/*
 * The contents of this file are subject to the terms 
 * of the Common Development and Distribution License 
 * (the License).  You may not use this file except in
 * compliance with the License.
 * 
 * You can obtain a copy of the license at 
 * https://glassfish.dev.java.net/public/CDDLv1.0.html or
 * glassfish/bootstrap/legal/CDDLv1.0.txt.
 * See the License for the specific language governing 
 * permissions and limitations under the License.
 * 
 * When distributing Covered Code, include this CDDL 
 * Header Notice in each file and include the License file 
 * at glassfish/bootstrap/legal/CDDLv1.0.txt.  
 * If applicable, add the following below the CDDL Header, 
 * with the fields enclosed by brackets [] replaced by
 * you own identifying information: 
 * "Portions Copyrighted [year] [name of copyright owner]"
 * 
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 */


package com.sun.appserv.security;

import java.util.Properties;
import java.util.logging.Logger;
import java.util.logging.Level;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedExceptionAction;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
                         
import com.sun.logging.LogDomains;
import com.sun.enterprise.appclient.AppContainer;
import com.sun.enterprise.security.auth.LoginContextDriver;
import com.sun.enterprise.security.auth.login.ClientPasswordLoginModule;
import com.sun.enterprise.server.ApplicationServer;
import com.sun.web.security.WebProgrammaticLogin;


/**
 * Implement programmatic login.
 *
 * <P>This class allows deployed applications to supply a name and
 * password directly to the security service. This info will be used
 * to attempt to login to the current realm. If authentication succeeds,
 * a security context is established as this user.
 *
 * <P>This allows applications to programmatically handle authentication.
 * The use of this mechanism is not recommended since it bypasses the
 * standard J2EE mechanisms and places all burden on the application
 * developer.
 *
 * <P>Invoking this method requires the permission
 * ProgrammaticLoginPermission with the method name being invoked.
 *
 * <P>There are two forms of the login method, one which includes the HTTP
 * request and response objects for use by servlets and one which can be used
 * by EJBs.
 *
 * 
 */

public class ProgrammaticLogin
{
    private static Logger logger =
        LogDomains.getLogger(LogDomains.SECURITY_LOGGER);

    private static ProgrammaticLoginPermission plLogin =
        new ProgrammaticLoginPermission("login");

    private static ProgrammaticLoginPermission plLogout =
        new ProgrammaticLoginPermission("logout");

    private static boolean isServer =
        (ApplicationServer.getServerContext() != null);

    private static javax.security.auth.callback.CallbackHandler handler = new com.sun.enterprise.security.auth.login.LoginCallbackHandler(false);
    
    /**
     * Attempt to login.
     *
     * <P>Upon successful return from this method the SecurityContext will
     * be set in the name of the given user as its Subject.
     *
     * <p>On client side, realm and errors parameters will be ignored and
     * the actual login will not occur until we actually access a resource
     * requiring a login.  And a java.rmi.AccessException with 
     * COBRA NO_PERMISSION will occur when actual login is failed.
     *
     * <P>This method is intented primarily for EJBs wishing to do
     * programmatic login. If servlet code used this method the established
     * identity will be propagated to EJB calls but will not be used for
     * web container manager authorization. In general servlets should use
     * the servlet-specific version of login instead.
     *
     * @param user User name.
     * @param password Password for user.
     * @param realm the realm name in which the user should be logged in.
     * @param errors errors=true, propagate any exception encountered to the user
     * errors=false, no exceptions are propagated.
     * @return Boolean containing true or false to indicate success or
     *     failure of login.
     * @throws Exception any exception encountered during Login.
     */
    public Boolean login(final String user, final String password, 
        final String realm, boolean errors) throws Exception
    {
        Boolean authenticated = null;
        // check permission to login
        try {

            // exception thrown on failure
            checkLoginPermission(user); 

