Authenticating Microsoft Account Credentials Code Example

If your Bing Ads users use a Microsoft account, you will use OAuth to authenticate them. For information about using OAuth, see Authentication with OAuth. If you're currently using the Bing Ads SDK for .NET to authenticate the user's Microsoft account credentials, you may continue to do so.

The following examples show how to get an OAuth token that you use to set the AuthenticationToken header to. The example is broken out into two part: the first example shows a simple client that calls the second example which implements the code grant flow process.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using Content.OAuth;      // Reference to CodeGrantFlow DLL
using Newtonsoft.Json;    // NuGet Json.NET


namespace Content
{
    class Program
    {
        // The client ID that you were given when you
        // registered your application. This is for a 
        // desktop app so there's not client secret.

        private static string _clientId = "<clientidgoeshere>";   

        // If _storedRefreshToken is null, CodeGrantFlow goes
        // through the entire process of getting the user credentials
        // and permissions. If _storedRefreshToken contains the refresh
        // token, CodeGrantFlow returns the new access and refresh tokens.

        private static string _storedRefreshToken = null;
        private static CodeGrantOauth _tokens = null;
        private static DateTime _tokenExpiration;


        static void Main(string[] args)
        {
            try
            {
                // TODO: Add logic to get the logged on user's refresh token 
                // from secured storage. 
                
                _tokens = GetOauthTokens(_storedRefreshToken);


                Console.WriteLine("access token:" + _tokens.AccessToken.Substring(0, 15) + "...");
                Console.WriteLine("refresh token: " + _tokens.RefreshToken.Substring(0, 15) + "...");
                Console.WriteLine("token expires: " + _tokens.Expiration);
            }
            catch (Exception e)
            {
                Console.WriteLine("\n" + e.Message);
            }
        }


        // Gets the OAuth tokens. If the refresh token doesn't exist, get 
        // the user's consent and a new access and refresh token.

        private static CodeGrantOauth GetOauthTokens(string refreshToken)
        {
            CodeGrantOauth auth = new CodeGrantOauth(_clientId); 

            if (string.IsNullOrEmpty(refreshToken))
            {
                auth.GetAccessToken();
            }
            else
            {
                auth.RefreshAccessToken(refreshToken);

                // Refresh tokens can become invalid for several reasons
                // such as the user's password changed.

                if (!string.IsNullOrEmpty(auth.Error))
                {
                    auth = GetOauthTokens(null);
                }
            }

            // TODO: Store the new refresh token in secured storage
            // for the logged on user.

            _storedRefreshToken = auth.RefreshToken;
            _tokenExpiration = DateTime.Now.AddSeconds(auth.Expiration);

            return auth;
        }
    }
}

Code grant flow implementation

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.IO;
using System.Windows.Forms;  // Add reference
using System.Net;            // .Net 4.5 required for WebUtility.UrlEncode
using System.Drawing;        // Add reference
using Newtonsoft.Json;       // NuGet Json.NET


namespace Content.OAuth
{
    // This class supports the OAuth 2.0 Authorization Code Grant flow
    // for a desktop app.

    public class CodeGrantOauth : Form
    {
        private WebBrowser _browser = null;  // Used to get user consent

        private string _accessToken = null;
        private string _refreshToken = null;
        private string _authorizationCode = null;
        private int _expiration;
        private string _error = null;

        // Production OAuth server endpoints.

        private string AuthorizationUri = "https://login.live.com/oauth20_authorize.srf";  // Authorization code endpoint
        private string RedirectUri = "https://login.live.com/oauth20_desktop.srf";  // Callback endpoint
        private string RefreshUri = "https://login.live.com/oauth20_token.srf";  // Get tokens endpoint

        private string RedirectPath = "/oauth20_desktop.srf";
        private string ErrorPath = "/err.srf";

        // Parameters to pass to requests. 
        // codeQueryString is the query string for the authorizationUri. To force user log in, include the &prompt=login parameter.
        // accessBody is the request body used with the refreshUri to get the access token using the authorization code.
        // refreshBody is the request body used with the refreshUri to get the access token using a refresh token.

        private string CodeQueryString = "?client_id={0}&scope=bingads.manage&response_type=code&redirect_uri={1}";
        private string AccessBody = "client_id={0}&code={1}&grant_type=authorization_code&redirect_uri={2}";
        private string RefreshBody = "client_id={0}&grant_type=refresh_token&redirect_uri={1}&refresh_token={2}";

        private string _clientId = null;
        private string _uri = null;

        public string AccessToken { get { return this._accessToken; } }
        public string RefreshToken { get { return this._refreshToken; } }
        public int Expiration { get { return this._expiration; } }
        public string Error { get { return this._error; } }


        // Must instantiate the class by passing the apps client ID.

        public CodeGrantOauth(string clientId) 
        {
            if (string.IsNullOrEmpty(clientId))
            {
                throw new ArgumentException("The client ID is missing.");
            }

            this._clientId = clientId;
            this._uri = string.Format(this.AuthorizationUri + this.CodeQueryString, this._clientId, RedirectUri);
        }

        // Add the browser to the form.

