(VB.NET) SharePoint Rest API using OAuth

Demonstrates how to get an OAuth2 access token as described at How to access SharePoint Rest API using OAuth

Note: This example requires Chilkat v9.5.0.78 or greater.

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' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim oauth2 As New Chilkat.OAuth2
Dim success As Boolean

' The ListenPort should match the port in your localhost Reply URL of your Azure AD app.
' Your Reply URL must be exactly "http://localhost:LISTEN_PORT/"
'    * Do not use "https"
'    * Make sure the ending "/" is included.
'    * You may choose any port number that doesn't collide with anything else.
oauth2.ListenPort = 3017

oauth2.AuthorizationEndpoint = "https://login.microsoftonline.com/TENANT_ID/oauth2/authorize"
oauth2.TokenEndpoint = "https://login.windows.net/TENANT_ID/oauth2/token?api-version=1.0"

' Replace these with actual values.
' Use the application ID
oauth2.ClientId = "CLIENT_ID"
' Use the password
oauth2.ClientSecret = "CLIENT_SECRET"

oauth2.CodeChallenge = False

' This example performs what is described here:  How to access SharePoint Rest API using OAuth
oauth2.Scope = "openid"
oauth2.Resource = "https://graph.microsoft.com/"

' The following three properties were added in Chilkat v9.5.0.78
oauth2.IncludeNonce = True
oauth2.ResponseMode = "form_post"
oauth2.ResponseType = "id_token+code"

' Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
Dim url As String = oauth2.StartAuth()
If (oauth2.LastMethodSuccess <> True) Then
    Debug.WriteLine(oauth2.LastErrorText)
    Exit Sub
End If


' At this point, your application should load the URL in a browser.
' For example, 
' in C#: System.Diagnostics.Process.Start(url);
' in Java: Desktop.getDesktop().browse(new URI(url));
' in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
'              wsh.Run url
' 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 LinkedIn 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...

' Now wait for the authorization.
' We'll wait for a max of 30 seconds.
Dim numMsWaited As Integer = 0
While (numMsWaited < 30000) And (oauth2.AuthFlowState < 3)
    oauth2.SleepMs(100)
    numMsWaited = numMsWaited + 100
End While

' If there was no response from the browser within 30 seconds, then 
' the AuthFlowState will be equal to 1 or 2.
' 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
' 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
' In that case, cancel the background task started in the call to StartAuth.
If (oauth2.AuthFlowState < 3) Then
    oauth2.Cancel()
    Debug.WriteLine("No response from the browser!")
    Exit Sub
End If



' Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
' The possible AuthFlowState values are:
' 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
' 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
' 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
If (oauth2.AuthFlowState = 5) Then
    Debug.WriteLine("OAuth2 failed to complete.")
    Debug.WriteLine(oauth2.FailureInfo)
    Exit Sub
End If


If (oauth2.AuthFlowState = 4) Then
    Debug.WriteLine("OAuth2 authorization was denied.")
    Debug.WriteLine(oauth2.AccessTokenResponse)
    Exit Sub
End If


If (oauth2.AuthFlowState <> 3) Then
    Debug.WriteLine("Unexpected AuthFlowState:" & oauth2.AuthFlowState)
    Exit Sub
End If


Debug.WriteLine("OAuth2 authorization granted!")
Debug.WriteLine("Access Token = " & oauth2.AccessToken)