Chilkat Online Tools

Obtain Microsoft Graph OAuth2 Access Token

This tool demonstrates how to get a Microsoft Graph OAuth2 access token using three-legged OAuth2 in an ASP.NET application. This is also known as the "authorization code grant flow". This is when your ASP.NET app acts on the behalf of a third-party user, your app must obtain the user's permission before it can make requests that access and update that third-party's confidential resources. A User access token carries a third-party's authorization to access specific resources, and this type of token is obtained through the authorization code grant flow.

The C# Source Code for this Page

             
@{

    Layout = "~/_LayoutPage1.cshtml";
}


@{
    string access_token = "";
    string state = "";


    // Check to see if this is our redirect containing the access token.
    if (!string.IsNullOrEmpty(Request.Params["state"]))
    {
        state = Request["state"];

        // Make sure this is the redirect for our session.
        if (!state.Equals(Session["oauth2_state"]))
        {
            access_token = "invalid_state";
        }
        else if (!string.IsNullOrEmpty(Request.Params["code"]))
        {
            access_token = Request["code"];
        }
    }
}

@{

    Chilkat.HttpRequest req = new Chilkat.HttpRequest();
    req.AddParam("client_id", "18c456bd-db76-44fe-9724-9e5d820c68ff");
    req.AddParam("redirect_uri", "https://tools.chilkat.io/msgraph_oauth2.cshtml");
    req.AddParam("response_type", "code");
    req.AddParam("scope", "openid profile offline_access user.readwrite mail.readwrite mail.send files.readwrite");
    string stateData = "12345678";  // Replace this with random data..
    req.AddParam("state", stateData);
    Session["oauth2_state"] = stateData;

    string auth_url = "https://login.microsoftonline.com/common/oauth2/v2.0/authorize?" + req.GetUrlEncodedParams();

}

<div class="container">
    <h2>Obtain Microsoft Graph OAuth2 Access Token</h2>
    <p>
        This tool demonstrates how to get a Microsoft Graph OAuth2 access token using
        three-legged OAuth2 in an ASP.NET application.  This is also known as the "authorization code grant flow".
        This is when your ASP.NET app acts on the behalf of a third-party user, your app must obtain the user's permission
        before it can make requests that access and update that third-party's confidential resources. A User access token carries
        a third-party's authorization to access specific resources, and this type of token is obtained through the authorization code grant flow.
    </p>
    <div class="panel panel-default">
        <div class="panel-body">
            <a href="@auth_url" class="btn btn-primary" role="button">Begin OAuth2</a>
        </div>
    </div>
    <div class="panel panel-default">
        @{
            if (!string.IsNullOrEmpty(access_token))
            {
                @:<p><b></b>Microsoft Graph access token:</b> @access_token</p>
            }
            if (!string.IsNullOrEmpty(state))
            {
                @:<p>state: @state</p>
            }
        }
    </div>

    <div class="panel panel-default">
        <h2>The C# Source Code for this Page</h2>
        <pre>
        @{ 
            Chilkat.FileAccess fac = new Chilkat.FileAccess();
            string path = Server.MapPath("~/msgraph_oauth2.cshtml");
            string src = fac.ReadEntireTextFile(path,"utf-8");
            @: @src
        }
        </pre>
    </div>