HTTP error 403 if POST is not used - c#

I am trying to send protobuf data via REST from c# winform application. When I use the HTTP request with POST method( as shown in code below) it works perfect and returns "OK" status.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://xxxxx.execute-api.eu-west-1.amazonaws.com/test/input");
request.Headers["Authorization"] = "xxxyyyzzz"
request.Method = "POST";
request.ContentType = "application/octet-stream";
byte[] bytes = System.IO.File.ReadAllBytes("C:\\MyProtobuf.proto");
request.ContentLength = bytes.Length;
Stream requestStream = request.GetRequestStream();
requestStream.Write(bytes, 0, bytes.Length);
HttpWebResponse myHttpWebResponse = (HttpWebResponse)request.GetResponse();
MessageBox.Show(myHttpWebResponse .StatusCode.ToString());
myHttpWebResponse .Close();
But if I simply want to check if website is alive or not using below code it gives me 403. Forbidden error.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://xxxxx.execute-api.eu-west-1.amazonaws.com/test/input");
request.Headers["Authorization"] = "xxxyyyzzz";
HttpWebResponse myHttpWebResponse = (HttpWebResponse)request.GetResponse();
MessageBox.Show(myHttpWebResponse .StatusCode.ToString());
myHttpWebResponse .Close();
what could be the possible reason for this error ?

your services serves POST method verb so you must call this service with post method, otherwise you should change your service methods to support get method.

Related

Call Http Post method in c# passing the Method name

I have a problem in "translating" this HTML page into c # code.
I have to pass an xml file to a production machine and I would like to do it from a c # application instead of manually, as shown in the attached screenshot.
I wrote this code c #:
WebRequest request = WebRequest.Create(#"http://Machine_IP/JTI/");
byte[] bytes;
bytes = System.Text.Encoding.ASCII.GetBytes(d.InnerXml);
request.ContentType = "text/xml; encoding='utf-8'";
request.ContentLength = bytes.Length;
request.Method = "POST";
Stream requestStream = request.GetRequestStream();
requestStream.Write(bytes, 0, bytes.Length);
requestStream.Close();
HttpWebResponse response;
response = (HttpWebResponse)request.GetResponse();
if (response.StatusCode == HttpStatusCode.OK)
{
Stream responseStream = response.GetResponseStream();
string responseStr = new StreamReader(responseStream).ReadToEnd();
}
I can't figure out how to pass name = "ImportJobs".
If I make a "generic" POST, the machine does not receive the xml file.
I should do a POST as an ImportJobs method.
The supplier, as specifications, gives me the following:
Request
HTTP method: POST
Encryption type (Enctype): Multipart/form-data
URL: http://MachineName/JTI
Command: ImportJobs
Parameters: None
Multipart data section:The XML job description
Response
Data none
Can anyone help me?
thanks a lot
HTML Example

HttpWebRequest returns (400) Bad Request

The request gives the following error:
The remote server returned an error: (400) Bad Request.
I cann't find a solution on internet. Does anyone knows how to solve this?
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(#"https://maps.googleapis.com/maps/api/geocode/json");
request.ContentType = "application/x-www-form-urlencoded";
request.Method = "POST";
var parameters = string.Format("language={0}&latlng={1}&client={2}&signature={3}", "nl", "51.123456,5.612345", "gme-aa", "******_******=");
byte[] byteArray = Encoding.UTF8.GetBytes(parameters);
request.ContentLength = byteArray.Length;
Stream dataStream = request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();
/*
* Read HttpWeb Response
*/
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
dataStream = response.GetResponseStream();
StreamReader reader = new StreamReader(dataStream);
string Response = reader.ReadToEnd();
response.Close();
EDIT:
I'm working inside Lowcode platform Outsystems. Outsystems creates the url inside WebRequest.Create() without the paramaters. So, I have access to webRequest object and need to pass the parameters.
You have to use HTTP "GET" Method.
In a GET request, you pass parameters as part of the query string.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create($"https://maps.googleapis.com/maps/api/geocode/json?language=fr&latlng=51.123456,5.612345&key={apiKey}");
request.ContentType = "application/x-www-form-urlencoded";
request.Method = "GET";
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
string result = new StreamReader(response.GetResponseStream()).ReadToEnd();
}
According the documentation, the API is expecting a POST method and receiving the parameters in the URL and not the body.
If you are using the OutSystems platform you can use the Consume REST API functionality to easily call the web service without using code. Configure your API like this (you can copy the example JSON from the documentation page above):

