CodeAccessPermission Classe

Definição

public ref class CodeAccessPermission abstract : System::Security::IPermission, System::Security::IStackWalk

public abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalk

[System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalk

[System.Serializable]
public abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalk

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalk

type CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalk

[<System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
type CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalk

[<System.Serializable>]
type CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalk

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalk

Public MustInherit Class CodeAccessPermission
Implements IPermission, IStackWalk

Herança

Object

CodeAccessPermission

Derivado

System.Configuration.ConfigurationPermission

System.Data.Common.DBDataPermission

System.Data.OracleClient.OraclePermission

System.Drawing.Printing.PrintingPermission

System.Messaging.MessageQueuePermission

Mais…

Atributos

ObsoleteAttribute SerializableAttribute ComVisibleAttribute

Implementações

IPermission ISecurityEncodable IStackWalk

Exemplos

O exemplo de código a seguir mostra uma permissão derivada da CodeAccessPermission classe .

//#define debug
// This custom permission is intended only for the purposes of illustration.
// The following code shows how to create a custom permission that inherits
// from CodeAccessPermission. The code implements all required overrides.
// A wildcard character ('*') is implemented for the Name property.

using namespace System;
using namespace System::Security;
using namespace System::Security::Permissions;
using namespace System::IO;
using namespace System::Security::Policy;
using namespace System::Collections;
using namespace System::Text;

[assembly:System::Reflection::AssemblyKeyFile("Key.snk")];
[assembly:System::Security::AllowPartiallyTrustedCallersAttribute];

[Serializable]
public ref class NameIdPermission: public CodeAccessPermission, public IUnrestrictedPermission
{
private:
   String^ m_Name;
   bool m_Unrestricted;

public:
   NameIdPermission( String^ name )
   {
      m_Name = name;
   }

   NameIdPermission( PermissionState state )
   {
      if ( state == PermissionState::None )
      {
         m_Name = "";
      }
      else if ( state == PermissionState::Unrestricted )
      {
         throw gcnew ArgumentException( "Unrestricted state is not allowed for identity permissions." );
      }
      else
      {
         throw gcnew ArgumentException( "Invalid permission state." );
      }
   }

   property String^ Name 
   {
      String^ get()
      {
         return m_Name;
      }
      void set( String^ value )
      {
         m_Name = value;
      }
   }

public:
   virtual IPermission^ Copy() override
   {
      String^ name = m_Name;
      return gcnew NameIdPermission( name );
   }

public:
   virtual bool IsUnrestricted()
   {
      // Always false, unrestricted state is not allowed.
      return m_Unrestricted;
   }

private:
   bool VerifyType( IPermission^ target )
   {
      return dynamic_cast<NameIdPermission^>(target) != nullptr;
   }

public:
   virtual bool IsSubsetOf( IPermission^ target ) override
   {
#if ( debug ) 
      Console::WriteLine( "************* Entering IsSubsetOf *********************" );
#endif

      if ( target == nullptr )
      {
         Console::WriteLine( "IsSubsetOf: target == null" );
         return false;
      }

#if ( debug ) 
      Console::WriteLine( "This is = {0}", ((NameIdPermission)this).Name );
      Console::WriteLine( "Target is {0}", ((NameIdPermission)target).m_Name );
#endif

      try
      {
         NameIdPermission^ operand = dynamic_cast<NameIdPermission^>(target);
         
         // The following check for unrestricted permission is only included as an example for
         // permissions that allow the unrestricted state. It is of no value for this permission.
         if ( true == operand->m_Unrestricted )
         {
            return true;
         }
         else if ( true == this->m_Unrestricted )
         {
            return false;
         }

         if ( this->m_Name != nullptr )
         {
            if ( operand->m_Name == nullptr )
            {
               return false;
            }
            if ( this->m_Name->Equals( "" ) )
            {
               return true;
            }
         }

         if ( this->m_Name->Equals( operand->m_Name ) )
         {
            return true;
         }
         else
         {
            // Check for wild card character '*'.
            int i = operand->m_Name->LastIndexOf( "*" );

            if ( i > 0 )
            {
               String^ prefix = operand->m_Name->Substring( 0, i );
               if ( this->m_Name->StartsWith( prefix ) )
               {
                  return true;
               }
            }
         }
         return false;
      }
      catch ( InvalidCastException^ ) 
      {
         throw gcnew ArgumentException( String::Format( "Argument_WrongType", this->GetType()->FullName ) );
      }
   }

public:
   virtual IPermission^ Intersect( IPermission^ target ) override
   {
      Console::WriteLine( "************* Entering Intersect *********************" );
      if ( target == nullptr )
      {
         return nullptr;
      }

