X509Chain Class
.NET Framework Class Library
X509Chain Class

Represents a chain-building engine for X509Certificate2 certificates.

Namespace:  System.Security.Cryptography.X509Certificates
Assembly:  System (in System.dll)
Visual Basic (Declaration)
Public Class X509Chain
Visual Basic (Usage)
Dim instance As X509Chain
C#
public class X509Chain
Visual C++
public ref class X509Chain
JScript
public class X509Chain

The X509Chain object has a global error status called ChainStatus that should be used for certificate validation. The rules governing certificate validation are complex, and it is easy to oversimplify the validation logic by ignoring the error status of one or more of the elements involved. The global error status takes into consideration the status of each element in the chain.

The following code example opens the current user's personal certificate store, allows you to select a certificate, then writes certificate and certificate chain information to the console. The output depends on the certificate you select.

Visual Basic
Imports System
Imports System.Security.Cryptography
Imports System.Security.Cryptography.X509Certificates
Imports System.IO



Class TestX509Chain

    Shared Sub Main(ByVal args() As String)
        'Create new X509 store from local certificate store.
        Dim store As New X509Store("MY", StoreLocation.CurrentUser)
        store.Open(OpenFlags.OpenExistingOnly Or OpenFlags.ReadWrite)

        'Output store information.
        Console.WriteLine("Store Information")
        Console.WriteLine("Number of certificates in the store: {0}", store.Certificates.Count)
        Console.WriteLine("Store location: {0}", store.Location)
        Console.WriteLine("Store name: {0} {1}", store.Name, Environment.NewLine)

        'Put certificates from the store into a collection so user can select one.
        Dim fcollection As X509Certificate2Collection = CType(store.Certificates, X509Certificate2Collection)
        Dim collection As X509Certificate2Collection = X509Certificate2UI.SelectFromCollection(fcollection, "Select an X509 Certificate", "Choose a certificate to examine.", X509SelectionFlag.SingleSelection)
        Dim certificate As X509Certificate2 = collection(0)
        X509Certificate2UI.DisplayCertificate(certificate)
        'Output chain information of the selected certificate.
        Dim ch As New X509Chain()
        ch.Build(certificate)
        Console.WriteLine("Chain Information")
        ch.ChainPolicy.RevocationMode = X509RevocationMode.Online
        Console.WriteLine("Chain revocation flag: {0}", ch.ChainPolicy.RevocationFlag)
        Console.WriteLine("Chain revocation mode: {0}", ch.ChainPolicy.RevocationMode)
        Console.WriteLine("Chain verification flag: {0}", ch.ChainPolicy.VerificationFlags)
        Console.WriteLine("Chain verification time: {0}", ch.ChainPolicy.VerificationTime)
        Console.WriteLine("Chain status length: {0}", ch.ChainStatus.Length)
        Console.WriteLine("Chain application policy count: {0}", ch.ChainPolicy.ApplicationPolicy.Count)
        Console.WriteLine("Chain certificate policy count: {0} {1}", ch.ChainPolicy.CertificatePolicy.Count, Environment.NewLine)
        'Output chain element information.
        Console.WriteLine("Chain Element Information")
        Console.WriteLine("Number of chain elements: {0}", ch.ChainElements.Count)
        Console.WriteLine("Chain elements synchronized? {0} {1}", ch.ChainElements.IsSynchronized, Environment.NewLine)

        Dim element As X509ChainElement
        For Each element In ch.ChainElements
            Console.WriteLine("Element issuer name: {0}", element.Certificate.Issuer)
            Console.WriteLine("Element certificate valid until: {0}", element.Certificate.NotAfter)
            Console.WriteLine("Element certificate is valid: {0}", element.Certificate.Verify())
            Console.WriteLine("Element error status length: {0}", element.ChainElementStatus.Length)
            Console.WriteLine("Element information: {0}", element.Information)
            Console.WriteLine("Number of element extensions: {0}{1}", element.Certificate.Extensions.Count, Environment.NewLine)

            If ch.ChainStatus.Length > 1 Then
                Dim index As Integer
                For index = 0 To element.ChainElementStatus.Length
                    Console.WriteLine(element.ChainElementStatus(index).Status)
                    Console.WriteLine(element.ChainElementStatus(index).StatusInformation)
                Next index
            End If
        Next element
        store.Close()
    End Sub
End Class
C#
using System;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.IO;

class TestX509Chain
{
    static void Main(string[] args)
    {
        //Create new X509 store from local certificate store.
        X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
        store.Open(OpenFlags.OpenExistingOnly | OpenFlags.ReadWrite);

        //Output store information.
        Console.WriteLine ("Store Information");
        Console.WriteLine ("Number of certificates in the store: {0}", store.Certificates.Count);
        Console.WriteLine ("Store location: {0}", store.Location);
        Console.WriteLine ("Store name: {0} {1}", store.Name, Environment.NewLine);
    
