AllowPartiallyTrustedCallersAttribute Класс

Определение

Пространство имен:

System.Security

Сборка:

System.Runtime.dll

Исходный код:

AllowPartiallyTrustedCallersAttribute.cs

Позволяет вызывать сборку частично доверенным кодом. Без этого объявления можно использовать сборку только полностью доверенным вызывающим абонентам. Этот класс не может быть унаследован.

public ref class AllowPartiallyTrustedCallersAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Assembly, AllowMultiple=false, Inherited=false)]
public sealed class AllowPartiallyTrustedCallersAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Assembly, AllowMultiple=false, Inherited=false)>]
type AllowPartiallyTrustedCallersAttribute = class
    inherit Attribute

Public NotInheritable Class AllowPartiallyTrustedCallersAttribute
Inherits Attribute

Наследование

Object

Attribute

AllowPartiallyTrustedCallersAttribute

Атрибуты

AttributeUsageAttribute

Примеры

В следующем примере показано, как использовать класс AllowPartiallyTrustedCallersAttribute.

// The following HTML code can be used to call the user control in this sample.
//
//  <OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800"
//  height="300" style="font-size:12;">
// To run this test control you must create a strong name key, snkey.snk, and
// a code group that gives full trust to assemblies signed with snkey.snk.
// The user control displays an OpenFileDialog box, then displays a text box containing the name of
// the file selected and a list box that displays the contents of the file.  The selected file must
// contain text in order for the control to display the data properly.
// Caution  This sample demonstrates the use of the Assert method.  Calling Assert removes the
// requirement that all code in the call chain must be granted permission to access the specified
// resource, it can open up security vulnerabilities if used incorrectly or inappropriately. Therefore,
// it should be used with great caution.  Assert should always be followed with a RevertAssert
// command to restore the security settings.
#using <System.Windows.Forms.dll>
#using <System.Data.dll>
#using <System.Drawing.dll>
#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::ComponentModel;
using namespace System::Drawing;
using namespace System::Data;
using namespace System::Windows::Forms;
using namespace System::IO;
using namespace System::Security;
using namespace System::Security::Permissions;
using namespace System::Reflection;
using namespace System::Runtime::CompilerServices;

// This strong name key is used to create a code group that gives permissions to this assembly.
// The AllowPartiallyTrustedCallersAttribute requires the assembly to be signed with a strong name key.
// This attribute is necessary since the control is called by either an intranet or Internet
// Web page that should be running under restricted permissions.
// The userControl1 displays an OpenFileDialog box, then displays a text box containing the name of 
// the file selected and a list box that displays the contents of the file.  The selected file must 
// contain text in order for the control to display the data properly.

[assembly:AssemblyKeyFile("snKey.snk")];
[assembly:AssemblyVersion("1.0.0.0")];
[assembly:AllowPartiallyTrustedCallers];
public ref class UserControl1: public System::Windows::Forms::UserControl
{
private:
   System::Windows::Forms::TextBox^ textBox1;
   System::Windows::Forms::ListBox^ listBox1;

   // Required designer variable.
   System::ComponentModel::Container^ components;

public:
// Demand the zone requirement for the calling application.
[ZoneIdentityPermission(SecurityAction::Demand, Zone = SecurityZone::Intranet)]
   UserControl1()
   {
      
      // This call is required by the Windows.Forms Form Designer.
      InitializeComponent();
      
      // The OpenFileDialog box should not require any special permissions.
      OpenFileDialog^ fileDialog = gcnew OpenFileDialog;
      if ( fileDialog->ShowDialog() == DialogResult::OK )
      {
         
         // Reading the name of the selected file from the OpenFileDialog box
         // and reading the file requires FileIOPermission.  The user control should 
         // have this permission granted through its code group; the Web page that calls the 
         // control should not have this permission.  The Assert command prevents a stack walk 
         // that would fail because the caller does not have the required FileIOPermission.  
         // The use of Assert can open up security vulnerabilities if used incorrectly or 
         // inappropriately. Therefore, it should be used with great caution.
         // The Assert command should be followed by a RevertAssert as soon as the file operation 
         // is completed.
         (gcnew FileIOPermission( PermissionState::Unrestricted ))->Assert();
         textBox1->Text = fileDialog->FileName;

