What ways are there for a website to detect automated connections made through C# Httpwebrequest?
Such as c#'s default user-agent? Operating System? or what..
have this problem with any other language, just C#?
I'm being blocked from accessing a certain website using Httpwebrequest, I don't
Also it's definitely not my IP address & nor are there any faults in my code as I've tested connections to other websites which work just fine.. Also I stated above I can make connections to the website using C++, C, Vb.net, Java, Python & so on, there is also no difference in header information either.
EDIT:
// Create a request using a URL that can receive a post.
WebRequest request = WebRequest.Create ("http://services.runescape.com/m=hiscore_oldschool/overall.ws");
// Set the Method property of the request to POST.
request.Method = "POST";
// Create POST data and convert it to a byte array.
string postData = "user1=Zezima&submit=Search";
byte[] byteArray = Encoding.UTF8.GetBytes (postData);
// Set the ContentType property of the WebRequest.
request.ContentType = "application/x-www-form-urlencoded";
// Set the ContentLength property of the WebRequest.
request.ContentLength = byteArray.Length;
// Get the request stream.
Stream dataStream = request.GetRequestStream ();
// Write the data to the request stream.
dataStream.Write (byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close ();
// Get the response.
WebResponse response = request.GetResponse ();
// Display the status.
Console.WriteLine (((HttpWebResponse)response).StatusDescription);
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream ();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader (dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd ();
// Display the content.
Console.WriteLine (responseFromServer);
// Clean up the streams.
reader.Close ();
dataStream.Close ();
response.Close ();
private const string Url = "http://services.runescape.com/m=hiscore_oldschool/overall.ws";
private static HttpWebRequest BuildWebRequest()
{
var request = WebRequest.Create(Url) as HttpWebRequest;
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.Timeout = 40000;
request.ServicePoint.Expect100Continue = true;
string body = "user1=Zezima&submit=Search";
byte[] bytes = Encoding.Default.GetBytes(body);
using (var requestStream = request.GetRequestStream())
{
requestStream.Write(bytes, 0, bytes.Length);
}
return request;
}
static void Main(string[] args)
{
try
{
HttpWebRequest request = BuildWebRequest();
var response = request.GetResponse() as HttpWebResponse;
var responseContent = new StreamReader(response.GetResponseStream()).ReadToEnd();
Console.Write("Success - " + response.StatusCode);
}
catch (Exception e)
{
Console.Write(e);
}
}
I can take the response from the website. It is not empty.
Related
I'm trying to write an old native Android app with Ionic and I need help for the http request. I'm newbie in AngularJS (js too).
My Android code has a function like:
String address = "http://www.example.com";
DefaultHttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(address);
List<NameValuePair> pairs = new ArrayList<NameValuePair>();
pairs.add(new BasicNameValuePair("param", sParam));
try {
post.setEntity(new UrlEncodedFormEntity(pairs));
HttpResponse response = client.execute(post);
BufferedReader rd = new BufferedReader(new InputStreamReader(responsegetEntity().getContent()));
StringBuilder sBuilder = new StringBuilder();
String sLine = "";
while ((sLine = rd.readLine()) != null) {
sBuilder.append(sLine).append("\n");
}
String sContent = sBuilder.toString();
(...parsing sContent...)
} catch (Exception e) {
//something
}
and if there are more then one page I call a function like
String address = "http://www.example.com/result.do?page="+ iPage;
HttpPost post = new HttpPost(address);
List<NameValuePair> pairs = new ArrayList<NameValuePair>();
pairs.add(new BasicNameValuePair("param", sParam));
Cookie ck = client.getCookieStore().getCookies().get(0);
pairs.add(new BasicNameValuePair("param_ck", ck.getValue()));
try {
post.setEntity(new UrlEncodedFormEntity(pairs));
HttpResponse response = client.execute(post);
(..parsing..)
}
So, I read the html content of a webpage (I'm not the owner) and I do somethings with that.
