Sign In using raw HttpRequestMessage in ASP.NET MVC - asp.net-mvc

Question

I have been testing some code to sign in users to their Microsoft/school/work accounts using raw HttpRequestMessage and HttpResponseMessage. I know there are libraries available to do this but I want to test the raw approach as well (especially usage of refresh tokens), while looking for the right library to handle it.
I'm currently learning authentication, with limited knowledge of ASP.NET/Core.
I'm following this guide: https://learn.microsoft.com/en-us/graph/auth-v2-user
I've just modified the SignIn() method in AccountController in an example project that used more high level libraries to sign in.
I'm requesting an authorization code.
The SignIn() code:
public void SignIn()
{
using (var httpClient = new HttpClient())
{
try
{
var tenant = "my tenant id";
var clientId = ConfigurationManager.AppSettings["ida:AppID"];
var responseType = "id_token+code";
var redirectURI = ConfigurationManager.AppSettings["ida:RedirectUri"];
var responseMode = "form_post";//query";
var appScopes = ConfigurationManager.AppSettings["ida:AppScopes"];
var scopes = $"openid profile offline_access {appScopes}";
var state = "12345";
//var prompt = "consent";
var url = string.Format("https://login.microsoftonline.com/{0}/oauth2/v2.0/authorize", tenant);
var body = string.Format("client_id={1}&response_type={2}&redirect_uri={3}&response_mode={4}&scope={5}&state={6}", tenant, clientId, responseType, redirectURI, responseMode, scopes, state);
var request = new HttpRequestMessage(HttpMethod.Post, url);
request.Content = new StringContent(body, Encoding.UTF8, "application/x-www-form-urlencoded");
var response = httpClient.SendAsync(request, HttpCompletionOption.ResponseContentRead).Result;
var content = response.Content.ReadAsStringAsync().Result;
}
catch (Exception ex)
{
}
}
//if (!Request.IsAuthenticated)
//{
// // Signal OWIN to send an authorization request to Azure
// Request.GetOwinContext().Authentication.Challenge(
// new AuthenticationProperties { RedirectUri = "/" },
// OpenIdConnectAuthenticationDefaults.AuthenticationType);
//}
}
I'm just returning void from the method now because I'm not sure what I should return yet.
Debugging and looking at the response variable, the status code is 200, and has some other information to it. However, the content of the HttpResponseMessage, when I paste it into a file and opening it in a browser, displays (or redirects to) https://login.microsoftonline.com/cookiesdisabled, which shows a message saying that I could not be logged in because my browser blocks cookies. However, I don't think this really is the case.
How can I resolve this and have the user log in and consent, and get the authorization code?
I couldn't really find any example in ASP.NET that uses this raw approach. Is it not recommended?

Answer 1

You should fistly understand how OAuth 2.0 authorization code flow works in Azure AD V2.0 :
Microsoft identity platform and OAuth 2.0 authorization code flow
The general process would be like :
When login in client application, user will be redirect to Azure AD login endpoint(https://login.microsoftonline.com/{0}/oauth2/v2.0/authorize) and provides info like which client(client_id) in which tenant(tenant id) user wants to login , and redirect back to which url(redirect_uri) after successful login.
User enter credential , Azure AD validate credential and issue code and redirect user back to redirect url provided in step 1 (Also match one of the redirect_uris you registered in the portal).
The client application will get the code and send http post request with code to acquire access token .
So if you want to manally implement the code flow in your application , you can refer to below code sample :
public async Task<IActionResult> Login()
{
string authorizationUrl = string.Format(
"https://login.microsoftonline.com/{0}/oauth2/v2.0/authorize?response_type=code&client_id={1}&redirect_uri={2}&scope={3}",
"tenantID", "ClientID", "https://localhost:44360/Home/CatchCode",
"openid offline_access https://graph.microsoft.com/user.read");
return Redirect(authorizationUrl);
}
private static readonly HttpClient client = new HttpClient();
public async Task<ActionResult> CatchCode(string code)
{
var values = new Dictionary<string, string>
{
{ "grant_type", "authorization_code" },
{ "client_id", "XXXXXX"},
{ "code", code},
{ "redirect_uri", "https://localhost:44360/Home/CatchCode"},
{ "scope", "https://graph.microsoft.com/user.read"},
{ "client_secret", "XXXXXXXXXXX"},
};
var content = new FormUrlEncodedContent(values);
//POST the object to the specified URI
var response = await client.PostAsync("https://login.microsoftonline.com/cb1c3f2e-a2dd-4fde-bf8f-f75ab18b21ac/oauth2/v2.0/token", content);
//Read back the answer from server
var responseString = await response.Content.ReadAsStringAsync();
//you can deserialize an Object use Json.NET to get tokens
}
That just is simple code sample which will get Microsoft Graph's access token , you still need to care about url encode and catch exception , but it shows how code flow works .