search results sometimes come incomplete if
            // connection is not reset - not sure why.
            getConnection().reconnect();
            try
            {
                return getUser(userRequest.getUser().getUserID(), config.getUserRequestsDN());
            }
            catch (UserNotFoundException e)
            {
                throw new RuntimeException("BUG: new user " + userDN.toNormalizedString() +
                    " not found because " + e.getMessage());
            }
        }
        catch (LDAPException e)
        {
            logger.error("addUser Exception: " + e, e);
            LdapUserDAO.checkUserLDAPResult(e.getResultCode());
            throw new RuntimeException("Unexpected LDAP exception", e);
        }
    }

    /**
     * Package level method for unit testing to add a User directly to the
     * Users tree.
     */
    User<T> newUser(final UserRequest<T> userRequest)
        throws TransientException, UserAlreadyExistsException
    {
        DN userDN;
        try
        {
            userDN = getUserDN(userRequest.getUser().getUserID().getName());
            addUser(userRequest, userDN);

            // AD: Search results sometimes come incomplete if
            // connection is not reset - not sure why.
            getConnection().reconnect();
            try
            {
                return getUser(userRequest.getUser().getUserID(), config.getUsersDN());
            }
            catch (UserNotFoundException e)
            {
                throw new RuntimeException("BUG: new user " + userDN.toNormalizedString() +
                                           " not found because " + e.getMessage());
            }
        }
        catch (LDAPException e)
        {
            logger.error("newUser Exception: " + e, e);
            LdapUserDAO.checkUserLDAPResult(e.getResultCode());
            throw new RuntimeException("Unexpected LDAP exception", e);
        }
    }

    private void addUser(final UserRequest<T> userRequest, final DN userDN)
        throws TransientException, UserAlreadyExistsException
    {
        final User<T> user = userRequest.getUser();
        final Class userType = user.getUserID().getClass();
        final String searchField = userLdapAttrib.get(userType);

        if (searchField == null)
        {
            throw new IllegalArgumentException("Unsupported principal type " + userType);
        }

        try
        {
            // add new user
            List<Attribute> attributes = new ArrayList<Attribute>();
            addAttribute(attributes, LDAP_OBJECT_CLASS, LDAP_INET_ORG_PERSON);
            addAttribute(attributes, LDAP_OBJECT_CLASS, LDAP_CADC_ACCOUNT);
            addAttribute(attributes, LDAP_COMMON_NAME, user.getUserID()
                .getName());
            addAttribute(attributes, LDAP_DISTINGUISHED_NAME, userDN
                .toNormalizedString());
            addAttribute(attributes, LADP_USER_PASSWORD, userRequest
                .getPassword());

            for (UserDetails details : user.details)
            {
                if (details.getClass() == PersonalDetails.class)
                {
                    PersonalDetails pd = (PersonalDetails) details;
                    addAttribute(attributes, LDAP_FIRST_NAME, pd.getFirstName());
                    addAttribute(attributes, LDAP_LAST_NAME, pd.getLastName());
                    addAttribute(attributes, LDAP_ADDRESS, pd.address);
                    addAttribute(attributes, LDAP_CITY, pd.city);
                    addAttribute(attributes, LDAP_COUNTRY, pd.country);
                    addAttribute(attributes, LDAP_EMAIL, pd.email);
                    addAttribute(attributes, LDAP_INSTITUTE, pd.institute);
                }
                else if (details.getClass() == PosixDetails.class)
                {
                    throw new UnsupportedOperationException(
                        "Support for users PosixDetails not available");
                }
            }

            AddRequest addRequest = new AddRequest(userDN, attributes);
            LDAPResult result = getConnection().add(addRequest);
            LdapDAO.checkLdapResult(result.getResultCode());
        }
        catch (LDAPException e)
        {
            logger.error("addUser Exception: " + e, e);
            LdapUserDAO.checkUserLDAPResult(e.getResultCode());
            throw new RuntimeException("Unexpected LDAP exception", e);
        }
    }

    /**
     * Get the user specified by userID.
     *
     * @param userID The userID.
     * @return User instance.
     * @throws UserNotFoundException  when the user is not found.
     * @throws TransientException     If an temporary, unexpected problem occurred.
     * @throws AccessControlException If the operation is not permitted.
     */
    public User<T> getUser(final T userID)
            throws UserNotFoundException, TransientException,
                   AccessControlException
    {
        return getUser(userID, config.getUsersDN());
    }


