LdapGroupDAO.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.
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 *  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
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 *  This file is part of the             Ce fichier fait partie du projet
 *  OpenCADC project.                    OpenCADC.
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 */
package ca.nrc.cadc.ac.server.ldap;

import java.security.AccessControlException;
import java.security.Principal;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;

import javax.security.auth.x500.X500Principal;

import org.apache.log4j.Logger;

import ca.nrc.cadc.ac.ActivatedGroup;
import ca.nrc.cadc.ac.Group;
import ca.nrc.cadc.ac.GroupAlreadyExistsException;
import ca.nrc.cadc.ac.GroupNotFoundException;
import ca.nrc.cadc.ac.Role;
import ca.nrc.cadc.ac.User;
import ca.nrc.cadc.ac.UserNotFoundException;
import ca.nrc.cadc.net.TransientException;

import com.unboundid.ldap.sdk.AddRequest;
import com.unboundid.ldap.sdk.Attribute;
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.Modification;
import com.unboundid.ldap.sdk.ModificationType;
import com.unboundid.ldap.sdk.ModifyRequest;
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.controls.ProxiedAuthorizationV2RequestControl;

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

    
    private LdapUserDAO<T> userPersist;

    public LdapGroupDAO(LdapConfig config, LdapUserDAO<T> userPersist)
    {
        super(config);
        if (userPersist == null)
        {
            throw new IllegalArgumentException(
                    "User persistence instance required");
        }
        this.userPersist = userPersist;
    }

    /**
     * Creates the group.
     * 
     * @param group The group to create
     * 
     * @return created group
     * 
     * @throws GroupAlreadyExistsException If a group with the same ID already 
     *                                     exists.
     * @throws TransientException If an temporary, unexpected problem occurred.
     * @throws UserNotFoundException If owner or a member not valid user.
     */
    public Group addGroup(Group group)
        throws GroupAlreadyExistsException, TransientException,
               UserNotFoundException, AccessControlException
    {
        if (group.getOwner() == null)
        {
            throw new IllegalArgumentException("Group owner must be specified");
        }
        
        if (!isCreatorOwner(group.getOwner()))
        {
            throw new AccessControlException("Group owner must be creator");
        }

        try
        {
            getGroup(group.getID());
            throw new GroupAlreadyExistsException(group.getID());
        }
        catch (GroupNotFoundException ex)
        {
            try
            {        
                if (!group.getProperties().isEmpty())
                {
                    throw new UnsupportedOperationException(
                            "Support for groups properties not available");
                }
                
                Group inactiveGroup = getInactiveGroup(group.getID());
                if (inactiveGroup != null)
                {
                    return reactiveGroup(group, inactiveGroup);
                }
                
                DN ownerDN = userPersist.getUserDN(group.getOwner());
                Attribute ownerAttribute = 
                        new Attribute("owner", ownerDN.toNormalizedString());
                
                // add group to groups tree
                LDAPResult result = addGroup(group, ownerAttribute);
                
                // add group to admin groups tree
                result = addAdminGroup(group, ownerAttribute);
                
                try
                {
                    return getGroup(group.getID());
                }
                catch (GroupNotFoundException e)
                {
                    throw new RuntimeException("BUG: new group not found");
                }
            }
            catch (LDAPException e)
            {
                e.printStackTrace();
                throw new RuntimeException(e);
            }
        }
    }

    /**
     * Get the group with the given Group ID.
     * 
     * @param groupID The Group unique ID.
     * 
     * @return A Group instance
     * 
     * @throws GroupNotFoundException If the group was not found.
     * @throws TransientException  If an temporary, unexpected problem occurred.
     */
    public Group getGroup(String groupID)
        throws GroupNotFoundException, TransientException,
               AccessControlException
    {
        return getGroup(groupID, true);
    }

    private Group getGroup(String groupID, boolean withMembers)
        throws GroupNotFoundException, TransientException, 
               AccessControlException
    {
        try
        {
            Filter filter = Filter.createANDFilter(
                    Filter.createEqualityFilter("cn", groupID),
                    Filter.createNOTFilter(
                        Filter.createEqualityFilter("nsaccountlock", "TRUE")));
            