I tried $http.post but I'm not sure if it's the same
.factory('Service', function($q,$http) {
return {
getResult: function(param) {
var q = $q.defer();
var address = "http://www.example.com";
var sParam = "param";
$http({
url: address,
method: "POST",
data: {
'param' : sParam
}
})
.then(function(response) {
(...)
q.resolve(position);
},
function(error) {
(...)
q.reject(error);
});
return q.promise;
}
};
});
PS: I get the
No 'Access-Control-Allow-Origin' header is present on the requested resource.
with that.
Can you help me?
I am not entirely sure why you don't get a similar error with your Android code, or even if you were supposed to, as I am not familiar with native Android itself. But the reason that you get this with Angular in Ionic is that the server requires to implement CORS to get rid of that.
From MDN:
A resource makes a cross-origin HTTP request when it requests a resource from a different domain than the one which the first resource itself serves. For example, an HTML page served from http://domain-a.com makes an src request for http://domain-b.com/image.jpg. Many pages on the web today load resources like CSS stylesheets, images and scripts from separate domains.
I am trying to send an array of guids as postdata using a javascript function. The recieving aspx page needs to process this data.
The javascript that calls the page is as following:
function(webadress, guidarray) {
var params = 'menubar=no,status=no,toolbar=no,resizable=no, scrollbars=no';
var win = document.createElement("form");
win.target = 'Map';
win.method = 'POST';
win.action = webadress;
var winInput = document.createElement('input');
winInput.type = 'text';
winInput.name = 'guidcollection';
winInput.value = guidarray;
win.appendChild(winInput);
win.setAttribute("target", "_blank");
window.open(webadress, '', params);
win.submit();
}
The aspx page attempts to read the post data as following:
protected void Page_Load(object sender, EventArgs e)
{
object PostGuids = HttpContext.Current.Request.Form["guidcollection"];
// Do something with PostGuids
}
Somehow it fails, and when i debug the aspx page I see that HttpContext is not defined. Using fiddler I can determine that the sessionId is not set. I see the message 'This request did not send any cookie data.' in the Cookies tab.
What can i do to receive the post data? One of the requirements for the website is that cookie data on the client is not allowed. Is it possible to receive Post data without a sessionId? or should i look for alternatives like ViewState? Using a query string won't work because the length of the data will exceed the 2048 character limit of a querystring.
I have managed to get this working with the following changes:
function(webadress, guidarray) {
var params = 'menubar=no,status=no,toolbar=no,resizable=no, scrollbars=no';
var win = document.createElement("form");
win.target = 'Map';
win.method = 'POST';
win.action = webadress;
var winInput = document.createElement('input');
winInput.type = 'text';
winInput.name = 'guidcollection';
winInput.value = guidarray;
win.appendChild(winInput);
document.body.appendChild(win);
window.open(webadress, 'Map', params);
win.submit();
}
and server side:
protected void Page_Load(object sender, EventArgs e)
{
if (this.Request.Form.HasKeys())
{
object PostGuids = this.Request.Form["guidcollection"];
// Do something with PostGuids
}
}
I still have no idea why the HttpContext remains undefined, but this way i can access the guid data correctly. If some one can explain that to me, i'll be glad to accept that as the answer.
I am attempting to pass a PDF I have generated on frontend javascript using jsPDF to a Spring Framework MVC backend. Below is the front end code I have written:
var filename = "thefile";
var constructURL = '/daas-rest-services/dashboard/pdfPrintUpload/' + filename;
var url = restService.getUrl(constructURL);
var fileBytes = btoa(pdf.output());
$http.post(url, fileBytes).success(function(data) {
console.log(data);
})
.error(function(e, a) {
console.log(e);
console.log(a);
});
The pdf variable has been generated properly and can confirm is opens correctly when calling pdf.save("filename"). Below is the Java code which has been written on the Spring MVC backend for this call:
#RequestMapping(method = RequestMethod.POST, value = "/pdfPrintUpload/{documentName}")
public #ResponseBody String postPrintDocument(#PathVariable String documentName, #RequestParam byte[] fileBytes) {
String methodName = "postPrintDocument";
if(logger.isLoggable(Level.FINER)){
logger.entering(CLASS_NAME, methodName);
}
String check;
if(fileBytes != null){
check = "not null";
} else {
check = "null ";
}
//Decoding the bytestream
//Save to file location
//return file location
String returnValue = "HI " + documentName + " " + check;
if (logger.isLoggable(Level.FINER)) {
logger.exiting(CLASS_NAME, methodName);
}
return returnValue;
}
Each time I make a request, I am getting 400 Errors telling me:
Error 400: Required byte[] parameter 'fileBytes' is not present
I can confirm in the request payload that a large amount of data is being transmitted, however the backend does not seem to want to accept the parameter.
