package com.nailabs.abac.credential;

import java.security.*;
import java.security.cert.*;
import org.w3c.dom.*;
import org.apache.xml.security.signature.*;
import org.apache.xml.security.exceptions.*;
import org.apache.xml.security.transforms.Transforms;
import org.apache.xml.security.utils.*;

public class SignDomain extends Application {
    /** signature algorithm is set to DSA */
    protected static String SIG_TYPE = XMLSignature.ALGO_ID_SIGNATURE_DSA;
    /** digest algorithm is SHA-1 */
    protected static String DIGEST_TYPE = Constants.ALGO_ID_DIGEST_SHA1;

    protected static String KEY_PAIR_TYPE = "DSA";

    protected PrivateKey privateKey = null;

    protected PublicKey publicKey = null;
    
    protected X509Certificate cert = null;

    protected String base64Digest;

    protected String hexDigest;

    /** 
     * Constructor for the application which reads in an XML document, 
     * parses the doc into a DOM tree, signs the document, and writes
     * the signed tree into an XML file. Cryptographic material is supplied
     * by a Java keystore.
     */
    public SignDomain(String argv[]) {
	super(argv);
	name = "SignDomain";
	parseParameters();
	getKeys();
	readDoc();
	signDoc();
	writeDoc();
    }

    private void signDoc() {
	try {
	    String baseURI = outXML.toURL().toString();
	    XMLSignature sig = new XMLSignature( doc, baseURI, SIG_TYPE);
	    docElement.appendChild( sig.getElement() );
	    Transforms transforms = new Transforms( doc );
	    transforms.addTransform( Transforms.TRANSFORM_ENVELOPED_SIGNATURE);
	    transforms.addTransform( Transforms.TRANSFORM_C14N_WITH_COMMENTS);
	    String referenceURI = noComments ? "" : "#xpointer(/)";
	    sig.addDocument(referenceURI,transforms, DIGEST_TYPE);
	    sig.addKeyInfo( publicKey );
	    sig.sign( privateKey );
	    
	    //Element digestValueElem = sig.getSignedInfo().item( 0 ).getChildElementLocalName( 0, Constants.SignatureSpecNS, Constants._TAG_DIGESTVALUE );
	    //byte[] elemDig = Base64.decode( digestValueElem );
	    byte[] elemDig = sig.getSignedInfo().item(0).getDigestValue();
	    base64Digest = Base64.encode( elemDig );
	    //hexDigest = HexDump.byteArrayToHexString(elemDig);
            hexDigest = "";
	} catch( org.apache.xml.security.exceptions.XMLSecurityException sec) {
	    sec.printStackTrace();
	} catch( java.net.MalformedURLException murle ) {
	    murle.printStackTrace();
	} catch( Exception e ) {
	    e.printStackTrace();
	}
    }
    
    private void printDigest() {
	System.out.println( base64Digest );
	System.out.println( hexDigest );
    }

    private void generateKeyPair() {
	try {
	    KeyPairGenerator kpg = KeyPairGenerator.getInstance( "DSA" );
	    kpg.initialize( 512 );
	    KeyPair newKeyPair = kpg.generateKeyPair();
	    privateKey = newKeyPair.getPrivate();
	    publicKey = newKeyPair.getPublic();
	} catch( java.security.NoSuchAlgorithmException nsae ) {
	    nsae.printStackTrace();
	}
    }

    /** standard main routine for launching the application */
    public static void main(String argv[]) {
	SignDomain sc = new SignDomain(argv);
    }

}