import java.security.Security;
import java.security.cert.*;
import java.io.*;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.cms.CMSEnvelopedDataGenerator;
import org.bouncycastle.cms.CMSProcessableByteArray;
import org.bouncycastle.cms.CMSEnvelopedData;
import java.util.Arrays;

/* Create Enveloped pkcs #7 signature using BC provider
			     M. Gallant  06/30/2003  */

class EnvelopFile {

 public static void main(String args[]) {
   if (args.length < 2)
	usage();

 //Plug the Provider into the JCA/JCE
  Security.addProvider(new BouncyCastleProvider());

  FileInputStream freader = null;
  File f = null;
  X509Certificate cert = null;

//------  Get the content data from file -------------
  f = new File(args[0]) ;
  int sizecontent = ((int) f.length());
  byte[] contentbytes = new byte[sizecontent];

  try {
    freader = new FileInputStream(f);
    System.out.print("\nContent Bytes: " + freader.read(contentbytes, 0, sizecontent));
    freader.close();
   }
  catch(IOException ioe) {
	System.out.println(ioe.toString());
	return;
	}

//------  Get recipient certificate from file -------------

 try{
  InputStream inStream = new FileInputStream(args[1]);
  CertificateFactory cf = CertificateFactory.getInstance("X.509");
  cert = (X509Certificate)cf.generateCertificate(inStream);
  inStream.close();
 }
 catch(Exception exc){
  System.out.println("Couldn't instantiate X.509 certificate");
  return;
 }

// --- Use Bouncy Castle provider to create enveloped message ---
 String algorithm = CMSEnvelopedDataGenerator.RC2_CBC;
 int keysize = 128;  // bits
 CMSEnvelopedDataGenerator  fact = new CMSEnvelopedDataGenerator();
 fact.addKeyTransRecipient(cert);
 CMSProcessableByteArray content = new CMSProcessableByteArray(contentbytes);
 try{
  CMSEnvelopedData  envdata = fact.generate(content, algorithm, keysize, "BC");
  byte[] enveloped = envdata.getEncoded() ;
  System.out.println("Got encoded pkcs7 bytes " + enveloped.length + " bytes") ;
   FileOutputStream envfos = new FileOutputStream("BCenveloped.p7");
   envfos.write(enveloped);
   envfos.close();
 }
 catch(Exception ex){
  System.out.println("COuldn't generate enveloped signature") ;
 }
}

 private static void usage() {
  System.out.println("Usage:\n java EnvelopFile  <contentfile> <certfile> ") ;
  System.exit(1);
 }
}