Developer Libraries » Trusted Intents

    public File getApkFile() {

        return apkFile;

    }

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemLongClickListener;

public class AppListFragment extends ListFragment

        implements LoaderCallbacks<List<AppEntry>>, OnItemLongClickListener {

        getListView().setOnItemLongClickListener(this);

        String urlString = "https://androidobservatory.org/?searchby=binhash&q="

                + Utils.getBinaryHash(appEntry.getApkFile(), "sha1");

        intent.setData(Uri.parse(urlString));

        intent.putExtra(Intent.EXTRA_TITLE, R.string.by_apk_hash);

        startActivity(intent);

    }

    @Override

    public boolean onItemLongClick(AdapterView<?> parent, View v, int position, long id) {

        AppEntry appEntry = (AppEntry) adapter.getItem(position);

        Intent intent = new Intent(getActivity(), WebViewActivity.class);

        String urlString = "https://androidobservatory.org/?searchby=pkg&q="

                + appEntry.getPackageName();

        return true;

package info.guardianproject.checkey;

import android.util.Log;

import java.io.BufferedInputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.math.BigInteger;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

public final class Utils {

    public static String getBinaryHash(File apk, String algo) {

        FileInputStream fis = null;

        BufferedInputStream bis = null;

        try {

            MessageDigest md = MessageDigest.getInstance(algo);

            fis = new FileInputStream(apk);

            bis = new BufferedInputStream(fis);

            byte[] dataBytes = new byte[524288];

            int nread = 0;

            while ((nread = bis.read(dataBytes)) != -1)

                md.update(dataBytes, 0, nread);

            byte[] mdbytes = md.digest();

            return toHexString(mdbytes);

        } catch (IOException e) {

            Log.e("FDroid", "Error reading \"" + apk.getAbsolutePath() + "\" to compute SHA1 hash.");

            return null;

        } catch (NoSuchAlgorithmException e) {

            Log.e("FDroid", "Device does not support " + algo + " MessageDisgest algorithm");

            return null;

        } finally {

            if (fis != null)

                try {

                    fis.close();

                } catch (IOException e) {

                    return null;

                }

        }

    }

    /**

     * Computes the base 16 representation of the byte array argument.

     *

     * @param bytes an array of bytes.

     * @return the bytes represented as a string of hexadecimal digits.

     */

    public static String toHexString(byte[] bytes) {

        BigInteger bi = new BigInteger(1, bytes);

        return String.format("%0" + (bytes.length << 1) + "X", bi);

    }

}