403 error response when submitting a post request to Instagram

I'm trying to "programmatically" login to Instagram with a HTTP post request. Although, whenever I try to do it to this URL: https://instagram.com/accounts/login/ - it gives me a 404 error. However, if I remove the slash from the end, e.g. /accounts/login, then it will work, however, the response body just seems to be a simple GET request as they simply just output the same as if it was a GET request. I'm actually expecting an error message as response.
The code is written in C# and is nothing fancy; basically a http web request and then I write the post data in the TCP stream. The website is using a CSRF token which needs to be included in the post request, so I first grab this key by using a simple GET request, and then continuing with the POST.
Is there any technical aspect that I'm missing? I've tried the code and done the same on several other websites and all attempts were successful.
The code looks much like this (same problem):
WebResponse Response;
HttpWebRequest Request;
Uri url = new Uri("https://instagram.com/accounts/login/");
CookieContainer cookieContainer = new CookieContainer();
Request = (HttpWebRequest)WebRequest.Create(url);
Request.Method = "GET";
Request.CookieContainer = cookieContainer;
// Get the first response to obtain the cookie where you will find the "csrfmiddlewaretoken" value
Response = Request.GetResponse();
string Parametros = "csrfmiddlewaretoken=" + cookieContainer.GetCookies(url)["csrftoken"].Value + "&username=USER&password=PASSWORD&next="; // This whill set the correct url to access
Request = (HttpWebRequest)WebRequest.Create(url); // it is important to use the same url used for the first request
Request.Method = "POST";
Request.ContentType = "application/x-www-form-urlencoded";
Request.UserAgent = "Other";
// Place the cookie container to obtain the new cookies for further access
Request.CookieContainer = cookieContainer;
Request.Headers.Add("Cookie",Response.Headers.Get("Set-Cookie")); // This is the most important step, you have to place the cookies at the header (without this line you will get the 403 Forbidden exception
byte[] byteArray = Encoding.UTF8.GetBytes(Parametros);
Request.ContentLength = byteArray.Length;
Stream dataStream = Request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();
Response = Request.GetResponse(); // Fails here
Thanks in advance!

google api oauth access token retrieval - 400 bad request

I'm trying to retrieve the oauth access token to make calls to some google apis in asp.net mvc, and I wrote the following code for an action:
public ActionResult GetOAuthToken()
{
String url = "https://accounts.google.com/o/oauth2/token";
// Create a request using a URL that can receive a post.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
// Set the Method property of the request to POST.
request.Method = "POST";
request.Host = "accounts.google.com";
// Create POST data and convert it to a byte array.
string postData = String.Format("code={0}&client_id={1}&client_secret={2}&redirect_uri={3}&grant_type=authorization_code", Request.QueryString["code"].ToString(), OAuthConfig.client_id, OAuthConfig.client_secret, OAuthConfig.token_redirect_uri);
ASCIIEncoding encoding = new ASCIIEncoding();
byte[] byteArray = encoding.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();
// SOME CODE TO PROCESS THE RESPONSE
Response.Redirect("/Home");
return View();
}
OAuthConfig is just a class that contains the client id, client secret etc.
I keep getting 'The remote server returned an error: (400) Bad Request.' at the request.GetResponse() line. Where am I going wrong?
Google does provide a higher level library to work with its services, this handles the formatting of the urls and I find it makes it a lot easier to work with their apis. See http://code.google.com/p/google-api-dotnet-client/

ASP HttpWebRequest and Redirect

OK, I have a client doing a POST to a server with some data. The server receives the post, and answers with a redirect. The problem is that the client does not redirects. Also, I've tried to check the StatusCode of the response the client gets, and it is always the same "OK". Instead of the redirect code. What am I missing?
In the client side I have something like this:
StringBuilder sb;
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://localhost/serv/Default.aspx");
request.Method = "POST";
byte[] data = Encoding.ASCII.GetBytes(GetDATA());
request.ContentType = "text/xml";
request.ContentLength = data.Length;
Stream stream = request.GetRequestStream();
stream.Write(data, 0, data.Length);
request.AllowAutoRedirect = true;
request.MaximumAutomaticRedirections = 10;
HttpWebResponse response = (HttpWebResponse) request.GetResponse();
response.Close(); } catch(Exception ex) {}
In the server side I have just this line:
HttpContext.Current.Response.Redirect("http://www.google.com", true);
In this case, the client receives an answer and does not do nothing.
Thanks.
When you have "AllowAutoRedirect" set to true, it means that your HttpWebRequest object will make a 2nd webrequest once it sees a redirect. When you see the "200 OK" from the response object, it is because you are seeing the response for "www.google.com". You can check the Response.ResponseURI to verify this.
You'll need to turn off the "AllowAutoRedirect", then check the response code like Oded said.

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