            // try to login. doPrivileged is used since application code does
            // not have permissions to process the jaas login.
            authenticated = (Boolean)
                AccessController.doPrivileged(new PrivilegedAction() {
                    public java.lang.Object run() {
                    // if realm is null, LCD will log into the default realm
                        if (isServer) {
                            LoginContextDriver.login(user, password, realm);
                        } else {
                            int type = AppContainer.USERNAME_PASSWORD;
                            System.setProperty(
                                ClientPasswordLoginModule.LOGIN_NAME, user);
                            System.setProperty(
                                ClientPasswordLoginModule.LOGIN_PASSWORD,
                                password);
                            //should not set realm here
                            LoginContextDriver.doClientLogin(type, handler);
                        }
                        return Boolean.valueOf(true);
                    }
                });
        } catch (Exception e) {
            logger.severe("Programmatic login failed: "+e.toString());
            if(errors == true){ // propagate the exception ahead
                throw e;    
            } else{
                authenticated = Boolean.valueOf(false);
            }
        }        
        return authenticated;
    }

    /** Attempt to login.
     *
     * <P>Upon successful return from this method the SecurityContext will
     * be set in the name of the given user as its Subject.
     *
     * <p>On client side, the actual login will not occur until we actually
     * access a resource requiring a login.  And a java.rmi.AccessException
     * with COBRA NO_PERMISSION will occur when actual login is failed.
     *
     * <P>This method is intented primarily for EJBs wishing to do
     * programmatic login. If servlet code used this method the established
     * identity will be propagated to EJB calls but will not be used for
     * web container manager authorization. In general servlets should use
     * the servlet-specific version of login instead.
     *
     * @param user User name.
     * @param password Password for user.
     * @return Boolean containing true or false to indicate success or
     *     failure of login.
     */
    public Boolean login(final String user, final String password)
    {
        // call login with realm-name = null and request for errors = false
        Boolean authenticated = null;
        try{
            authenticated = login(user, password, null, false);
        } catch(Exception e){
            // sanity checking, will never come here
            authenticated = Boolean.valueOf(false); 
        }
        return authenticated;
    }    
    /** Attempt to login. This method is specific to servlets (and JSPs).
     *
     * <P>Upon successful return from this method the SecurityContext will
     * be set in the name of the given user as its Subject. In addition, the
     * principal stored in the request is set to the user name. If a session
     * is available, its principal is also set to the user provided.
     *
     * @returns Boolean containing true or false to indicate success or
     *     failure of login.
     * @param realm
     * @param errors
     * @param user User name.
     * @param password Password for user.
     * @param request HTTP request object provided by caller application. It
     *     should be an instance of HttpRequestFacade.
     * @param response HTTP response object provided by called application. It
     *     should be an instance of HttpServletResponse.
     * @throws Exception any exceptions encountered during login
     * @return Boolean indicating true for successful login and false otherwise
     */
    public Boolean login(final String user, final String password, 
                         final String realm, 
                         final HttpServletRequest request,
                         final HttpServletResponse response, boolean errors)
                         throws Exception
    {
        Boolean authenticated = null;
        try{
            // check permission to login        
            checkLoginPermission(user);
            // try to login. doPrivileged is used since application code does
            // not have permissions to process the jaas login.
            authenticated = (Boolean)
                AccessController.doPrivileged(new PrivilegedAction() {
                    public java.lang.Object run() {
                        return WebProgrammaticLogin.login(user, password, realm,
                                                          request, response);
                    }
                });
        } catch(Exception e){
            if(errors != true){
                authenticated = Boolean.valueOf(false);
            } else{
                throw e;
            }
        }            
        return authenticated;
    }

