/*

* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

package com.nokia.mj.impl.security.midp.authorization;

import java.util.Vector;

import java.util.Hashtable;

import java.security.Permission;

import com.nokia.mj.impl.utils.Uid;

import com.nokia.mj.impl.utils.Tokenizer;

import com.nokia.mj.impl.utils.exception.InvalidAttributeException;

import com.nokia.mj.impl.utils.InstallerDetailedErrorMessage;

import com.nokia.mj.impl.utils.InstallerErrorMessage;

import com.nokia.mj.impl.utils.OtaStatusCode;

import com.nokia.mj.impl.security.midp.common.PermissionAttribute;

import com.nokia.mj.impl.security.midp.common.PolicyBasedPermission;

import com.nokia.mj.impl.security.midp.common.PolicyBasedPermissionImpl;

import com.nokia.mj.impl.security.midp.common.UserSecuritySettings;

import com.nokia.mj.impl.security.common.PermissionBase;

import com.nokia.mj.impl.security.midp.storage.*;

import com.nokia.mj.impl.storage.StorageSession;

import com.nokia.mj.impl.security.utils.Logger;

/**

 * Permission resolver: it resolves a list of permissions against another list

 * of permissions, returning the list of permissions which resolved the

 * permissions. Resolving means callint the implies method of Permission

 * objects

 */

public final class PermissionResolver

{

    /*

     * Cache for Permission objects

     */

    // Add synchronization for access to these hashtables

    private static Hashtable policyPermissionInstances = new Hashtable();

    private static Hashtable grantedPermissionInstances = new Hashtable();

    public static Vector resolvePermissions(

        Uid msUID,

        PermissionAttribute[] requestedPermissions,

        PolicyBasedPermission[] policyPermissions)

    {

        if (requestedPermissions == null)

        {

            return null;

        }

        Vector resolvedPermissions = new Vector();

        for (int i=0; i<requestedPermissions.length; i++)

        {

            if (requestedPermissions[i].isLegacyAttribute())

            {

                Vector legacyPermissions = resolveLegacyPermission(requestedPermissions[i],

                                           policyPermissions);

                // add legacyPermissions into resolved permissions

                // Is it possible to provide the vector to resolveLegacyPermission method which will fill it?

                if (legacyPermissions != null && legacyPermissions.size() > 0)

                {

                    for (int j=0; j<legacyPermissions.size(); j++)

                    {

                        resolvedPermissions.addElement(

                            legacyPermissions.elementAt(j));

                    }

                }

                else if (requestedPermissions[i].getImportance()

                         == PermissionAttribute.MANDATORY_PERMISSION)

                {

                    Logger.logError("Permission " + requestedPermissions[i].getName() + " not supported");

                    throw new InvalidAttributeException(

                        InstallerErrorMessage.INST_CORRUPT_PKG,

                        null, /* no params for short msg */

                        InstallerDetailedErrorMessage.ATTR_UNSUPPORTED,

                        new String[] {requestedPermissions[i].getAttributeName()},

                        OtaStatusCode.APPLICATION_AUTHORIZATION_FAILURE);

                }

                continue;

            }

            try

            {

                Permission p = (Permission)ClassInstantiator.newInstance(

                                   requestedPermissions[i].getName(),

                                   requestedPermissions[i].getTarget(),

                                   requestedPermissions[i].getActionList());

                Vector resolvedPermissionSet = resolvePermission(

                                                   msUID, p, policyPermissions);

                if (resolvedPermissionSet != null)

                {

                    if (identicalSettings(resolvedPermissionSet))

                    {

                        PolicyBasedPermission rPerm = (PolicyBasedPermission)

                                                      resolvedPermissionSet.elementAt(0);

                        if (rPerm.getUserSecuritySettings() == null)

                        {

                            resolvedPermissions.addElement(

                                new PolicyBasedPermissionImpl(

                                    requestedPermissions[i].getName(),

                                    requestedPermissions[i].getTarget(),

                                    requestedPermissions[i].getActionList(),

                                    rPerm.getType()));

                        }

                        else

                        {

                            resolvedPermissions.addElement(

                                new PolicyBasedPermissionImpl(

                                    requestedPermissions[i].getName(),

                                    requestedPermissions[i].getTarget(),

                                    requestedPermissions[i].getActionList(),

                                    rPerm.getUserSecuritySettings()));

                        }

                    }

                    else

                    {

                        for (int j=0; j<resolvedPermissionSet.size(); j++)

