I'm attempting to use C# as a scripting language using CSharpCodeProvider (using VS2010 and .NET 4.0). I want the scripts to be run in a restricted AppDomain with minimal permissions. Currently, I'm getting an exception while trying to instantiate a class in the AppDomain (The call to CreateInstanceAndUnwrap()). Here is some simplified code that reproduces the exception:
using System;
using System.Collections.Generic;
using Microsoft.CSharp;
using System.CodeDom;
using System.CodeDom.Compiler;
using System.Security;
using System.Security.Policy;
using System.Security.Permissions;
using System.Reflection;
using System.Runtime.Remoting;
namespace ConsoleApp
{
class Program
{
static void Main(string[] args)
{
// set permissions
PermissionSet permissions = new PermissionSet(PermissionState.None);
permissions.AddPermission(new SecurityPermission( SecurityPermissionFlag.Execution));
AppDomainSetup adSetup = new AppDomainSetup();
adSetup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory;
//Create a list of fully trusted assemblies
Assembly[] asms = AppDomain.CurrentDomain.GetAssemblies();
List<StrongName> sns = new List<StrongName>();
for (int x = 0; x < asms.Length; x++)
{
StrongName sn = asms[x].Evidence.GetHostEvidence<StrongName>();
if (sn != null && sns.Contains(sn) == false)
sns.Add(sn);
}
//this includes: "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
AppDomain domain = AppDomain.CreateDomain("NewAppDomain", AppDomain.CurrentDomain.Evidence, adSetup, permissions);//, sns);//, sn4, sn, sn2, sn3);
try
{
String asmName = Assembly.GetExecutingAssembly().FullName;
String typeName = typeof(ConsoleApp.ScriptRunner).FullName;
//Throws exception here
ScriptRunner scriptRunner = domain.CreateInstanceAndUnwrap(asmName, typeName) as ScriptRunner;
}
catch (SecurityException se)
{
System.Diagnostics.Debug.WriteLine(se.Message);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.Message);
}
}
}
public class ScriptRunner : MarshalByRefObject
{
public ScriptRunner()
{
//A breakpoint placed here is never reached.
CompilerParameters param;
param = new CompilerParameters();
param.CompilerOptions = "";
param.GenerateExecutable = false;
param.GenerateInMemory = true;
param.IncludeDebugInformation = false;
// C# compiler
CSharpCodeProvider codeProvider = new CSharpCodeProvider();
CompilerResults results = codeProvider.CompileAssemblyFromFile(param, "Danger.cs");
}
}
}
The exception is being thrown from mscorlib and it is a System.Reflection.TargetInvocationException that has an inner System.Security.SecurityException. Here is the exception:
System.Reflection.TargetInvocationException was unhandled
Message=Exception has been thrown by the target of an invocation.
Source=mscorlib
StackTrace:
at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache)
at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean skipCheckThis, Boolean fillCache)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Activator.CreateInstance(String assemblyName, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, Evidence securityInfo, StackCrawlMark& stackMark)
at System.Activator.CreateInstance(String assemblyName, String typeName)
at System.AppDomain.CreateInstance(String assemblyName, String typeName)
at System.AppDomain.CreateInstanceAndUnwrap(String assemblyName, String typeName)
at System.AppDomain.CreateInstanceAndUnwrap(String assemblyName, String typeName)
at ConsoleApp.Program.Main(String[] args) in C:\Documents and Settings\NaultyCS\my documents\visual studio 2010\Projects\ConsoleApplication4\ConsoleApplication4\Program.cs:line 46
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.
Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.
Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.
Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.
Threading.ThreadHelper.ThreadStart()
InnerException: System.Security.SecurityException
Message=Request failed.
Source=ConsoleApplication4
GrantedSet=<PermissionSet class="System.Security.PermissionSet"
version="1">
<IPermission class="System.Security.Permissions.SecurityPermission, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
version="1"
Flags="Execution"/>
</PermissionSet>
PermissionState=<PermissionSet class="System.Security.PermissionSet"
version="1"
Unrestricted="true"/>
RefusedSet=""
Url=file:///C:/Documents and Settings/NaultyCS/my documents/visual studio 2010/Projects/ConsoleApplication4/ConsoleApplication4/bin/Debug/ConsoleApplication4.EXE
StackTrace:
at ConsoleApp.ScriptRunner..ctor()
InnerException:
So it appears to me that mscorlib is demanding full trust. I've added it as a fully trusted assembly, but it has no effect. What am I doing wrong here?
