URLConnection and POST method android - java

I am trying to make a post request using the reference of this documentation. But the problem is that the PHP developer at the other end is not able to receive the value of the parameter hence is not able to send a proper response. Am I missing something out here.
// Edits ;
I am making a HTTP Post request. As you can seen the code below. I am writing the arguments and parameters (location_id=3) to the outputstream. I have also pasted the code for PHP which i have been using. Now the problem is:
The parameter value ( which is 3 ) is not received at the PHP code so I am getting a response which is surrounded by the else block. So I just want to know if there is an error in the android code or the PHP code
#Override
protected Boolean doInBackground(String... params) {
Log.d(Constants.LOG_TAG,Constants.FETCH_ALL_THEMES_ASYNC_TASK);
Log.d(Constants.LOG_TAG," The url to be fetched "+params[0]);
try {
url = new URL(params[0]);
urlConnection = (HttpURLConnection) url.openConnection();
// /* optional request header */
// urlConnection.setRequestProperty("Content-Type", "application/json");
//
// /* optional request header */
// urlConnection.setRequestProperty("Accept", "application/json");
/* for Get request */
urlConnection.setChunkedStreamingMode(0);
urlConnection.setDoOutput(true);
urlConnection.setDoInput(true);
urlConnection.setRequestMethod("POST");
List<BasicNameValuePair> nameValuePairs = new ArrayList<BasicNameValuePair>();
nameValuePairs.add(new BasicNameValuePair("location_id",params[1]));
outputStream = urlConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream));
bufferedWriter.write(writeToOutputStream(nameValuePairs));
int statusCode = urlConnection.getResponseCode();
/* 200 represents HTTP OK */
if (statusCode == 200) {
inputStream = new BufferedInputStream(urlConnection.getInputStream());
response = convertInputStreamToString(inputStream);
Log.d(Constants.LOG_TAG, " The response is " + response);
return true;
}
else {
return false;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if(inputStream != null){
inputStream.close();
}
if(outputStream != null){
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return false;
}
// Here is the code for writeToOutputStream
public String writeToOutputStream(List<BasicNameValuePair> keyValuePair)throws UnsupportedEncodingException{
String result="";
boolean firstTime = true;
for(BasicNameValuePair pair : keyValuePair){
if(firstTime){
firstTime = false;
}
else{
result = result.concat("&");
}
result = result + URLEncoder.encode(pair.getKey(), "UTF-8");
result = result + "=";
result = result+ URLEncoder.encode(pair.getValue(),"UTF-8");
}
Log.d(Constants.LOG_TAG," The result is "+result);
return result;
}
// Here is the code for convertInputStream to String
public String convertInputStreamToString(InputStream is) throws IOException {
String line="";
String result="";
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
while((line = bufferedReader.readLine()) != null){
Log.d(Constants.LOG_TAG," The line value is "+line);
result += line;
}
/* Close Stream */
if(null!=inputStream){
inputStream.close();
}
return result;
}
Here is the PHP CODE
<?php
include 'config.php';
header ('Content-Type:application/json');
if(isset($_POST['location_id']))
{
$id=$_POST['location_id'];
$selectThemeQuery = mysql_query("select theme_id from location_theme where location_id='$id'",$conn) or die (mysql_error());
$noRows = mysql_num_rows($selectThemeQuery);
//echo "HI";
if($noRows > 0)
{
$result = array();
while($row = mysql_fetch_assoc($selectThemeQuery))
{
$themeid = $row['theme_id'];
//echo "HI";
$selectNameQuery = mysql_query("select theme_name,theme_image from theme where theme_id='$themeid'",$conn) or die(mysql_error());
$numRows = mysql_num_rows($selectNameQuery);
if($numRows > 0)
{
while($rows = mysql_fetch_assoc($selectNameQuery))
{
$name = $rows['theme_name'];
$image = $rows['theme_image'];
$result[] = array('theme_id'=>$themeid,'theme_name'=>$name, 'theme_image'=>$image);
}
}
}
//echo json_encode($result);
echo json_encode("Hi");
}
else
{
$data2[] = array('Notice'=>false);
echo json_encode($data2);
}
}
else
{
echo "Not Proper Data";
}
?>

Remove:
urlConnection.setChunkedStreamingMode(0);
You use a buffered writer so it can only buffer instead of write.
To force all been written:
bufferedWriter.write(writeToOutputStream(nameValuePairs));
bufferedWriter.flush();
And then ask for a response code. And don't call a response code a status code.
writeToOutputStream() ??? What a terrible name. That function does not write to an output stream. It justs makes a text string.

