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I'm a totally beginner with webrequest, so I have no idea about what cause the error I get.

I try to login on a form following the microsoft tutorial for webrequest, but when I want to get the server response, I have the following error :

"the remote server returned an error (404) not found"

So I know that the URL I use actually exist and then wonder which part of the code is bad. Maybe it's because I'm doing an HTTPS request unlike the tutorial and it changes something ? Also, I'm a little confused by getting directly the answer from the server : shouldn't there be kind of a trigger to know when the server answered ?

Dim request = WebRequest.Create("https://ssl.vocabell.com/mytica2/login")
request.Credentials = CredentialCache.DefaultCredentials
request.Method = "POST"
Dim byteArray = Encoding.UTF8.GetBytes("_username=x&_password=x")
request.ContentType = "application/x-www-form-urlencoded"
request.ContentLength = byteArray.Length
Dim dataStream = request.GetRequestStream()
dataStream.Write(byteArray, 0, byteArray.Length)
dataStream.Close()
Dim reponse = request.GetResponse() 'ERROR
MsgBox(CType(reponse, HttpWebResponse).StatusDescription)
Using ds = reponse.GetResponseStream
     Dim reader = New StreamReader(ds)
     MsgBox(reader.ReadToEnd)
End Using
reponse.Close()

Thank you for your time, and if you have any relevant tutorial on the topic I would be glad to read it !

ADyson
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Gary F
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  • May not work but try changing `request.Method = "POST"` to `request.Method = "GET"` , worth a try – K.Madden Jul 01 '19 at 10:45
  • "shouldn't there be kind of a trigger to know when the server answered ?" ...this code is synchronous, so basically your VB code waits until it gets a response before it continues. If you were doing an asynchronous request then that would be a valid consideration. – ADyson Jul 01 '19 at 10:45
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    @K.Madden you've no more idea than I have what the remote site expects, but from experience I doubt it accepts a username and password as GET / querystring parameters - that's usually considered a big security no-no. The request above is clearly trying to simulate a form postback, so I'd be very surprised if changing to GET was helpful. Also normally if the site is configured correctly then using the wrong HTTP method should result in a 405 (Method Not Allowed) response rather than a 404 (Not Found). – ADyson Jul 01 '19 at 10:47
  • @ADyson Ah okay thanks for explaining, i just recalled from when I dd asp from a while ago as a fairly new beginner i saw somewhere online and it helped me. Being the beginner I was didn't look into security and all! Thanks – K.Madden Jul 01 '19 at 10:50
  • Thanks for your answer ! @ADyson yes, I thought that the error came from the code so I didn't think it was useful to give the real url that I try to interact with, here it is : https://ssl.vocabell.com/mytica2/login – Gary F Jul 01 '19 at 10:52

1 Answers1

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The page you've mentioned does exist and uses HTTPS, but if you look at the form tag within it, it's like this: 

<form class="login-form form-horizontal" action="/mytica2/login_check" method="POST">

This means it doesn't post the form back to the same URL as the page, instead it sends it to the URL contained within that "action" attribute. If you're trying to use your code to simulate the submission of the login form then it looks like you need to send your POST request to https://ssl.vocabell.com/mytica2/login_check instead.

ADyson
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