Service to Service call and Graph APi - office365api

Question

I registered a web API https://dev.office.com/app-registration. I kept sign URL
localhost:8000 and RedirectURI as localhost:8000.
After this, I created a console application to access the graph API. Here is the code. But it doesnt work. I get the error "access denied".
Am I missing anything here?
One more thing, I checked the access_token and I dont see any user information there.
string clientId = "<>";
string clientsecret = "<>";
string tenant = "my.com";
var authUri = "https://login.microsoftonline.com/" + tenant + "/oauth2/token";
var RESOURCE_URL = "https://graph.microsoft.com";
HttpClient client = new HttpClient();
var authContext = new AuthenticationContext(authUri);
var credential = new ClientCredential(clientId: clientId, clientSecret: clientsecret);
var result = authContext.AcquireTokenAsync(RESOURCE_URL, credential).Result;
Console.WriteLine(result.AccessToken.ToString());
client.DefaultRequestHeaders.Add("Authorization", "bearer " + result.AccessToken);
var httpContent = new StringContent(content, Encoding.GetEncoding("utf-8"), "application/json");
var response = client.GetAsync("https://graph.microsoft.com/v1.0/users/ankushb/calendar/events").Result;
// var response = client.PostAsync("https://graph.microsoft.com/v1.0/groups", httpContent).Result;
Console.WriteLine(response.Content.ReadAsStringAsync().Result);

