public class FormUploader2 extends AsyncTask<String,Void,String> {

    String username = omitted;
    String password = omitted;
    String crlf = "\r\n";
    String twoHyphens = "--";
    String boundary = "*****";
    String formName = "CR Debitage Form v1_2019-01-14_14-42-01.xml";
    File file;

    protected String doInBackground(String...p){
        String result = " ";

        //Load file
        file = new File(Environment.getExternalStorageDirectory(), formName);

        if(file.isFile()) {
            try {
                final URL url = new URL("http://omitted/ODKAggregate/submission");
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();

                // Check server response
                String debug = "";
                int status = conn.getResponseCode();

                if (status == HttpURLConnection.HTTP_UNAUTHORIZED) {
                    //This is expected as we haven't supplied any login credentials.  Unfortunately
                    //Android's built in digest authentication support is shit, so we have to build it based
                    //on this failed response
                    HttpURLConnection connection = tryDigestAuthentication(conn, username, password);

                    if(connection == null){
                        throw new IOException("Authentication Error- Digest processing failed");
                    } else {
                        conn = connection;
                        upload(conn);
                    }

                } else {
                    throw new IOException("Authentication Error: " + status);
                }
            } catch (IOException i) {
                i.printStackTrace();
                Log.e("IO Exception - ", i.toString());
            }
        } else {
            result = "No File detected";
        }

        return result;
    }

    public void upload(HttpURLConnection conn) {
        try {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.US);
            String formattedDate = sdf.format(new Date());

            conn.setDoOutput(true);
            conn.setRequestProperty("Content-Type", "multipart/form-data");
            conn.setRequestProperty("X-OpenRosa-Version", "1.0");
            conn.setRequestProperty("Date", formattedDate);
            conn.setRequestProperty("Accept-Encoding", "gzip, deflate");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("Cache-Control", "no-cache");
            conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);

            OutputStream outputStream = conn.getOutputStream();
            PrintWriter writer = new PrintWriter(new OutputStreamWriter(outputStream, Charset.forName("UTF-8").newEncoder()), true);

            writer.append(twoHyphens + boundary + crlf);
            writer.append("Content-Disposition: form-data; name=\"xml_submission_file\"; filename=\"" + formName + "\"" + crlf);
            writer.append("Content-Type: text/xml;" + crlf + crlf);
            writer.flush();

            FileInputStream inputStream = new FileInputStream(file);
            byte[] buffer = new byte[4096];
            int bytesRead = -1;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }

            outputStream.flush();
            inputStream.close();
            writer.append(crlf);
            writer.flush();
            writer.append(crlf);
            writer.flush();
            writer.append(twoHyphens + boundary + twoHyphens);
            writer.append(crlf);

            String post = writer.toString();
            writer.close();

            // Check server response
            String debug = "";
            int status = conn.getResponseCode();

            if (status == HttpURLConnection.HTTP_OK) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                String line = null;
                while ((line = reader.readLine()) != null) {
                    debug = debug + line;
                }

                reader.close();
                conn.disconnect();
            } else {
                throw new IOException("Server returned non-OK status: " + status + " " + post);
            }
        } catch (MalformedURLException m) {
            m.printStackTrace();
            Log.e("URL Exception - ", m.toString());
        } catch (IOException i) {
            i.printStackTrace();
            Log.e("IO Exception - ", i.toString());
        }
    }

    public static HttpURLConnection tryDigestAuthentication(HttpURLConnection input, String username, String password) {
        String auth = input.getHeaderField("WWW-Authenticate");
        if(auth == null || !auth.startsWith("Digest ")){
            return null;
        }

        final HashMap<String, String> authFields = splitAuthFields(auth.substring(7));

        MessageDigest md5 = null;
        try{
            md5 = MessageDigest.getInstance("MD5");
        } catch(NoSuchAlgorithmException e){
            return null;
        }

        String j = ":";
        String HA1 = null;

        try{
            md5.reset();
            String ha1str = username + j + authFields.get("realm") + j + password;
            md5.update(ha1str.getBytes("ISO-8859-1"));
            byte[] ha1bytes = md5.digest();
            HA1 = bytesToHexString(ha1bytes);
        } catch(UnsupportedEncodingException e){
            return null;
        }

        String HA2 = null;
        try{
            md5.reset();
            String ha2str = (input.getRequestMethod() + j + input.getURL().getPath());
            md5.update(ha2str.getBytes("ISO-8859-1"));
            HA2 = bytesToHexString(md5.digest());
        } catch(UnsupportedEncodingException e){
            return null;
        }

        String HA3 = null;
        String cnoice = generateCNonce();
        try{
            md5.reset();
            String ha3str = (HA1 + j + authFields.get("nonce") + j + "1" + cnoice + "auth" + HA2);
            md5.update(ha3str.getBytes("ISO-8859-1"));
            HA3 = bytesToHexString(md5.digest());
        } catch(UnsupportedEncodingException e){
            return null;
        }

        StringBuilder sb = new StringBuilder(128);
        sb.append("Digest ");
        sb.append("username").append("=\"").append(username).append("\", ");
        sb.append("realm").append("=\"").append(authFields.get("realm")).append("\", ");
        sb.append("nonce").append("=\"").append(authFields.get("nonce")).append("\", ");
        sb.append("uri").append("=\"").append(input.getURL().getPath()).append("\", ");
        sb.append("response").append("=\"").append(HA3).append("\", ");
        sb.append("qop").append('=').append("auth").append(", ");
        sb.append("nc").append("=\"").append("1").append("\", ");
        sb.append("cnonce").append("=\"").append(cnoice).append("\"");

        //sb.append("algorithm").append("=\"").append(authFields.get("algorithm")).append("\"");

        try{
            final HttpURLConnection result = (HttpURLConnection)input.getURL().openConnection();
            result.addRequestProperty("Authorization", sb.toString());
            return result;
        }
        catch(IOException e){
            return null;
        }
    }

    private static HashMap<String, String> splitAuthFields(String authString)
    {
        final HashMap<String, String> fields = Maps.newHashMap();
        final CharMatcher trimmer = CharMatcher.anyOf("\"\t ");
        final Splitter commas = Splitter.on(',').trimResults().omitEmptyStrings();
        final Splitter equals = Splitter.on('=').trimResults(trimmer).limit(2);
        String[] valuePair;
        for(String keyPair : commas.split(authString)){
            valuePair = Iterables.toArray(equals.split(keyPair), String.class);
            fields.put(valuePair[0], valuePair[1]);
        }
        return fields;
    }

    private static final String HEX_LOOKUP = "0123456789abcdef";
    private static String bytesToHexString(byte[] bytes)
    {
        StringBuilder sb = new StringBuilder(bytes.length * 2);
        for(int i = 0; i < bytes.length; i++){
            sb.append(HEX_LOOKUP.charAt((bytes[i] & 0xF0) >> 4));
            sb.append(HEX_LOOKUP.charAt((bytes[i] & 0x0F) >> 0));
        }
        return sb.toString();
    }

    public static class AuthenticationException extends IOException
    {
        private static final long serialVersionUID = 1L;
        public AuthenticationException()
        {
            super("Problems authenticating");
        }
    }

    private static String generateCNonce() {
        String s = "";
        for (int i = 0; i < 8; i++)

            s += Integer.toHexString(new Random().nextInt(16));
        return s;
    }

}