            SearchRequest searchRequest =  new SearchRequest(
                    config.getGroupsDN(), SearchScope.SUB, 
                    filter, new String[] {"entrydn", "cn", "description", 
                                          "owner", "uniquemember", 
                                          "modifytimestamp"});

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

            SearchResultEntry group = 
                    getConnection().searchForEntry(searchRequest);
            if (group == null)
            {
                String msg = "Group not found " + groupID;
                logger.debug(msg);
                throw new GroupNotFoundException(groupID);
            }
            String groupCN = group.getAttributeValue("cn");
            DN groupOwner = group.getAttributeValueAsDN("owner");
            Date lastModified = 
                group.getAttributeValueAsDate("modifytimestamp");
            
            User<X500Principal> owner;
            try
            {
                owner = userPersist.getMember(groupOwner);
            }
            catch (UserNotFoundException e)
            {
                throw new RuntimeException("BUG: group owner not found");
            }
            
            Group ldapGroup = new Group(groupCN, owner);
            ldapGroup.description = group.getAttributeValue("description");
            ldapGroup.lastModified = lastModified;

            if (withMembers)
            {
                if (group.getAttributeValues("uniquemember") != null)
                {
                    for (String member : group
                            .getAttributeValues("uniquemember"))
                    {
                        DN memberDN = new DN(member);
                        if (memberDN.isDescendantOf(config.getUsersDN(), false))
                        {
                            User<X500Principal> user;
                            try
                            {
                                user = userPersist.getMember(memberDN);
                            }
                            catch (UserNotFoundException e)
                            {
                                throw new RuntimeException(
                                    "BUG: group member not found");
                            }
                            ldapGroup.getUserMembers().add(user);
                        }
                        else if (memberDN.isDescendantOf(config.getGroupsDN(),
                                                         false))
                        {
                            ldapGroup.getGroupMembers().add(new Group(memberDN.getRDNString().replace("cn=", "")));
                        }
                        else
                        {
                            throw new RuntimeException(
                                "BUG: unknown member DN type: " + memberDN);
                        }
                    }
                }
            }
            
            return ldapGroup;
        }
        catch (LDAPException e1)
        {
            // TODO check which LDAP exceptions are transient and which
            // ones are
            // access control
            throw new TransientException("Error getting the group", e1);
        }
    }

    /**
     * Modify the given group.
     *
     * @param group The group to update.
     * 
     * @return The newly updated group.
     * 
     * @throws GroupNotFoundException If the group was not found.
     * @throws TransientException If an temporary, unexpected problem occurred.
     * @throws AccessControlException If the operation is not permitted.
     * @throws UserNotFoundException If owner or group members not valid users.
     */
    public Group modifyGroup(Group group)
        throws GroupNotFoundException, TransientException,
               AccessControlException, UserNotFoundException
    {
        // check if group exists
        Group oldGroup = getGroup(group.getID());
        
        return modifyGroup(group, oldGroup, null);
    }
    
    private Group modifyGroup(Group newGroup, Group oldGroup,
                             List<Modification> modifications)
        throws UserNotFoundException, TransientException,
               AccessControlException
    {
        if (!newGroup.getProperties().isEmpty())
        {
            throw new UnsupportedOperationException(
                    "Support for groups properties not available");
        }

        List<Modification> modifs = new ArrayList<Modification>();
        if (modifications != null)
        {
            modifs.addAll(modifications);
        }

        if (newGroup.description == null && oldGroup.description != null)
        {
            modifs.add(new Modification(ModificationType.DELETE, 
                                        "description"));
        }
        else if (newGroup.description != null && oldGroup.description == null)
        {
            modifs.add(new Modification(ModificationType.ADD, "description", 
                                        newGroup.description));
        }
        else if (newGroup.description != null && oldGroup.description != null)
        {
            modifs.add(new Modification(ModificationType.REPLACE, "description", 
                                        newGroup.description));
        }