    /**
     * Get the user specified by userID.
     *
     * @param userID  The userID.
     * @param usersDN The LDAP tree to search.
     * @return User instance.
     * @throws UserNotFoundException  when the user is not found.
     * @throws TransientException     If an temporary, unexpected problem occurred.
     * @throws AccessControlException If the operation is not permitted.
     */
    private User<T> getUser(final T userID, final String usersDN)
            throws UserNotFoundException, TransientException,
                   AccessControlException
    {
        String searchField = userLdapAttrib.get(userID.getClass());
        if (searchField == null)
        {
            throw new IllegalArgumentException(
                    "Unsupported principal type " + userID.getClass());
        }

        searchField = "(&(objectclass=inetorgperson)(" +
                      searchField + "=" + userID.getName() + "))";
        logger.debug(searchField);

        SearchResultEntry searchResult = null;
        try
        {
            SearchRequest searchRequest =
                    new SearchRequest(usersDN, SearchScope.SUB,
                                      searchField, userAttribs);

            if (isSecure(usersDN))
            {
                searchRequest.addControl(
                        new ProxiedAuthorizationV2RequestControl(
                                "dn:" + getSubjectDN().toNormalizedString()));
            }

            searchResult = getConnection().searchForEntry(searchRequest);
        }
        catch (LDAPException e)
        {
            LdapDAO.checkLdapResult(e.getResultCode());
        }

        if (searchResult == null)
        {
            String msg = "User not found " + userID.toString();
            logger.debug(msg);
            throw new UserNotFoundException(msg);
        }
        User<T> user = new User<T>(userID);
        user.getIdentities().add(new HttpPrincipal(searchResult.getAttributeValue(
            userLdapAttrib.get(HttpPrincipal.class))));

        String fname = searchResult.getAttributeValue(LDAP_FIRST_NAME);
        String lname = searchResult.getAttributeValue(LDAP_LAST_NAME);
        PersonalDetails personaDetails = new PersonalDetails(fname, lname);
        personaDetails.address = searchResult.getAttributeValue(LDAP_ADDRESS);
        personaDetails.city = searchResult.getAttributeValue(LDAP_CITY);
        personaDetails.country = searchResult.getAttributeValue(LDAP_COUNTRY);
        personaDetails.email = searchResult.getAttributeValue(LDAP_EMAIL);
        personaDetails.institute = searchResult
                .getAttributeValue(LDAP_INSTITUTE);
        user.details.add(personaDetails);

        return user;
    }

    /**
     * Obtain whether the given DN tree requires authentication.
     *
     * @param usersDN The usersDN to check.
     * @return True if requires authentication, False otherwise.
     */
    private boolean isSecure(final String usersDN)
    {
        return !usersDN.equals(config.getUserRequestsDN());
    }

    /**
     * Get all users.  This will query the main tree only, and will return the
     * user name as the map's key, with the user's full name as the value.
     *
     * @return A map of string keys to string values.
     * @throws TransientException If an temporary, unexpected problem occurred.
     */
    public Map<String, PersonalDetails> getUsers()
            throws TransientException
    {
        final Map<String, PersonalDetails> users =
                new HashMap<String, PersonalDetails>();

        try
        {
            final Filter filter = Filter.createPresenceFilter(LDAP_UID);
            final String[] attributes = new String[]{LDAP_UID,
                                                     LDAP_FIRST_NAME,
                                                     LDAP_LAST_NAME,
                                                     LDAP_NSACCOUNTLOCK};
            final SearchRequest searchRequest =
                    new SearchRequest(config.getUsersDN(),
                                      SearchScope.SUB, filter, attributes);

            try
            {
                final SearchResult searchResult =
                        getConnection().search(searchRequest);

                LdapDAO.checkLdapResult(searchResult.getResultCode());
                for (SearchResultEntry next : searchResult.getSearchEntries())
                {
                    if (!next.hasAttribute(LDAP_NSACCOUNTLOCK))
                    {
                        final String trimmedFirstName =
                                next.getAttributeValue(LDAP_FIRST_NAME).trim();
                        final String trimmedLastName =
                                next.getAttributeValue(LDAP_LAST_NAME).trim();
                        final String trimmedUID =
                                next.getAttributeValue(LDAP_UID).trim();

