/*
    * Copyright 2000-2004 The Apache Software Foundation.
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    *      http://www.apache.org/licenses/LICENSE-2.0
    * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.jetspeed.services.security.ldap;
  
  import java.security.Principal;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Vector;
  import javax.naming.NamingEnumeration;
  import javax.naming.directory.Attributes;
  import javax.naming.directory.BasicAttributes;
  import javax.naming.directory.DirContext;
  import javax.naming.directory.SearchResult;
  import javax.servlet.ServletConfig;
  
  // Jetspeed classes
  import org.apache.jetspeed.om.profile.Profile;
  import org.apache.jetspeed.om.security.JetspeedUser;
  import org.apache.jetspeed.om.security.UserNamePrincipal;
  import org.apache.jetspeed.om.security.ldap.LDAPUser;
  import org.apache.jetspeed.services.JetspeedLDAP;
  import org.apache.jetspeed.services.JetspeedSecurity;
  import org.apache.jetspeed.services.Profiler;
  import org.apache.jetspeed.services.PsmlManager;
  import org.apache.jetspeed.services.ldap.LDAPURL;
  import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
  import org.apache.jetspeed.services.logging.JetspeedLogger;
  import org.apache.jetspeed.services.rundata.JetspeedRunData;
  import org.apache.jetspeed.services.rundata.JetspeedRunDataService;
  import org.apache.jetspeed.services.security.CredentialsManagement;
  import org.apache.jetspeed.services.security.JetspeedSecurityException;
  import org.apache.jetspeed.services.security.JetspeedSecurityService;
  import org.apache.jetspeed.services.security.NotUniqueUserException;
  import org.apache.jetspeed.services.security.UnknownUserException;
  import org.apache.jetspeed.services.security.UserException;
  import org.apache.jetspeed.services.security.UserManagement;
  
  // Turbine classes
  import org.apache.turbine.services.InitializationException;
  import org.apache.turbine.services.TurbineBaseService;
  import org.apache.turbine.services.TurbineServices;
  import org.apache.turbine.services.resources.ResourceService;
  import org.apache.turbine.services.rundata.RunDataService;
  
  /***
   *
   * @author <a href="mailto:ender@kilicoglu.nom.tr">Ender KILICOGLU</a>
   * @author <a href="mailto:sami.leino@netorek.fi">Sami Leino</a>
   *
   * @version $Id: LDAPUserManagement.java,v 1.10 2004/02/23 03:52:33 jford Exp $
   *
   */
  public class LDAPUserManagement extends TurbineBaseService
                                  implements UserManagement,
                                             CredentialsManagement
  {
      /***
       * Static initialization of the logger for this class
       */    
      private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(LDAPUserManagement.class.getName());
      
      // Constants
      private final static String CONFIG_SECURE_PASSWORDS_KEY       = "secure.passwords";
      private final static String CONFIG_SECURE_PASSWORDS_ALGORITHM = "secure.passwords.algorithm";
      private final static String CONFIG_SECURE_PASSWORDS_SUFFIX    = "secure.passwords.suffix";
      private final static String CONFIG_NEWUSER_ROLES              = "newuser.roles";
      private final static String[] DEFAULT_CONFIG_NEWUSER_ROLES    = { "user" };
  
      private final static String[] ATTRS = { "ou", "userPassword", "uid", "mail", "sn", "givenName", 
                                              "uidNumber", "name", "objectdata", "objectClass",
                                              "usergrouprole", "lastlogindate", "lastmodifieddate",
                                              "creationdate", "confirm", "disabled" };
      
      // Class variables
      protected static boolean securePasswords                      = false;
      protected static String passwordsAlgorithm                    = "crypt";
      protected static String passwordsSuffix                       = "{crypt}";
  
      // Instance variables
      protected JetspeedRunDataService runDataService               = null;
      protected String roles[]                                      = null;
  
      ///////////////////////////////////////////////////////////////////////////
      // User Management Interfaces
  