    /**
     * Attempt to login. This method is specific to servlets (and JSPs).
     *
     * <P>Upon successful return from this method the SecurityContext will
     * be set in the name of the given user as its Subject. In addition, the
     * principal stored in the request is set to the user name. If a session
     * is available, its principal is also set to the user provided.
     *
     * @param user User name.
     * @param password Password for user.
     * @param request HTTP request object provided by caller application. It
     *     should be an instance of HttpRequestFacade.
     * @param response HTTP response object provided by called application. It
     *     should be an instance of HttpServletResponse.
     * @return Boolean containing true or false to indicate success or
     *     failure of login.
     *
     */
    public Boolean login(final String user, final String password, 
                         final HttpServletRequest request,
                         final HttpServletResponse response)
    {
        Boolean authenticated = null;    
        try{
            // pass a null realmname and errors=false
            authenticated = login(user, password, null, request, response, false);
        }catch (Exception e){
            // sanity check will never come here
            authenticated = Boolean.valueOf(false);
        }
        return authenticated;
    }
    /**
     * Attempt to logout.
     * @returns Boolean containing true or false to indicate success or
     *     failure of logout.
     *
     */
    public Boolean logout()
    {
        Boolean loggedout = null;
        try{
           loggedout = logout(false);
        } catch(Exception e){
            // sanity check will never come here
            loggedout = Boolean.valueOf(false);
        }
        return loggedout;
    }
    /**
     * Attempt to logout.
     * @param errors, errors = true, the method will propagate the exceptions 
     * encountered while logging out, errors=false will return a Boolean value
     * of false indicating failure of logout
     * @return Boolean containing true or false to indicate success or
     *     failure of logout.
     * @throws Exception encountered while logging out, if errors==false
     *
     */
    public Boolean logout(boolean errors) throws Exception
    {
        Boolean loggedout = null;
        // check logout permission
        try{
            checkLogoutPermission();
            AccessController.doPrivileged(new PrivilegedAction() {
                public java.lang.Object run() {
                    if (isServer) {
                        LoginContextDriver.logout();
                    } else {
                        Properties sysProp = System.getProperties();    
                        sysProp.remove(ClientPasswordLoginModule.LOGIN_NAME);
                        sysProp.remove(ClientPasswordLoginModule.LOGIN_PASSWORD);
                        LoginContextDriver.doClientLogout();
                        //If user try to access a protected resource after here
                        //then it will prompt for password in appclient or
                        //just fail in standalone client.
                    }
                    return null;
                }
            });
            loggedout = Boolean.valueOf(true);
        } catch (Exception e) {
            logger.log(Level.WARNING, "Programmatic logout failed: "+e.toString());
            if(errors){
                throw e;
            } else{
                loggedout = Boolean.valueOf(false);
            }
        }
        return loggedout;
    }

    /**
     * Attempt to logout. Also removes principal from request (and session
     * if available).
     *
     * @returns Boolean containing true or false to indicate success or
     *     failure of logout.
     *
     */
    public Boolean logout(final HttpServletRequest request,
                          final HttpServletResponse response)
    {
        Boolean loggedout = null;
        try{
            loggedout = logout(request, response, false);
        }catch(Exception e){
            // sanity check, will never come here
            loggedout = Boolean.valueOf(false);
        }
        return loggedout;
    }

    /**
     * Attempt to logout. Also removes principal from request (and session
     * if available).
     * @param errors, errors = true, the method will propagate the exceptions 
     * encountered while logging out, errors=false will return a Boolean value
     * of false indicating failure of logout
     *
     * @return Boolean containing true or false to indicate success or
     *     failure of logout.
     * @throws Exception, exception encountered while logging out and if errors
     * == true
     */
    public Boolean logout(final HttpServletRequest request,
                          final HttpServletResponse response, 
                          boolean errors) throws Exception
    {
        // check logout permission
        Boolean loggedout = null;
        try{
            checkLogoutPermission();
            loggedout = (Boolean)
                AccessController.doPrivileged(new PrivilegedExceptionAction() {
                public java.lang.Object run() throws Exception{
                    return WebProgrammaticLogin.logout(request, response);
                }
            });
        }catch(Exception e){
            if(errors){
                throw e;
            }else{
                loggedout = Boolean.valueOf(false);
            }
        }
        return loggedout;
    }

    
    /**
     * Check whether caller has login permission.
     *
     */   
    private void checkLoginPermission(String user) throws Exception
    {
        try {
            if(logger.isLoggable(Level.FINE)){
                logger.log(Level.FINE, "ProgrammaticLogin.login() called for user: " 
                    + user);
            }
            SecurityManager sm = System.getSecurityManager();
            if (sm != null) {
                sm.checkPermission(plLogin);
            }

        } catch (Exception e) {
            logger.warning("proglogin.noperm");
            throw e;
        }
    }


    /**
     * Check if caller has logout permission.
     *
     */
    private void checkLogoutPermission() throws Exception
    {
        try {
            if(logger.isLoggable(Level.FINE)){
                logger.log(Level.FINE, "ProgrammaticLogin.logout() called.");
            }
            SecurityManager sm = System.getSecurityManager();
            if (sm != null) {
                sm.checkPermission(plLogout);
            }
            
        } catch (Exception e) {
            logger.warning("prologout.noperm");
            throw e;
        }
    }
    



}