The purpose of doing this is that I want to be able to get the data from the pdf and then decode it on the backend so I can later publish the pdf to a location on the server. Is there something I am missing in my code for these requests to keep failing, and is there an easier more efficient way to achieve this functionality?
The solution was changing the #RequestParam to #RequestBody. #RequestParam is a parameter which is sent in the path.
#RequestParam vs #PathVariable
Try using ng-file-upload. The link and the examples are available on the link
ng-file-upload
for the sever side code try using this
#RequestMapping(value = "/pdfPrintUpload")
#ResponseBody
public void postPrintDocument(#RequestParam("file") MultipartFile file) {
InputStream is = file.getInputStream();
OutputStream os = new FileOutputStream(/*path to save file*/);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer)) > 0)
os.write(buffer, 0, length);
is.close();
os.close();
} catch (Exception e) {
e.printStackTrace();
}
}
So I have an interesting question. I have a form where a user draws an image on a canvas (think a signature pad). I then need to send the image to my C# Controller (I am using ASP.NET MVC 5). The code I have functions for shorter strings, but when I try to pass the PNG data, it is too long and I recieve a HTTP Error 414. The request URL is too long error. Here is my code:
Html:
<form id="mainForm" action="submitUserAnswer" method="post">
<input type="hidden" id="userOutput" name="output" value="" />
//...other form elements, signature box, etc.
</form>
Javascript:
function goToNextQuestion() {
var output = $('#signature').jSignature("getData");
$('#userOutput').val(output);
$('#mainForm').submit();
}
C#:
public ActionResult submitUserAnswer()
{
//use the userOutput for whatever
//submit string to the database, do trigger stuff, whatever
//go to next question
System.Collections.Specialized.NameValueCollection nvc = Request.Form;
string userOutput = nvc["output"];
ViewBag.Question = userOutput;
return RedirectToAction("redirectToIndex", new { input = userOutput });
}
public ActionResult redirectToIndex(String input)
{
ViewBag.Answer = input;
return View("Index");
}
My png data is very long, so the error makes sense. My question is how can I get the png data back to my controller?
Maybe you just need to increase allowed GET request URL length.
If that doesn't works I have an aspx WebForm that saves a signature, and I use a WebMethod
[ScriptMethod, WebMethod]
public static string saveSignature(string data)
{
/*..Code..*/
}
and I call it like this:
PageMethods.saveSignature(document.getElementById('canvas').toDataURL(), onSucess, onError);
also I have to increase the length of the JSON request and it works fine, with no problems with the lenght.
In MVC there isn't WebMethods, but JSON and AJAX requests do the job, just save the data in a session variable, and then use it when need it.
Hope it helps
You have error because your data is string (base64) and have max limit for send characters, better way is to create blob (png file) from base64 at client side, and send it to server. Edit. All listed code here, exists in stackoverflow posts.
function dataURItoBlob(dataURI) {
// convert base64 to raw binary data held in a string
// doesn't handle URLEncoded DataURIs - see SO answer #6850276 for code that does this
var byteString = atob(dataURI.split(',')[1]);
// separate out the mime component
var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0]
// write the bytes of the string to an ArrayBuffer
var ab = new ArrayBuffer(byteString.length);
var ia = new Uint8Array(ab);
for (var i = 0; i < byteString.length; i++) {
ia[i] = byteString.charCodeAt(i);
}
var blob = null;
// TypeError old chrome and FF
window.BlobBuilder = window.BlobBuilder ||
window.WebKitBlobBuilder ||
window.MozBlobBuilder ||
window.MSBlobBuilder;
if(window.BlobBuilder){
var bb = new BlobBuilder();
bb.append(ab);
blob = bb.getBlob(mimeString);
}else{
blob = new Blob([ab], {type : mimeString});
}
return blob;
}
function sendFileToServer(file, url, onFileSendComplete){
var formData = new FormData()
formData.append("file",file);
var xhr = new XMLHttpRequest();
xhr.open('POST', url, true);
xhr.onload = onFileSendComplete;
xhr.send(formData);
}
var base64 = $('#signature').jSignature("getData");
var blob = dataURItoBlob(base64);
var onComplete = function(){alert("file loaded to server");}
sendFileToServer(blob, "/server", onComplete)
I am trying send a file to a servlet.