#if ( debug ) 
      Console::WriteLine( "This is = {0}", ((NameIdPermission)this).Name );
      Console::WriteLine( "Target is {0}", ((NameIdPermission)target).m_Name );
#endif 

      if (  !VerifyType( target ) )
      {
         throw gcnew ArgumentException( String::Format( "Argument is wrong type.", this->GetType()->FullName ) );
      }

      NameIdPermission^ operand = dynamic_cast<NameIdPermission^>(target);

      if ( operand->IsSubsetOf( this ) )
      {
         return operand->Copy();
      }
      else if ( this->IsSubsetOf( operand ) )
      {
         return this->Copy();
      }
      else
      {
         return nullptr;
      }
   }

public:
   virtual IPermission^ Union( IPermission^ target ) override
   {
#if ( debug ) 
      Console::WriteLine( "************* Entering Union *********************" );
#endif 

      if ( target == nullptr )
      {
         return this;
      }

#if ( debug ) 
      Console::WriteLine( "This is = {0}", ((NameIdPermission)this).Name );
      Console::WriteLine( "Target is {0}", ((NameIdPermission)target).m_Name );
#endif 

      if (  !VerifyType( target ) )
      {
         throw gcnew ArgumentException( String::Format( "Argument_WrongType", this->GetType()->FullName ) );
      }

      NameIdPermission^ operand = dynamic_cast<NameIdPermission^>(target);

      if ( operand->IsSubsetOf( this ) )
      {
         return this->Copy();
      }
      else if ( this->IsSubsetOf( operand ) )
      {
         return operand->Copy();
      }
      else
      {
         return nullptr;
      }
   }

public:
   virtual void FromXml( SecurityElement^ e ) override
   {
      // The following code for unrestricted permission is only included as an example for
      // permissions that allow the unrestricted state. It is of no value for this permission.
      String^ elUnrestricted = e->Attribute("Unrestricted");
      if ( nullptr != elUnrestricted )
      {
         m_Unrestricted = Boolean::Parse( elUnrestricted );
         return;
      }

      String^ elName = e->Attribute("Name");
      m_Name = elName == nullptr ? nullptr : elName;
   }

public:
   virtual SecurityElement^ ToXml() override
   {
      // Use the SecurityElement class to encode the permission to XML.
      SecurityElement^ esd = gcnew SecurityElement( "IPermission" );
      String^ name = NameIdPermission::typeid->AssemblyQualifiedName;
      esd->AddAttribute( "class", name );
      esd->AddAttribute( "version", "1.0" );
      
      // The following code for unrestricted permission is only included as an example for
      // permissions that allow the unrestricted state. It is of no value for this permission.
      if ( m_Unrestricted )
      {
         esd->AddAttribute( "Unrestricted", true.ToString() );
      }

      if ( m_Name != nullptr )
      {
         esd->AddAttribute( "Name", m_Name );
      }

      return esd;
   }
};

//#define debug
// This custom permission is intended only for the purposes of illustration.
// The following code shows how to create a custom permission that inherits
// from CodeAccessPermission. The code implements all required overrides.
// A wildcard character ('*') is implemented for the Name property.
using System;
using System.Security;
using System.Security.Permissions;
using System.IO;
using System.Security.Policy;
using System.Collections;
using System.Text;