For Android, I would suggest using a library like Spring-Android.
Spring-Android contains a RestTemplate class, which is a quite effective REST-Client. For example, a simple POST request would be...
myRestTemplate.exchange("http://www.example.net", HttpMethod.POST, new HttpEntity( ...some JSON string ...), String.class );
To create the JSON String, I suggest a library like Jackson, which should work fine on Android, see for example here. Not sure if Jackson integrates as fine in Spring-Android as it does in Spring-Web, but in any case, using it to create the Json Strings manually should work just fine.

for post method
create a string builder first
StringBuilder strbul=new StringBuilder();
then append the data like
strbul.append("name=sangeet&state=kerala");
then write to output stream like
httpurlconnection.getOutput().write(strbul.toString().getBytes("UTF-8"));
php script will recieve that data on
$_POST['name'] and $_POST['state']

Related

Reflected XSS on BufferedReader readLine() method

I have scanned a java web project with the Checkmarx tool, and the analysis marks an XSS vulnerability in a method where a web service is executed that responds a JSON, the vulnerability is in the line while((output = Encode.forJava(br.readLine())) != null) {, specifically in br.readLine().
Checkmarx says:
The attacker would be able to alter the returned web page by simply
providing modified data in the user input readLine, which is read by
the NetClientPost method. This input then flows through the code
straight to the output web page, without sanitization.
This can enable a Reflected Cross-Site Scripting (XSS) attack.
I tried with OWASP for Java, implementing the method Encode.forJava(), but the vulnerability continues to appear in the analysis. This is the implementation of the method:
public String NetClientPost (String urlSer, String param){
String result ="";
try {
InetAddress ip = InetAddress.getLocalHost();
String host = ip.getHostAddress();
doTrustToCertificates();
URL url = new URL(urlSer);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setConnectTimeout(2000);
String input = param;
String output = "";
try(OutputStream os = conn.getOutputStream()) {
os.write(input.getBytes());
os.flush();
if (conn.getResponseCode() != 200) {
throw new RuntimeException("Failed : HTTP code : " + conn.getResponseCode());
}
try (BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())))) {
while ((output = Encode.forJava(br.readLine())) != null) {//LINE OF CHECKMARX XSS
result += output;
}
}
}
conn.disconnect();
return result;
} catch (MalformedURLException e) {
return result;
} catch (IOException e) {
return result;
} catch (Exception e) {
return result;
}
}
Any have an idea of how to solve this?
Try parsing the incoming data as JSON and then serializing it back to a string before sending it on.
That way you can be sure that your method only returns JSON to the client. If for some reason, your incoming data isn't JSON, then your method would encounter an error parsing the JSON, which you can then handle appropriately.
Encode.forJava isn't a helpful method to use here: it is used to encode a string to be inserted into a Java string literal.
output = Encode.forHtmlAttribute(br.readLine() works for me

