我正在尝试将 IronPython 集成到 C# 应用程序中以进行脚本编写。我还希望脚本在一组限制它们访问文件系统/网络/敏感系统资源的安全策略下运行。
研究表明，最流行的方法是使用 CAS。这很好用，它不允许用户使用套接字、访问文件系统等。但是，当我尝试为脚本注入变量以与之交互时，每次访问某些参数时都会出现安全异常。这只发生在我在程序集中定义的变量上。如果我使用标准的 .NET 类型（如 Dictionary），它就可以正常工作。
我的代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Security.Policy;
using System.Security.Permissions;
using System.Security;
using System.IO;
using Microsoft.Scripting.Hosting;
using IronPython.Hosting;
using System.Runtime.Remoting;
using System.Net;
namespace python_in_appdomain
{
[Serializable]
public class Whatever
{
public int i;
public Whatever(int i)
{
this.i = i;
}
}
class Program
{
static void Main(string[] args)
{
Remoting();
}
public static void Remoting()
{
AppDomainSetup setup = new AppDomainSetup();
Assembly thisAssembly = Assembly.GetExecutingAssembly();
setup.ApplicationBase = Path.GetDirectoryName(thisAssembly.Location);
AssemblyName name = typeof(Program).Assembly.GetName();
StrongName sn = new StrongName(
new StrongNamePublicKeyBlob(name.GetPublicKey()),
name.Name,
name.Version
);
PermissionSet pset = new PermissionSet(PermissionState.None);
pset.AddPermission(new SecurityPermission(SecurityPermissionFlag.Execution));
pset.AddPermission(new ReflectionPermission(PermissionState.Unrestricted));
setup.PartialTrustVisibleAssemblies = new[] { sn.Name + ", PublicKey=" + sn.PublicKey.ToString() };
AppDomain domain = AppDomain.CreateDomain("Sandbox", AppDomain.CurrentDomain.Evidence, setup, pset, sn);
String script = @"
d.Add('hello', 1)
w.i = 5
";
Whatever w = new Whatever(4);
Dictionary<string, int> d = new Dictionary<string,int>();
ScriptRuntime py = Python.CreateRuntime(domain);
ScriptEngine engine = py.GetEngine("py");
ScriptScope scope = engine.CreateScope();
scope.SetVariable("w", w);
scope.SetVariable("d", d);
int result;
Console.WriteLine(w.i);
d.TryGetValue("hello", out result);
Console.WriteLine(result);
Console.WriteLine("-----");
try
{
engine.Execute(script, scope);
}
catch (Exception exc)
{
Console.WriteLine(exc.ToString());
}
w = scope.GetVariable<Whatever>("w");
d = scope.GetVariable<Dictionary<string,int>>("d");
Console.WriteLine("-----");
Console.WriteLine(w.i);
d.TryGetValue("hello", out result);
Console.WriteLine(result);
}
}
}
注释掉第 55 行的“wi=5”会导致程序在受限的安全设置下正常执行。在第 47 行将 PermissionState 设置为 Unrestricted 允许脚本的两行正常执行。以下是我收到的错误消息：
System.Security.SecurityException: Request failed.
at System.Runtime.CompilerServices.RuntimeHelpers._CompileMethod(IRuntimeMethodInfo method)
at System.Reflection.Emit.DynamicMethod.CreateDelegate(Type delegateType, Object target)
at System.Dynamic.Utils.TypeExtensions.CreateDelegate(MethodInfo methodInfo, Type delegateType, Object target)
at System.Linq.Expressions.Compiler.LambdaCompiler.CreateDelegate()
at System.Linq.Expressions.Compiler.LambdaCompiler.Compile(LambdaExpression lambda, DebugInfoGenerator debugInfoGenerator)
at System.Linq.Expressions.Expression`1.Compile()
at System.Runtime.CompilerServices.CallSiteBinder.BindCore[T](CallSite`1 site, Object[] args)
at System.Dynamic.UpdateDelegates.UpdateAndExecute2[T0,T1,TRet](CallSite site, T0 arg0, T1 arg1)
at Microsoft.Scripting.Interpreter.DynamicInstruction`3.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.LightLambda.Run2[T0,T1,TRet](T0 arg0, T1 arg1)
at IronPython.Compiler.PythonScriptCode.RunWorker(CodeContext ctx)
at IronPython.Compiler.PythonScriptCode.Run(Scope scope)
at IronPython.Compiler.RuntimeScriptCode.InvokeTarget(Scope scope)
at IronPython.Compiler.RuntimeScriptCode.Run(Scope scope)