[assembly:System.Reflection.AssemblyKeyFile("Key.snk")]
[assembly:System.Security.AllowPartiallyTrustedCallersAttribute()]

namespace MyPermission
{
    [Serializable()] sealed public class   NameIdPermission : CodeAccessPermission, IUnrestrictedPermission
    {
        private String m_Name;
        private bool m_Unrestricted;

        public  NameIdPermission(String name)
        {
            m_Name = name;
        }

        public  NameIdPermission(PermissionState state)
        {
            if (state == PermissionState.None)
            {
                m_Name = "";
            }
            else
                if (state == PermissionState.Unrestricted)
            {
                throw new ArgumentException("Unrestricted state is not allowed for identity permissions.");
            }
            else
            {
                throw new ArgumentException("Invalid permission state.");
            }
        }

        public String Name
        {
            set{m_Name = value;}
            get{ return m_Name;}
        }
        public override IPermission Copy()
        {
            string name = m_Name;
            return new  NameIdPermission( name );
        }
        public bool IsUnrestricted()
        {
            // Always false, unrestricted state is not allowed.
            return m_Unrestricted;
        }

        private bool VerifyType(IPermission target)
        {
            return (target is  NameIdPermission);
        }
        public override bool IsSubsetOf(IPermission target)
        {
#if(debug)
            Console.WriteLine ("************* Entering IsSubsetOf *********************");
#endif
            if (target == null)
            {
                Console.WriteLine ("IsSubsetOf: target == null");
                return false;
            }
#if(debug)

            Console.WriteLine ("This is = " + (( NameIdPermission)this).Name);
            Console.WriteLine ("Target is " + (( NameIdPermission)target).m_Name);
#endif
            try
            {
                 NameIdPermission operand = ( NameIdPermission)target;

                // The following check for unrestricted permission is only included as an example for
                // permissions that allow the unrestricted state. It is of no value for this permission.
                if (true == operand.m_Unrestricted)
                {
                    return true;
                }
                else if (true == this.m_Unrestricted)
                {
                    return false;
                }

                if (this.m_Name != null)
                {
                    if (operand.m_Name == null) return false;

                    if (this.m_Name == "") return true;
                }

                if (this.m_Name.Equals (operand.m_Name))
                {
                    return true;
                }
                else
                {
                    // Check for wild card character '*'.
                    int i = operand.m_Name.LastIndexOf ("*");

                    if (i > 0)
                    {
                        string prefix = operand.m_Name.Substring (0, i);

                        if (this.m_Name.StartsWith (prefix))
                        {
                            return true;
                        }
                    }
                }

                return false;
            }
            catch (InvalidCastException)
            {
                throw new ArgumentException (String.Format ("Argument_WrongType", this.GetType ().FullName));
            }
        }
        public override IPermission Intersect(IPermission target)
        {
            Console.WriteLine ("************* Entering Intersect *********************");
            if (target == null)
            {
                return null;
            }
#if(debug)
            Console.WriteLine ("This is = " + (( NameIdPermission)this).Name);
            Console.WriteLine ("Target is " + (( NameIdPermission)target).m_Name);
#endif
            if (!VerifyType(target))
            {
                throw new ArgumentException (String.Format ("Argument is wrong type.", this.GetType ().FullName));
            }

             NameIdPermission operand = ( NameIdPermission)target;

            if (operand.IsSubsetOf (this)) return operand.Copy ();
            else if (this.IsSubsetOf (operand)) return this.Copy ();
            else
                return null;
        }

        public override IPermission Union(IPermission target)
        {
#if(debug)
            Console.WriteLine ("************* Entering Union *********************");
#endif
            if (target == null)
            {
                return this;
            }
#if(debug)
            Console.WriteLine ("This is = " + (( NameIdPermission)this).Name);
            Console.WriteLine ("Target is " + (( NameIdPermission)target).m_Name);
#endif
            if (!VerifyType(target))
            {
                throw new ArgumentException (String.Format ("Argument_WrongType", this.GetType ().FullName));
            }

             NameIdPermission operand = ( NameIdPermission)target;

            if (operand.IsSubsetOf (this)) return this.Copy ();
            else if (this.IsSubsetOf (operand)) return operand.Copy ();
            else
                return null;
        }
        
        
        
        
       public override void FromXml(SecurityElement e)
        {
            // The following code for unrestricted permission is only included as an example for
            // permissions that allow the unrestricted state. It is of no value for this permission.
            String elUnrestricted = e.Attribute("Unrestricted");
            if (null != elUnrestricted)
            {
                m_Unrestricted = bool.Parse(elUnrestricted);
                return;
            }

