SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package java.lang;

import cc.squirreljme.runtime.cldc.annotation.Api;
import cc.squirreljme.runtime.cldc.debug.Debugging;
import java.security.AccessController;
import java.security.Permission;
import java.util.PropertyPermission;

/**
 * This is the security manager which controls access to various functions of
 * the virtual machine.
 * 
 * Access is checked by {@link AccessController#checkPermission(Permission)}. 
 * 
 * @since 2020/07/02
 */
@Api
public class SecurityManager
{
    /** The current security manager, defaults to the system one. */
    static volatile SecurityManager _CURRENT_MANAGER =
        new SecurityManager();
    
    /**
     * Initializes the security manager, if a security manager already exists
     * then the
     *
     * @throws SecurityException If the manager could not be created.
     * @since 2018/09/18 
     */
    @Api
    public SecurityManager()
        throws SecurityException
    {
        // Lock on this class, since multiple threads cannot mess around with
        // this check
        synchronized (SecurityManager.class)
        {
            // If one already exists, check to see if it can be created first
            SecurityManager current = SecurityManager._CURRENT_MANAGER;
            if (current != null)
                current.checkPermission(
                    new RuntimePermission("createSecurityManager"));
        }
    }
    
    @Api
    public void checkAccept(String __a, int __b)
    {
        throw Debugging.todo();
    }
    
    /**
     * Checks if the given thread may be modified.
     *
     * @param __t The thread to check.
     * @throws SecurityException If threads cannot be modified.
     * @since 2018/11/21
     */
    @Api
    public void checkAccess(Thread __t)
        throws SecurityException
    {
        this.checkPermission(new RuntimePermission("modifyThread"));
    }
    
    @Api
    public void checkConnect(String __a, int __b)
    {
        throw Debugging.todo();
    }
    
    @Api
    public void checkDelete(String __a)
    {
        throw Debugging.todo();
    }
    
    /**
     * Checks that the virtual machine can exit with the given code.
     *
     * @param __code The exit code.
     * @throws SecurityException If exit is not permitted.
     * @since 2018/10/13
     */
    @Api
    public void checkExit(int __code)
        throws SecurityException
    {
        this.checkPermission(new RuntimePermission("exitVM." + __code));
    }
    
    @Api
    public void checkListen(int __a)
    {
        throw Debugging.todo();
    }
    
    /**
     * Checks whether the given permission is permitted.
     *
     * @param __p The permission to check.
     * @throws NullPointerException On null arguments.
     * @throws SecurityException If permission is denied.
     * @since 2018/09/18
     */
    @Api
    public void checkPermission(Permission __p)
        throws NullPointerException, SecurityException
    {
        if (__p == null)
            throw new NullPointerException("NARG");
        
        AccessController.checkPermission(__p);
    }
    
    /**
     * Checks if the given system property can be accessed.
     *
     * @param __key The key to check.
     * @throws IllegalArgumentException If the key is empty.
     * @throws NullPointerException On null arguments.
     * @throws SecurityException If access to the property is denied.
     * @since 2018/09/18
     */
    @Api
    public void checkPropertyAccess(String __key)
        throws IllegalArgumentException, NullPointerException,
            SecurityException
    {
        if (__key == null)
            throw new NullPointerException("NARG");
        
        /* {@squirreljme.error ZZ1j Request to check access to system property
        with an empty key.} */
        if (__key.isEmpty())
            throw new IllegalArgumentException("ZZ1j");
        
        // Forward
        this.checkPermission(new PropertyPermission(__key, "read"));
    }
    
    @Api
    public void checkRead(String __a)
    {
        throw Debugging.todo();
    }
    
    @Api
    public void checkWrite(String __a)
    {
        throw Debugging.todo();
    }
}