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PublicKey Class

Represents a certificate's public key information. This class cannot be inherited.

System::Object
  System.Security.Cryptography.X509Certificates::PublicKey

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

public ref class PublicKey sealed

The PublicKey type exposes the following members.

  NameDescription
Public methodPublicKeyInitializes a new instance of the PublicKey class using an object identifier (OID) object of the public key, an ASN.1-encoded representation of the public key parameters, and an ASN.1-encoded representation of the public key value.
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  NameDescription
Public propertyEncodedKeyValueGets the ASN.1-encoded representation of the public key value.
Public propertyEncodedParametersGets the ASN.1-encoded representation of the public key parameters.
Public propertyKeyGets an RSACryptoServiceProvider or DSACryptoServiceProvider object representing the public key.
Public propertyOidGets an object identifier (OID) object of the public key.
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  NameDescription
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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The PublicKey object contains the object identifier (Oid) representing the public key algorithm, the ASN-encoded parameters, and the ASN.1-encoded key value.

The following example demonstrates how to use the public key from a X509Certificate2 object to encrypt a file. It also shows how to decrypt the encrypted file using the private key for that certificate.

No code example is currently available or this language may not be supported.

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


#using <System.dll>

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

//Reads a file.
array<Byte>^ ReadFile( String^ fileName )
{
   FileStream^ f = gcnew FileStream( fileName,FileMode::Open,FileAccess::Read );
   int size = (int)f->Length;
   array<Byte>^data = gcnew array<Byte>(size);
   size = f->Read( data, 0, size );
   f->Close();
   return data;
}

[SecurityPermissionAttribute(SecurityAction::LinkDemand, Unrestricted = true)]
int main()
{
   array<String^>^args = Environment::GetCommandLineArgs();

   //Test for correct number of arguments.
   if ( args->Length < 2 )
   {
      Console::WriteLine( "Usage: CertInfo <filename>" );
      return  -1;
   }

   try
   {
      System::Security::Cryptography::X509Certificates::X509Certificate2 ^ x509 =
            gcnew System::Security::Cryptography::X509Certificates::X509Certificate2;

      //Create X509Certificate2 object from .cer file.
      array<Byte>^rawData = ReadFile( args[ 1 ] );

      x509->Import(rawData);

      //Print to console information contained in the certificate.
      Console::WriteLine( "{0}Subject: {1}{0}", Environment::NewLine, x509->Subject );
      Console::WriteLine( "{0}Issuer: {1}{0}", Environment::NewLine, x509->Issuer );
      Console::WriteLine( "{0}Version: {1}{0}", Environment::NewLine, x509->Version );
      Console::WriteLine( "{0}Valid Date: {1}{0}", Environment::NewLine, x509->NotBefore );
      Console::WriteLine( "{0}Expiry Date: {1}{0}", Environment::NewLine, x509->NotAfter );
      Console::WriteLine( "{0}Thumbprint: {1}{0}", Environment::NewLine, x509->Thumbprint );
      Console::WriteLine( "{0}Serial Number: {1}{0}", Environment::NewLine, x509->SerialNumber );
      Console::WriteLine( "{0}Friendly Name: {1}{0}", Environment::NewLine, x509->PublicKey->Oid->FriendlyName );
      Console::WriteLine( "{0}Public Key Format: {1}{0}", Environment::NewLine, x509->PublicKey->EncodedKeyValue->Format(true) );
      Console::WriteLine( "{0}Raw Data Length: {1}{0}", Environment::NewLine, x509->RawData->Length );
      Console::WriteLine( "{0}Certificate to string: {1}{0}", Environment::NewLine, x509->ToString( true ) );
      Console::WriteLine( "{0}Certificate to XML String: {1}{0}", Environment::NewLine, x509->PublicKey->Key->ToXmlString( false ) );

      //Add the certificate to a X509Store.
      X509Store ^ store = gcnew X509Store;
      store->Open( OpenFlags::MaxAllowed );
      store->Add( x509 );
      store->Close();
   }
   catch ( DirectoryNotFoundException^ )
   {
      Console::WriteLine( "Error: The directory specified could not be found." );
   }
   catch ( IOException^ )
   {
      Console::WriteLine( "Error: A file in the directory could not be accessed." );
   }
   catch ( NullReferenceException^ )
   {
      Console::WriteLine( "File must be a .cer file. Program does not have access to that type of file." );
   }

}



.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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