I cant insert data from a java program to laravel app via api

I am new to laravel and I would like to save data to my online server via laravel api from a java program but I am getting errors.
this is my route on api.php:
Route::middleware('auth:api')->get('/user', function (Request $request) {
return $request->user();
});
Route::post('hooks','ApiTestController#store');
my ApiTestController: its just handles POST request then saves to the table.
public function store(Request $request)
{
$postdata = json_decode($request->input('post_data'), true);
$datas = $postdata['header'];
$data = $datas[0];
$testH = new TestH();
$testH->test_date = $data['test_date'];
$testH->expiration = $data['test_date'];
$testH->source = $data['source'];
$testH->save();
return $testH;
}
and my java code :
try {
//local development server url
URL url = new URL("http://127.0.0.1:8000/api/hooks");
URLConnection con = url.openConnection();
// activate the output
con.setDoOutput(true);
PrintStream ps = new PrintStream(con.getOutputStream());
//create the JSON String
String json = null;
StringWriter sw = new StringWriter();
JSONWriter wr = new JSONWriter(sw);
try {
wr.object().key("header").array();
wr.object();
wr.key("test_date").value(new Date());
wr.key("source").value("TEST");
wr.key("expiration").value(new Date());
wr.endObject();
wr.endArray().endObject();
json = sw.toString();
System.out.println(json);
} catch (JSONException ex) {
Logger.getLogger(WebConnectSample.class.getName()).log(Level.SEVERE, null, ex);
}
// send to laravel server
ps.print("post_data="+json);
HttpURLConnection httpConn = (HttpURLConnection) con;
InputStream is;
if (httpConn.getResponseCode() >= 419) {
is = httpConn.getErrorStream();
} else {
is = httpConn.getInputStream();
}
// read the server reply
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
System.out.println(line);
// close the print stream
}
ps.close();
} catch (Exception e) {
e.printStackTrace();
}
}
the thing is when I dont save via $testH->save() everything works fine. but if I include it java returns with the following error:
Type error: Argument 1 passed to Illuminate\Routing\Middleware\ThrottleRequests::addHeaders() must be an instance of Symfony\Component\HttpFoundation\Response, string given, called in C:\Users\relixusdev\Documents\WebProjects\tcmsite\vendor\laravel\framework\src\Illuminate\Routing\Middleware\ThrottleRequests.php on line 61
any idea what part causes the error? does it have to do with authentication? i just want to be able to save to the online database via my java program.
Try using Route group with prefix as below
Route::group(['prefix' => 'api'], function() {
Route::post('hooks','ApiTestController#store');
});
if anyone comes here having the same problem, i found out that the problem is that I dont have the created_at and updated_at column at my table. I didn't realized its a requirement for laravel. silly me.

Android - Size in chars of an http response

I am not an pro developing android. I wanted to download a JSON object from my server, but only code I could find was this:
private String downloadUrl(String myurl) throws IOException {
InputStream is = null;
// Only display the first 500 characters of the retrieved
// web page content.
int len = 500;
try {
URL url = new URL(myurl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setRequestMethod("GET");
conn.setDoInput(true);
// Starts the query
conn.connect();
int response = conn.getResponseCode();
Log.d("ServerConnection", "The response is: " + response);
is = conn.getInputStream();;
//is.
// Convert the InputStream into a string
String contentAsString = readIt(is, len);
return contentAsString;
// Makes sure that the InputStream is closed after the app is
// finished using it.
} catch (MalformedURLException e) {
//
return "error";
} catch (IOException e) {
//
return "error";
} finally {
if (is != null) {
is.close();
}
}
}
And it works fine, I cant understand. But it has a int len = 500, and my returned json is cropped to 500 chars. I tried changing to a great number, but it puts spaces at the end. How can I know the size in chars of the String contained by the InputSteam?
Thanks
You can check the Content-Length header value of your response:
Map<String, List<String>> headers = connection.getHeaderFields();
for (Entry<String, List<String>> header : headers.entrySet()) {
if(header.getKey().equals("Content-Legth")){
len=Integer.parseInt(header.getValue());
}
}
or you can your response in a buffered reader like this:
InputStream is = connection.getInputStream();
InputStreamReader reader = new InputStreamReader(is);
StringBuilder builder = new StringBuilder();
int c = 0;
while ((c = reader.read()) != -1) {
builder.append((char) c);
}
Yout can use Apache Commons IO IOUtils.toString to convert InputStream to String or use Gson to read object from input stream directly:
return gson.fromJson(new InputStreamReader(inputStream), YourType.class);