     ///////////////////////////////////////////////////////////////////////////
 
     /***
      * Retrieves a <code>JetspeedUser</code> given the primary principle.
      * The principal can be any valid Jetspeed Security Principal:
      *   <code>org.apache.jetspeed.om.security.UserNamePrincipal</code>
      *   <code>org.apache.jetspeed.om.security.UserIdPrincipal</code>
      *
      * The security service may optionally check the current user context
      * to determine if the requestor has permission to perform this action.
      *
      * @param principal a principal identity to be retrieved.
      *
      * @return a <code>JetspeedUser</code> associated to the principal identity.
      * @exception UserException when the security provider has a general failure retrieving a user.
      * @exception UnknownUserException when the security provider cannot match
      *            the principal identity to a user.
      * @exception InsufficientPrivilegeException when the requestor is denied
      *                                           due to insufficient privilege
      */
     public JetspeedUser getUser(Principal principal)
         throws JetspeedSecurityException
     {
         BasicAttributes attr = new BasicAttributes();
         Vector userurls = new Vector();
         LDAPUser user = null;
 
         try
         {
             userurls = JetspeedLDAP.search(JetspeedLDAP.buildURL("ou=users"),
                        "(&(uid="+principal.getName()+")(objectclass=jetspeeduser))", ATTRS, true);
         }
         catch (Exception e)
         {
             logger.error( "Failed to retrieve user '" + principal.getName() + "'", e );
             throw new UserException("Failed to retrieve user '" + principal.getName() + "'", e);
         }
          
         if (userurls.size() == 1)
         {
             user = new LDAPUser((LDAPURL) ((Vector)userurls.elementAt(0)).firstElement());
             return user;
         }
         else if(userurls.size() > 1)
         {
             throw new UserException("Multiple Users with same username '" + principal.getName() + "'");
         }
         else
         {
             throw new UnknownUserException("Unknown user '" + principal.getName() + "'");
         }
     }
 
     /***
      * Retrieves a collection of all <code>JetspeedUser</code>s.
      * The security service may optionally check the current user context
      * to determine if the requestor has permission to perform this action.
      *
      * @return a collection of <code>JetspeedUser</code> entities.
      * @exception UserException when the security provider has a general failure retrieving users.
      * @exception InsufficientPrivilegeException when the requestor is denied due to insufficient privilege
      */
     public Iterator getUsers()
         throws JetspeedSecurityException
     {
         String filter = "(objectclass=jetspeeduser)";
         return getUsersUsingLDAPSpecificFilter(filter, null);
     }
 
     /***
      * Retrieves a collection of <code>JetspeedUser</code>s filtered by a security
      * provider-specific query string. For example SQL, OQL, JDOQL.
      * The security service may optionally check the current user context
      * to determine if the requestor has permission to perform this action.
      *
      * @return a collection of <code>JetspeedUser</code> entities.
      * @exception UserException when the security provider has a general failure retrieving users.
      * @exception InsufficientPrivilegeException when the requestor is denied due to insufficient privilege
      *
      */
     public Iterator getUsers(String filter)
         throws JetspeedSecurityException
     {
         // String ldapFilter = convert(filter);
         return getUsersUsingLDAPSpecificFilter(filter, null);
     }
 
     /***
      * Retrieves a collection of <code>JetspeedUser</code>s filtered by a security
      * provider-specific query string. For example SQL, OQL, JDOQL.
      * The security service may optionally check the current user context
      * to determine if the requestor has permission to perform this action.
      *
      * @return a collection of <code>JetspeedUser</code> entities.
      * @exception UserException when the security provider has a general failure retrieving users.
      * @exception InsufficientPrivilegeException when the requestor is denied due to insufficient privilege
      */
     protected Iterator getUsersUsingLDAPSpecificFilter(String filter, String[] attributesToFetch)
         throws JetspeedSecurityException
     {
         String baseDN = "ou=users";
         NamingEnumeration userEnum = null;
         List resultList = new Vector(1024);
 
         try
         {
             LDAPURL url = JetspeedLDAP.buildURL( baseDN );
             DirContext ctx = JetspeedLDAP.getService().connect(url);
             userEnum = JetspeedLDAP.search(ctx, url.getDN(), filter, attributesToFetch, JetspeedLDAP.getService().SUB);
 
             while (userEnum.hasMoreElements())
             {
                 LDAPUser user = buildUser(((SearchResult)userEnum.nextElement()).getAttributes());
                 resultList.add( user );
             }
 
