/*

* 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.common;

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

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

import com.nokia.mj.impl.security.packageprotection.PackageNames;

import java.util.Hashtable;

import java.util.Enumeration;

import java.util.Vector;

/**

 * This class reads the security extensions from the extensions

 * deployment packages.

 *

 * A security extension is a group of permissions and their usage

 * with regard to protection domains, function groups and security

 * prompt texts.

 *

 * Security extensions are contained into the extensions ODC files

 * as system properties, as follows:

 *   -Dcom.nokia.mj.addon.protected.<odcname>=<comma separated list

 *                                             of protected packages>

 *   -Dcom.nokia.mj.addon.restricted.<odcname>=<comma separated list

 *                                             of restricted packages>

 *   -Dcom.nokia.mj.addon.permissions.<odcname>=<";" separated list

 *                                             of permission mappings>

 *   -Dcom.nokia.mj.addon.policies.<odcname>=<";" separated list

 *                                             of policies file names>

 * where:

 *   <odcname> is always the odc filename without path and extension

 *   <permission mappings> has following syntax:

 *      <named-permission>","<permission-class-name>","<taget>","<actionList>

 *

 * This class validates the security extensions and discards the invalid

 * elements of the security extension by writing a WARNING log entry into

 * JavaSecurity.log

 */

public final class SecurityExtensionsReader

{

    /**

     * The extensions of the ODC file containing the security

     * extensions definitions

     */

    public final static String POLICIES_SEPARATOR = "";

    /**

     * The extensions of the ODC file containing the security

     * extensions definitions

     */

    private final static String ODC_EXTENSIONS = ".odc";

    /**

     * The names of the system properties defining the

     * security extension

     */

    private final static String PROTECTED_PACKAGE_PROPERTY    = "com.nokia.mj.addon.protected.";

    private final static String RESTRICTED_PACKAGE_PROPERTY   = "com.nokia.mj.addon.restricted.";

    private final static String PERMISSION_MAPPINGS_PROPERTY  = "com.nokia.mj.addon.permissions.";

    private final static String SECURITY_POLICIES_PROPERTY    = "com.nokia.mj.addon.policies.";

    /**

     * The allowed locations for the security extensions policies

     */

    private final static String ALLOWED_POLICY_FILE_LOCATION1 = "c:\\resource\\";

    private final static String ALLOWED_POLICY_FILE_LOCATION2 = "c:/resource/";

    /**

     * Internal data members

     */

    private static final int PROTECTED_PACKAGES = 1;

    private static final int RESTRICTED_PACKAGES = 2;

    private static Vector extProtectedPackageNames = new Vector();

    private static Vector extRestrictedPackageNames = new Vector();

    private static Vector extPoliciesFileNames = new Vector();

    private static Hashtable extPermissionMappings = new Hashtable();

    /**

     * Boolean used in lazy initialization: the system properties

     * are read only once when they are needed for the first time

     */

    private static boolean initialized = false;

    /**

     * Retrieves the names of all the installed security extensions

     */

    public static Vector getExtPoliciesFileNames()

    {

        lazyInit();

        return extPoliciesFileNames;

    }

    /**

     * Retrieves the names of all the protected packages brought in by

     * security extensions

     */

    public static Vector getExtProtectedPackages()

    {

        lazyInit();

        return extProtectedPackageNames;

    }

    /**

     * Retrieves the names of all the restricted packages brought in by

     * security extensions

     */

    public static Vector getExtRestrictedPackages()

    {

        lazyInit();

        return extRestrictedPackageNames;

    }

    /**

     * Retrieves the permission mapping of a certain named-permission,

     * if found among the permission mappings brought in by all the

     * security extensions

     */

    public static MIDPPermission getExtPermission(String permissionName)

    {

        lazyInit();

        return (MIDPPermission)extPermissionMappings.get(permissionName);

    }

    /**

     * Loggs a discard operation of an invalid security extension element

     */

    public static void discard(String discardReason)

    {

        Logger.logWarning(discardReason);

    }

    /*** ----------------------------- PACKAGE ---------------------------- */

    /*** ----------------------------- PRIVATE ---------------------------- */

    /**

     * Lazy initialization of the security extension definitions

     */

    private static void lazyInit()

    {

        if (!initialized)

        {

            handleExtensions();

            initialized = true;

        }

    }

    /**

     * Reads the list of extensions and goes through each of the extension's

     * (ODC-based) system properties, reading and validating the

     * details of the security extension.