                        {

                            resolvedPermissions.addElement(

                                resolvedPermissionSet.elementAt(j));

                        }

                    }

                }

                else

                {

                    // the permission was not resovled

                    if (requestedPermissions[i].getImportance()

                            == PermissionAttribute.MANDATORY_PERMISSION)

                    {

                        Logger.logError("Permission " + requestedPermissions[i].getName() + " not supported");

                        throw new InvalidAttributeException(

                            InstallerErrorMessage.INST_CORRUPT_PKG,

                            null, /* no params for short msg */

                            InstallerDetailedErrorMessage.ATTR_UNSUPPORTED,

                            new String[] {requestedPermissions[i].getAttributeName()},

                            OtaStatusCode.APPLICATION_AUTHORIZATION_FAILURE);

                    }

                }

            }

            catch (InstantiationException e)

            {

                if (requestedPermissions[i].getImportance()

                        == PermissionAttribute.MANDATORY_PERMISSION)

                {

                    Logger.logError("Permission " + requestedPermissions[i].getName() + " not supported");

                    throw new InvalidAttributeException(

                        InstallerErrorMessage.INST_CORRUPT_PKG,

                        null, /* no params for short msg */

                        InstallerDetailedErrorMessage.ATTR_UNSUPPORTED,

                        new String[] {requestedPermissions[i].getAttributeName()},

                        OtaStatusCode.APPLICATION_AUTHORIZATION_FAILURE);

                }

                // ignore, since the permission was optional

            }

        }

        if (resolvedPermissions.size() == 0)

        {

            return null;

        }

        return resolvedPermissions;

    }

    public static Vector resolvePermission(

        StorageSession aStorageSession,

        Uid msUID,

        Permission requestedPermission)

    {

        return resolvePermission(requestedPermission,

                                 getGrantedPermissionInstances(aStorageSession, msUID));

    }

    /**

     * Indication that certain settings have changed. This is implemented

     * so that the new settings are updated into the cache

     */

    // Add synchronization

    static void settingsChanged(Uid msUID, UserSecuritySettings newSettings)

    {

        Vector oldPermissionInstancesAndSettings =

            (Vector)grantedPermissionInstances.remove(msUID);

        if (oldPermissionInstancesAndSettings != null)

        {

            Vector newPermissionInstancesAndSettings = new Vector();

            for (int i=0; i < oldPermissionInstancesAndSettings.size(); i++)

            {

                PermisionInstanceAndSettings p = (PermisionInstanceAndSettings)

                                                 oldPermissionInstancesAndSettings.elementAt(i);

                if (p.getSettings() != null && p.getSettings().getName()

                        .equals(newSettings.getName()))

                {

                    // add new settings

                    newPermissionInstancesAndSettings.addElement(

                        new PermisionInstanceAndSettings(

                            p.getPermissionInstance(), newSettings));

                }

                else

                {

                    // keep the old settings

                    newPermissionInstancesAndSettings.addElement(p);

                }

            }

            grantedPermissionInstances.put(msUID,

                                           newPermissionInstancesAndSettings);

        }

    }

    private static Vector resolvePermission(

        Permission requestedPermission,

        Vector permissionInstances)

    {

        if (permissionInstances == null

                || requestedPermission == null)

        {

            return null;

        }

        Vector resolvedPermissions = new Vector();

        // stage 1: try the simple permissions (simple permission = permission with single action)

        for (int i=0; i<permissionInstances.size(); i++)

        {

            PermisionInstanceAndSettings p =

                (PermisionInstanceAndSettings)permissionInstances

                .elementAt(i);

            Object policyPermission = p.getPermissionInstance();

            if (policyPermission.getClass().isInstance(requestedPermission)

                    && ((Permission)policyPermission).implies(requestedPermission))

            {

                resolvedPermissions.addElement(

                    getResolvedPermission(

                        requestedPermission,

                        policyPermission,

                        p.getSettings(),

                        requestedPermission.getClass().getName(),

                        requestedPermission.getName(),

                        requestedPermission.getActions()));

                return resolvedPermissions;

            }

        }

        // stage 2: try the requested complex permissions (complex permission = permission with multiple actions)

        String[] actions = Tokenizer.split(requestedPermission.getActions(),

                                           ",");

        if (actions != null && actions.length > 0)

        {

            for (int i=0; i<actions.length; i++)

            {

                boolean permissionResolved = false;

                try

                {

                    Permission p1 = (Permission)ClassInstantiator.newInstance(

                                        requestedPermission.getClass().getName(),

                                        requestedPermission.getName(), actions[i]);

                    for (int j=0; j<permissionInstances.size(); j++)

