//****************************************************************
//
// SignedXMLCerts
// Retrieves X509 certificates embedded in signed XML document
//
// Copyright (C) 2004.  Michel I. Gallant
//
//
//*****************************************************************


using System;
using System.IO;
using System.Xml;
using System.Security.Cryptography.X509Certificates;
using System.Runtime.InteropServices;

//------ For Pinvoke to display certs GUI ---------
public class Win32 {
 [DllImport("crypt32.dll", CharSet=CharSet.Auto, SetLastError=true)]
	public static extern IntPtr CertCreateCertificateContext(
	uint dwCertEncodingType,
	byte[] pbCertEncoded,
	uint cbCertEncoded) ;

 [DllImport("crypt32.dll", CharSet=CharSet.Auto)]
	public static extern bool CertFreeCertificateContext(
	IntPtr pCertContext) ;

 [DllImport("cryptui.dll", SetLastError=true)]
	public static extern bool CryptUIDlgViewCertificate(
	ref PCCRYPTUI_VIEWCERTIFICATE_STRUCT   pCertViewInfo,
	ref bool pfPropertiesChanged) ;
}


 [StructLayout(LayoutKind.Sequential)]
  public struct PCCRYPTUI_VIEWCERTIFICATE_STRUCT
  {
	public uint dwSize;		//required
	public IntPtr hwndParent;
	public uint dwFlags;
	public String  szTitle;
	public IntPtr pCertContext;	//required
	public IntPtr rgszPurposes;
	uint cPurposes;
	IntPtr hWVTStateData;
	bool fpCryptProviderDataTrustedUsage;
	uint idxSigner;
	uint idxCert;
	bool fCounterSigner;
	uint idxCounterSigner;
	uint cStores;
	IntPtr rghStores;
	uint cPropSheetPages;
	IntPtr rgPropSheetPages;
	public uint nStartPage;	//required
  }




public class SignedXmlCerts
{
  public static void Main(string[] args)
  {
    if(args.Length !=1) {
 	Console.WriteLine("Usage:   SignedXmlCerts  <signedxmlfile>");
	return;
	}

    String signedxmldoc = args[0] ;
	if(!File.Exists(args[0])) {
	 Console.WriteLine("File {0} not found", args[0]);
	 return;
	}

    //Create the XmlDocument.
    XmlDocument doc = new XmlDocument();
    doc.Load(signedxmldoc);

    XmlNodeList elemList = doc.GetElementsByTagName("X509Certificate");
    byte[] certBytes = null;

    for (int i=0; i < elemList.Count; i++)
    {   
	String b64cert = elemList[i].InnerXml ;
        Console.WriteLine("---- X509 Certificates in xigned XML document '{0}' ----\n", signedxmldoc);
	try	//see if the file is a valid Base64 encoded cert
	{        
           certBytes = Convert.FromBase64String(b64cert) ;
	   X509Certificate x509cert =  new X509Certificate(certBytes);
	   showCertInfo(x509cert);
	   showCertGUI(certBytes) ;  //display the native certs GUI via Pinvoke
	}
	catch(System.FormatException formexc)
	{
	   Console.WriteLine(formexc.Message);
	}
	catch(System.Security.Cryptography.CryptographicException cryptb64)
	{
	   Console.WriteLine(cryptb64.Message);
	}
    }  
 }

 private static void showCertInfo(X509Certificate x509cert) {
	Console.WriteLine("\nName: " + x509cert.GetName());
	Console.WriteLine("\nIssuer: " + x509cert.GetIssuerName());
	Console.WriteLine("\nSerial Number: " + x509cert.GetSerialNumberString());
	Console.WriteLine("\nExpiration Date: " + x509cert.GetExpirationDateString());
	//Console.WriteLine("PublicKey: " + x509cert.GetPublicKeyString());
 }



private static void showCertGUI(byte[] x509cert) {
 IntPtr hCertCntxt = IntPtr.Zero;
 const uint X509_ASN_ENCODING   = 0x00000001;
 const uint PKCS_7_ASN_ENCODING = 0x00010000;
 uint encoding = X509_ASN_ENCODING | PKCS_7_ASN_ENCODING ;

 hCertCntxt = Win32.CertCreateCertificateContext(encoding, x509cert, (uint)x509cert.Length);

  if(hCertCntxt != IntPtr.Zero){  //show certificate properties panel
	PCCRYPTUI_VIEWCERTIFICATE_STRUCT vcstruct = new PCCRYPTUI_VIEWCERTIFICATE_STRUCT() ;
	vcstruct.dwSize = (uint)Marshal.SizeOf(vcstruct);
	vcstruct.pCertContext = hCertCntxt;
	vcstruct.szTitle = "KeyPal Certificate Display";
	vcstruct.nStartPage = 0;
	bool propschanged = false;
	Win32.CryptUIDlgViewCertificate(ref vcstruct, ref propschanged) ; //show the cert
	}

//-------  Clean Up  -----------
  if(hCertCntxt != IntPtr.Zero)
	Win32.CertFreeCertificateContext(hCertCntxt);
 }



}