     */

    private static void handleExtensions()

    {

        String extOdcList = System.getProperty("com.nokia.mj.addon.list");

        if (extOdcList != null)

        {

            //Split the list to vector

            String[] result = Tokenizer.split(extOdcList, ";");

            if (result != null)

            {

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

                {

                    String extOdcFile = result[i];

                    // Support also plain .jar extensions (for Java 1.3 compatibility)

                    if (extOdcFile.endsWith(ODC_EXTENSIONS))

                    {

                        handleAddOnSystemProperties(extOdcFile);

                    }

                }

            }

        }

    }

    /**

     * Validates the security extension read as an (ODC-based) system property

     */

    private static void handleAddOnSystemProperties(String extOdcFile)

    {

        char pathSeparator = System.getProperty("file.separator").charAt(0);

        // Locate the last file separator

        int lastFileSeparator =

            extOdcFile.lastIndexOf(pathSeparator);

        // The line must contain at least one file separator and the

        // name of the file must end with .odc.

        if (lastFileSeparator >= 0)

        {

            // Strip away the path and file name extension. E.g.

            // c:\foo\eswtmobile.odc would be eswtmobile

            String propertyName = extOdcFile.substring(

                                      lastFileSeparator+1,

                                      extOdcFile.length()-

                                      ODC_EXTENSIONS.length());

            // validate&set the security extensions

            setExtPackageNames(extOdcFile,

                               PROTECTED_PACKAGES, System.getProperty(

                                   PROTECTED_PACKAGE_PROPERTY + propertyName));

            setExtPackageNames(

                extOdcFile,

                RESTRICTED_PACKAGES, System.getProperty(

                    RESTRICTED_PACKAGE_PROPERTY + propertyName));

            setExtPermissionMappings(

                extOdcFile,

                System.getProperty(

                    PERMISSION_MAPPINGS_PROPERTY + propertyName));

            setExtPoliciesFileNames(extOdcFile,

                                    System.getProperty(

                                        SECURITY_POLICIES_PROPERTY + propertyName));

        }

    }

    /**

     * Validates the security extension package names applying the following

     * rule: package names collisions are only allowed for same type of

     * packages (e.g. an extension can not declare as protected a package

     * name which is already declared restricted)

     */

    private static void setExtPackageNames(String odcFile, int packageType,

                                           String packageNamesSystemProperty)

    {

        // sanity check

        if (packageNamesSystemProperty == null)

        {

            return;

        }

        String[] basePackageNames = (packageType == PROTECTED_PACKAGES

                                     ? PackageNames.restrictedPackages : PackageNames.protectedPackages);

        String[] extPackageNames = Tokenizer.split(packageNamesSystemProperty,

                                   ",");

        Vector okPackageNames = new Vector();

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

        {

            boolean found = find(extPackageNames[i], basePackageNames);

            if (!found)

            {

                // one more check against the already existing extensions

                // package names

                Vector otherPackageNames = (packageType == PROTECTED_PACKAGES

                                            ? extRestrictedPackageNames : extProtectedPackageNames);

                found = find(extPackageNames[i], otherPackageNames);

            }

            if (!found)

            {

                okPackageNames.addElement(extPackageNames[i]);

            }

            else

            {

                discard(odcFile, extPackageNames[i]

                        + " is declared as "

                        + (packageType == PROTECTED_PACKAGES ? "protected": "restricted")

                        + " but it is already declared as "

                        + (packageType == PROTECTED_PACKAGES ? "restricted": "protected"));

