在沙箱AppDomain中运行运行时编译的C#脚本 [英] Running a runtime compiled C# script in a sandbox AppDomain
问题描述
我的应用程序应该可由C#中的用户编写脚本，但用户的脚本应在受限制的AppDomain中运行，以防止脚本意外造成损坏，但是我无法真正使它正常工作，并且由于我对AppDomains的理解令人遗憾有限，我无法真正说出原因.
My application should be scriptable by the users in C#, but the user's script should run in a restricted AppDomain to prevent scripts accidentally causing damage, but I can't really get it to work, and since my understanding of AppDomains is sadly limited, I can't really tell why.
我目前正在尝试的解决方案基于此答案 https://stackoverflow.com/a/5998886/276070.
The solution I am currently trying is based on this answer https://stackoverflow.com/a/5998886/276070.
这是我的情况的模型(除驻留在全名程序集中的Script.cs之外的所有内容).请原谅代码墙，我无法再进一步压缩这个问题.
This is a model of my situation (everything except Script.cs residing in a strongly named assembly). Please excuse the wall of code, I could not condense the problem any further.
class Program
{
static void Main(string[] args)
{
// Compile the script
CodeDomProvider codeProvider = CodeDomProvider.CreateProvider("CSharp");
CompilerParameters parameters = new CompilerParameters()
{
GenerateExecutable = false,
OutputAssembly = System.IO.Path.GetTempFileName() + ".dll",
};
parameters.ReferencedAssemblies.Add(Assembly.GetEntryAssembly().Location);
CompilerResults results = codeProvider.CompileAssemblyFromFile(parameters, "Script.cs");
// ... here error checks happen ....//
var sandbox = Sandbox.Create();
var script = (IExecutable)sandbox.CreateInstance(results.PathToAssembly, "Script");
if(script != null)
script.Execute();
}
}
public interface IExecutable
{
void Execute();
}
沙箱类:
public class Sandbox : MarshalByRefObject
{
const string BaseDirectory = "Untrusted";
const string DomainName = "Sandbox";
public static Sandbox Create()
{
var setup = new AppDomainSetup()
{
ApplicationBase = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, BaseDirectory),
ApplicationName = DomainName,
DisallowBindingRedirects = true,
DisallowCodeDownload = true,
DisallowPublisherPolicy = true
};
var permissions = new PermissionSet(PermissionState.None);
permissions.AddPermission(new ReflectionPermission(ReflectionPermissionFlag.RestrictedMemberAccess));
permissions.AddPermission(new SecurityPermission(SecurityPermissionFlag.Execution));
var domain = AppDomain.CreateDomain(DomainName, null, setup, permissions,
typeof(Sandbox).Assembly.Evidence.GetHostEvidence<StrongName>());
return (Sandbox)Activator.CreateInstanceFrom(domain, typeof(Sandbox).Assembly.ManifestModule.FullyQualifiedName, typeof(Sandbox).FullName).Unwrap();
}
public object CreateInstance(string assemblyPath, string typeName)
{
new FileIOPermission(FileIOPermissionAccess.Read | FileIOPermissionAccess.PathDiscovery, assemblyPath).Assert();
var assembly = Assembly.LoadFile(assemblyPath);
CodeAccessPermission.RevertAssert();
Type type = assembly.GetType(typeName); // ****** I get null here
if (type == null)
return null;
return Activator.CreateInstance(type);
}
}
已加载的脚本:
using System;
public class Script : IExecutable
{
public void Execute()
{
Console.WriteLine("Boo");
}
}
在SandBox的CreateInstance中，我总是在标记的行得到null.我尝试了多种形式的名称命名，包括使用反射从results.CompiledAssembly读取类型名称(或完全限定名称).
我在这里做什么错了?
In CreateInstance of SandBox, I always get null at the marked line. I tried various forms of giving the name, including reading the type name (or fuly qualified name) from results.CompiledAssembly using reflection.
What am I doing wrong here?
推荐答案
我要检查的第一件事是是否存在编译错误(由该问题引起的几次头痛)
The first thing that i'll check is if there are compilation errors (i had several headache caused by this issues)
第二个想法是关于程序集的解析.我总是将AppDomain.CurrentDomain.AssemblyResolve的事件处理程序添加为安全检查，在其中寻找丢失的Assembly的已知路径.当未找到的程序集是我刚刚编译的程序集时，我为其添加静态引用并返回它.
The second idea is about the resolution of assemblies. I always add as a security check an event handler for AppDomain.CurrentDomain.AssemblyResolve, where i seek on my known path for the missing Assemblies. When the not found assembly is the one i just compiled i add a static reference to it and return it.
我通常这样做的是:
- 使用编译器在文件系统上创建新的程序集
- 使用File.ReadAllBytes 加载其内容
- 使用我将在其中使用对象的AppDomain中的Assembly.Load加载dll.
- 添加AppDomain.CurrentDomain.AssemblyResolve事件
以防万一(因为我经常使用)，我创建了一个小型库来实现这种事情
Just in case (since i use this a lot) i created a small library to accomply this kind of things
代码和文档在这里: Kendar Expression Builder 当nuget包在这里时: Nuget Sharp Template
The code and documentation are here: Kendar Expression Builder While the nuget package is here: Nuget Sharp Template
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