        List<String> newMembers = new ArrayList<String>();
        for (User<?> member : newGroup.getUserMembers())
        {
            if (!oldGroup.getUserMembers().remove(member))
            {
                DN memberDN;
                try
                {
                    memberDN = userPersist.getUserDN(member);
                }
                catch (LDAPException e)
                {
                    throw new UserNotFoundException(
                            "User not found " + member.getUserID());
                }
                newMembers.add(memberDN.toNormalizedString());
            }
        }
        for (Group gr : newGroup.getGroupMembers())
        {
            if (gr.equals(newGroup))
            {
                throw new IllegalArgumentException(
                        "cyclical reference from group member to group");
            }

            if (!oldGroup.getGroupMembers().remove(gr))
            {
                DN grDN = getGroupDN(gr.getID());
                newMembers.add(grDN.toNormalizedString());
            }
        }
        if (!newMembers.isEmpty())
        {
            modifs.add(new Modification(ModificationType.ADD, "uniquemember", 
                (String[]) newMembers.toArray(new String[newMembers.size()])));
        }

        List<String> delMembers = new ArrayList<String>();
        for (User<?> member : oldGroup.getUserMembers())
        {
            DN memberDN;
            try
            {
                memberDN = this.userPersist.getUserDN(member);
            }
            catch (LDAPException e)
            {
                throw new UserNotFoundException(
                        "User not found " + member.getUserID());
            }
            delMembers.add(memberDN.toNormalizedString());
        }
        for (Group gr : oldGroup.getGroupMembers())
        {
            DN grDN = getGroupDN(gr.getID());
            delMembers.add(grDN.toNormalizedString());
        }
        if (!delMembers.isEmpty())
        {
            modifs.add(new Modification(ModificationType.DELETE, "uniquemember",
                (String[]) delMembers.toArray(new String[delMembers.size()])));
        }

        ModifyRequest modifyRequest = 
                new ModifyRequest(getGroupDN(newGroup.getID()), modifs);
        try
        {
            modifyRequest.addControl(
                    new ProxiedAuthorizationV2RequestControl(
                            "dn:" + getSubjectDN().toNormalizedString()));
            LDAPResult result = getConnection().modify(modifyRequest);
        }
        catch (LDAPException e1)
        {
            throw new RuntimeException("LDAP problem", e1);
        }
        try
        {
            return getGroup(newGroup.getID());
        }
        catch (GroupNotFoundException e)
        {
            throw new RuntimeException("BUG: modified group not found");
        }
    }

    /**
     * Deletes the group.
     * 
     * @param groupID The group to delete
     * 
     * @throws GroupNotFoundException If the group was not found.
     * @throws TransientException If an temporary, unexpected problem occurred.
     */
    public void deleteGroup(String groupID)
        throws GroupNotFoundException, TransientException,
               AccessControlException
    {
        Group group = getGroup(groupID);
        List<Modification> modifs = new ArrayList<Modification>();
        modifs.add(new Modification(ModificationType.ADD, "nsaccountlock", "true"));
        
        if (group.description != null)
        {
            modifs.add(new Modification(ModificationType.DELETE, "description"));
        }
        
        if (!group.getGroupMembers().isEmpty() || 
            !group.getUserMembers().isEmpty())
        {
            modifs.add(new Modification(ModificationType.DELETE, "uniquemember"));
        }

        ModifyRequest modifyRequest = 
                new ModifyRequest(getGroupDN(group.getID()), modifs);
        try
        {
            modifyRequest.addControl(
                    new ProxiedAuthorizationV2RequestControl(
                            "dn:" + getSubjectDN().toNormalizedString()));
            LDAPResult result = getConnection().modify(modifyRequest);
        }
        catch (LDAPException e1)
        {
            throw new RuntimeException("LDAP problem", e1);
        }
        
        try
        {
            getGroup(group.getID());
            throw new RuntimeException("BUG: group not deleted " + 
                                       group.getID());
        }
        catch (GroupNotFoundException ignore) {}
    }
    
