Facebook Conceal - Image Encryption and Decryption

Question

I am trying to encrypt and decrypt image using Facebook Conceal Library. This is the first time i am using it and hence bear with me if its trivial. I have looked at other q

Answer 1

Here is how i solved the problem.. encryption and decryption works fine now.

// Encrypts the image and saves to directory

public void encodeAndSaveFile(Bitmap photo, int code) {

    try {
        ContextWrapper cw = new ContextWrapper(getApplicationContext());
        File directory = cw.getDir(DIRECTORY, Context.MODE_PRIVATE);
        File mypath = new File(directory, ENCRYPTEDFILENAME);

        Crypto crypto = new Crypto(new SharedPrefsBackedKeyChain(this),
                new SystemNativeCryptoLibrary());

        if (!crypto.isAvailable()) {
            return;
        }

        OutputStream fileStream = new BufferedOutputStream(
                new FileOutputStream(mypath));
        OutputStream outputStream = crypto.getCipherOutputStream(
                fileStream, new Entity("Password"));
        outputStream.write(bitmapToBytes(photo));
        outputStream.close();
    } catch (UnsupportedOperationException e) {
        e.printStackTrace();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

// convert Bitmap to bytes
private byte[] bitmapToBytes(Bitmap photo) {

    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    photo.compress(Bitmap.CompressFormat.PNG, 100, stream);
    byte[] byteArray = stream.toByteArray();
    return byteArray;
}

// convert bytes to Bitmap
private Bitmap bytesToBitmap(byte[] bytes) {

    Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

    return bitmap;
}

// decode encrypted file and returns Bitmap
private Bitmap decodeFile(String filename) {

    Crypto crypto = new Crypto(new SharedPrefsBackedKeyChain(this),
            new SystemNativeCryptoLibrary());

    ContextWrapper cw = new ContextWrapper(getApplicationContext());
    File directory = cw.getDir(DIRECTORY, Context.MODE_PRIVATE);
    File file = new File(directory, filename);

    try {
        FileInputStream fileStream = new FileInputStream(file);
        InputStream inputStream = crypto.getCipherInputStream(fileStream,
                new Entity("Password"));

        ByteArrayOutputStream out = new ByteArrayOutputStream();

        int read;
        byte[] buffer = new byte[1024];

        while ((read = inputStream.read(buffer)) != -1) {
            out.write(buffer, 0, read);
        }

        inputStream.close();

        Bitmap bitmap = bytesToBitmap(out.toByteArray());
        return bitmap;
    } catch (Exception e) {
        e.printStackTrace();
    }

    return null;
}

Here is how i am calling encodeAndSaveFile() and decodeFile(), in onActivityResult(), after returning from camera.

encodeAndSaveFile((Bitmap) data.getExtras().get("data"),
                        requestCode);
Bitmap decryptedImage = decodeFile(ENCRYPTEDFILENAME);