                    {

                        PermisionInstanceAndSettings p =

                            (PermisionInstanceAndSettings)permissionInstances

                            .elementAt(j);

                        Object policyPermission = p.getPermissionInstance();

                        if (policyPermission.getClass().isInstance(p1)

                                && ((Permission)policyPermission).implies(p1))

                        {

                            permissionResolved = true;

                            // add the permission to the result only of not found among the existing ones

                            PolicyBasedPermissionImpl permission1 =

                                getResolvedPermission(requestedPermission,

                                                      policyPermission,

                                                      p.getSettings(),

                                                      requestedPermission.getClass().getName(),

                                                      requestedPermission.getName(),

                                                      actions[i]);

                            if (permission1.getActionList() == null

                                    || permission1.getActionList().length() == 0)

                            {

                                resolvedPermissions.addElement(permission1);

                                continue;

                            }

                            UserSecuritySettings settings1 = permission1.getUserSecuritySettings();

                            boolean found = false;

                            for (int k=0; k<resolvedPermissions.size(); k++)

                            {

                                PolicyBasedPermissionImpl permission2 =

                                    (PolicyBasedPermissionImpl)(resolvedPermissions.elementAt(k));

                                if (permission2.getActionList() != null

                                        && permission2.getActionList().length() > 0)

                                {

                                    UserSecuritySettings settings2 =

                                        permission2.getUserSecuritySettings();

                                    // group resolve permissions by name and settings

                                    if (permission1.getClass().getName().equals(permission2.getClass().getName())

                                            && ((permission1.getName() != null && permission2.getName() != null

                                                 && permission1.getName().equals(permission2.getName()))

                                                || (permission1.getName() == null && permission2.getName() == null))

                                            && ((settings1 != null && settings2 != null && settings1.equals(settings2))

                                                || (settings1 == null && settings2 == null)))

                                    {

                                        // replace element at position k with another one having

                                        // the combined actions

                                        resolvedPermissions.setElementAt(getResolvedPermission(

                                                                             permission1.getPromptDetails(),

                                                                             p.getSettings(),

                                                                             requestedPermission.getClass().getName(),

                                                                             requestedPermission.getName(),

                                                                             permission2.getActionList() + "," + permission1.getActionList()),

                                                                         k);

                                        found = true;

                                        break;

                                    }

                                }

                            }

                            if (!found)

                            {

                                resolvedPermissions.addElement(permission1);

                            }

                            break;

                        }

                    }

                }

                catch (InstantiationException e)

                {

                    // ignore it

                }

                if (!permissionResolved)

                {

                    resolvedPermissions.removeAllElements();

                    break;

                }

            }

            if (resolvedPermissions.size() > 0)

            {

                return resolvedPermissions;

            }

        }

        // stage 3: try the granted complex permissions (complex permission = permission with multiple actions)

        //      - step 1: group permissions having same name, target and settings

        //                into a list of complex permissions (= permissions with

        //                same name, target and settings but with the composite

        //                action (comma separated list of individual actions)

        //      - step 2: try to resolve the requested permission against the

        //                list of complet permissions

        Vector tmp = new Vector();

        for (int i=0; i<permissionInstances.size(); i++)

        {

            tmp.addElement(permissionInstances.elementAt(i));

        }

        while (tmp.size() > 0)

        {

            PermisionInstanceAndSettings instance1 =

                (PermisionInstanceAndSettings)tmp.elementAt(0);

            tmp.removeElementAt(0);

            Permission permission1 = (Permission)instance1.getPermissionInstance();

            UserSecuritySettings settings1 = instance1.getSettings();

            String compositeAction = "";

            // put the individual actions into a vector so that the composite

            // action is made only by unique actions (duplicates are discarded)

            Vector uniqueActions = new Vector();

            int i=0;

            while (i<tmp.size())

            {

                PermisionInstanceAndSettings instance2 =

                    (PermisionInstanceAndSettings)tmp.elementAt(i);

                Permission permission2 = (Permission)instance2.getPermissionInstance();

                UserSecuritySettings settings2 = instance2.getSettings();

                if (permission1.getClass().getName().equals(permission2.getClass().getName())

                        && ((permission1.getName() != null && permission2.getName() != null

                             && permission1.getName().equals(permission2.getName()))

                            || (permission1.getName() == null && permission2.getName() == null))