             JetspeedLDAP.getService().checkAndCloseContext(ctx);
         }
         catch ( Exception e )
         {
             logger.error( "Failed to retrieve user with filter:" + filter, e );
             throw new UserException( "Failed to retrieve user with filter:" + filter, e );
         }
 
         return ( resultList.iterator() );
     }
 
     protected LDAPUser buildUser(Attributes attributes)
     {
         return new LDAPUser(attributes);
     }
     
     /***
      * Saves a <code>JetspeedUser</code>'s attributes into permanent storage.
      * The user's account is required to exist in the storage.
      * The security service may optionally check the current user context
      * to determine if the requestor has permission to perform this action.
      *
      * @exception UserException when the security provider has a general failure retrieving users.
      * @exception InsufficientPrivilegeException when the requestor is denied due to insufficient privilege
      */
     public void saveUser(JetspeedUser user)
         throws JetspeedSecurityException
     {
         if(!accountExists(user, true))
         {
             throw new UnknownUserException("Cannot save user '" + user.getUserName() +
                                            "', User doesn't exist");
         }
         try
         {
             ((LDAPUser)user).update(false);
         }
         catch(Exception e)
         {
             logger.error( "Failed to save user object ", e);
             throw new UserException("Failed to save user object ", e);
         }
     }
 
     /***
      * Adds a <code>JetspeedUser</code> into permanent storage.
      * The security service can throw a <code>NotUniqueUserException</code> when the public
      * credentials fail to meet the security provider-specific unique constraints.
      * The security service may optionally check the current user context
      * to determine if the requestor has permission to perform this action.
      *
      * @exception UserException when the security provider has a general failure retrieving users.
      * @exception NotUniqueUserException when the public credentials fail to meet
      *                                   the security provider-specific unique constraints.
      * @exception InsufficientPrivilegeException when the requestor is denied due to insufficient privilege
      */
     public void addUser(JetspeedUser user)
         throws JetspeedSecurityException
     {
         if(accountExists(user))
         {
             throw new NotUniqueUserException("The account '" +
                 user.getUserName() + "' already exists");
         }
 
         String initialPassword = user.getPassword();
         String encrypted = JetspeedSecurity.encryptPassword(initialPassword);
         user.setPassword(encrypted);
         ((LDAPUser)user).update(true);
 
         addDefaultPSML(user);
     }
 
     /*
      * A default PSML page is added for the user, and the Jetspeed default roles
      * are assigned to the new user.
      *
      * @param user The new user.
      * @throws
      */
     protected void addDefaultPSML(JetspeedUser user)
         throws JetspeedSecurityException
     {
         for (int ix = 0; ix < roles.length; ix++)
         {
             try
             {
 
                 JetspeedSecurity.grantRole(user.getUserName(),
                       JetspeedSecurity.getRole(roles[ix]).getName());
             }
             catch(Exception e)
             {
                 logger.error("Could not grant role: " + roles[ix] + " to user " + user.getUserName(), e);
             }
         }
         try
         {
             JetspeedRunData rundata = getRunData();
             if (rundata != null)
             {
                 Profile profile = Profiler.createProfile();
                 profile.setUser(user);
                 profile.setMediaType("html");
                 Profiler.createProfile(getRunData(), profile);
             }
         }
         catch (Exception e)
         {
             logger.error( "Failed to create profile for new user ", e );
             removeUser(new UserNamePrincipal(user.getUserName()));
             throw new UserException("Failed to create profile for new user ", e);
         }
     }
 
