SecurityAction SecurityAction SecurityAction SecurityAction Enum

Definition

Specifies the security actions that can be performed using declarative security.

public enum class SecurityAction
[System.Runtime.InteropServices.ComVisible(true)]
[System.Obsolete("CAS support is not available with Silverlight applications.")]
[Serializable]
public enum SecurityAction
type SecurityAction = 
Public Enum SecurityAction
Inheritance
SecurityActionSecurityActionSecurityActionSecurityAction
Attributes
ComVisibleAttribute ObsoleteAttribute SerializableAttribute

Fields

Assert Assert Assert Assert 3

The calling code can access the resource identified by the current permission object, even if callers higher in the stack have not been granted permission to access the resource (see Using the Assert Method).

Demand Demand Demand Demand 2

All callers higher in the call stack are required to have been granted the permission specified by the current permission object.

Deny Deny Deny Deny 4

The ability to access the resource specified by the current permission object is denied to callers, even if they have been granted permission to access it (see Using the Deny Method).

InheritanceDemand InheritanceDemand InheritanceDemand InheritanceDemand 7

The derived class inheriting the class or overriding a method is required to have been granted the specified permission..

LinkDemand LinkDemand LinkDemand LinkDemand 6

The immediate caller is required to have been granted the specified permission. Do not use in the .NET Framework 4. For full trust, use SecurityCriticalAttribute instead; for partial trust, use Demand.

PermitOnly PermitOnly PermitOnly PermitOnly 5

Only the resources specified by this permission object can be accessed, even if the code has been granted permission to access other resources.

RequestMinimum RequestMinimum RequestMinimum RequestMinimum 8

The request for the minimum permissions required for code to run. This action can only be used within the scope of the assembly.

RequestOptional RequestOptional RequestOptional RequestOptional 9

The request for additional permissions that are optional (not required to run). This request implicitly refuses all other permissions not specifically requested. This action can only be used within the scope of the assembly.

RequestRefuse RequestRefuse RequestRefuse RequestRefuse 10

The request that permissions that might be misused will not be granted to the calling code. This action can only be used within the scope of the assembly.

Examples

This example shows how to notify the CLR that code in called methods has only IsolatedStoragePermission, and also demonstrates how to write and read from isolated storage.

using namespace System;
using namespace System::Security;
using namespace System::Security::Permissions;
using namespace System::IO::IsolatedStorage;
using namespace System::IO;


static void WriteIsolatedStorage()
{
    try
    {
        // Attempt to create a storage file that is isolated by
        // user and assembly. IsolatedStorageFilePermission
        // granted to the attribute at the top of this file
        // allows CLR to load this assembly and execution of this
        // statement.
        Stream^ fileCreateStream = gcnew
            IsolatedStorageFileStream(
            "AssemblyData",
            FileMode::Create,
            IsolatedStorageFile::GetUserStoreForAssembly());

        StreamWriter^ streamWriter = gcnew StreamWriter(
            fileCreateStream);
        try
        {
            // Write some data out to the isolated file.

            streamWriter->Write("This is some test data.");
            streamWriter->Close();	
        }
        finally
        {
            delete fileCreateStream;
            delete streamWriter;
        } 
    }
    catch (IOException^ ex)
    {
        Console::WriteLine(ex->Message);
    }

    try
    {
        Stream^ fileOpenStream =
            gcnew IsolatedStorageFileStream(
            "AssemblyData",
            FileMode::Open,
            IsolatedStorageFile::GetUserStoreForAssembly());
        // Attempt to open the file that was previously created.

        StreamReader^ streamReader = gcnew StreamReader(
            fileOpenStream);
        try
        { 
            // Read the data from the file and display it.

            Console::WriteLine(streamReader->ReadLine());
            streamReader->Close();
        }
        finally
        {
            delete fileOpenStream;
            delete streamReader;
        }
    }
    catch (FileNotFoundException^ ex)
    {
        Console::WriteLine(ex->Message);
    }
    catch (IOException^ ex)
    {
        Console::WriteLine(ex->Message);
    }
}
// Notify the CLR to only grant IsolatedStorageFilePermission to called methods. 
// This restricts the called methods to working only with storage files that are isolated 
// by user and assembly.
[IsolatedStorageFilePermission(SecurityAction::PermitOnly, UsageAllowed = IsolatedStorageContainment::AssemblyIsolationByUser)]
int main()
{
	WriteIsolatedStorage();
}

