An activity that will load a .BKS Keystore in Android and Sign an XML file using Apache Santuario (xmlSecurity)

Android .BKS - Sign XML

package sign.bematech.com.br.signxmlandroid;

import android.app.Activity;
import android.os.Bundle;

import org.apache.xml.security.Init;
import org.apache.xml.security.c14n.Canonicalizer;
import org.apache.xml.security.exceptions.XMLSecurityException;
import org.apache.xml.security.signature.XMLSignature;
import org.apache.xml.security.transforms.Transforms;
import org.apache.xml.security.utils.Constants;
import org.apache.xml.security.utils.ElementProxy;
import org.w3c.dom.Document;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.Key;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.xml.parsers.DocumentBuilderFactory;


public class SignActivity extends Activity {



    private static final String PRIVATE_KEY_ALIAS = "bematechkey";
    private static final String PRIVATE_KEY_PASS = "bema123";

    private static final String KEY_STORE_PASS = "bema123";
    private static final String KEY_STORE_TYPE = "BKS";


    private static KeyStore keyStore;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        sign();

    }

    private void sign(){


        InputStream in = null;

        try {


            keyStore = KeyStore.getInstance(KEY_STORE_TYPE);

            in = getResources().openRawResource(R.raw.bematech);

            keyStore.load(in, KEY_STORE_PASS.toCharArray());


        } catch (KeyStoreException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (CertificateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        try {

            try {

                InputStream fileInputStream = getAssets().open("test.xml");
                ByteArrayOutputStream signedOutputStream = signXml(fileInputStream, keyStore);

                System.out.print(signedOutputStream);


            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }


        } finally {
            //IOUtils.closeQuietly(fileInputStream);
        }

    }

    public ByteArrayOutputStream signXml(InputStream xmlFile, KeyStore keyStore) throws Exception {

        final Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(xmlFile);

        Init.init();
        ElementProxy.setDefaultPrefix(Constants.SignatureSpecNS, "");

        XMLSignature xmlSignature = createSignature(doc);

        final Transforms transforms = new Transforms(doc);

        transforms.addTransform(Transforms.TRANSFORM_ENVELOPED_SIGNATURE);
        transforms.addTransform(Transforms.TRANSFORM_C14N_OMIT_COMMENTS);

        xmlSignature.addDocument("", transforms, Constants.ALGO_ID_DIGEST_SHA1);

        final Key privateKey = keyStore.getKey(PRIVATE_KEY_ALIAS, PRIVATE_KEY_PASS.toCharArray());

        final X509Certificate cert = (X509Certificate) keyStore.getCertificate(PRIVATE_KEY_ALIAS);

        xmlSignature.addKeyInfo(cert);
        xmlSignature.addKeyInfo(cert.getPublicKey());

        xmlSignature.sign(privateKey);
        doc.getDocumentElement().appendChild(xmlSignature.getElement());

        final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        outputStream.write(Canonicalizer.getInstance(Canonicalizer.ALGO_ID_C14N_OMIT_COMMENTS).canonicalizeSubtree(doc));

        return outputStream;

    }



    private static XMLSignature createSignature(Document doc) {


        XMLSignature xmlSignature = null;

        String uri = "#NFe13140782373077000171650290000030531000030538";


        try {

            xmlSignature = new XMLSignature(doc, uri, XMLSignature.ALGO_ID_SIGNATURE_RSA);


        } catch (XMLSecurityException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        return xmlSignature;

    }
}