X509Certificate2 クラスとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

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X509Certificate2 クラス

メモ : このクラスは、.NET Framework version 2.0 で新しく追加されたものです。

X.509 証明書を表します。このクラスは継承できません。

名前空間: System.Security.Cryptography.X509Certificates
アセンブリ: System (system.dll 内)
構文

Visual Basic (宣言)

Public Class X509Certificate2
    Inherits X509Certificate

Visual Basic (使用法)

Dim instance As X509Certificate2

public class X509Certificate2 : X509Certificate

C++

public ref class X509Certificate2 : public
 X509Certificate

public class X509Certificate2 extends X509Certificate

JScript

public class X509Certificate2 extends
 X509Certificate

解説

国際標準化機構 (ISO: International Organization for Standardization) の作業部会で考案された X.509 構造体。この構造体を使用して、ID、資格、所有者の属性 (アクセス許可、年齢、性別、場所、所属など) などの各種の情報を表すことができます。この構造体については ISO 仕様で非常に詳しく説明されていますが、X509Certificate2 クラスは、IETF (Internet Engineering Task Force) PKIX (Public Key Infrastructure, X.509) 作業部会が発行した仕様で定義されている使用法のシナリオをモデル化するためにデザインされています。これらの仕様の中で最も詳しい仕様は、RFC 3280 の「Certificate and Certificate Revocation List (CRL) Profile」です。

Topic	Location
方法 : X.509 証明書で XML 要素を復号化する	.NET Framework: セキュリティ
方法 : X.509 証明書で XML 要素を暗号化する	.NET Framework: セキュリティ

使用例

証明書ファイルを引数として受け取り、その証明書の各種プロパティをコンソールに出力するコマンドライン形式の実行可能ファイルを作成するコード例を次に示します。

C++

#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;
}

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." );
   }

}