                        users.put(trimmedUID,
                                  new PersonalDetails(trimmedFirstName,
                                                      trimmedLastName));
                    }
                }
            }
            catch (LDAPSearchException e)
            {
                if (e.getResultCode() == ResultCode.NO_SUCH_OBJECT)
                {
                    final String message = "Could not find users root";
                    logger.debug(message, e);
                    throw new IllegalStateException(message);
                }
            }
        }
        catch (LDAPException e1)
        {
            logger.debug("getGroupNames Exception: " + e1, e1);
            LdapDAO.checkLdapResult(e1.getResultCode());
            throw new IllegalStateException("Unexpected exception: " + e1
                    .getMatchedDN(), e1);
        }

        return users;
    }

    /**
     * Updated the user specified by User.
     *
     * @param user
     * @return User instance.
     * @throws UserNotFoundException  when the user is not found.
     * @throws TransientException     If an temporary, unexpected problem occurred.
     * @throws AccessControlException If the operation is not permitted.
     */
    public User<T> modifyUser(final User<T> user)
            throws UserNotFoundException, TransientException, AccessControlException
    {
        User existingUser = getUser(user.getUserID());

        List<Modification> mods = new ArrayList<Modification>();
        for (UserDetails details : user.details)
        {
            if (details.getClass() == PersonalDetails.class)
            {
                PersonalDetails pd = (PersonalDetails) details;
                addModification(mods, LDAP_FIRST_NAME, pd.getFirstName());
                addModification(mods, LDAP_LAST_NAME, pd.getLastName());
                addModification(mods, LDAP_ADDRESS, pd.address);
                addModification(mods, LDAP_CITY, pd.city);
                addModification(mods, LDAP_COUNTRY, pd.country);
                addModification(mods, LDAP_EMAIL, pd.email);
                addModification(mods, LDAP_INSTITUTE, pd.institute);
            }
            else if (details.getClass() == PosixDetails.class)
            {
                throw new UnsupportedOperationException(
                    "Support for users PosixDetails not available");
            }
        }

        try
        {
            ModifyRequest modifyRequest = new ModifyRequest(getUserDN(user), mods);
            modifyRequest.addControl(
                new ProxiedAuthorizationV2RequestControl(
                    "dn:" + getSubjectDN().toNormalizedString()));
            LdapDAO.checkLdapResult(getConnection().modify(modifyRequest).getResultCode());
        }
        catch (LDAPException e)
        {
            e.printStackTrace();
            logger.debug("Modify Exception: " + e, e);
            LdapDAO.checkLdapResult(e.getResultCode());
        }
        try
        {
            return getUser(user.getUserID());
        }
        catch (UserNotFoundException e)
        {
            throw new RuntimeException(
                "BUG: modified user not found (" + user.getUserID() + ")");
        }
    }

    /**
     * Update a user's password. The given user and authenticating user must match.
     *
     * @param user
     * @param oldPassword   current password.
     * @param newPassword   new password.
     * @throws UserNotFoundException If the given user does not exist.
     * @throws TransientException   If an temporary, unexpected problem occurred.
     * @throws AccessControlException If the operation is not permitted.
     */
    public void setPassword(User<T> user, final String oldPassword, final String newPassword)
        throws UserNotFoundException, TransientException, AccessControlException
    {
        try
        {
            DN userDN = getUserDN(user);
            DN subjectDN =  getSubjectDN();
            if (!userDN.equals(subjectDN))
            {
                throw new AccessControlException("Given user and authenticating user do not match");
            }

            ProxiedAuthorizationV2RequestControl control =
                new ProxiedAuthorizationV2RequestControl("dn:" + getSubjectDN().toNormalizedString());
            Control[] controls = new Control[] {control};

            PasswordModifyExtendedRequest passwordModifyRequest =
                new PasswordModifyExtendedRequest(userDN.toNormalizedString(), oldPassword, newPassword, controls);

            PasswordModifyExtendedResult passwordModifyResult = (PasswordModifyExtendedResult)
                getConnection().processExtendedOperation(passwordModifyRequest);
            LdapDAO.checkLdapResult(passwordModifyResult.getResultCode());
        }
        catch (LDAPException e)
        {
            logger.debug("setPassword Exception: " + e);
            LdapDAO.checkLdapResult(e.getResultCode());
        }
    }

    /**
     * Delete the user specified by userID.
     *
     * @param userID The userID.
     * @throws UserNotFoundException  when the user is not found.
     * @throws TransientException     If an temporary, unexpected problem occurred.
     * @throws AccessControlException If the operation is not permitted.
     */
    public void deleteUser(final T userID)
            throws UserNotFoundException, TransientException,
                   AccessControlException
    {

