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How to force/Manually add authenticaion to POST WebRequest

I need to provide authentication for a POST request. I have never done this before so I have been searching for methods to accomplish this.
I have found this method but it did not work. The message I received was 401 Unauthorized.
Dim myCred As New NetworkCredential("USERNAME", "PASSWORD")
        Dim credsCache As New CredentialCache()
        credsCache.Add(New Uri(Uri), "Basic", myCred)
        Dim request As WebRequest = WebRequest.Create(Uri)
        request.Credentials = credsCache

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I found other posts indicating that sometimes the authentication has to be forced. I have been trying to get this code to work but I do not know how to declare the AUTHORIZATION
Dim request As WebRequest
Dim credidentials As String = "userName" + ":" + "Password"
Authorization = Convert.ToBase64String(Encoding.[Default].GetBytes(credidentials))  'How do I declare Authorization?
request.Headers("Authorization") = "Basic " + Authorization

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How do I declare authorization or how do I "force" authorization?

Avatar of ste5an
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What kind of  authentication do you need? What does the spec says?
Avatar of mpdillon


I was not given a type of authorization. But that is a really good question. I have never done this before and I did not know there were different types. I just checked and it is not listed in the spec.

I have requested that the authorization type be identified. I should hear back this morning.
It is basic authentication.
Seems you're pretty close..

This should work:

Imports System.Net
Imports System.Text

Module Module1

    Sub Main()

        Dim username As String = "username"
        Dim password As String = "passwort"
        Dim url As String = "http://your.url"
        Dim credentials As String = Convert.ToBase64String(Encoding.ASCII.GetBytes(username + ":" + password))

        Dim webClient As WebClient = New WebClient()

        webClient.Headers(HttpRequestHeader.Authorization) = "Basic " + credentials
        webClient.UploadString(url, "your string")


    End Sub

End Module

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On site elsewhere now. Will try later today and let you know. Thanks. It looks correct to me.
Ok. Thank you.  I ran into an error. Please see the attached image.

Also when I read the code earlier today, I didn't notice that there does not seem to be a RESPONSE component. In my scenario, my code is to POST string to a web sever and listen for the RESPONSE. At the moment I do not know how to tell if the POST was successful. How would I add that to the code?
This means, that you're running out of memory on your machine. See Troubleshooting the error "Not enough storage is available to complete this operation".

So I would reboot the machine and see whether that error is reproducible. If so, what does x in you sample contain? I would start testing the upload procedure with a simple and short string. Cause I think the error may depend on the way you're handling the XML (those reader lines in your image).
The length of x is 6784 characters. Task manager indicates that 2.5 GB on 5.8 GB of memory are being used. I will reboot and try again.

Unfortunately, I do not have the option of testing with a short string. The Company receiving the data is a large multinational and they are a bit inflexible.

The string I am sending is a XML notification of shipment. The bulk of its length is due the signature image which I converted to Base 64.
Image? This may be already the problem. An image is often uncompressed in memory.. Especially when you do some Bitmap fiddling.
I apologize for the delay. There was a windows update that got hung on this workstation.

After the reboot, the same error occurred.

The code to convert the image to base 64 seems straight forward to me. I have attached the string, x, that is being posted. To that string I have added a few carriage returns to isolate the signature text. I have also tried to find all references that might identify the companies involved. I have changed every reference I could identify.

In addition to the error there is something I do not understand. What is Console.ReadLine doing? Is it reading a response somehow? If so I need to read that response into a string variable and compare it to the possible response from the server. I haven't been given those responses yet but I am sure I will receive them at some point.

Thank you very much for our continued interest. I would not be making any progress without your assistance.
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OK. Thanks for the explanation. I did the exact same thing when I started this program. I first built it as a console app. I tested the console app there first to ensure I had the ServiceContract, DataContract and DataMembers correct. I had never done this before. I built a Client console app for testing. Testing yielded the results I expected. I did not realize I could use a console command in a non console app.
Anyway I tried several different methods to Build a response for the WebClient in the code you shared but was not successful. I would like the response to read directly into a string variable. How would I do that?
Thank you for all your assistance. I have finally arrived at a solution. Below is my final code for POST with BASIC Authentication

Private Sub PostXMLfile(ByVal x As String, ByRef WebString As String)
        Dim username As String = "username"
        Dim password As String = "password"
        Dim request As HttpWebRequest
        Dim response As HttpWebResponse = Nothing
        Dim reader As StreamReader
        Dim xmlDocAsStr As String = x
        Dim byteArray(xmlDocAsStr.Length - 1) As Byte
        Dim objUTF8Encoding As New UTF8Encoding
        Dim Uri As String = ""
        Dim postStream As Stream = Nothing
        'Some code from:
            ' Create the web request 
            request = DirectCast(WebRequest.Create(Uri), HttpWebRequest)
            byteArray = objUTF8Encoding.GetBytes(xmlDocAsStr)
            request.Method = "POST"
            request.ContentLength = byteArray.Length
            request.ContentType = "text/xml"
            ' Add authentication to request  
            request.Credentials = New NetworkCredential(username, password)
                postStream = request.GetRequestStream()
                postStream.Write(byteArray, 0, byteArray.Length)
                If Not postStream Is Nothing Then postStream.Close()
            End Try
            '' Get response  
            response = DirectCast(request.GetResponse(), HttpWebResponse)
            reader = New System.IO.StreamReader(response.GetResponseStream(), Encoding.ASCII)
            WebString = reader.ReadToEnd()
            If Not response Is Nothing Then response.Close()
        End Try

    End Sub

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Thanks again.
Thanks for staying with me. I know it took a long time to resolve.