at Microsoft.Scripting.SourceUnit.Execute(Scope scope, ErrorSink errorSink)
at Microsoft.Scripting.Hosting.ScriptSource.Execute(ScriptScope scope)
at Microsoft.Scripting.Hosting.ScriptEngine.Execute(String expression, ScriptScope scope)
at Microsoft.Scripting.Hosting.ScriptEngine.Execute(String expression, ScriptScope scope)
at python_in_appdomain.Program.Remoting() in C:\Users\dave\Documents\Visual Studio 2010\Projects\IronPythonTest\IronPythonTest\Program.cs:line 7
6
The action that failed was:
Demand
The type of the first permission that failed was:
System.Security.PermissionSet
The demand was for:
<PermissionSet class="System.Security.PermissionSet"
version="1"
Unrestricted="true"/>
The granted set of the failing assembly was:
<PermissionSet class="System.Security.PermissionSet"
version="1">
<IPermission class="System.Security.Permissions.ReflectionPermission, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
version="1"
Unrestricted="true"/>
<IPermission class="System.Security.Permissions.SecurityPermission, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
version="1"
Flags="Execution"/>
</PermissionSet>
The assembly or AppDomain that failed was:
Microsoft.Dynamic, Version=1.1.0.20, Culture=neutral, PublicKeyToken=7f709c5b713576e1
The method that caused the failure was:
Int32 Run(Microsoft.Scripting.Interpreter.InterpretedFrame)
The Zone of the assembly that failed was:
Internet
The Url of the assembly that failed was:
file:///C:/Users/dave/Documents/Visual Studio 2010/Projects/IronPythonTest/IronPythonTest/bin/Debug/Microsoft.Dynamic.DLL
Unhandled Exception: System.Security.SecurityException: Request failed.
at System.Delegate.BindToMethodInfo(Object target, IRuntimeMethodInfo method, RuntimeType methodType, DelegateBindingFlags flags)
at System.Delegate.CreateDelegate(Type type, MethodInfo method, Boolean throwOnBindFailure)
at System.Dynamic.Utils.TypeExtensions.CreateDelegate(MethodInfo methodInfo, Type delegateType)
at System.Runtime.CompilerServices.CallSite`1.MakeUpdateDelegate()
at System.Runtime.CompilerServices.CallSite`1.GetUpdateDelegate(T& addr)
at System.Runtime.CompilerServices.CallSite`1.GetUpdateDelegate()
at System.Runtime.CompilerServices.CallSite`1.Create(CallSiteBinder binder)
at System.Func`2.Invoke(T arg)
at Microsoft.Scripting.Runtime.DynamicOperations.GetOrCreateSite[T](CallSiteBinder siteBinder, Func`2 factory)
at Microsoft.Scripting.Runtime.DynamicOperations.GetOrCreateSite[T1,TResult](CallSiteBinder siteBinder)
at Microsoft.Scripting.Runtime.DynamicOperations.ConvertTo[T](Object obj)
at IronPython.Runtime.PythonContext.ScopeGetVariable[T](Scope scope, String name)
at Microsoft.Scripting.Hosting.ScriptScope.GetVariable[T](String name)
at Microsoft.Scripting.Hosting.ScriptScope.GetVariable[T](String name)
at python_in_appdomain.Program.Remoting() in C:\Users\dave\Documents\Visual Studio 2010\Projects\IronPythonTest\IronPythonTest\Program.cs:line 8
3
at python_in_appdomain.Program.Main(String[] args) in C:\Users\dave\Documents\Visual Studio 2010\Projects\IronPythonTest\IronPythonTest\Program.
cs:line 31
这个错误令人震惊地直截了当。它说它期望完全不受限制地访问这种操作。有没有办法解决？为什么字典有效但我的变量无效？有没有办法让 IronPython 像字典一样对待我的变量？我错过了一些非常明显的东西吗？
非常感谢您的帮助。
2012 年 12 月 21 日更新
我一直在胡闹，想出了一个可行的解决方案。像这样（使用相同的权限对象）创建 AppDomain 可以让一切正常工作。
AppDomainSetup setup = new AppDomainSetup();
setup.ApplicationBase = System.Environment.CurrentDirectory;
AppDomain domain = AppDomain.CreateDomain("IPyEngine", new Evidence(), setup, pset);
我不能说我完全理解为什么，尽管我可以看到我没有提供我的程序集的证据，也没有将任何程序集添加到信任列表中。在我确定我没有做任何非常愚蠢的事情之前，我不想将其标记为答案。