    /**
     * Obtain a Collection of Groups that fit the given query.
     * 
     * @param userID The userID.
     * @param role Role of the user, either owner, member, or read/write.
     * @param groupID The Group ID.
     * 
     * @return Collection of Groups
     *         matching GROUP_READ_ACI.replace(ACTUAL_GROUP_TOKEN,
     *         readGrDN.toNormalizedString()) the query, or empty
     *         Collection. Never null.
     * @throws TransientException  If an temporary, unexpected problem occurred.
     * @throws UserNotFoundException
     * @throws GroupNotFoundException
     */
    public Collection<Group> getGroups(T userID, Role role, String groupID)
        throws TransientException, AccessControlException,
               GroupNotFoundException, UserNotFoundException
    {
        User<T> user = new User<T>(userID);
        DN userDN;
        try
        {   
            userDN = userPersist.getUserDN(user);
        }
        catch (LDAPException e)
        {
            // TODO check which LDAP exceptions are transient and which
            // ones are
            // access control
            throw new TransientException("Error getting user", e);
        }
        
        if (role == Role.OWNER)
        {
            return getOwnerGroups(user, userDN, groupID);
        }
        else if (role == Role.MEMBER)
        {
            return getMemberGroups(user, userDN, groupID);
        }
        else if (role == Role.RW)
        {
            return getRWGroups(user, userDN, groupID);
        }
        throw new IllegalArgumentException("Unknown role " + role);
    }
    
    protected Collection<Group> getOwnerGroups(User<T> user, DN userDN,
                                               String groupID)
        throws TransientException, AccessControlException,
               GroupNotFoundException, UserNotFoundException
    {
        try
        {                           
            Filter filter = Filter.createEqualityFilter("owner", 
                                                        userDN.toString());
            if (groupID != null)
            {
                getGroup(groupID);
                filter = Filter.createANDFilter(filter, 
                                Filter.createEqualityFilter("cn", groupID));
            }
            
            SearchRequest searchRequest =  new SearchRequest(
                    config.getGroupsDN(), SearchScope.SUB, filter, 
                    new String[] {"cn", "description", "modifytimestamp"});
            
            searchRequest.addControl(
                    new ProxiedAuthorizationV2RequestControl("dn:" + 
                            getSubjectDN().toNormalizedString()));
            
            Collection<Group> groups = new ArrayList<Group>();
            SearchResult results = getConnection().search(searchRequest);
            for (SearchResultEntry result : results.getSearchEntries())
            {
                String groupName = result.getAttributeValue("cn");
                // Ignore existing illegal group names.
                try
                {
                    Group group = new Group(groupName, user);
                    group.description = result.getAttributeValue("description");
                    group.lastModified = 
                        result.getAttributeValueAsDate("modifytimestamp");
                    groups.add(group);
                }
                catch (IllegalArgumentException ignore) { }   
            }
            
            return groups; 
        }
        catch (LDAPException e1)
        {
            // TODO check which LDAP exceptions are transient and which
            // ones are
            // access control
            throw new TransientException("Error getting groups", e1);
        }
    }
    
    protected Collection<Group> getMemberGroups(User<T> user, DN userDN, 
                                                String groupID)
        throws TransientException, AccessControlException,
               GroupNotFoundException, UserNotFoundException
    {
        if (groupID != null)
        {
            Collection<Group> groups = new ArrayList<Group>();
            if (userPersist.isMember(user.getUserID(), groupID))
            {
                groups.add(getGroup(groupID));
            }
            return groups;
        }
        else
        {
            return userPersist.getUserGroups(user.getUserID());
        }
    }
    
    protected Collection<Group> getRWGroups(User<T> user, DN userDN,
                                            String groupID)
        throws TransientException, AccessControlException,
               GroupNotFoundException, UserNotFoundException
    {
        try
        {
            Collection<Group> queryGroups =  new ArrayList<Group>();
            if (groupID != null)
            {
                queryGroups.add(new Group(groupID, user));
            }
            else
            {
                // List of Groups the user belongs to.
                queryGroups.addAll(getMemberGroups(user, userDN, groupID));
            
