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.NET Framework Class Library
X509Certificate2..::.PublicKey Property

Gets a PublicKey object associated with a certificate.

Namespace: System.Security.Cryptography.X509Certificates
Assembly: System (in System.dll)
Syntax
Public ReadOnly Property PublicKey As PublicKey
public PublicKey PublicKey { get; }
public:
property PublicKey^ PublicKey {
	PublicKey^ get ();
}
member PublicKey : PublicKey
Exceptions
ExceptionCondition
CryptographicException

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

Remarks

This property returns a PublicKey object, which contains the object identifier (Oid) representing the public key algorithm, the ASN.1-encoded parameters, and the ASN.1-encoded key value.

You can also obtain the key as an AsymmetricAlgorithm object by referencing the PublicKey property. This property supports only RSA or DSA keys, so it returns either an RSACryptoServiceProvider or a DSACryptoServiceProvider object that represents the public key.

Examples

The following code example creates a command-line executable that takes a certificate file as an argument and prints various certificate properties to the console.


Imports System
Imports System.Security.Cryptography
Imports System.Security.Permissions
Imports System.IO
Imports System.Security.Cryptography.X509Certificates



Class CertSelect

    Shared Sub Main()
        Try
            Dim store As New X509Store("MY", StoreLocation.CurrentUser)
            store.Open(OpenFlags.ReadOnly Or OpenFlags.OpenExistingOnly)
            Dim collection As X509Certificate2Collection = CType(store.Certificates, X509Certificate2Collection)
            Dim fcollection As X509Certificate2Collection = CType(collection.Find(X509FindType.FindByTimeValid, DateTime.Now, False), X509Certificate2Collection)
            Dim scollection As X509Certificate2Collection = 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)
            Dim x509 As X509Certificate2
            For Each x509 In scollection
                Dim rawdata As Byte() = 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()
            Next x509
            store.Close()
        Catch cExcept As CryptographicException
            Console.WriteLine("Information could not be written out for this certificate.")
        End Try

    End Sub
End Class


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.");
			}
		
	}
}


#using <System.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Security::Permissions;
using namespace System::IO;
using namespace System::Security::Cryptography::X509Certificates;
int main()
{
   try
   {
      X509Store ^ store = gcnew X509Store( "MY",StoreLocation::CurrentUser );
      store->Open( static_cast<OpenFlags>(OpenFlags::ReadOnly | OpenFlags::OpenExistingOnly) );
      X509Certificate2Collection ^ collection = dynamic_cast<X509Certificate2Collection^>(store->Certificates);
      X509Certificate2Collection ^ fcollection = dynamic_cast<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 );
      System::Collections::IEnumerator^ myEnum = scollection->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         X509Certificate2 ^ x509 = safe_cast<X509Certificate2 ^>(myEnum->Current);
         array<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 );
         x509->Reset();
      }
      store->Close();
   }
   catch ( CryptographicException^ ) 
   {
      Console::WriteLine( "Information could not be written out for this certificate." );
   }

}


Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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