安全性如何创建Java沙盒？

Question

我想让我的应用程序运行其他人的代码，也就是插件。但是，我有什么办法可以确保安全，这样他们就不会编写恶意代码了。我如何控制他们能做什么或不能做什么

我偶然发现JVM有一个“内置沙盒”特性——这是什么？这是唯一的方法吗？是否有用于制作沙盒的第三方Java库

我有什么选择？链接到指南和例子是感激的

Answer 1

对于AWT/Swing应用程序，您需要使用非标准的AppContext类，该类可以随时更改。因此，为了有效，您需要启动另一个进程来运行插件代码，并处理两者之间的通信（有点像Chrome）。插件过程将需要一个SecurityManager集和一个ClassLoader来隔离插件代码并对插件类应用适当的ProtectionDomain

Answer 2

下面是使用SecurityManager解决问题的方法：

https://svn.code.sf.net/p/loggifier/code/trunk/de.unkrig.commons.lang/src/de/unkrig/commons/lang/security/Sandbox.java

package de.unkrig.commons.lang.security;

import java.security.AccessControlContext;
import java.security.Permission;
import java.security.Permissions;
import java.security.ProtectionDomain;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.WeakHashMap;

import de.unkrig.commons.nullanalysis.Nullable;

/**
 * This class establishes a security manager that confines the permissions for code executed through specific classes,
 * which may be specified by class, class name and/or class loader.
 * <p>
 * To 'execute through a class' means that the execution stack includes the class. E.g., if a method of class {@code A}
 * invokes a method of class {@code B}, which then invokes a method of class {@code C}, and all three classes were
 * previously {@link #confine(Class, Permissions) confined}, then for all actions that are executed by class {@code C}
 * the <i>intersection</i> of the three {@link Permissions} apply.
 * <p>
 * Once the permissions for a class, class name or class loader are confined, they cannot be changed; this prevents any
 * attempts (e.g. of the confined class itself) to release the confinement.
 * <p>
 * Code example:
 * <pre>
 *  Runnable unprivileged = new Runnable() {
 *      public void run() {
 *          System.getProperty("user.dir");
 *      }
 *  };
 *
 *  // Run without confinement.
 *  unprivileged.run(); // Works fine.
 *
 *  // Set the most strict permissions.
 *  Sandbox.confine(unprivileged.getClass(), new Permissions());
 *  unprivileged.run(); // Throws a SecurityException.
 *
 *  // Attempt to change the permissions.
 *  {
 *      Permissions permissions = new Permissions();
 *      permissions.add(new AllPermission());
 *      Sandbox.confine(unprivileged.getClass(), permissions); // Throws a SecurityException.
 *  }
 *  unprivileged.run();
 * </pre>
 */
public final
class Sandbox {

    private Sandbox() {}

    private static final Map<Class<?>, AccessControlContext>
    CHECKED_CLASSES = Collections.synchronizedMap(new WeakHashMap<Class<?>, AccessControlContext>());

    private static final Map<String, AccessControlContext>
    CHECKED_CLASS_NAMES = Collections.synchronizedMap(new HashMap<String, AccessControlContext>());

    private static final Map<ClassLoader, AccessControlContext>
    CHECKED_CLASS_LOADERS = Collections.synchronizedMap(new WeakHashMap<ClassLoader, AccessControlContext>());

    static {

        // Install our custom security manager.
        if (System.getSecurityManager() != null) {
            throw new ExceptionInInitializerError("There's already a security manager set");
        }
        System.setSecurityManager(new SecurityManager() {

            @Override public void
            checkPermission(@Nullable Permission perm) {
                assert perm != null;

                for (Class<?> clasS : this.getClassContext()) {

                    // Check if an ACC was set for the class.
                    {
                        AccessControlContext acc = Sandbox.CHECKED_CLASSES.get(clasS);
                        if (acc != null) acc.checkPermission(perm);
                    }

                    // Check if an ACC was set for the class name.
                    {
                        AccessControlContext acc = Sandbox.CHECKED_CLASS_NAMES.get(clasS.getName());
                        if (acc != null) acc.checkPermission(perm);
                    }

                    // Check if an ACC was set for the class loader.
                    {
                        AccessControlContext acc = Sandbox.CHECKED_CLASS_LOADERS.get(clasS.getClassLoader());
                        if (acc != null) acc.checkPermission(perm);
                    }
                }
            }
        });
    }

    // --------------------------

    /**
     * All future actions that are executed through the given {@code clasS} will be checked against the given {@code
     * accessControlContext}.
     *
     * @throws SecurityException Permissions are already confined for the {@code clasS}
     */
    public static void
    confine(Class<?> clasS, AccessControlContext accessControlContext) {

        if (Sandbox.CHECKED_CLASSES.containsKey(clasS)) {
            throw new SecurityException("Attempt to change the access control context for '" + clasS + "'");
        }

        Sandbox.CHECKED_CLASSES.put(clasS, accessControlContext);
    }

    /**
     * All future actions that are executed through the given {@code clasS} will be checked against the given {@code
     * protectionDomain}.
     *
     * @throws SecurityException Permissions are already confined for the {@code clasS}
     */
    public static void
    confine(Class<?> clasS, ProtectionDomain protectionDomain) {
        Sandbox.confine(
            clasS,
            new AccessControlContext(new ProtectionDomain[] { protectionDomain })
        );
    }

    /**
     * All future actions that are executed through the given {@code clasS} will be checked against the given {@code
     * permissions}.
     *
     * @throws SecurityException Permissions are already confined for the {@code clasS}
     */
    public static void
    confine(Class<?> clasS, Permissions permissions) {
        Sandbox.confine(clasS, new ProtectionDomain(null, permissions));
    }

    // Code for 'CHECKED_CLASS_NAMES' and 'CHECKED_CLASS_LOADERS' omitted here.

}

Answer 3

看看the java-sandbox project，它允许轻松创建非常灵活的沙盒来运行不受信任的代码

Answer 4

你在找security manager。可以通过指定policy来限制应用程序的权限

Answer 5

关于这个问题的讨论启发我启动了自己的沙箱项目

https://github.com/Black-Mantha/sandbox

在这篇文章中，我遇到了一个重要的安全性问题：“如何允许沙箱之外的代码绕过SecurityManager？”

我将沙盒代码放在它自己的线程组中，并且在该组之外时总是授予权限。如果仍然需要在该组中运行特权代码（例如在回调中），则可以使用ThreadLocal仅为该线程设置标志。类加载器将阻止沙盒访问ThreadLocal。此外，如果这样做，则需要禁止使用终结器，因为它们在ThreadGroup之外的专用线程中运行

Answer 6

• 定义和注册您自己的安全管理器将允许您限制代码的功能-有关SecurityManager，请参阅oracle文档

>P>也可以考虑<强>创建一个单独的加载代码的机制，即可以编写或实例化另一个类加载器，以便从一个特殊的地方加载代码。您可能有加载代码的约定，例如从特殊目录或特殊格式的zip文件（如WAR文件和JAR文件）加载代码。如果你正在编写一个类加载器，它会让你处于必须完成工作才能加载代码的境地。这意味着，如果看到想要拒绝的内容（或依赖项），就可能无法加载代码http://java.sun.com/javase/6/docs/api/java/lang/ClassLoader.html