                // List of Groups the user owns;
                queryGroups.addAll(getOwnerGroups(user, userDN, groupID));
            }
            
            System.out.println("# groups: " + queryGroups.size());
                    
            List<Filter> filters = new ArrayList<Filter>();
            for (Group member : queryGroups)
            {
//                // Require both groupRead and groupWrite
//                if (member.groupRead != null && member.groupWrite != null)
//                {
//                    DN groupRead = getGroupDN(member.groupRead.getID());
//                    String groupReadAci = 
//                        GROUP_READ_ACI.replace(ACTUAL_GROUP_TOKEN, 
//                                           groupRead.toNormalizedString());
//                    DN groupWrite = getGroupDN(member.groupRead.getID());
//                    String groupWriteAci = 
//                        GROUP_WRITE_ACI.replace(ACTUAL_GROUP_TOKEN, 
//                                            groupWrite.toNormalizedString());
//                    System.out.println(groupReadAci);
//                    System.out.println(groupWriteAci);
//
//                    Filter filter = Filter.createANDFilter(
//                            Filter.createEqualityFilter("aci", groupReadAci),
//                            Filter.createEqualityFilter("aci", groupWriteAci));
//                    filters.add(filter);
//                }
            }

            Collection<Group> groups = new ArrayList<Group>();
            if (filters.isEmpty())
            {
                return groups;
            }
            
            Filter filter = Filter.createORFilter(filters);
            SearchRequest searchRequest =  new SearchRequest(
                        config.getGroupsDN(), SearchScope.SUB, filter, 
                        new String[] {"cn", "owner", "description", 
                                      "modifytimestamp"});

            searchRequest.addControl(
                    new ProxiedAuthorizationV2RequestControl("dn:" + 
                            getSubjectDN().toNormalizedString()));
            
            SearchResult results = getConnection().search(searchRequest);
            for (SearchResultEntry result : results.getSearchEntries())
            {
                String groupName = result.getAttributeValue("cn");
                DN ownerDN = result.getAttributeValueAsDN("owner");
                User<X500Principal> owner = userPersist.getMember(ownerDN);
                
                // Ignore existing illegal group names.
                try
                {
                    Group group = new Group(groupName, owner);
                    group.description = result.getAttributeValue("description");
                    group.lastModified = 
                            result.getAttributeValueAsDate("modifytimestamp");
                    groups.add(group);
                }
                catch (IllegalArgumentException ignore) { }   
            }
            return groups;
        }
        catch (LDAPException e)
        {
            // TODO check which LDAP exceptions are transient and which
            // ones are
            // access control
            throw new TransientException("Error getting groups", e);
        }
    }
    