     /***
      * Removes a <code>JetspeedUser</code> from the permanent store.
      * The security service may optionally check the current user context
      * to determine if the requestor has permission to perform this action.
      *
      * @param principal the principal identity to be retrieved.
      * @exception UserException when the security provider has a general failure retrieving a user.
      * @exception UnknownUserException when the security provider cannot match
      *            the principal identity to a user.
      * @exception InsufficientPrivilegeException when the requestor is denied due to insufficient privilege
      */
     public void removeUser(Principal principal)
         throws JetspeedSecurityException
     {
         BasicAttributes attr= new BasicAttributes();
         Vector userurls = new Vector();
         LDAPUser user = (LDAPUser)getUser(principal);
 
         try
         {
             JetspeedLDAP.deleteEntry(user.getldapurl());
             PsmlManager.removeUserDocuments(user);
         }
         catch(Exception e)
         {
             logger.error( "Failed to remove account '" + user.getUserName() + "'", e );
             throw new UserException("Failed to remove account '" +
                 user.getUserName() + "'", e);
         }
 
     }
 
     ///////////////////////////////////////////////////////////////////////////
     // Credentials Management
     ///////////////////////////////////////////////////////////////////////////
 
     /***
      * Allows for a user to change their own password.
      *
      * @param user the JetspeedUser to change password
      * @param oldPassword the current password supplied by the user.
      * @param newPassword the current password requested by the user.
      * @exception UserException when the security provider has a general failure retrieving a user.
      * @exception UnknownUserException when the security provider cannot match
      *            the principal identity to a user.
      * @exception InsufficientPrivilegeException when the requestor is denied due to insufficient privilege
      */
     public void changePassword( JetspeedUser user,
                                 String oldPassword,
                                 String newPassword )
         throws JetspeedSecurityException
     {
         oldPassword = JetspeedSecurity.convertPassword(oldPassword);
         newPassword = JetspeedSecurity.convertPassword(newPassword);
 
         if(!accountExists(user))
         {
             throw new UnknownUserException("The account '" +
                 user.getUserName() + "' does not exist");
         }
         else if (!passwordsMatch(user, oldPassword))
         {
             throw new UserException(
                "The supplied old password for '" + user.getUserName() +
                 "' was incorrect");
         }
 
         String encrypted = JetspeedSecurity.encryptPassword( newPassword );
         user.setPassword(encrypted);
 
         // save the changes in the database immediately, to prevent the password
         // being 'reverted' to the old value if the user data is lost somehow
         // before it is saved at session's expiry.
         saveUser(user);
     }
 
     /***
      * Forcibly sets new password for a User.
      *
      * Provides an administrator the ability to change the forgotten or
      * compromised passwords. Certain implementatations of this feature
      * would require administrative level access to the authenticating
      * server / program.
      *
      * @param user              the user to change the password for.
      * @param password          the new password.
      *
      * @exception UserException        when the security provider has a general
      *                                 failure retrieving a user.
      * @exception UnknownUserException when the security provider cannot match
      *            the principal identity to a user.
      * @exception InsufficientPrivilegeException   when the requestor is
      *                                             denied due to insufficient privilege
      */
     public void forcePassword( JetspeedUser user, String password )
         throws JetspeedSecurityException
     {
         if(!accountExists(user))
         {
             throw new UnknownUserException("The account '" +
                 user.getUserName() + "' does not exist");
         }
 
         String encrypted = JetspeedSecurity.encryptPassword( password );
         user.setPassword(encrypted);
 
 
         // save the changes in the database immediately, to prevent the
         // password being 'reverted' to the old value if the user data
         // is lost somehow before it is saved at session's expiry.
         saveUser(user);
     }
 
