Wie kann überprüft werden, ob das DSC (USB-Token) beim Signieren des Dokuments angeschlossen ist?

Question

Ich signiere das XML-Dokument digital. Hier ist mein Code:

private void mbSign_Click_1(object sender, EventArgs e) 
{ 
    try 
    { 
      CadesSignature cs = new CadesSignature(FStrDSCSNo); 
          cs.DigitalSignatureCertificate = DigitalCertificate.LoadCertificate(false, string.Empty, "Select Certificate", "Select the certificate for digital signature"); 
          RSACryptoServiceProvider rsaEncryptor = (RSACryptoServiceProvider)cs.DigitalSignatureCertificate.PrivateKey; 

     L_ADSC_ValidTo = cs.DigitalSignatureCertificate.NotAfter.ToShortDateString(); 

     if (DateTime.Now <= DateTime.ParseExact(L_ADSC_ValidTo, "dd/MM/yyyy", null)) 
         { 
          FObjLog.WriteToLog("Valid DSC"); 
          L_ADSC_CertStatus = "A"; 
          // Sign the XML document. 
          //DataTable dt_SignXMlAndSignaute = new DataTable(); 
          SignXml(rsaEncryptor); 
         } 
} 

catch (CryptographicException) 
      { 
       MessageBox.Show("Invalid DSC Selection.Please Choose Correct DSC"); 
       FObjLog.WriteToLog("Invalid DSC Selection.Please Choose Correct DSC"); 
      } 
      catch (NullReferenceException) 
      { 
       MessageBox.Show("Please Attach DSC"); 
       FObjLog.WriteToLog("Please Attach DSC"); 
      } 

    } 
public void SignXml(RSA Key) 
     { 
XmlDocument LXMLDoc = new XmlDocument(); 
      if (File.Exists(LXMLPath)) 
      { 
       LXMLDoc.Load(LXMLPath); 
      } 
       if (LXMLDoc == null) 
        throw new ArgumentException("LXMLDoc"); 
       if (Key == null) 
        throw new ArgumentException("Key"); 

       // Create a SignedXml object. 
       SignedXml signedXml = new SignedXml(LXMLDoc); 

       // Add the key to the SignedXml document. 
       signedXml.SigningKey = Key; 

       // Create a reference to be signed. 
       Reference reference = new Reference(); 
       //reference.Uri = txtfilepath.Text; 
       reference.Uri = ""; 

       // Add an enveloped transformation to the reference. 
       XmlDsigEnvelopedSignatureTransform env = new XmlDsigEnvelopedSignatureTransform(); 
       reference.AddTransform(env); // calculating Digest value 

       // Add the reference to the SignedXml object. 
       signedXml.AddReference(reference); 

       // Add an RSAKeyValue KeyInfo (optional; helps recipient find key to validate). 
       KeyInfo keyInfo = new KeyInfo(); 
       keyInfo.AddClause(new RSAKeyValue((RSA)Key)); 
       signedXml.KeyInfo = keyInfo; 

       signedXml.ComputeSignature(); 

       string FullSignatureValue = ""; 
       string SignatureValue = ""; 
       XmlElement xmlDigitalSignature = signedXml.GetXml(); 
       FullSignatureValue = xmlDigitalSignature.InnerText; 
       string[] Sign = FullSignatureValue.Split(new char[] { '=' }, 2); 


       SignatureValue = Sign[1].ToString(); 

       signedXml = new SignedXml(LXMLDoc); 
LXMLDoc.DocumentElement.AppendChild(LXMLDoc.ImportNode(xmlDigitalSignature, true)); 
} 

Hier i das Dokument zu unterzeichnen bin in der Lage, aber ich bin nicht in der Lage zu überprüfen, ob die USB-Token während der Anmeldung verbunden ist. Hier passiert, selbst wenn das USB-Token nicht angeschlossen ist, erscheint das Zertifikat zur Auswahl, da das Zertifikat lokal verfügbar ist. Wenn Sie alle Zertifikate aus dem Internet Explorer entfernen und versuchen, mit einem nicht angeschlossenen USB-Token zu signieren, müssen Sie eine DSC-Karte (USB-Token) anhängen. Ich möchte das Dokument nur signieren, wenn das DSC (USB-Token) angeschlossen ist. Wie stelle ich sicher, dass der USB-Stick beim Signieren angeschlossen ist?