Sending two values into php webpage with java

I am trying to send two string values from my java program into my php page and i seem to be having some difficulty figuring out how this all works.
public static void main (String args[]) throws IOException{
Scanner input = new Scanner (System.in);
String sampleValue = input.next();
String sampleValue1 = input.next();
URL url = new URL("http://woah.x10host.com/randomfact.php");
String result = "";
String data = "fName=" + URLEncoder.encode(sampleValue, "UTF-8");
String id = "lName=" + URLEncoder.encode(sampleValue1, "UTF-8");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
try {
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
// Send the POST data
DataOutputStream dataOut = new DataOutputStream(connection.getOutputStream());
dataOut.writeBytes(id);
dataOut.writeBytes(data);
dataOut.flush();
System.out.println("Data has been posted");
dataOut.close();
BufferedReader in = null;
try {
String line;
in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
while ((line = in.readLine()) != null) {
result += line;
}
} finally {
if (in != null) {
in.close();
}
}
} finally {
connection.disconnect();
System.out.println(result);
}
}
}
my PHP code is
<?php
$conn = mysqli_connect("localhost","woahx10h_funfact","spk","woahx10h_woah");
// CHECK CONNECTION
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$value_data = $_POST['fName'];
$value_id = $_POST['lName'];
echo $value_data;
echo $value_id;
$conn->close();
?>
However, every time i run the java program, values from both data and id seem to be stored in the $value. I want the value from data to be stored in $value_data while the value from x to be stored in $value_id
You have to add ampersand (&) between each two parameters. So in this case all you have to do is edit your code like this:
...
dataOut.writeBytes(id);
dataOut.writeBytes("&");
dataOut.writeBytes(data);
...
If you would want to add another parameter to the request you would have to add another ampersand and then the parameter, for example:
...
dataOut.writeBytes(id);
dataOut.writeBytes("&");
dataOut.writeBytes(data);
dataOut.writeBytes("&");
dataOut.writeBytes(parameter3);
...

How to get VIEWSTATE before posting using HttpURLConnection (android/java)?

I am writing an Android application, and have been looking for a way to get the _VIEWSTATE from the server I want to post to so I can put it in my Http post content. A few people recommended regex, but then some other pros were strongly opposed to parsing HTML with regex. So, how to parse the _VIEWSTATE ? I am using HttpURLConnection/HttpsURLConnection in an AsyncTask. Also, don't I need to put the InputStream reader first, to get the _VIEWSTATE first? All the android examples put the input stream after the output stream. Here is what my code looks like so far (posting to one site that has three pages that have to be "clicked through"):
In my Activity, I call the Async task like this:
//execute AsyncTask for all three reports
submit_report.execute(report1, report2, report3);
My Async task doInBackground method:
class UploadReportTask extends AsyncTask<HashMap<String,String>, ProgressBar, Void> {
//this is called on task.execute
protected Void doInBackground(HashMap<String,String>...maps) {
System.out.println("Report is being uploaded");
URL url = null;
try {
url = new URL(getString(R.string.url_dnc));
} catch (MalformedURLException e) {
e.printStackTrace();
}
HttpURLConnection urlConnection = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
} catch (IOException e) {
e.printStackTrace();
}
try {
urlConnection.setDoOutput(true);
urlConnection.setRequestProperty("Accept-Charset", utf);
urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=" + utf);
urlConnection.setChunkedStreamingMode(0);
//For each map in maps, encode the map,
//get the headers, add the headers to the map, convert to bytes,
//then post the bytes,
//get response.
for (HashMap<String,String> map : maps){
byte[] payload = makePayload(map);
OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
//urlConn.connect //I think this happens here
out.write(payload);
InputStream in = new BufferedInputStream(urlConnection.getInputStream());
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
int length = in.read();
String result, line = reader.readLine();
result = line;
while (length != -1){
result+=line;
}
System.out.println(result);
out.flush();
out.close();
}
} catch (IOException e) {
e.printStackTrace();
}
finally{
urlConnection.disconnect();
}
return null;
}
protected String parseViewstate(String response){
int i = 0;
String viewstate = "";
while (true){
int found = response.indexOf("\"__VIEWSTATE\"", i);
if (found == -1) break;
int start = found + 38; //check numbers from start of "__V"
int end = (response.indexOf("/>", start)) -2;
viewstate = response.substring(start, end);
i = end + 1;
}return viewstate;
}

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