This documentation is archived and is not being maintained.

X509Certificate2.PrivateKey Property

Gets or sets the AsymmetricAlgorithm object that represents the private key associated with a certificate.

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

public AsymmetricAlgorithm PrivateKey { get; set; }
/** @property */
public AsymmetricAlgorithm get_PrivateKey ()

/** @property */
public void set_PrivateKey (AsymmetricAlgorithm value)

public function get PrivateKey () : AsymmetricAlgorithm

public function set PrivateKey (value : AsymmetricAlgorithm)

Not applicable.

Property Value

An AsymmetricAlgorithm object, which is either an RSA or DSA cryptographic service provider.

Exception typeCondition

CryptographicException

The key value is not an RSA or DSA key, or the key is unreadable.

ArgumentNullException

The value being set for this property is a null reference (Nothing in Visual Basic).

NotSupportedException

The key algorithm for this private key is not supported.

CryptographicUnexpectedOperationException

The X.509 keys do not match.

ArgumentException

The cryptographic service provider key is a null reference (Nothing in Visual Basic).

Currently this property supports only RSA or DSA keys, so it returns either an RSACryptoServiceProvider or a DSACryptoServiceProvider object. If no private key is associated with the certificate, a null reference (Nothing in Visual Basic) is returned.

The following code example opens the current user certificate store, selects only active certificates, then allows the user to select one or more certificates. The example then writes certificate information to the console.

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

class CertSelect
{
	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)
				{
					byte[] rawdata = x509.RawData;
					Console.WriteLine("Content Type: {0}{1}",X509Certificate2.GetCertContentType(rawdata),Environment.NewLine);
					Console.WriteLine("Friendly Name: {0}{1}",x509.FriendlyName,Environment.NewLine);
					Console.WriteLine("Certificate Verified?: {0}{1}",x509.Verify(),Environment.NewLine);
					Console.WriteLine("Simple Name: {0}{1}",x509.GetNameInfo(X509NameType.SimpleName,true),Environment.NewLine);
					Console.WriteLine("Signature Algorithm: {0}{1}",x509.SignatureAlgorithm.FriendlyName,Environment.NewLine);
					Console.WriteLine("Private Key: {0}{1}",x509.PrivateKey.ToXmlString(false),Environment.NewLine);
					Console.WriteLine("Public Key: {0}{1}",x509.PublicKey.Key.ToXmlString(false),Environment.NewLine);
					Console.WriteLine("Certificate Archived?: {0}{1}",x509.Archived,Environment.NewLine);
					Console.WriteLine("Length of Raw Data: {0}{1}",x509.RawData.Length,Environment.NewLine);
					X509Certificate2UI.DisplayCertificate(x509);
					x509.Reset();
				}
			store.Close();
			}
		catch (CryptographicException)
			{
				   Console.WriteLine("Information could not be written out for this certificate.");
			}
		
	}
}

import System.*;
import System.Security.Cryptography.*;
import System.Security.Permissions.*;
import System.IO.*;
import System.Security.Cryptography.X509Certificates.*;

public class CertSelect
{
	/** @attribute SecurityPermission(SecurityAction.LinkDemand,
		Unrestricted = true) */
    public static void main(String[] args)
    {
        try {
            X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
            store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);

            X509Certificate2Collection collection =
                (X509Certificate2Collection)store.get_Certificates();
            X509Certificate2Collection fCollection =
                (X509Certificate2Collection)collection.Find(
                X509FindType.FindByTimeValid, DateTime.get_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}",
                (Int32)sCollection.get_Count(), Environment.get_NewLine());
            for (int iCtr = 0; iCtr < sCollection.get_Count(); iCtr++) {
                X509Certificate2 x509 =
                    (X509Certificate2)(sCollection.get_Item(iCtr));
                ubyte rawData[] = x509.get_RawData();

                Console.WriteLine("Content Type: {0}{1}",
                    X509Certificate2.GetCertContentType(rawData),
                    Environment.get_NewLine());
                Console.WriteLine("Friendly Name: {0}{1}",
                    x509.get_FriendlyName(), Environment.get_NewLine());
                Console.WriteLine("Certificate Verified?: {0}{1}",
                    (System.Boolean)x509.Verify(), Environment.get_NewLine());
                Console.WriteLine("Simple Name: {0}{1}",
                    x509.GetNameInfo(X509NameType.SimpleName, true),
                    Environment.get_NewLine());
                Console.WriteLine("Signature Algorithm: {0}{1}",
                    x509.get_SignatureAlgorithm().get_FriendlyName(),
                    Environment.get_NewLine());
                Console.WriteLine("Private Key: {0}{1}",
                    x509.get_PrivateKey().ToXmlString(false),
                    Environment.get_NewLine());
                Console.WriteLine("Public Key: {0}{1}",
                    x509.get_PublicKey().get_Key().ToXmlString(false),
                    Environment.get_NewLine());
                Console.WriteLine("Certificate Archived?: {0}{1}",
                    (System.Boolean)x509.get_Archived(),
                    Environment.get_NewLine());
                Console.WriteLine("Length of Raw Data: {0}{1}",
                    (Int32)x509.get_RawData().length,
                    Environment.get_NewLine());
                X509Certificate2UI.DisplayCertificate(x509);
                x509.Reset();
            }
            store.Close();
        }
        catch (CryptographicException exp) {
            Console.WriteLine("Information could not be written out for this "
                + "certificate.");
        }
    } //main
} //CertSelect

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

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0
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