java code for pswd protection+digital sign (for all pgs)

[pavithra murthy]

hello friend ,

i have written a java code for digitally signing and password protect a pdf document using itext.jar...
now what is happening is i am using export.cer and keystore.ks which i created using a keytool command in command prompt. so when i open the pdf the signature is invalid ...only when i manually click on the signature and verify it then it will get validated...also when i send the pdf to my friends computer the same thing is happening .Could anyone please help me out in solving this issue..
is this because i am using some non trusted certificate and keystore

Also if i have to get a trusted certificate from Versign or so...how actually do they give me the private key similar to keystore.ks
the code is given below . please could anyone help me out !!!

import java.io.FileOutputStream;
import java.util.*;
import java.io.*;

import com.lowagie.text.pdf.PdfEncryptor;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfStamper;
import com.lowagie.text.pdf.PdfWriter;
import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.AcroFields;
import com.lowagie.text.pdf.PdfPKCS7;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfSignatureAppearance;
import com.lowagie.text.pdf.PdfStamper;
import com.lowagie.text.pdf.*;


import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.Iterator;

public class testencrypt {
   
  public static void main(String[] args) throws IOException {

	  try
	  {

	String password="";String username="";
          
			  //....................
			  HashMap hm = new HashMap(); 
			  BufferedReader dataIn = new BufferedReader(new InputStreamReader(System.in) );

			  System.out.println("USERNAME"+":"+"PASSWORD");
			  hm .put("pavithra", "pvm4kor");
			  hm .put("shompa", "sos5kor");
			  hm .put("vinod", "vim2kor");
			  hm .put("shiva", "snk3kor");

			  // Get a set of the entries
			  Set set = hm.entrySet();
			  // Get an iterator
			  Iterator i = set.iterator();

			  System.out.println("Please enter your username");
			  username = dataIn.readLine();

			  // Display elements
			  String mName;
	  while(i.hasNext()) 
		  {                  
				  Map.Entry me = (Map.Entry)i.next();
				  System.out.print(me.getKey() + ": ");
				  System.out.println(me.getValue());
									  
				  //cheks when username is entered with the password                         
				  if   (username.equals((String)me.getKey())) 
				  {
					  password= (String)me.getValue();
					  System.out.println("password           "+password);
				  }

                 //code password protect pdf 
				  if (password.equals((String)me.getValue()))
				  {
					  System.out.println("hello");
					//  mName=(String)me.getValue();
					 PdfReader readerx = new PdfReader("d:\\Exportbegleitdokument.pdf");
					 PdfStamper stamper = new PdfStamper(readerx, new FileOutputStream("d:\\protectedPassword.pdf"));
					 //stamper.setEncryption("Hello".getBytes(), password.getBytes(), PdfWriter.AllowPrinting | PdfWriter.AllowCopy, PdfWriter.STRENGTH40BITS);
					 stamper.setEncryption("Hello".getBytes(),password.getBytes(), PdfWriter.AllowPrinting| PdfWriter.AllowCopy, PdfWriter.STRENGTH40BITS );
					 stamper.close();
				
							    //digitally signing pdf
						  PdfReader reader = new PdfReader("d:\\protectedPassword.pdf",password.getBytes());
						  int nomPage = reader.getNumberOfPages();
						  System.out.println("nomPage: "+nomPage);

                        ///----------------------------------
          //vvvvvvvvvvvvvvvvvvvvvvvvvvvvdigitally signing code 
try{
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
ks.load(new FileInputStream("keystores.ks"), "my_password".toCharArray());
String alias = (String)ks.aliases().nextElement();
PrivateKey key = (PrivateKey)ks.getKey(alias, "my_password".toCharArray());
java.security.cert.Certificate[] chain = ks.getCertificateChain(alias);
//PdfReader reader = new PdfReader("ch01out.pdf");
      
			for (int j=1; j<=nomPage; j++)
			{

				FileOutputStream fout = new FileOutputStream("signed"+j+".pdf");
				//PdfStamper stp = PdfStamper.createSignature(reader, fout, '\0');
				PdfStamper stp = PdfStamper.createSignature(reader, fout, '\0', null, true);
				//PdfStamper.setEncryption(chain,AllowDegradedPrinting,ENCRYPTION_AES);
				PdfSignatureAppearance sap = stp.getSignatureAppearance();
				sap.setCrypto(key, chain, null, PdfSignatureAppearance.VERISIGN_SIGNED);
				sap.setReason("I'm the author");
				sap.setLocation("Lisbon");
				// comment next line to have an invisible signature
				sap.setVisibleSignature(new Rectangle(100, 100, 200, 200), j, null);
				stp.close();
				  reader = new PdfReader("signed"+j+".pdf",password.getBytes());
			}
    		for(int j=1;j<=nomPage;j++)
			{
				File fileStr = new File("signed"+j+".pdf");
				if(j!=nomPage)
				{
					fileStr.delete();
				}
				//to verify sign
				if(j == nomPage)
				{
					try {
						CertificateFactory cf = CertificateFactory.getInstance("X509");
						//Collection col = cf.generateCertificates(new FileInputStream("exports.cer"));
						Collection col = cf.generateCertificates(new FileInputStream("d:\\VeriSign Class 1 Public Primary Certification Authority - G3.cer"));
						KeyStore kall = KeyStore.getInstance(KeyStore.getDefaultType());
						kall.load(null, null);
						for (Iterator it = col.iterator(); it.hasNext();) {
						    X509Certificate cert = (X509Certificate)it.next();
						    kall.setCertificateEntry(cert.getSerialNumber().toString(Character.MAX_RADIX), cert);
						}
						//KeyStore kall = PdfPKCS7.loadCacertsKeyStore();
						PdfReader reader2 = new PdfReader("signed"+j+".pdf");
						AcroFields af = reader2.getAcroFields();
						ArrayList names = af.getSignatureNames();
						for (int k = 0; k < names.size(); ++k) 
						{
							String name = (String)names.get(k);
							System.out.println("Signature name: " + name);
							System.out.println("Signature covers whole document: " + af.signatureCoversWholeDocument(name));
							System.out.println("Document revision: " + af.getRevision(name) + " of " + af.getTotalRevisions());
							
							PdfPKCS7 pk = af.verifySignature(name);
							Calendar cal = pk.getSignDate();
							java.security.cert.Certificate pkc[] = pk.getCertificates();
							System.out.println("Subject: " + PdfPKCS7.getSubjectFields(pk.getSigningCertificate()));
							System.out.println("Document modified: " + !pk.verify());
							Object fails[] = PdfPKCS7.verifyCertificates(pkc, kall, null, cal);
							if (fails == null)
								System.out.println("Certificates verified against the KeyStore");
							else
								System.out.println("Certificate failed: " + fails[1]);
						}
					}
					catch(Exception e) {e.printStackTrace();}
				}

			}

}
catch(Exception e) {e.printStackTrace();}

//vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
						///---------------------------------
  }
         }//while 

}//first try
catch(Exception ex) {ex.printStackTrace();};
}//main
}//class