// This code produces the following output.
//
//  This is some test data.
using System;
using System.Security.Permissions;
using System.IO.IsolatedStorage;
using System.IO;

// Notify the CLR to only grant IsolatedStorageFilePermission to called methods. 
// This restricts the called methods to working only with storage files that are isolated 
// by user and assembly.
[IsolatedStorageFilePermission(SecurityAction.PermitOnly, UsageAllowed = IsolatedStorageContainment.AssemblyIsolationByUser)]
public sealed class App
{
    static void Main()
    {
        WriteIsolatedStorage();

    }
    private static void WriteIsolatedStorage()
    {
        // Attempt to create a storage file that is isolated by user and assembly.
        // IsolatedStorageFilePermission granted to the attribute at the top of this file 
        // allows CLR to load this assembly and execution of this statement.
        using (Stream s = new IsolatedStorageFileStream("AssemblyData", FileMode.Create, IsolatedStorageFile.GetUserStoreForAssembly()))
        {

            // Write some data out to the isolated file.
            using (StreamWriter sw = new StreamWriter(s))
            {
                sw.Write("This is some test data.");
            }
        }

        // Attempt to open the file that was previously created.
        using (Stream s = new IsolatedStorageFileStream("AssemblyData", FileMode.Open, IsolatedStorageFile.GetUserStoreForAssembly()))
        {
            // Read the data from the file and display it.
            using (StreamReader sr = new StreamReader(s))
            {
                Console.WriteLine(sr.ReadLine());
            }
        }
    }
}

// This code produces the following output.
//
//  Some test data.
Option Strict On
Imports System
Imports System.Security.Permissions
Imports System.IO.IsolatedStorage
Imports System.IO


' Notify the CLR to only grant IsolatedStorageFilePermission to called methods. 
' This restricts the called methods to working only with storage files that are isolated 
' by user and assembly.
<IsolatedStorageFilePermission(SecurityAction.PermitOnly, UsageAllowed:=IsolatedStorageContainment.AssemblyIsolationByUser)> _
Public NotInheritable Class App

    Shared Sub Main()
        WriteIsolatedStorage()
    End Sub 'Main
    Shared Sub WriteIsolatedStorage()
        ' Attempt to create a storage file that is isolated by user and assembly.
        ' IsolatedStorageFilePermission granted to the attribute at the top of this file 
        ' allows CLR to load this assembly and execution of this statement.
        Dim s As New IsolatedStorageFileStream("AssemblyData", FileMode.Create, IsolatedStorageFile.GetUserStoreForAssembly())
        Try

            ' Write some data out to the isolated file.
            Dim sw As New StreamWriter(s)
            Try
                sw.Write("This is some test data.")
            Finally
                sw.Dispose()
            End Try
        Finally
            s.Dispose()
        End Try

        ' Attempt to open the file that was previously created.
        Dim t As New IsolatedStorageFileStream("AssemblyData", FileMode.Open, IsolatedStorageFile.GetUserStoreForAssembly())
        Try
            ' Read the data from the file and display it.
            Dim sr As New StreamReader(t)
            Try
                Console.WriteLine(sr.ReadLine())
            Finally
                sr.Dispose()
            End Try
        Finally
            t.Dispose()
        End Try

    End Sub
End Class 'App

' This code produces the following output.
'
'  Some test data.

Remarks

The following table describes the time that each security action takes place and the targets that it supports.

Important

In the .NET Framework 4, runtime support has been removed for enforcing the Deny, RequestMinimum, RequestOptional, and RequestRefuse permission requests. These requests should not be used in code that is based on .NET Framework 4 or later. For more information about this and other changes, see Security Changes.

You should not use LinkDemand in the .NET Framework 4. Instead, use the SecurityCriticalAttribute to restrict usage to fully trusted applications, or use Demand to restrict partially trusted callers.

Declaration of security action Time of action Targets supported
LinkDemand (do not use in the .NET Framework 4) Just-in-time compilation Class, method
InheritanceDemand Load time Class, method
Demand Run time Class, method
Assert Run time Class, method
Deny (obsolete in the .NET Framework 4) Run time Class, method
PermitOnly Run time Class, method
RequestMinimum (obsolete in the .NET Framework 4) Grant time Assembly
RequestOptional (obsolete in the .NET Framework 4) Grant time Assembly
RequestRefuse (obsolete in the .NET Framework 4) Grant time Assembly

For additional information about attribute targets, see Attribute.

Applies to