            String elName = e.Attribute( "Name" );
            m_Name = elName == null ? null : elName;
        }
        public override SecurityElement ToXml()
        {
            // Use the SecurityElement class to encode the permission to XML.
            SecurityElement esd = new SecurityElement("IPermission");
            String name = typeof( NameIdPermission).AssemblyQualifiedName;
            esd.AddAttribute("class", name);
            esd.AddAttribute("version", "1.0");

            // The following code for unrestricted permission is only included as an example for
            // permissions that allow the unrestricted state. It is of no value for this permission.
            if (m_Unrestricted)
            {
                esd.AddAttribute("Unrestricted", true.ToString());
            }
            if (m_Name != null) esd.AddAttribute( "Name", m_Name );
            return esd;
        }
     }
}

' This custom permission is intended only for the purposes of illustration.
' The following code shows how to create a custom permission that inherits
' from CodeAccessPermission. The code implements all required overrides.
' A wildcard character ('*') is implemented for the Name property.
Imports System.Security
Imports System.Security.Permissions
Imports System.IO
Imports System.Security.Policy
Imports System.Collections

<assembly: System.Reflection.AssemblyKeyFile("Key.snk")>

<assembly: System.Security.AllowPartiallyTrustedCallersAttribute()>
Namespace MyPermission

    <Serializable()> _
                   Public NotInheritable Class NameIdPermission
        Inherits CodeAccessPermission
        Implements IUnrestrictedPermission
        Private m_Name As String
        Private m_Unrestricted As Boolean


        Public Sub New(ByVal name As String)
            m_name = name
        End Sub


        Public Sub New(ByVal state As PermissionState)
            If state = PermissionState.None Then
                m_name = ""
            ElseIf state = PermissionState.Unrestricted Then
                Throw New ArgumentException("Unrestricted state is not allowed for identity permissions.")
            Else
                Throw New ArgumentException("Invalid permission state.")
            End If
        End Sub

        Public Property Name() As String
            Get
                Return m_name
            End Get
            Set(ByVal Value As String)
                m_name = Value
            End Set
        End Property

        Public Overrides Function Copy() As IPermission
            Dim name As String
            name = m_name
            Return New NameIdPermission(name)
        End Function 'Copy

        Public Function IsUnrestricted() As Boolean Implements IUnrestrictedPermission.IsUnrestricted
            ' Always false, unrestricted state is not allowed.
            Return m_Unrestricted
        End Function
        Private Function VerifyType(ByVal target As IPermission) As Boolean
            Return TypeOf target Is NameIdPermission
        End Function 'VerifyType

        Public Overrides Function IsSubsetOf(ByVal target As IPermission) As Boolean

#If (Debug) Then

            Console.WriteLine("************* Entering IsSubsetOf *********************")
#End If
            If target Is Nothing Then
                Console.WriteLine("IsSubsetOf: target == null")
                Return False
            End If
#If (Debug) Then
            Console.WriteLine(("This is = " + CType(Me, NameIdPermission).Name))
            Console.WriteLine(("Target is " + CType(target, NameIdPermission).m_name))
#End If
            Try
                Dim operand As NameIdPermission = CType(target, NameIdPermission)

                ' The following check for unrestricted permission is only included as an example for
                ' permissions that allow the unrestricted state. It is of no value for this permission.
                If True = operand.m_Unrestricted Then
                    Return True
                ElseIf True = Me.m_Unrestricted Then
                    Return False
                End If

                If Not (Me.m_name Is Nothing) Then
                    If operand.m_name Is Nothing Then
                        Return False
                    End If
                    If Me.m_name = "" Then
                        Return True
                    End If
                End If
                If Me.m_name.Equals(operand.m_name) Then
                    Return True
                Else
                    ' Check for wild card character '*'.
                    Dim i As Integer = operand.m_name.LastIndexOf("*")

                    If i > 0 Then
                        Dim prefix As String = operand.m_name.Substring(0, i)

                        If Me.m_name.StartsWith(prefix) Then
                            Return True
                        End If
                    End If
                End If

                Return False
            Catch
                Throw New ArgumentException(String.Format("Argument_WrongType", Me.GetType().FullName))
            End Try
        End Function