Answer 1

Die CryptoAPI- und CNG-Systemschnittstellen (und .NET-Klassen, die diese Schnittstellen verwenden) bieten High-Level-Abstraktionen, mit denen Sie die Hardware nicht überprüfen können. Wenn Sie die PKCS # 11-Schnittstelle verwenden, können Sie möglicherweise erreichen, was Sie wollen. PKCS # 11 hat jedoch auch seine Nachteile.

Answer 2

CryptoAPI und CNG legen keine Kartenstatusinformationen offen, für die Sie WINSCARD möchten. Insbesondere möchten Sie SCARDGetStatusChange aufrufen.

private void WaitChangeStatus(object sender, DoWorkEventArgs e) 
    { 
     while (!e.Cancel) 
     { 
      SmartCardErrorCode result; 

      // Obtain a lock when we use the context pointer, which may be modified in the Dispose() method. 
      lock (this) 
      { 
       if (!this.HasContext) 
       { 
        return; 
       } 

       // This thread will be executed every 1000ms. 
       // The thread also blocks for 1000ms, meaning 
       // that the application may keep on running for 
       // one extra second after the user has closed the Main Form. 
       result = (SmartCardErrorCode)UnsafeNativeMethods.GetStatusChange(this.context, 1000, this.states, (uint)this.states.Length); 
      } 

      if ((result == SmartCardErrorCode.Timeout)) 
      { 
       // Time out has passed, but there is no new info. Just go on with the loop 
       continue; 
      } 
      else if (result != SmartCardErrorCode.Succeeed) 
      { 
       // TODO OnExceptionRaised 
       continue; 
      } 

      for (int i = 0; i <= this.states.Length - 1; i++) 
      { 
       // Check if the state changed from the last time. 
       if ((this.states[i].EventState & CardState.Changed) == CardState.Changed) 
       { 
        // Check what changed. 
        SmartCardState state = SmartCardState.None; 
        if ((this.states[i].EventState & CardState.Present) == CardState.Present 
         && (this.states[i].CurrentState & CardState.Present) != CardState.Present) 
        { 
         // The card was inserted.        
         state = SmartCardState.Inserted; 
        } 
        else if ((this.states[i].EventState & CardState.Empty) == CardState.Empty 
         && (this.states[i].CurrentState & CardState.Empty) != CardState.Empty) 
        { 
         // The card was ejected. 
         state = SmartCardState.Ejected; 
        } 
        if (state != SmartCardState.None && this.states[i].CurrentState != CardState.Unaware) 
        { 
         SmartCardEventArgs args = new SmartCardEventArgs(); 
         args.Manager = this; 

         switch(state) 
         { 
          case SmartCardState.Inserted: 
          { 
           // Checa o ATR para monitorar apenas DESFire EV1 
           if (OnCardInserted != null) 
           { 
            // Obtém o ATR 
            byte[] atr = this.GetAtr(this.states[i].ATRBytes, this.states[i].ATRLength); 

            // Cria SmartCard object and associa ao EventArgs 
            SmartCard card = new SmartCard(atr); 
            args.Card = card; 

            // Dispara Evento 
            OnCardInserted(this, args); 
           } 
           break; 
          } 
          case SmartCardState.Ejected: 
          { 
           if (OnCardRemoved != null) 
           { 
            OnCardRemoved(this, args); 
           } 
           break; 
          } 
          default: 
          { 
           // TODO Log 

           // Null to force Garbage Collection 
           args = null; 

           break; 
          } 
         } 
        } 

        //Update the current state for the next time they are checked. 
        this.states[i].CurrentState = this.states[i].EventState; 
       } 
      } 
     } 
    }