     /***
      * This method provides client-side encryption of passwords.
      *
      * If <code>secure.passwords</code> are enabled in 
      * JetspeedSecurity.properties,
      * the password will be encrypted, if not, it will be returned unchanged.
      * The <code>secure.passwords.algorithm</code> property can be used
      * to chose which digest algorithm should be used for performing the
      * encryption. <code>SHA</code> is used by default.
      *
      * @param password the password to process
      * 
      * @return processed password
      *
      */
     public String encryptPassword( String password )
         throws JetspeedSecurityException
     {
         if (securePasswords == false)
         {
             return password;
         }
         else if(password == null)
         {
             return null;
         }
         else if(password.startsWith(passwordsSuffix))
         {
             // A kludge
             return password;
         }
  
         return passwordsSuffix + UnixCrypt.crypt(password);
     }
 
     /***
      * <p>Check's if user's current password matches with the
      * supplied password.</p>
      * 
      * @param user             User whose password will be checked
      * @param suppliedPassword Password to match
      *
      * @return                 True if passwords match.
      *
      */ 
     public static boolean passwordsMatch(JetspeedUser user, String suppliedPassword)
     {
         if (securePasswords == false)
         {
             return user.getPassword().equals(suppliedPassword);
         }
         else
         {
             return UnixCrypt.matches(user.getPassword().substring(passwordsSuffix.length()), suppliedPassword);
         }
     }
 
     ///////////////////////////////////////////////////////////////////////////
     // Service Init
     ///////////////////////////////////////////////////////////////////////////
 
     /***
      * This is the early initialization method called by the
      * Turbine <code>Service</code> framework
      * @param conf The <code>ServletConfig</code>
      * @exception throws a <code>InitializationException</code> if the service
      * fails to initialize
      */
     public synchronized void init(ServletConfig conf)
         throws InitializationException
     {
         if (getInit()) return;
 
         super.init(conf);
 
         // get configuration parameters from Jetspeed Resources
         ResourceService serviceConf = ((TurbineServices)TurbineServices.getInstance())
                                                      .getResources(JetspeedSecurityService.SERVICE_NAME);
 
         securePasswords = serviceConf.getBoolean(CONFIG_SECURE_PASSWORDS_KEY,
                                                   securePasswords);
         passwordsAlgorithm = serviceConf.getString(CONFIG_SECURE_PASSWORDS_ALGORITHM,
                                                    passwordsAlgorithm);
         passwordsSuffix = serviceConf.getString(CONFIG_SECURE_PASSWORDS_SUFFIX,
                                                    passwordsSuffix);
 
         try
         {
             roles = serviceConf.getStringArray(CONFIG_NEWUSER_ROLES);
         }
         catch (Exception e)
         {
         }
 
         if (null == roles || roles.length == 0)
         {
             roles = DEFAULT_CONFIG_NEWUSER_ROLES;
         }
 
         this.runDataService = (JetspeedRunDataService)TurbineServices.getInstance()
                .getService(RunDataService.SERVICE_NAME);
 
         setInit(true);
      }
 
     ///////////////////////////////////////////////////////////////////////////
     // Internal
     ///////////////////////////////////////////////////////////////////////////
 
     /***
      * Check whether a specified user's account exists.
      *
      * The login name is used for looking up the account.
      *
      * @param user             The user to be checked.
      * @param checkUniqueId    Make sure that we aren't 
      *                         overwriting another user
      *                         with different id.
      *
      * @return true            If the specified account exists
      *
      * @throws UserException   If there was a general db access error
      *
      */
     protected boolean accountExists( JetspeedUser user )
         throws UserException
     {
         return accountExists(user, false);
     }
 
     protected boolean accountExists( JetspeedUser user, boolean checkUniqueId )
         throws UserException
     {
         UserNamePrincipal principal = new UserNamePrincipal(user.getUserName());
 
         try
         {
             getUser(principal);
             return true;
         }
         catch (Exception e)
         {
             return false;
         }
     }
 
     protected JetspeedRunData getRunData()
     {
         JetspeedRunData rundata = null;
 
         if (this.runDataService != null)
         {
             rundata = this.runDataService.getCurrentRunData();
         }
 
         return rundata;
     }
 
 }