//    protected Collection<Group> getRWGroups2(User<T> user, DN userDN, 
//                                             String groupID)
//        throws TransientException, AccessControlException,
//               GroupNotFoundException, UserNotFoundException
//    {
//        try
//        {
//            Collection<Group> groups = new ArrayList<Group>();
//            
//            Collection<Group> queryGroups =  new ArrayList<Group>();
//            if (groupID != null)
//            {
//                queryGroups.add(new Group(groupID, user));
//            }
//            else
//            {
//                // List of Groups the user belongs to.
//                queryGroups.addAll(getMemberGroups(user, userDN, groupID));
//            
//                // List of Groups the user owns;
//                queryGroups.addAll(getOwnerGroups(user, userDN, groupID));
//            }
//            
//            for (Group member : queryGroups)
//            {
//                // Require both groupRead and groupWrite
//                if (member.groupRead != null && member.groupWrite != null)
//                {
//                    DN groupRead = getGroupDN(member.groupRead.getID());
//                    String groupReadAci = 
//                            GROUP_READ_ACI.replace(ACTUAL_GROUP_TOKEN, 
//                                            groupRead.toNormalizedString());
//                    DN groupWrite = getGroupDN(member.groupWrite.getID());
//                    String groupWriteAci = 
//                            GROUP_WRITE_ACI.replace(ACTUAL_GROUP_TOKEN, 
//                                            groupWrite.toNormalizedString());
//
//                    Filter filter = Filter.createANDFilter(
//                            Filter.createEqualityFilter("aci", groupReadAci),
//                            Filter.createEqualityFilter("aci", groupWriteAci));
//
//                    SearchRequest searchRequest = new SearchRequest(
//                            config.getGroupsDN(), SearchScope.SUB, filter, 
//                            new String[] {"cn", "owner", "description", 
//                                          "modifytimestamp"});
//
//                    searchRequest.addControl(
//                            new ProxiedAuthorizationV2RequestControl("dn:" + 
//                                    getSubjectDN().toNormalizedString()));
//
//                    SearchResult results = getConnection().search(searchRequest);
//                    for (SearchResultEntry result : results.getSearchEntries())
//                    {
//                        String groupName = result.getAttributeValue("cn");
//                        DN ownerDN = result.getAttributeValueAsDN("owner");
//                        User<X500Principal> owner = userPersist.getMember(ownerDN);
//
//                        // Ignore existing illegal group names.
//                        try
//                        {
//                            Group group = new Group(groupName, owner);
//                            group.description = result.getAttributeValue("description");
//                            group.lastModified = 
//                                    result.getAttributeValueAsDate("modifytimestamp");
//                            groups.add(group);
//                        }
//                        catch (IllegalArgumentException ignore) { } 
//                    }
//                }
//            }
//            return groups;
//        }
//        catch (LDAPException e)
//        {
//            // TODO check which LDAP exceptions are transient and which
//            // ones are
//            // access control
//            throw new TransientException("Error getting groups", e);
//        }
//    }
    
    protected Group getInactiveGroup(final String groupID)
        throws UserNotFoundException, LDAPException
    {
        Filter filter = Filter.createANDFilter(
                Filter.createEqualityFilter("cn", groupID),
                Filter.createEqualityFilter("nsaccountlock", "true"));

        SearchRequest searchRequest =  new SearchRequest(
                config.getGroupsDN(), SearchScope.SUB, 
                filter, new String[] {"cn", "owner"});

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

        SearchResultEntry searchResult = 
                getConnection().searchForEntry(searchRequest);
        
        if (searchResult == null)
        {
            String msg = "Inactive Group not found " + groupID;
            logger.debug(msg);
            return null;
        }

        String groupCN = searchResult.getAttributeValue("cn");
        DN groupOwner = searchResult.getAttributeValueAsDN("owner");

        User<X500Principal> owner = userPersist.getMember(groupOwner);

        return new Group(groupCN, owner);
    }
    
    protected Group reactiveGroup(final Group newGroup, 
                                  final Group inactiveGroup)
        throws UserNotFoundException, LDAPException, TransientException
    {
        // Check requestor owns the group.
        DN ownerDN = userPersist.getUserDN(newGroup.getOwner());
        if (!ownerDN.equals(getSubjectDN()))
        {
           throw new AccessControlException(
               "Unable to activate group " + newGroup.getID() + 
               " because " + getSubjectDN().toString()
               + " is not the owner"); 
        }

        List<Modification> mods = new ArrayList<Modification>();
        mods.add(new Modification(ModificationType.DELETE, "nsaccountlock"));

        Group modifiedGroup = modifyGroup(newGroup, inactiveGroup, mods);
        Group activatedGroup = 
                new ActivatedGroup(modifiedGroup.getID(),
                                   modifiedGroup.getOwner());
        activatedGroup.description = modifiedGroup.description;
        activatedGroup.getProperties()
                .addAll(modifiedGroup.getProperties());
        activatedGroup.getGroupMembers()
                .addAll(modifiedGroup.getGroupMembers());
        activatedGroup.getUserMembers()
                .addAll(modifiedGroup.getUserMembers());
        return activatedGroup;
    }
    
