AppDomain.DoCallBack需要ReflectionPermission？

Question

我有这个类，我在AppDomain中创建这个类的实例除了SecurityPermissionFlag.Execute之外没有任何权限。

class IsolationEntryPoint : MarshalByRefObject
{
    // main is the original AppDomain with all the permissions
    public void Enter(AppDomain main)
    {
        // these work correctly
        Console.WriteLine("Currently in: " + AppDomain.CurrentDomain.FriendlyName);
        Console.WriteLine("Host: " + main.FriendlyName);

        // the exception is thrown here
        main.DoCallBack(this.MyCallBack);
    }

    public void MyCallBack()
    {
        Console.WriteLine("Currently in: " + AppDomain.CurrentDomain.FriendlyName);
    }
}

奇怪的是，我看到SecurityException在DoCallback行中说：

请求'System.Security.Permissions.ReflectionPermission，mscorlib、Version=4.0.0.0、Culture=neutral、PublicKeyToken=b77a5c561934e089‘类型的权限失败。

MSDNsays 这关于AppDomain.DoCallBack的权限要求：

当通过诸如ReflectionPermission等机制调用后期绑定时，就会出现Type.InvokeMember。

调用没有使用像 Type.InvokeMember这样的东西，为什么我会得到异常呢？

编辑

为了清晰起见，下面是使用隔离对象创建AppDomain的代码：

    [STAThread]
    static void Main(string[] args)
    {

        var setup = new AppDomainSetup();
        setup.ApplicationBase = Path.GetDirectoryName(Assembly.GetExecutingAssembly().CodeBase);

        var evidence = new Evidence();

        var permissions = new PermissionSet(PermissionState.None);
        permissions.AddPermission(new SecurityPermission(SecurityPermissionFlag.Execution));

        var domain = AppDomain.CreateDomain(
            "isolationDomain",
            evidence,
            setup,
            permissions);

        var handle = Activator.CreateInstanceFrom(
            domain, typeof(IsolationEntryPoint).Assembly.ManifestModule.FullyQualifiedName,
            typeof(IsolationEntryPoint).FullName);

        var instance = (IsolationEntryPoint)handle.Unwrap();

        instance.Enter(AppDomain.CurrentDomain);
    }

这两段代码是我的完整应用程序，没有其他任何东西(所以异常应该很容易再现)。

谢谢你的帮忙

Answer 1

解决方案实际上非常简单:您忽略了向class IsolationEntryPoint添加公共访问修饰符，即在更改类签名之后，您的示例运行得很好：

public class IsolationEntryPoint : MarshalByRefObject
{
    // [...]
}

Answer 2

我试过下面的方法，看起来很管用。

class Program
{

    static void Main(string[] args)
    {
        SecurityPermission t = new SecurityPermission(SecurityPermissionFlag.Execution);
        t.Demand();
        IsolationEntryPoint x = new IsolationEntryPoint();
        x.Enter(AppDomain.CurrentDomain);
    }
}


class IsolationEntryPoint : MarshalByRefObject
{
    // main is the original AppDomain with all the permissions 
    public void Enter(AppDomain main)
    {
        // these work correctly 
        Console.WriteLine("Currently in: " + AppDomain.CurrentDomain.FriendlyName);
        Console.WriteLine("Host: " + main.FriendlyName);

        // the exception is thrown here 
        main.DoCallBack(this.MyCallBack);
    }

    public void MyCallBack()
    {
        Console.WriteLine("Currently in: " + AppDomain.CurrentDomain.FriendlyName);
    }
}