Answer 1

There are two basic authentication flow for OAuth2 that Azure AD use.
First is authorization code grant flow which used to access to web APIs by native clients and websites.In this flow, the user delegates access to a client application.
Second is Client Credentials grant flow which permits a web service (a confidential client) to use its own credentials to authenticate when calling another web service, instead of impersonating a user. In this scenario, the client is typically a middle-tier web service, a daemon service, or web site.
The code above is using the Client Credentials grant flow, that's the reason there is no user information.
In your scenario, you should register an native app(console application is not confidential clients which should not use the secret to request for the token ) and use the authorization code grant flow to enable users sign-in with their account. And to use this flow in a console application, we need to prompt a web dialog navigate to the login-in page and get the auth code to request for the access token.
Here is an sample to authenticate the app with authorization code grant flow:
var oauth = new OauthConfiguration
{
Authority = "https://login.microsoftonline.com",
Tenant = "common",
ClientId = "{clientId}",
RedirectURI = "{redirectURL}",
Secret = ""
};
var tokenResponse = new OAuth2.OauthWebAuthHelper(oauth).AcquireTokenWithResource("https://graph.microsoft.com");
var accessToken = tokenResponse.GetValue("access_token").Value<string>();
var refreshToken = tokenResponse.GetValue("refresh_token").Value<string>();
namespace OAuth2
{
public class OauthWebAuthHelper
{
public enum Version
{
V1 = 1,
V2 = 2
}
private OauthConfiguration _configuration;
private const string OAUTH2_AUTHORIZE_V1_SUFFIX = #"oauth2/";
private const string OAUTH2_AUTHORIZE_V2_SUFFIX = #"oauth2/v2.0";
private string _authorizeSuffix;
public OauthWebAuthHelper(OauthConfiguration configuration, Version version = Version.V1)
{
_configuration = configuration;
switch (version)
{
case Version.V1: _authorizeSuffix = OAUTH2_AUTHORIZE_V1_SUFFIX; break;
case Version.V2: _authorizeSuffix = OAUTH2_AUTHORIZE_V2_SUFFIX; break;
}
}
public void LogOut()
{
var dialog = new WebBrowserDialog();
dialog.Open(string.Format("{0}/logout", EndPointUrl));
}
protected string EndPointUrl
{
get
{
return string.Format("{0}/{1}/{2}", _configuration.Authority, _configuration.Tenant, _authorizeSuffix);
}
}
public JObject GetAuthorizationCode()
{
JObject response = new JObject();
var parameters = new Dictionary<string, string>
{
{ "response_type", "code" },
{ "client_id", _configuration.ClientId },
{ "redirect_uri", _configuration.RedirectURI },
{ "prompt", "login"}
};
var requestUrl = string.Format("{0}/authorize?{1}", EndPointUrl, BuildQueryString(parameters));
var dialog = new WebBrowserDialog();
dialog.OnNavigated((sender, arg) =>
{
if (arg.Url.AbsoluteUri.StartsWith(_configuration.RedirectURI))
{
var collection = HttpUtility.ParseQueryString(arg.Url.Query);
foreach (var key in collection.AllKeys)
{
response.Add(key, collection[key]);
}
dialog.Close();
}
});
dialog.Open(requestUrl);
return response;
}
public JObject GetAuthorizationCode(string scope)
{
JObject response = new JObject();
var parameters = new Dictionary<string, string>
{
{ "response_type", "code" },
{ "client_id", _configuration.ClientId },
{ "redirect_uri", _configuration.RedirectURI },
{ "prompt", "login"},
{ "scope", scope}
};
var requestUrl = string.Format("{0}/authorize?{1}", EndPointUrl, BuildQueryString(parameters));
var dialog = new WebBrowserDialog();
dialog.OnNavigated((sender, arg) =>
{
if (arg.Url.AbsoluteUri.StartsWith(_configuration.RedirectURI))
{
var collection = HttpUtility.ParseQueryString(arg.Url.Query);
foreach (var key in collection.AllKeys)
{
response.Add(key, collection[key]);
}
dialog.Close();
}
});
dialog.Open(requestUrl);
return response;
}
public JObject AcquireTokenWithResource(string resource)
{
var codeResponse = GetAuthorizationCode();
var code = codeResponse.GetValue("code").Value<string>();
var parameters = new Dictionary<string, string>
{
{ "resource", resource},
{ "client_id", _configuration.ClientId },
{ "code", code},
{ "grant_type", "authorization_code" },
{ "redirect_uri", _configuration.RedirectURI},
{ "client_secret",_configuration.Secret}
};
var client = new HttpClient();
var content = new StringContent(BuildQueryString(parameters), Encoding.GetEncoding("utf-8"), "application/x-www-form-urlencoded");
var url = string.Format("{0}/token", EndPointUrl);
var response = client.PostAsync(url, content).Result;
var text = response.Content.ReadAsStringAsync().Result;
return JsonConvert.DeserializeObject(text) as JObject;
}
public JObject RefreshTokenWithResource(string refreshToken)
{
var parameters = new Dictionary<string, string>
{
{ "client_id", _configuration.ClientId },
{ "refresh_token", refreshToken},
{ "grant_type", "refresh_token" }
};
var client = new HttpClient();
var content = new StringContent(BuildQueryString(parameters), Encoding.GetEncoding("utf-8"), "application/x-www-form-urlencoded");
var url = string.Format("{0}/token", EndPointUrl);
var response = client.PostAsync(url, content).Result;
var text = response.Content.ReadAsStringAsync().Result;
return JsonConvert.DeserializeObject(text) as JObject;
}
public JObject AcquireTokenWithScope(string scope)
{
var codeResponse = GetAuthorizationCode(scope);
var code = codeResponse.GetValue("code").Value<string>();
var parameters = new Dictionary<string, string>
{
{ "client_id", _configuration.ClientId },
{ "code", code},
{ "grant_type", "authorization_code" },
{ "redirect_uri", _configuration.RedirectURI},
};
var client = new HttpClient();
var content = new StringContent(BuildQueryString(parameters), Encoding.GetEncoding("utf-8"), "application/x-www-form-urlencoded");
var url = string.Format("{0}/token", EndPointUrl);
var response = client.PostAsync(url, content).Result;
var text = response.Content.ReadAsStringAsync().Result;
return JsonConvert.DeserializeObject(text) as JObject;
}
private string BuildQueryString(IDictionary<string, string> parameters)
{
var list = new List<string>();
foreach (var parameter in parameters)
{
if (!string.IsNullOrEmpty(parameter.Value))
list.Add(string.Format("{0}={1}", parameter.Key, HttpUtility.UrlEncode(parameter.Value)));
}
return string.Join("&", list);
}
}
public class OauthConfiguration
{
public string Authority { get; set; }
public string Tenant { get; set; }
public string ClientId { get; set; }
public string RedirectURI { get; set; }
public string Secret { get; set; }
}
public class WebBrowserDialog
{
private const int DEFAULT_WIDTH = 400;
private const int DEFAULT_HEIGHT = 500;
private Form _displayLoginForm;
private string _title;
private WebBrowser _browser;
private WebBrowserNavigatedEventHandler _webBrowserNavigatedEventHandler;
public WebBrowserDialog()
{
_title = "OAuth Basic";
_browser = new WebBrowser();
_browser.Width = DEFAULT_WIDTH;
_browser.Height = DEFAULT_HEIGHT;
_browser.Navigated += WebBrowserNavigatedEventHandler;
_displayLoginForm = new Form();
_displayLoginForm.SuspendLayout();
_displayLoginForm.Width = DEFAULT_WIDTH;
_displayLoginForm.Height = DEFAULT_HEIGHT;
_displayLoginForm.Text = _title;
_displayLoginForm.Controls.Add(_browser);
_displayLoginForm.ResumeLayout(false);
}
public void OnNavigated(WebBrowserNavigatedEventHandler handler)
{
_webBrowserNavigatedEventHandler = handler;
}
protected void WebBrowserNavigatedEventHandler(object sender, WebBrowserNavigatedEventArgs e)
{
if(_webBrowserNavigatedEventHandler != null)
{
_webBrowserNavigatedEventHandler.Invoke(sender, e);
}
}
public void Open(string url)
{
_browser.Navigate(url);
_displayLoginForm.ShowDialog();
}
public void Close()
{
_displayLoginForm.Close();
}
}
}
And you can get more samples about Microsoft Graph from here.