                        && ((settings1 != null && settings2 != null && settings1.equals(settings2))

                            || (settings1 == null && settings2 == null)))

                {

                    tmp.removeElementAt(i);

                    if (permission1.getActions() != null && permission1.getActions().length() > 0)

                    {

                        if (!uniqueActions.contains(permission1.getActions()))

                        {

                            if (compositeAction.length() > 0)

                            {

                                compositeAction += ",";

                            }

                            compositeAction += permission1.getActions();

                            uniqueActions.addElement(permission1.getActions());

                        }

                    }

                    if (permission2.getActions() != null && permission2.getActions().length() > 0)

                    {

                        if (!uniqueActions.contains(permission2.getActions()))

                        {

                            if (compositeAction.length() > 0)

                            {

                                compositeAction += ",";

                            }

                            compositeAction += permission2.getActions();

                            uniqueActions.addElement(permission2.getActions());

                        }

                    }

                }

                else

                {

                    i++;

                }

            }

            if (compositeAction.length() > 0 && compositeAction.indexOf(',') != -1)

            {

                try

                {

                    Permission perm = (Permission)ClassInstantiator.newInstance(

                                          permission1.getClass().getName(),

                                          permission1.getName(),

                                          compositeAction);

                    if (perm.getClass().isInstance(requestedPermission)

                            && perm.implies(requestedPermission))

                    {

                        resolvedPermissions.addElement(

                            getResolvedPermission(

                                requestedPermission,

                                permission1,

                                settings1,

                                requestedPermission.getClass().getName(),

                                requestedPermission.getName(),

                                requestedPermission.getActions()));

                        return resolvedPermissions;

                    }

                }

                catch (InstantiationException ex) {}

            }

        }

        if (resolvedPermissions.size() == 0)

        {

            return null;

        }

        return resolvedPermissions;

    }

    private static Vector resolvePermission(

        Uid msUID,

        Permission requestedPermission,

        PolicyBasedPermission[] policyPermissions)

    {

        Vector permissionInstances = getPolicyPermissionInstances(

                                         msUID, policyPermissions);

        return resolvePermission(requestedPermission, permissionInstances);

    }

    private static PolicyBasedPermissionImpl getResolvedPermission(

        PermissionBase securityPromptDetails,

        UserSecuritySettings userSettings,

        String permissionName,

        String targetName,

        String actionList)

    {

        PermissionBase securityPromptDetails2 = securityPromptDetails;

        if (securityPromptDetails != null

                && (!PermissionBase.matchActions(securityPromptDetails.getActions(),actionList)

                    || !PermissionBase.matchActions(actionList, securityPromptDetails.getActions())))

        {

            // the new instance is created only if the actions are different

            try

            {

                securityPromptDetails2 = (PermissionBase)ClassInstantiator

                                         .newInstance(securityPromptDetails.getClass().getName(),

                                                      securityPromptDetails.getName(),

                                                      actionList);

            }

            catch (InstantiationException e2)

            {

                // ignore it (no details)

            }

        }

        return new PolicyBasedPermissionImpl(

                   permissionName,

                   targetName,

                   actionList,

                   userSettings,

                   securityPromptDetails2);

    }

    private static PolicyBasedPermissionImpl getResolvedPermission(

        Permission requestedPermission,

        Object policyPermission,

        UserSecuritySettings userSettings,

        String permissionName,

        String targetName,

        String actionList)

    {

        PermissionBase securityPromptDetails = null;

        if (requestedPermission instanceof PermissionBase)

        {

            securityPromptDetails = (PermissionBase)requestedPermission;

        }

        else if (policyPermission instanceof PermissionBase)

        {

            try

            {

                securityPromptDetails = (PermissionBase)ClassInstantiator

                                        .newInstance(policyPermission.getClass().getName(),

                                                     requestedPermission.getName(),

                                                     requestedPermission.getActions());

            }

            catch (InstantiationException e2)

            {

                // ignore it (no details)

            }

        }

        return new PolicyBasedPermissionImpl(

                   permissionName,

                   targetName,

                   actionList,

                   userSettings,

                   securityPromptDetails);

    }

    private static Vector getPolicyPermissionInstances(Uid msUID, PolicyBasedPermission[] policyPermissions)

    {

        // try retrieving the policy permissions from cache

        Vector policyPermissionInstancesAndSettings =

            (Vector)policyPermissionInstances.get(msUID);

        if (policyPermissionInstancesAndSettings != null)

        {

            return policyPermissionInstancesAndSettings;