        private void InitializeForm()
        {
            this.FormClosing += new FormClosingEventHandler(form_FormClosing);
            this.Size = new Size(420, 580);

            this._browser = new WebBrowser();
            this._browser.Dock = DockStyle.Fill;
            this._browser.Navigated += new WebBrowserNavigatedEventHandler(browser_Navigated);

            this.Controls.AddRange(new Control[] { this._browser });
        }

        // Get the access token by using the authorization code.

        public string GetAccessToken()
        {
            Thread oauthThread = new Thread(new ThreadStart(GetToken));
            oauthThread.SetApartmentState(ApartmentState.STA);
            oauthThread.Start();
            oauthThread.Join();

            try
            {
                if (!string.IsNullOrEmpty(this._authorizationCode))
                {
                    var accessTokenRequestBody = string.Format(this.AccessBody, this._clientId, this._authorizationCode, WebUtility.UrlEncode(RedirectUri));
                    AccessTokens tokens = GetTokens(this.RefreshUri, accessTokenRequestBody);
                    this._accessToken = tokens.AccessToken;
                    this._refreshToken = tokens.RefreshToken;
                    this._expiration = tokens.Expiration;
                }
            }
            catch (WebException)
            {
                this._error = "GetAccessToken failed likely due to an invalid client ID, client secret, or authorization code";
            }

            return this._accessToken;
        }

        // Starts the browser used to get consent and blocks until
        // the user gives consent or cancels the request.

        private void GetToken()
        {
            InitializeForm();
            this._browser.Navigate(this._uri);

            Application.EnableVisualStyles();
            Application.Run(this);
        }

        // Get the access token by using the refresh token.

        public string RefreshAccessToken(string refreshToken)
        {
            if (string.IsNullOrEmpty(refreshToken))
            {
                throw new ArgumentException("The refresh token is missing.");
            }

            try
            {
                var refreshTokenRequestBody = string.Format(this.RefreshBody, this._clientId, WebUtility.UrlEncode(RedirectUri), refreshToken);
                AccessTokens tokens = GetTokens(this.RefreshUri, refreshTokenRequestBody);
                this._accessToken = tokens.AccessToken;
                this._refreshToken = tokens.RefreshToken;
                this._expiration = tokens.Expiration;
            }
            catch (WebException)
            {
                this._error = "RefreshAccessToken failed likely due to an invalid client ID or refresh token";
            }

            return this._accessToken;
        }

        // The user either provided consent or canceled the request.

        private void form_FormClosing(object sender, EventArgs e)
        {
            Application.Exit();
        }

        // Captures all consent traffic. Filter the traffic for the redirect
        // URI. The URIs query string contains either the authorization code
        // or an error.

        private void browser_Navigated(object sender, WebBrowserNavigatedEventArgs e)
        {
            Dictionary\<string, string> parameters = null;

            if (!string.IsNullOrEmpty(e.Url.Query))
            {
                parameters = ParseFragment(e.Url.Query, new char[] { '&', '?' });
            }

            if (e.Url.AbsolutePath.Equals(RedirectPath))
            {
                if (parameters.ContainsKey("code"))
                {
                    this._authorizationCode = parameters["code"];
                }
                else if (parameters.ContainsKey("error_description"))
                {
                    this._error = WebUtility.UrlDecode(parameters["error_description"]);
                }

                this.Close();
            }
            else if (e.Url.AbsolutePath.Equals(ErrorPath))
            {
                if (parameters.ContainsKey("error_description"))
                {
                    this._error = WebUtility.UrlDecode(parameters["error_description"]);
                    this.Close(); ;
                }
            }
        }

        // Parses the query string.

        private Dictionary\<string, string> ParseFragment(string queryString, char[] delimeters)
        {
            var parameters = new Dictionary\<string, string>();

            string[] pairs = queryString.Split(delimeters, StringSplitOptions.RemoveEmptyEntries);

            foreach (string pair in pairs)
            {
                string[] nameValaue = pair.Split(new char[] { '=' });
                parameters.Add(nameValaue[0], nameValaue[1]);
            }

            return parameters;
        }

        // Called by GetAccessToken and RefreshAccessToken to get an access token.

        private static AccessTokens GetTokens(string uri, string body)
        {
            AccessTokens tokens = null;
            var request = (HttpWebRequest)WebRequest.Create(uri);
            request.Method = "POST";
            request.Accept = "application/json";
            request.ContentType = "application/x-www-form-urlencoded";

            request.ContentLength = body.Length;

            using (Stream requestStream = request.GetRequestStream())
            {
                StreamWriter writer = new StreamWriter(requestStream);
                writer.Write(body);
                writer.Close();
            }

            var response = (HttpWebResponse)request.GetResponse();

            using (Stream responseStream = response.GetResponseStream())
            {
                var reader = new StreamReader(responseStream);
                string json = reader.ReadToEnd();
                reader.Close();
                tokens = JsonConvert.DeserializeObject(json, typeof(AccessTokens)) as AccessTokens;
            }

            return tokens;
        }

    }

    // The body of the response from GetTokens is a JSON object that 
    // contains the following properties (and a couple of others
    // that we're not capturing).

    [JsonObject(MemberSerialization.OptIn)]
    class AccessTokens
    {
        [JsonProperty("expires_in")]
        public int Expiration { get; set; }

        [JsonProperty("access_token")]
        public string AccessToken { get; set; }

        [JsonProperty("refresh_token")]
        public string RefreshToken { get; set; }
    }
}