         // Display the contents of the file in the text box.
         FileStream^ fsIn = gcnew FileStream( textBox1->Text,FileMode::Open,FileAccess::Read,FileShare::Read );
         StreamReader^ sr = gcnew StreamReader( fsIn );
         
         // Process every line in the file
         for ( String ^ Line = sr->ReadLine(); Line != nullptr; Line = sr->ReadLine() )
         {
            listBox1->Items->Add( Line );

         }

         // file operations.
         FileIOPermission::RevertAssert();
      }
   }

private:

   /// <summary>
   /// Required method for Designer support - do not modify 
   /// the contents of this method with the code editor.
   /// </summary>
   void InitializeComponent()
   {
      this->textBox1 = gcnew System::Windows::Forms::TextBox;
      this->listBox1 = gcnew System::Windows::Forms::ListBox;
      this->SuspendLayout();
      
      // 
      // textBox1
      // 
      this->textBox1->Location = System::Drawing::Point( 208, 112 );
      this->textBox1->Name = "textBox1";
      this->textBox1->Size = System::Drawing::Size( 320, 20 );
      this->textBox1->TabIndex = 0;
      this->textBox1->Text = "textBox1";
      this->textBox1->TextChanged += gcnew System::EventHandler( this,&UserControl1::textBox1_TextChanged );
      
      // 
      // listBox1
      // 
      this->listBox1->Location = System::Drawing::Point( 200, 184 );
      this->listBox1->Name = "listBox1";
      this->listBox1->Size = System::Drawing::Size( 336, 108 );
      this->listBox1->TabIndex = 1;
      
      // 
      // UserControl1
      // 
      this->Controls->Add( this->listBox1 );
      this->Controls->Add( this->textBox1 );
      this->Name = "UserControl1";
      this->Size = System::Drawing::Size( 592, 400 );
      this->Load += gcnew System::EventHandler( this,&UserControl1::UserControl1_Load );
      this->ResumeLayout( false );
   }

   void UserControl1_Load( Object^ /*sender*/, System::EventArgs^ /*e*/ ){}

   void textBox1_TextChanged( Object^ /*sender*/, System::EventArgs^ /*e*/ ){}

};

// The following HTML code can be used to call the user control in this sample.
//
//		<OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800"
//		height="300" style="font-size:12;">

// To run this test control you must create a strong name key, snkey.snk, and 
// a code group that gives full trust to assemblies signed with snkey.snk.

// The user control displays an OpenFileDialog box, then displays a text box containing the name of 
// the file selected and a list box that displays the contents of the file.  The selected file must 
// contain text in order for the control to display the data properly.

// Caution  This sample demonstrates the use of the Assert method.  Calling Assert removes the 
// requirement that all code in the call chain must be granted permission to access the specified 
// resource, it can open up security vulnerabilities if used incorrectly or inappropriately. Therefore, 
// it should be used with great caution.  Assert should always be followed with a RevertAssert 
// command to restore the security settings.

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.IO;
using System.Security;
using System.Security.Permissions;
using System.Reflection;
using System.Runtime.CompilerServices;

// This strong name key is used to create a code group that gives permissions to this assembly.
[assembly: AssemblyKeyFile("snKey.snk")]
[assembly: AssemblyVersion("1.0.0.0")]

// The AllowPartiallyTrustedCallersAttribute requires the assembly to be signed with a strong name key.
// This attribute is necessary since the control is called by either an intranet or Internet
// Web page that should be running under restricted permissions.
[assembly:AllowPartiallyTrustedCallers]
namespace UserControl
{
    // The userControl1 displays an OpenFileDialog box, then displays a text box containing the name of 
    // the file selected and a list box that displays the contents of the file.  The selected file must 
    // contain text in order for the control to display the data properly.
    public class UserControl1 : System.Windows.Forms.UserControl
    {
        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.ListBox listBox1;
        // Required designer variable.
        private System.ComponentModel.Container components = null;