    }

    /**
     * Get all groups the user specified by userID belongs to.
     *
     * @param userID  The userID.
     * @param isAdmin
     * @return Collection of Group instances.
     * @throws UserNotFoundException  when the user is not found.
     * @throws TransientException     If an temporary, unexpected problem occurred., e.getMessage(
     * @throws AccessControlException If the operation is not permitted.
     */
    public Collection<DN> getUserGroups(final T userID, final boolean isAdmin)
            throws UserNotFoundException, TransientException,
                   AccessControlException
    {
        Collection<DN> groupDNs = new HashSet<DN>();
        try
        {
            String searchField = userLdapAttrib.get(userID.getClass());
            if (searchField == null)
            {
                throw new IllegalArgumentException(
                        "Unsupported principal type " + userID.getClass());
            }

            User<T> user = getUser(userID);
            Filter filter = Filter.createANDFilter(
                    Filter.createEqualityFilter(searchField,
                                                user.getUserID().getName()),
                    Filter.createPresenceFilter(LDAP_MEMBEROF));

            SearchRequest searchRequest =
                    new SearchRequest(config.getUsersDN(), SearchScope.SUB,
                                      filter, LDAP_MEMBEROF);

            searchRequest.addControl(
                    new ProxiedAuthorizationV2RequestControl("dn:" +
                                                             getSubjectDN()
                                                                     .toNormalizedString()));

            SearchResultEntry searchResult =
                    getConnection().searchForEntry(searchRequest);

            DN parentDN;
            if (isAdmin)
            {
                parentDN = new DN(config.getAdminGroupsDN());
            }
            else
            {
                parentDN = new DN(config.getGroupsDN());
            }

            if (searchResult != null)
            {
                String[] members = searchResult
                        .getAttributeValues(LDAP_MEMBEROF);
                if (members != null)
                {
                    for (String member : members)
                    {
                        DN groupDN = new DN(member);
                        if (groupDN.isDescendantOf(parentDN, false))
                        {
                            groupDNs.add(groupDN);
                        }
                    }
                }
            }
        }
        catch (LDAPException e)
        {
            LdapDAO.checkLdapResult(e.getResultCode());
        }
        return groupDNs;
    }

    /**
     * Check whether the user is a member of the group.
     *
     * @param userID  The userID.
     * @param groupID The groupID.
     * @return true or false
     * @throws UserNotFoundException  If the user is not found.
     * @throws TransientException     If an temporary, unexpected problem occurred.
     * @throws AccessControlException If the operation is not permitted.
     */
    public boolean isMember(final T userID, final String groupID)
            throws UserNotFoundException, TransientException,
                   AccessControlException
    {
        try
        {
            String searchField = userLdapAttrib.get(userID.getClass());
            if (searchField == null)
            {
                throw new IllegalArgumentException(
                        "Unsupported principal type " + userID.getClass());
            }

            User<T> user = getUser(userID);
            Filter filter = Filter.createANDFilter(
                    Filter.createEqualityFilter(searchField,
                                                user.getUserID().getName()),
                    Filter.createEqualityFilter(LDAP_MEMBEROF, groupID));

            SearchRequest searchRequest =
                    new SearchRequest(config.getUsersDN(), SearchScope.SUB,
                                      filter, LDAP_COMMON_NAME);

            searchRequest.addControl(
                    new ProxiedAuthorizationV2RequestControl("dn:" +
                                                             getSubjectDN()
                                                                     .toNormalizedString()));

            SearchResultEntry searchResults =
                    getConnection().searchForEntry(searchRequest);

            return (searchResults != null);
        }
        catch (LDAPException e)
        {
            LdapDAO.checkLdapResult(e.getResultCode());
        }
        return false;
    }

    /**
     * Returns a member user identified by the X500Principal only. The
     * returned object has the fields required by the GMS.
     * Note that this method binds as a proxy user and not as the
     * subject.
     *
     * @param userDN
     * @return
     * @throws UserNotFoundException
     * @throws LDAPException
     */
    User<X500Principal> getMember(DN userDN)
            throws UserNotFoundException, LDAPException
    {
        Filter filter =
                Filter.createEqualityFilter(LDAP_ENTRYDN,
                                            userDN.toNormalizedString());

        SearchRequest searchRequest =
                new SearchRequest(this.config.getUsersDN(), SearchScope.SUB,
                                  filter, memberAttribs);