    /**
     * 
     * @param group
     * @param ownerAttribute
     * @return
     * @throws UserNotFoundException
     * @throws LDAPException 
     */
    protected LDAPResult addGroup(final Group group, 
                                  final Attribute ownerAttribute)
        throws UserNotFoundException, LDAPException
    {
        // add new group
        List<Attribute> attributes = new ArrayList<Attribute>();
        attributes.add(ownerAttribute);
        attributes.add(new Attribute("objectClass", "groupofuniquenames"));
        attributes.add(new Attribute("cn", group.getID()));
        
        if (group.description != null)
        {
            attributes.add(new Attribute("description", group.description));
        }

        List<String> members = new ArrayList<String>();
        for (User<?> member : group.getUserMembers())
        {
            DN memberDN = this.userPersist.getUserDN(member);
            members.add(memberDN.toNormalizedString());
        }
        for (Group gr : group.getGroupMembers())
        {
            DN grDN = getGroupDN(gr.getID());
            members.add(grDN.toNormalizedString());
        }
        if (!members.isEmpty())
        {
            attributes.add(new Attribute("uniquemember", 
                (String[]) members.toArray(new String[members.size()])));
        }

        AddRequest addRequest = 
                new AddRequest(getGroupDN(group.getID()), attributes);

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

        return getConnection().add(addRequest);
    }
    
    /**
     * 
     * @param group
     * @param ownerAttribute
     * @return
     * @throws UserNotFoundException
     * @throws LDAPException 
     */
    protected LDAPResult addAdminGroup(final Group group, 
                                       final Attribute ownerAttribute)
        throws UserNotFoundException, LDAPException
    {
        // add new group
        List<Attribute> attributes = new ArrayList<Attribute>();
        attributes.add(ownerAttribute);
        attributes.add(new Attribute("objectClass", "groupofuniquenames"));
        attributes.add(new Attribute("cn", group.getID()));

        List<String> admins = new ArrayList<String>();
        for (User<?> user : group.getUserAdmins())
        {
            DN userDN = this.userPersist.getUserDN(user);
            admins.add(userDN.toNormalizedString());
        }
        for (Group gr : group.getGroupAdmins())
        {
            DN grDN = getGroupDN(gr.getID());
            admins.add(grDN.toNormalizedString());
        }
        if (!admins.isEmpty())
        {
            attributes.add(new Attribute("uniquemember", 
                (String[]) admins.toArray(new String[admins.size()])));
        }

        AddRequest addRequest = 
                new AddRequest(getAdminGroupDN(group.getID()), attributes);

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

        return getConnection().add(addRequest);
    }

    /**
     * Returns a group based on its LDAP DN. The returned group is bare
     * (contains only group ID, description, modifytimestamp).
     * 
     * @param groupDN
     * @return
     * @throws com.unboundid.ldap.sdk.LDAPException
     * @throws ca.nrc.cadc.ac.GroupNotFoundException
     * @throws ca.nrc.cadc.ac.UserNotFoundException
     */
    protected Group getGroup(DN groupDN)
        throws LDAPException, GroupNotFoundException, UserNotFoundException
    {
        SearchResultEntry searchResult = 
                getConnection().getEntry(groupDN.toNormalizedString(),
                                new String[] {"cn", "description"});

        if (searchResult == null)
        {
            String msg = "Group not found " + groupDN;
            logger.debug(msg);
            throw new GroupNotFoundException(groupDN.toNormalizedString());
        }

        Group group = new Group(searchResult.getAttributeValue("cn"));
        group.description = searchResult.getAttributeValue("description");
        return group;
    }

    /**
     * 
     * @param groupID
     * @return 
     */
    protected DN getGroupDN(final String groupID)
    {
        try
        {
            return new DN("cn=" + groupID + "," + config.getGroupsDN());
        }
        catch (LDAPException e)
        {
        }
        throw new IllegalArgumentException(groupID + " not a valid group ID");
    }
    
    /**