(VB.NET) Xero OAuth1 Authorization (3-legged)

Demonstrates 3-legged OAuth1 authorization for Xero

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

Dim consumerKey As String = "XERO_CONSUMER_KEY"
Dim consumerSecret As String = "XERO_CONSUMER_SECRET"

Dim requestTokenUrl As String = "https://api.xero.com/oauth/RequestToken"
Dim authorizeUrl As String = "https://api.xero.com/oauth/Authorize"
Dim accessTokenUrl As String = "https://api.xero.com/oauth/AccessToken"

' The port number is picked at random. It's some unused port that won't likely conflict with anything else..
Dim callbackUrl As String = "http://localhost:3017/"
Dim callbackLocalPort As Integer = 3017

' The 1st step in 3-legged OAuth1.0a is to send a POST to the request token URL to obtain an OAuth Request Token
Dim http As New Chilkat.Http
Dim success As Boolean

http.OAuth1 = True
http.OAuthConsumerKey = consumerKey
http.OAuthConsumerSecret = consumerSecret
http.OAuthCallback = callbackUrl

Dim req As New Chilkat.HttpRequest
Dim resp As Chilkat.HttpResponse = http.PostUrlEncoded(requestTokenUrl,req)
If (http.LastMethodSuccess <> True) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


' If successful, the resp.BodyStr contains something like this:  
' oauth_token=-Wa_KwAAAAAAxfEPAAABV8Qar4Q&oauth_token_secret=OfHY4tZBX2HK4f7yIw76WYdvnl99MVGB&oauth_callback_confirmed=true
Debug.WriteLine(resp.BodyStr)

Dim hashTab As New Chilkat.Hashtable
hashTab.AddQueryParams(resp.BodyStr)

Dim requestToken As String = hashTab.LookupStr("oauth_token")
Dim requestTokenSecret As String = hashTab.LookupStr("oauth_token_secret")
http.OAuthTokenSecret = requestTokenSecret



Debug.WriteLine("oauth_token = " & requestToken)
Debug.WriteLine("oauth_token_secret = " & requestTokenSecret)


' ---------------------------------------------------------------------------
' The next step is to form a URL to send to the authorizeUrl
' This is an HTTP GET that we load into a popup browser.
Dim sbUrlForBrowser As New Chilkat.StringBuilder
sbUrlForBrowser.Append(authorizeUrl)
sbUrlForBrowser.Append("?oauth_token=")
sbUrlForBrowser.Append(requestToken)
Dim urlForBrowser As String = sbUrlForBrowser.GetAsString()

' When the urlForBrowser is loaded into a browser, the response from Xero will redirect back to localhost:3017
' We'll need to start a socket that is listening on port 3017 for the callback from the browser.
Dim listenSock As New Chilkat.Socket

Dim backLog As Integer = 5
success = listenSock.BindAndListen(callbackLocalPort,backLog)
If (success <> True) Then
    Debug.WriteLine(listenSock.LastErrorText)
    Exit Sub
End If


' Wait for the browser's connection in a background thread.
' (We'll send load the URL into the browser following this..)
' Wait a max of 60 seconds before giving up.
Dim maxWaitMs As Integer = 60000
Dim task As Chilkat.Task = listenSock.AcceptNextConnectionAsync(maxWaitMs)
task.Run()

'  At this point, your application should load the URL in a browser.
'  For example,
'  in C#:  System.Diagnostics.Process.Start(urlForBrowser);
'  in Java: Desktop.getDesktop().browse(new URI(urlForBrowser));
'  in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
'               wsh.Run urlForBrowser
' in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
' in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
'  The Xero account owner would interactively accept or deny the authorization request.

'  Add the code to load the url in a web browser here...
'  Add the code to load the url in a web browser here...
'  Add the code to load the url in a web browser here...
' System.Diagnostics.Process.Start(urlForBrowser);

' Wait for the listenSock's task to complete.
success = task.Wait(maxWaitMs)
If (Not success Or (task.StatusInt <> 7) Or (task.TaskSuccess <> True)) Then
    If (Not success) Then
        ' The task.LastErrorText applies to the Wait method call.
        Debug.WriteLine(task.LastErrorText)
    Else
        ' The ResultErrorText applies to the underlying task method call (i.e. the AcceptNextConnection)
        Debug.WriteLine(task.Status)
        Debug.WriteLine(task.ResultErrorText)
    End If


    Exit Sub
End If


' If we get to this point, the connection from the browser arrived and was accepted.