            }

        }

        Vector packageNames = (packageType == PROTECTED_PACKAGES

                               ? extProtectedPackageNames : extRestrictedPackageNames);

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

        {

            packageNames.addElement(okPackageNames.elementAt(i));

        }

    }

    /**

     * Validates the names of the security extension's policies applying the

     * following rule: the policies can only be loaded from "c:\\resource\\"

     * or "c:/resource/"

     */

    private static void setExtPoliciesFileNames(String odcFile,

            String policiesSystemProperty)

    {

        String[] policiesFileNames = Tokenizer.split(policiesSystemProperty,

                                     ";");

        if (policiesFileNames != null)

        {

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

            {

                String policyFileName = policiesFileNames[i];

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

                {

                    policyFileName = policyFileName.toLowerCase();

                    if (policyFileName.startsWith(ALLOWED_POLICY_FILE_LOCATION1)

                            || (policyFileName.startsWith(ALLOWED_POLICY_FILE_LOCATION2)))

                    {

                        extPoliciesFileNames.addElement(policyFileName);

                    }

                    else

                    {

                        discard(odcFile, policyFileName + " points to unsafe location");

                    }

                }

            }

            // add the separator for new set of policies, so that the policies

            // could be treated as a group of related policies

            extPoliciesFileNames.addElement(POLICIES_SEPARATOR);

        }

    }

    /**

     * Validates the security extension's permission mappings applying the

     * following rule: permission mappings can not refer to any existing

     * named permissions nor to existing class names

     */

    private static void setExtPermissionMappings(String odcFile,

            String mappingsSystemProperty)

    {

        String[] mappings = Tokenizer.split(mappingsSystemProperty, ";");

        if (mappings != null)

        {

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

            {

                String mapping = mappings[i];

                String[] tokens = Tokenizer.split(mapping, ",");

                if (tokens != null && tokens.length >= 2)

                {

                    String namedPermName = tokens[0];

                    String classBasedPermName = null;

                    String classBasedPermTarget = null;

                    String classBasedPermActionList = null;

                    switch (tokens.length)

                    {

                    case 4:

                        classBasedPermActionList = tokens[3];

                    case 3:

                        classBasedPermTarget = tokens[2];

                    case 2:

                        classBasedPermName = tokens[1];

                    }

                    if (classBasedPermName != null)

                    {

                        boolean found = find(namedPermName,

                                             classBasedPermName,

                                             PermissionMappingTable.PERMISSION_MAPPING_TABLE);

                        if (!found)

                        {

                            // one more check against the existing extensions

                            // permission mappings

                            found = find(namedPermName,

                                         extPermissionMappings);

                        }

                        if (!found)

                        {

                            extPermissionMappings.put(

                                namedPermName,

                                new MIDPPermission(

                                    classBasedPermName,

                                    classBasedPermTarget,

                                    classBasedPermActionList));

                        }

                        else

                        {

                            discard(odcFile, mappings[i] + " refers to existing permission mapping");

                        }

                    }

                }

            }

        }

    }

    private static boolean find(String namedPermName, String classBasedPermName, Hashtable permMapping)

    {

        for (Enumeration e = permMapping.keys() ; e.hasMoreElements() ;)

        {

            Object key = e.nextElement();

            Object value = permMapping.get(key);

            if (((String)key).equalsIgnoreCase(namedPermName)

            {

                return true;

            }

        }

        return false;

    }

    private static boolean find(String packageName, Vector packageNames)

    {

        String[] tmp = new String[packageNames.size()];

        packageNames.copyInto(tmp);

        return find(packageName, tmp);

    }

    private static boolean find(String packageName, String[] packageNames)

    {

        packageName =  packageName.replace('.', '/');

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

        {

            String otherPackageName = packageNames[i].replace('.', '/');

            if (otherPackageName.startsWith(packageName)

                    || packageName.startsWith(otherPackageName))

            {

                return true;

            }

        }

        return false;

    }

    private static void discard(String odcFile, String discardReason)

    {

        Logger.logWarning(odcFile + " contains unsafe properties. Details: " + discardReason);

    }

}