        //Put certificates from the store into a collection so user can select one.
        X509Certificate2Collection fcollection = (X509Certificate2Collection)store.Certificates;
        X509Certificate2Collection collection = X509Certificate2UI.SelectFromCollection(fcollection, "Select an X509 Certificate", "Choose a certificate to examine.", X509SelectionFlag.SingleSelection);
        X509Certificate2 certificate = collection[0];
        X509Certificate2UI.DisplayCertificate(certificate);
        //Output chain information of the selected certificate.
        X509Chain ch = new X509Chain();
        ch.Build (certificate);
        Console.WriteLine ("Chain Information");
        ch.ChainPolicy.RevocationMode = X509RevocationMode.Online;
        Console.WriteLine ("Chain revocation flag: {0}", ch.ChainPolicy.RevocationFlag);
        Console.WriteLine ("Chain revocation mode: {0}", ch.ChainPolicy.RevocationMode);
        Console.WriteLine ("Chain verification flag: {0}", ch.ChainPolicy.VerificationFlags);
        Console.WriteLine ("Chain verification time: {0}", ch.ChainPolicy.VerificationTime);
        Console.WriteLine ("Chain status length: {0}", ch.ChainStatus.Length);
        Console.WriteLine ("Chain application policy count: {0}", ch.ChainPolicy.ApplicationPolicy.Count);
        Console.WriteLine ("Chain certificate policy count: {0} {1}", ch.ChainPolicy.CertificatePolicy.Count, Environment.NewLine);
        //Output chain element information.
        Console.WriteLine ("Chain Element Information");
        Console.WriteLine ("Number of chain elements: {0}", ch.ChainElements.Count);
        Console.WriteLine ("Chain elements synchronized? {0} {1}", ch.ChainElements.IsSynchronized, Environment.NewLine);
    
        foreach (X509ChainElement element in ch.ChainElements)
        {
            Console.WriteLine ("Element issuer name: {0}", element.Certificate.Issuer);
            Console.WriteLine ("Element certificate valid until: {0}", element.Certificate.NotAfter);
            Console.WriteLine ("Element certificate is valid: {0}", element.Certificate.Verify ());
            Console.WriteLine ("Element error status length: {0}", element.ChainElementStatus.Length);
            Console.WriteLine ("Element information: {0}", element.Information);
            Console.WriteLine ("Number of element extensions: {0}{1}", element.Certificate.Extensions.Count, Environment.NewLine);

            if (ch.ChainStatus.Length > 1)
            {
                for (int index = 0; index < element.ChainElementStatus.Length; index++)
                {
                    Console.WriteLine (element.ChainElementStatus[index].Status);
                    Console.WriteLine (element.ChainElementStatus[index].StatusInformation);
                }
            }
        }
        store.Close();
    }
}
Visual C++
#using <System.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::X509Certificates;
using namespace System::IO;

int main()
{
   //Create new X509 store from local certificate store.
   X509Store ^ store = gcnew X509Store( "MY",StoreLocation::CurrentUser );
   store->Open( static_cast<OpenFlags>(OpenFlags::OpenExistingOnly | OpenFlags::ReadWrite) );

   //Output store information.
   Console::WriteLine( "Store Information" );
   Console::WriteLine( "Number of certificates in the store: {0}", store->Certificates->Count );
   Console::WriteLine( "Store location: {0}", store->Location );
   Console::WriteLine( "Store name: {0} {1}", store->Name, Environment::NewLine );

   //Put certificates from the store into a collection so user can select one.
   X509Certificate2Collection ^ fcollection = dynamic_cast<X509Certificate2Collection^>(store->Certificates);
   X509Certificate2Collection ^ collection = X509Certificate2UI::SelectFromCollection(fcollection, "Select an X509 Certificate","Choose a certificate to examine.",X509SelectionFlag::SingleSelection);
   X509Certificate2 ^ certificate = collection[ 0 ];
   X509Certificate2UI::DisplayCertificate(certificate);

   //Output chain information of the selected certificate.
   X509Chain ^ ch = gcnew X509Chain;
   ch->Build( certificate );
   Console::WriteLine( "Chain Information" );
   ch->ChainPolicy->RevocationMode = X509RevocationMode::Online;
   Console::WriteLine( "Chain revocation flag: {0}", ch->ChainPolicy->RevocationFlag );
   Console::WriteLine( "Chain revocation mode: {0}", ch->ChainPolicy->RevocationMode );
   Console::WriteLine( "Chain verification flag: {0}", ch->ChainPolicy->VerificationFlags );
   Console::WriteLine( "Chain verification time: {0}", ch->ChainPolicy->VerificationTime );
   Console::WriteLine( "Chain status length: {0}", ch->ChainStatus->Length );
   Console::WriteLine( "Chain application policy count: {0}", ch->ChainPolicy->ApplicationPolicy->Count );
   Console::WriteLine( "Chain certificate policy count: {0} {1}", ch->ChainPolicy->CertificatePolicy->Count, Environment::NewLine );

   //Output chain element information.
   Console::WriteLine( "Chain Element Information" );
   Console::WriteLine( "Number of chain elements: {0}", ch->ChainElements->Count );
   Console::WriteLine( "Chain elements synchronized? {0} {1}", ch->ChainElements->IsSynchronized, Environment::NewLine );
   System::Collections::IEnumerator^ myEnum = ch->ChainElements->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      X509ChainElement ^ element = safe_cast<X509ChainElement ^>(myEnum->Current);
      Console::WriteLine( "Element issuer name: {0}", element->Certificate->Issuer );
      Console::WriteLine( "Element certificate valid until: {0}", element->Certificate->NotAfter );
      Console::WriteLine( "Element certificate is valid: {0}", element->Certificate->Verify() );
      Console::WriteLine( "Element error status length: {0}", element->ChainElementStatus->Length );
      Console::WriteLine( "Element information: {0}", element->Information );
      Console::WriteLine( "Number of element extensions: {0}{1}", element->Certificate->Extensions->Count, Environment::NewLine );
      if ( ch->ChainStatus->Length > 1 )
      {
         for ( int index = 0; index < element->ChainElementStatus->Length; index++ )
         {
            Console::WriteLine( element->ChainElementStatus[ index ].Status );
            Console::WriteLine( element->ChainElementStatus[ index ].StatusInformation );
         }
      }
   }

   store->Close();
}
System..::.Object
  System.Security.Cryptography.X509Certificates..::.X509Chain
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0
Tags What's this?: Add a tag
Community Content   What is Community Content?
Add new content RSS  Annotations
Processing
Page view tracker