' We no longer need the listen socket...
' Stop listening on port 3017.
listenSock.Close(10)

' First get the connected socket.
Dim sock As New Chilkat.Socket
sock.LoadTaskResult(task)


' Read the start line of the request..
Dim startLine As String = sock.ReceiveUntilMatch(vbCrLf)
If (sock.LastMethodSuccess <> True) Then
    Debug.WriteLine(sock.LastErrorText)
    Exit Sub
End If


' Read the request header.
Dim requestHeader As String = sock.ReceiveUntilMatch(vbCrLf & vbCrLf)
If (sock.LastMethodSuccess <> True) Then
    Debug.WriteLine(sock.LastErrorText)
    Exit Sub
End If


' The browser SHOULD be sending us a GET request, and therefore there is no body to the request.
' Once the request header is received, we have all of it.
' We can now send our HTTP response.
Dim sbResponseHtml As New Chilkat.StringBuilder
sbResponseHtml.Append("<html><body><p>Chilkat thanks you!</b></body</html>")

Dim sbResponse As New Chilkat.StringBuilder
sbResponse.Append("HTTP/1.1 200 OK" & vbCrLf)
sbResponse.Append("Content-Length: ")
sbResponse.AppendInt(sbResponseHtml.Length)
sbResponse.Append(vbCrLf)
sbResponse.Append("Content-Type: text/html" & vbCrLf)
sbResponse.Append(vbCrLf)
sbResponse.AppendSb(sbResponseHtml)

sock.SendString(sbResponse.GetAsString())
sock.Close(50)

' The information we need is in the startLine.
' For example, the startLine will look something like this:
'  GET /?oauth_token=abcdRQAAZZAAxfBBAAABVabcd_k&oauth_verifier=9rdOq5abcdCe6cn8M3jabcdj3Eabcd&org=mUkIZabcdKEababcd189t0 HTTP/1.1
Dim sbStartLine As New Chilkat.StringBuilder
sbStartLine.Append(startLine)
Dim numReplacements As Integer = sbStartLine.Replace("GET /?","")
numReplacements = sbStartLine.Replace(" HTTP/1.1","")
sbStartLine.Trim()

' oauth_token=abcdRQAAZZAAxfBBAAABVabcd_k&oauth_verifier=9rdOq5abcdCe6cn8M3jabcdj3Eabcd&org=mUkIZabcdKEababcd189t0
Debug.WriteLine("startline: " & sbStartLine.GetAsString())

hashTab.Clear()
hashTab.AddQueryParams(sbStartLine.GetAsString())

requestToken = hashTab.LookupStr("oauth_token")
Dim authVerifier As String = hashTab.LookupStr("oauth_verifier")

' ------------------------------------------------------------------------------
' Finally , we must exchange the OAuth Request Token for an OAuth Access Token.

http.OAuthToken = requestToken
http.OAuthVerifier = authVerifier
resp = http.PostUrlEncoded(accessTokenUrl,req)
If (http.LastMethodSuccess <> True) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


' Make sure a successful response was received.
If (resp.StatusCode <> 200) Then
    Debug.WriteLine(resp.StatusLine)
    Debug.WriteLine(resp.Header)
    Debug.WriteLine(resp.BodyStr)
    Exit Sub
End If


' If successful, the resp.BodyStr contains something like this:
' oauth_token=85123455-fF41296Bi3daM8eCo9Y5vZabcdxXpRv864plYPOjr&oauth_token_secret=afiYJOgabcdSfGae7BDvJVVTwys8fUGpra5guZxbmFBZo&oauth_expires_in=1800&xero_org_muid=abcdecNhPKabcdNjz189t0
Debug.WriteLine(resp.BodyStr)

hashTab.Clear()
hashTab.AddQueryParams(resp.BodyStr)

Dim accessToken As String = hashTab.LookupStr("oauth_token")
Dim accessTokenSecret As String = hashTab.LookupStr("oauth_token_secret")
Dim orgMuid As String = hashTab.LookupStr("xero_org_muid")
Dim expiresIn As String = hashTab.LookupStr("oauth_expires_in")



' The access token + secret is what should be saved and used for
' subsequent REST API calls.
Debug.WriteLine("Access Token = " & accessToken)
Debug.WriteLine("Access Token Secret = " & accessTokenSecret)
Debug.WriteLine("xero_org_muid = " & orgMuid)
Debug.WriteLine("oauth_expires_in  = " & expiresIn)

' Save this access token for future calls.
' Just in case we need xero_org_muid and oauth_expires_in, save those also..
Dim json As New Chilkat.JsonObject
json.AppendString("oauth_token",accessToken)
json.AppendString("oauth_token_secret",accessTokenSecret)
json.AppendString("xero_org_muid",orgMuid)
json.AppendString("oauth_expires_in",expiresIn)

Dim fac As New Chilkat.FileAccess
fac.WriteEntireTextFile("qa_data/tokens/xero.json",json.Emit(),"utf-8",False)

Debug.WriteLine("Success.")