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X500DistinguishedName Class

Represents the distinguished name of an X509 certificate. This class cannot be inherited.

Namespace:  System.Security.Cryptography.X509Certificates
Assembly:  System (in System.dll)

public sealed class X500DistinguishedName : AsnEncodedData

This class is like an extension to the SubjectName or IssuerName property, which is the name of the person or entity that the certificate is being issued to. X.500 is an international standard for distributed directory services. The distinguished name uses the following format:

[X500:/C=CountryCode/O=Organization/OU=OrganizationUnit/CN=CommonName]

The following field length limits apply:

Field

Length Limit

CountryCode

2 characters

Organization

Up to 64 characters

OrganizationUnit

Up to 32 characters

CommonName

Up to 64 characters

The following guidelines apply:

  • Field values can be uppercase or lowercase.

  • Delimiters are slash marks (/) and must appear before the first value and between subsequent values.

  • Delimiters can be followed by a space.

The following is an example of a correctly formatted name: [X500:/ C=US/ O=Microsoft/ OU=WGA/ CN=TedSt]

The following code example shows how to use the X500DistinguishedName class.

using System;
using System.Security.Cryptography;
using System.Security.Permissions;
using System.IO;
using System.Security.Cryptography.X509Certificates;

class X500Sample
{
	static void Main()
	{
		try
		{
			X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
			store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
			X509Certificate2Collection collection = (X509Certificate2Collection)store.Certificates;
			X509Certificate2Collection fcollection = (X509Certificate2Collection)collection.Find(X509FindType.FindByTimeValid, DateTime.Now, false);
			X509Certificate2Collection scollection = X509Certificate2UI.SelectFromCollection(fcollection, "Test Certificate Select", "Select a certificate from the following list to get information on that certificate", X509SelectionFlag.MultiSelection);
			Console.WriteLine("Number of certificates: {0}{1}", scollection.Count, Environment.NewLine);
			foreach (X509Certificate2 x509 in scollection)
			{
				X500DistinguishedName dname = new X500DistinguishedName(x509.SubjectName);
				Console.WriteLine("X500DistinguishedName: {0}{1}", dname.Name, Environment.NewLine);
				x509.Reset();
			}
			store.Close();
		}
		catch (CryptographicException)
		{
			Console.WriteLine("Information could not be written out for this certificate.");
		}

	}
}

System.Object
  System.Security.Cryptography.AsnEncodedData
    System.Security.Cryptography.X509Certificates.X500DistinguishedName

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
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