        Public Overrides Function Intersect(ByVal target As IPermission) As IPermission
            Console.WriteLine("************* Entering Intersect *********************")
            If target Is Nothing Then
                Return Nothing
            End If
#If (Debug) Then

            Console.WriteLine(("This is = " + CType(Me, NameIdPermission).Name))
            Console.WriteLine(("Target is " + CType(target, NameIdPermission).m_name))
#End If
            If Not VerifyType(target) Then
                Throw New ArgumentException(String.Format("Argument is wrong type.", Me.GetType().FullName))
            End If

            Dim operand As NameIdPermission = CType(target, NameIdPermission)

            If operand.IsSubsetOf(Me) Then
                Return operand.Copy()
            ElseIf Me.IsSubsetOf(operand) Then
                Return Me.Copy()
            Else
                Return Nothing
            End If
        End Function 'Intersect

        Public Overrides Function Union(ByVal target As IPermission) As IPermission
#If (Debug) Then

            Console.WriteLine("************* Entering Union *********************")
#End If
            If target Is Nothing Then
                Return Me
            End If
#If (Debug) Then
            Console.WriteLine(("This is = " + CType(Me, NameIdPermission).Name))
            Console.WriteLine(("Target is " + CType(target, NameIdPermission).m_name))
#End If
            If Not VerifyType(target) Then
                Throw New ArgumentException(String.Format("Argument_WrongType", Me.GetType().FullName))
            End If

            Dim operand As NameIdPermission = CType(target, NameIdPermission)

            If operand.IsSubsetOf(Me) Then
                Return Me.Copy()
            ElseIf Me.IsSubsetOf(operand) Then
                Return operand.Copy()
            Else
                Return Nothing
            End If
        End Function 'Union

        Public Overrides Sub FromXml(ByVal e As SecurityElement)
            ' The following code for unrestricted permission is only included as an example for
            ' permissions that allow the unrestricted state. It is of no value for this permission.
            Dim elUnrestricted As String = e.Attribute("Unrestricted")
            If Nothing <> elUnrestricted Then
                m_Unrestricted = Boolean.Parse(elUnrestricted)
                Return
            End If

            Dim elName As String = e.Attribute("Name")
            m_name = IIf(elName Is Nothing, Nothing, elName)
        End Sub

        Public Overrides Function ToXml() As SecurityElement
            ' Use the SecurityElement class to encode the permission to XML.
            Dim esd As New SecurityElement("IPermission")

            Dim name As String = GetType(NameIdPermission).AssemblyQualifiedName
            esd.AddAttribute("class", name)
            esd.AddAttribute("version", "1.0")

            ' The following code for unrestricted permission is only included as an example for
            ' permissions that allow the unrestricted state. It is of no value for this permission.
            If m_Unrestricted Then
                esd.AddAttribute("Unrestricted", True.ToString())
            End If
            If Not (m_Name Is Nothing) Then
                esd.AddAttribute("Name", m_Name)
            End If
            Return esd
        End Function 'ToXml
    End Class
End Namespace

Comentários

As permissões de acesso ao código usam uma caminhada de pilha para garantir que todos os chamadores do código tenham recebido uma permissão. Se um objeto de permissão for null, ele será tratado da mesma forma que um objeto de permissão com o estado PermissionState.None.

Normalmente, a pilha de chamadas é representada como crescente, de modo que os métodos mais altos na pilha de chamadas chamem métodos mais baixos na pilha de chamadas.

Os herdadores da CodeAccessPermission classe devem receber confiança total para funcionar corretamente como permissões que estendem a infraestrutura de segurança. Para determinar que os herdadores são totalmente confiáveis, CodeAccessPermission emite um InheritanceDemand para ControlEvidence = true e ControlPolicy = true.

Notas aos Implementadores

Ao herdar de CodeAccessPermission, você também deve implementar a IUnrestrictedPermission interface .

Os seguintes CodeAccessPermission membros devem ser substituídos: Copy(), Intersect(IPermission), IsSubsetOf(IPermission), ToXml(), FromXml(SecurityElement)e Union(IPermission).

Você também deve definir um construtor que usa um PermissionState como seu único parâmetro.

Você deve aplicar o SerializableAttribute atributo a uma classe que herda de CodeAccessPermission.

Construtores

Métodos

Aplica-se a