        SearchResultEntry searchResult =
                getConnection().searchForEntry(searchRequest);

        if (searchResult == null)
        {
            String msg = "Member not found " + userDN;
            logger.debug(msg);
            throw new UserNotFoundException(msg);
        }
        User<X500Principal> user = new User<X500Principal>(
                new X500Principal(searchResult.getAttributeValue(
                        userLdapAttrib.get(X500Principal.class))));
        String princ = searchResult.getAttributeValue(
                userLdapAttrib.get(HttpPrincipal.class));
        if (princ != null)
        {
            user.getIdentities().add(new HttpPrincipal(princ));
        }
        String fname = searchResult.getAttributeValue(LDAP_FIRST_NAME);
        String lname = searchResult.getAttributeValue(LDAP_LAST_NAME);
        user.details.add(new PersonalDetails(fname, lname));
        return user;
    }


    DN getUserDN(User<? extends Principal> user)
            throws UserNotFoundException, TransientException
    {
        String searchField =
                userLdapAttrib.get(user.getUserID().getClass());
        if (searchField == null)
        {
            throw new IllegalArgumentException(
                    "Unsupported principal type " + user.getUserID()
                            .getClass());
        }

        // change the DN to be in the 'java' format
        if (user.getUserID() instanceof X500Principal)
        {
            X500Principal orderedPrincipal = AuthenticationUtil.getOrderedForm(
                    (X500Principal) user.getUserID());
            searchField = "(" + searchField + "=" + orderedPrincipal
                    .toString() + ")";
        }
        else
        {
            searchField = "(" + searchField + "=" + user.getUserID().getName()
                          + ")";
        }

        logger.debug("Search field is: " + searchField);

        SearchResultEntry searchResult = null;
        try
        {
            SearchRequest searchRequest =
                    new SearchRequest(this.config.getUsersDN(), SearchScope.SUB,
                                      searchField, LDAP_ENTRYDN);


            searchResult =
                    getConnection().searchForEntry(searchRequest);

        }
        catch (LDAPException e)
        {
            LdapDAO.checkLdapResult(e.getResultCode());
        }

        if (searchResult == null)
        {
            String msg = "User not found " + user.getUserID().getName();
            logger.debug(msg);
            throw new UserNotFoundException(msg);
        }
        return searchResult.getAttributeValueAsDN(LDAP_ENTRYDN);
    }

    protected DN getUserDN(final String userID)
            throws LDAPException, TransientException
    {
        try
        {
            return new DN(LDAP_UID + "=" + userID + "," + config.getUsersDN());
        }
        catch (LDAPException e)
        {
            logger.debug("getUserDN Exception: " + e, e);
            LdapDAO.checkLdapResult(e.getResultCode());
        }
        throw new IllegalArgumentException(userID + " not a valid user ID");
    }

    protected DN getUserRequestsDN(final String userID)
            throws LDAPException, TransientException
    {
        try
        {
            return new DN(LDAP_UID + "=" + userID + "," + config
                    .getUserRequestsDN());
        }
        catch (LDAPException e)
        {
            logger.debug("getUserRequestsDN Exception: " + e, e);
            LdapDAO.checkLdapResult(e.getResultCode());
        }
        throw new IllegalArgumentException(userID + " not a valid user ID");
    }

    private void addAttribute(List<Attribute> attributes, final String name, final String value)
    {
        if (value != null && !value.isEmpty())
        {
            attributes.add(new Attribute(name, value));
        }
    }

    private void addModification(List<Modification> mods, final String name, final String value)
    {
        if (value != null && !value.isEmpty())
        {
            mods.add(new Modification(ModificationType.REPLACE, name, value));
        }
        else
        {
            mods.add(new Modification(ModificationType.REPLACE, name));
        }
    }

    /**
     * Checks the Ldap result code, and if the result is not SUCCESS,
     * throws an appropriate exception. This is the place to decide on
     * mapping between ldap errors and exception types
     *
     * @param code The code returned from an LDAP request.
     * @throws TransientException
     * @throws UserAlreadyExistsException
     */
    protected static void checkUserLDAPResult(final ResultCode code)
            throws TransientException, UserAlreadyExistsException
    {
        if (code == ResultCode.ENTRY_ALREADY_EXISTS)
        {
            throw new UserAlreadyExistsException("User already exists.");
        }
        else
        {
            LdapDAO.checkLdapResult(code);
        }
    }
}