              // Demand the zone requirement for the calling application.
              [ZoneIdentityPermission(SecurityAction.Demand, Zone = SecurityZone.Intranet)]
        public UserControl1()
        {
            // This call is required by the Windows.Forms Form Designer.
            InitializeComponent();

            // The OpenFileDialog box should not require any special permissions.
            OpenFileDialog fileDialog = new OpenFileDialog();
            if(fileDialog.ShowDialog() == DialogResult.OK)
            {
                // Reading the name of the selected file from the OpenFileDialog box
                // and reading the file requires FileIOPermission.  The user control should 
                // have this permission granted through its code group; the Web page that calls the 
                // control should not have this permission.  The Assert command prevents a stack walk 
                // that would fail because the caller does not have the required FileIOPermission.  
                // The use of Assert can open up security vulnerabilities if used incorrectly or 
                // inappropriately. Therefore, it should be used with great caution.
                // The Assert command should be followed by a RevertAssert as soon as the file operation 
                // is completed.
                new FileIOPermission(PermissionState.Unrestricted).Assert();
                textBox1.Text = fileDialog.FileName;
                // Display the contents of the file in the text box.
                FileStream fsIn = new FileStream(textBox1.Text, FileMode.Open, FileAccess.Read, 
                    FileShare.Read);
                StreamReader sr = new StreamReader(fsIn);
            
                // Process every line in the file
                for (String Line = sr.ReadLine(); Line != null; Line = sr.ReadLine()) 
                {
                    listBox1.Items.Add(Line);
                }
                // It is very important to call RevertAssert to restore the stack walk for
                // file operations.
                FileIOPermission.RevertAssert();
            }
        }

        // Clean up any resources being used.
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if( components != null )
                    components.Dispose();
            }
            base.Dispose( disposing );
        }

        #region Component Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify 
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.SuspendLayout();
            // 
            // textBox1
            // 
            this.textBox1.Location = new System.Drawing.Point(208, 112);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(320, 20);
            this.textBox1.TabIndex = 0;
            this.textBox1.Text = "textBox1";
            this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
            // 
            // listBox1
            // 
            this.listBox1.Location = new System.Drawing.Point(200, 184);
            this.listBox1.Name = "listBox1";
            this.listBox1.Size = new System.Drawing.Size(336, 108);
            this.listBox1.TabIndex = 1;
            // 
            // UserControl1
            // 
            this.Controls.Add(this.listBox1);
            this.Controls.Add(this.textBox1);
            this.Name = "UserControl1";
            this.Size = new System.Drawing.Size(592, 400);
            this.Load += new System.EventHandler(this.UserControl1_Load);
            this.ResumeLayout(false);
        }
        #endregion

        private void UserControl1_Load(object sender, System.EventArgs e)
        {
        }

        private void textBox1_TextChanged(object sender, System.EventArgs e)
        {
        }
    }
}

' The following HTML code can be used to call the user control in this sample.
'
'		<OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800"
'		height="300" style="font-size:12;">
' To run this test control you must create a strong name key, snkey.snk, and 
' a code group that gives full trust to assemblies signed with snkey.snk.
' The user control displays an OpenFileDialog box, then displays a text box containing the name of 
' the file selected and a list box that displays the contents of the file.  The selected file must 
' contain text in order for the control to display the data properly.
' Caution  This sample demonstrates the use of the Assert method.  Calling Assert removes the 
' requirement that all code in the call chain must be granted permission to access the specified 
' resource, it can open up security vulnerabilities if used incorrectly or inappropriately. Therefore, 
' it should be used with great caution.  Assert should always be followed with a RevertAssert 
' command to restore the security settings.