function sendToServlet(){
var file = Components.classes["#mozilla.org/file/local;1"].
createInstance(Components.interfaces.nsILocalFile);
file.initWithPath("C:\\Documents and Settings\\me\\Meus documentos\\Downloads\\music.mp3");
var boundary = "--------------" + (new Date).getTime();
var stream = Components.classes["#mozilla.org/network/file-input-stream;1"]
.createInstance(Components.interfaces.nsIFileInputStream);
stream.init(file, 0x04 | 0x08, 0644, 0x04); // file is an nsIFile instance
// Send
var req = Components.classes["#mozilla.org/xmlextras/xmlhttprequest;1"]
.createInstance(Components.interfaces.nsIXMLHttpRequest);
req.open('POST', 'http://localhost:8080/app/server' , false);
var contentType = "multipart/form-data; boundary=" + boundary;
req.setRequestHeader("Content-Type", contentType);
req.send(stream);
}
The source of javascript:
https://developer.mozilla.org/En/XMLHttpRequest/Using_XMLHttpRequest#Sending_binary_data
But does not work.
Hi, this the serlevt code used:
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
int size = 1024*20000;
long sizeFile = 0;
File savedFile = null;
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
if (!isMultipart) {
} else {
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setFileSizeMax(new Long("-1"));
List items = null;
try {
items = upload.parseRequest(request);
} catch (FileUploadException e) {
e.printStackTrace();
}
Iterator itr = items.iterator();
while (itr.hasNext()) {
FileItem item = (FileItem) itr.next();
try {
if (item.isFormField()) {
;
}else{
String itemName = item.getName();
int sizeName = itemName.length();
int end = itemName.indexOf('\n');
int start = itemName.lastIndexOf('\\');
itemName = itemName.substring(start + 1, sizeName-end-1);
savedFile = new File("C:\\Documents and Settings\\eric.silva\\Meus documentos\\"+itemName);
item.write(savedFile);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}//metodo
But when i try to send a file the servlet dont create the file sent.
Quando eu tento enviar via javascript a requisição é enviada. Mas o arquivo não é criado no lado do servidor. Acredito que o código apresentado no site da MDN esteja incompleto.
When I try to send via javascript the request is sent. But the file is not created on the server side. I believe the code shown on the site of the MDN is incomplete.
Note how the example code you are using is sending data with method PUT - valid multipart-formdata request needs to have some additional headers, not only the file itself. For example, the file you are sending should have a name (normally the name of the form field). You should use a FormData object instead, it will generate a valid request automatically. You should be able to create a File object directly. Something along these lines:
var file = File("C:\\Documents and Settings\\me\\Meus documentos\\Downloads\\music.mp3");
var data = new FormData();
data.append("file", file);
var req = Components.classes["#mozilla.org/xmlextras/xmlhttprequest;1"]
.createInstance(Components.interfaces.nsIXMLHttpRequest);
req.open('POST', 'http://localhost:8080/app/server', false);
request.send(data);
Note that creating File objects like this is only supported starting with Firefox 6.
The problem lies more likely in how you're trying to obtain the uploaded file with the servlet. Being a low level impelementation, the servlet doesn't have much of an abstraction for handling uploaded files (multi part requests). Luckily there are libraries who take care of that for you like commons.FileUpload:
http://commons.apache.org/fileupload/using.html
Just set up a servlet with fileUpload like it sais in the doc, then make a simple html page with a form that has a file upload input, and use that as a basic functional test to see that it works, then return to making your own client.