Imports System.Collections
Imports System.ComponentModel
Imports System.Drawing
Imports System.Data
Imports System.Windows.Forms
Imports System.IO
Imports System.Security
Imports System.Security.Permissions
Imports System.Reflection
Imports System.Runtime.CompilerServices

' This strong name key is used to create a code group that gives permissions to this assembly.

<Assembly: AssemblyKeyFile("snKey.snk")> 

<Assembly: AssemblyVersion("1.0.0.0")> 
' The AllowPartiallyTrustedCallersAttribute requires the assembly to be signed with a strong name key.
' This attribute is necessary since the control is called by either an intranet or Internet
' Web page that should be running under restricted permissions.

<Assembly: AllowPartiallyTrustedCallers()> 

' The userControl1 displays an OpenFileDialog box, then displays a text box containing the name of 
' the file selected and a list box that displays the contents of the file.  The selected file must 
' contain text in order for the control to display the data properly.

'Demand the zone requirement for the calling application.
<ZoneIdentityPermissionAttribute(SecurityAction.Demand, Zone:=SecurityZone.Intranet)> _
Public Class UserControl1
    Inherits System.Windows.Forms.UserControl
    Private WithEvents textBox1 As System.Windows.Forms.TextBox
    Private listBox1 As System.Windows.Forms.ListBox
    ' Required designer variable.
    Private components As System.ComponentModel.Container = Nothing


    Public Sub New()
        ' This call is required by the Windows.Forms Form Designer.
        InitializeComponent()

        ' The OpenFileDialog box should not require any special permissions.
        Dim fileDialog As New OpenFileDialog
        If fileDialog.ShowDialog() = DialogResult.OK Then
            ' Reading the name of the selected file from the OpenFileDialog box
            ' and reading the file requires FileIOPermission.  The user control should 
            ' have this permission granted through its code group; the Web page that calls the 
            ' control should not have this permission.  The Assert command prevents a stack walk 
            ' that would fail because the caller does not have the required FileIOPermission.  
            ' The use of Assert can open up security vulnerabilities if used incorrectly or 
            ' inappropriately. Therefore, it should be used with great caution.
            ' The Assert command should be followed by a RevertAssert as soon as the file operation 
            ' is completed.
            Dim fileIOPermission As New FileIOPermission(PermissionState.Unrestricted)
            fileIOPermission.Assert()
            textBox1.Text = fileDialog.FileName
            ' Display the contents of the file in the text box.
            Dim fsIn As New FileStream(textBox1.Text, FileMode.Open, FileAccess.Read, FileShare.Read)
            Dim sr As New StreamReader(fsIn)

            ' Process every line in the file
            Dim Line As String
            Line = sr.ReadLine()
            While Not (Line Is Nothing)
                listBox1.Items.Add(Line)
                Line = sr.ReadLine()
            End While
            ' It is very important to call RevertAssert to restore the stack walk for
            ' file operations.
            fileIOPermission.RevertAssert()
        End If
    End Sub


    ' Clean up any resources being used.
    Protected Overloads Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub


    ' Required method for Designer support - do not modify 
    ' the contents of this method with the code editor.
    Private Sub InitializeComponent()
        Me.textBox1 = New System.Windows.Forms.TextBox
        Me.listBox1 = New System.Windows.Forms.ListBox
        Me.SuspendLayout()
        ' 
        ' textBox1
        ' 
        Me.textBox1.Location = New System.Drawing.Point(208, 112)
        Me.textBox1.Name = "textBox1"
        Me.textBox1.Size = New System.Drawing.Size(320, 20)
        Me.textBox1.TabIndex = 0
        Me.textBox1.Text = "textBox1"
        ' 
        ' listBox1
        ' 
        Me.listBox1.Location = New System.Drawing.Point(200, 184)
        Me.listBox1.Name = "listBox1"
        Me.listBox1.Size = New System.Drawing.Size(336, 108)
        Me.listBox1.TabIndex = 1
        ' 
        ' UserControl1
        ' 
        Me.Controls.Add(listBox1)
        Me.Controls.Add(textBox1)
        Me.Name = "UserControl1"
        Me.Size = New System.Drawing.Size(592, 400)
        Me.ResumeLayout(False)
    End Sub

    Private Sub UserControl1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
    End Sub

    Private Sub textBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles textBox1.TextChanged
    End Sub
End Class

Комментарии

Важный

Частично доверенный код больше не поддерживается. Этот атрибут не действует в .NET Core.

Заметка

Платформа .NET Framework 4 вводит новые правила безопасности, влияющие на поведение атрибута AllowPartiallyTrustedCallersAttribute (см. раздел Security-Transparent Code, level 2). В .NET Framework 4 все коды по умолчанию являются прозрачными для безопасности, то есть частично доверенными. Тем не менее вы можете назначить им другие атрибуты прозрачности, а также отдельные типы и члены. Сведения об этих и других изменениях безопасности см. в изменения безопасности.

Сборки .NET Framework версии 2.0 () должны иметь строгое имя, чтобы эффективно использовать атрибут AllowPartiallyTrustedCallersAttribute (APTCA). Сборки .NET Framework 4 () не должны иметь строгое имя для эффективного атрибута APTCA, и они могут содержать прозрачный, критически важный для безопасности и безопасный критически важный код. Дополнительные сведения о применении атрибутов на уровне сборки см. в разделе Применение атрибутов.

По умолчанию, если строго именованная сборка явно не применяет этот атрибут на уровне сборки, она может вызываться только другими сборками, которым предоставлено полное доверие. Это ограничение применяется путем размещения LinkDemand для FullTrust на каждом общедоступном или защищенном методе для каждого общедоступного класса в сборке. Сборки, которые должны вызываться частично доверенным кодом, могут объявлять свое намерение с помощью AllowPartiallyTrustedCallersAttribute. Пример объявления в C# — [assembly:AllowPartiallyTrustedCallers]; примером в Visual Basic является <assembly:AllowPartiallyTrustedCallers>.

Осторожность

Наличие этого атрибута уровня сборки предотвращает поведение по умолчанию при размещении проверок безопасности FullTrustLinkDemand и делает сборку вызываемой из любой другой (частично или полностью доверенной) сборки.

При наличии атрибута APTCA все остальные функции проверки безопасности, как это предполагается, включая любые декларативные атрибуты безопасности уровня класса или метода. Этот атрибут блокирует только неявное, полностью доверенное требование вызывающего объекта.

Это не декларативный атрибут безопасности, а обычный атрибут (он является производным от System.Attribute, а не от System.Security.Permissions.SecurityAttribute).

Дополнительные сведения см. в разделе Использование библиотек из частично доверенного кода.

Конструкторы

AllowPartiallyTrustedCallersAttribute()

Инициализирует новый экземпляр класса AllowPartiallyTrustedCallersAttribute.

Свойства

PartialTrustVisibilityLevel	Возвращает или задает видимость частичного доверия по умолчанию для кода, помеченного атрибутом AllowPartiallyTrustedCallersAttribute (APTCA).
TypeId	При реализации в производном классе получает уникальный идентификатор для этого Attribute. (Унаследовано от Attribute)

Методы

Equals(Object)	Возвращает значение, указывающее, равен ли этот экземпляр указанному объекту. (Унаследовано от Attribute)
GetHashCode()	Возвращает хэш-код для этого экземпляра. (Унаследовано от Attribute)
GetType()	Возвращает Type текущего экземпляра. (Унаследовано от Object)
IsDefaultAttribute()	При переопределении в производном классе указывает, является ли значение этого экземпляра значением по умолчанию для производного класса. (Унаследовано от Attribute)
Match(Object)	При переопределении в производном классе возвращает значение, указывающее, равен ли этот экземпляр указанному объекту. (Унаследовано от Attribute)
MemberwiseClone()	Создает неглубокую копию текущей Object. (Унаследовано от Object)
ToString()	Возвращает строку, представляющую текущий объект. (Унаследовано от Object)