IdentityServer4 impersonating a user from .Net core app - jwt

I have a .Net core app that runs as a background task. I want to be able to make calls to my web server on behalf of the users its processing data for (I guess this would be classed as user impersonation).
My web server uses IdentityServer4 and I can authenticate the app against it using the code in
https://identitymodel.readthedocs.io/en/latest/client/token.html
To summarize, define the client server side
new Client
{
ClientId = "client",
// no interactive user, use the clientid/secret for authentication
AllowedGrantTypes = GrantTypes.ClientCredentials,
// secret for authentication
ClientSecrets =
{
new Secret("secret".Sha256())
},
// scopes that client has access to
AllowedScopes = { "api1" }
}
Create a auth token client side and use in an a http call
var client = new HttpClient();
var disco = await client.GetDiscoveryDocumentAsync("https://localhost:5001");
var tokenResponse = await client.RequestClientCredentialsTokenAsync(new ClientCredentialsTokenRequest
{
Address = disco.TokenEndpoint,
ClientId = "client",
ClientSecret = "secret",
Scope = "api1"
});
var apiClient = new HttpClient();
apiClient.SetBearerToken(tokenResponse.AccessToken);
...
This works, but when I user the bearer token I'm autheticated, but its not a 'user' thats logged in its the 'client' which has no claims.
So how do I get a bearer token that contains the claims I need to impersonate a user on the server?

You need to use the Authorization code flow instead of the clients credentials flow to get a token for the desired user. Then you save that token locally and use that to access the API on the behalf of the user.
If you have short-lived tokens, you can request a refresh token so that you can get new access tokens when it expires.
clients credentials flow is only used for machine to machine communication where no user is involved.

Related

Verify facebook token

I have a client application which authenticates with facebook and returns the token successfully. I would like to persist this data to the server without having to pass the entire object. Instead I would like to pass the resulting token from the client side authentication to my C# api in the authorization header and validate this token on the server.
Question, is it possible to verify the token on the server side? How to do it?
I am doing this via google, and need a facebook equivalent:
var googleResult = GoogleJsonWebSignature.ValidateAsync(
accessToken,
new GoogleJsonWebSignature.ValidationSettings
{
Audience = new[] { "secret key here.apps.googleusercontent.com" }
}
).GetAwaiter().GetResult();

How do I call my Cognito secured RestAPI from the browser when using next-auth?

I have an AWS RestApi secured by AWS Cognito. In addition to this I have a NextJS app using next-auth that provides user authentication against the Cognito User Pool.
I now want to call the RestApi directly from the browser, but cannot find a way to include the proper credentials. Since the only cookies present in my web-app begin with next-auth- I assume they are not suitable for the task.
So, how do I access the access token from the browser?
I ended up hooking up to two callbacks on the NextAuth configuration, like this:
NextAuth({
providers: [
CognitoProvider({
idToken: true,
issuer,
clientSecret,
clientId,
authorization,
}),
],
callbacks: {
session: async function ({ session, token }) {
return {
...session,
bearerToken: token.bearerToken ?? session.bearerToken,
};
},
async jwt({ token, account }) {
token.bearerToken = account?.id_token ?? token.bearerToken;
return token;
},
},
})
From the pages/api/auth/[...nextauth].ts file.
This makes the bearerToken available via the getSession call:
import { getSession } from "next-auth/react";
// ...
const { bearerToken } = await getSession();
You can use application like Postman to pass the Authorization header. I am not sure if your query is about getting the access token or about how to use the access token.
In order to get the access token and then to call your REST API, you need to have a server. Suppose you have your server with domain name "example.com". Then, put this server name in the callback URL of your Cognito user pool's app client.
After user authentication, Cognito will send the access token to "example.com". Then, you server will have the responsibility to correctly call the REST API with the access or ID token provided by Cognito.
For testing purpose, you can manually get the access token after authenticating with Cognito. Then, you can use application like Postman to make HTTP calls to your REST API endpoint with the access token. Put the token as value to the authorization header.

IdentityServer SSO - Trusted application

I need to SSO (single sign on) a user coming from an application of mine (identity provider using ASPNET Session State) and redirect them to another application of mine (service provider) that is configured to use implicit flow with IdentityServer4. I need to achieve this without requiring the user to log back in and without providing the user's password.
My initial thought was that I could use a client secret for the identity provider to redirect the user to the IdentityServer4 authentication end point with the access token as a query parameter and then use a custom validator or extension grant to issue an identity token for use with the service provider application without needing to also provide the user's password.
I've managed to issue an access token to the identity provider and then redirect the user to IdentityServer4, but issuing an identity token has proven difficult for me. I've poured over the samples and documentation and I'm confused to say the least.
I'm looking for direction on the appropriate approach to this scenario and perhaps a comprehensive example in C#. I've come to understand I can use a hybrid flow to issue an access token as well as an identity token. I think my biggest struggle is how to redirect the user and, based on the access token, issue the user an identity token (and if this is even an acceptable approach).
Simply put: I'd like to redirect the user from Application A to IdentityServer4 to Application B based on trust with the identity provider (via client secret?).
Note: I understand this could be considered an opinion-based question, but based on my research I believe there is one single best practice and that's what I'm asking for.
I managed to get this working by the following flow:
Authorize the user in Application A (Identity Provider)
Obtain Access Token from Identity Server 4 via Token Endpoint and shared secret.
Add access token as a query string parameter since headers are not preserved on redirect.
Redirect the user to an Account controller method that accepts identifying information such as username. This method is protected by a custom middleware class that checks the query string for an access token parameter. If the token exists, it is added to the authentication header; this authorizes the user to hit this controller method.
The controller method will then sign the user in and redirect them to the /connect/authorize/login endpoint.
Finally, the login endpoint sets the cookie and redirects the user to Application B (Service Provider), whose URL is specified via the redirect_uri query parameter.
Configuration for shared secret:
Add appropriate grant type, secret and new scope name to the client. The new scope will help in debugging Access token issues in your logs (especially if you have multiple applications hitting your ID4 server). Also make sure to add the Service Provider's URL to the client RedirectUris, otherwise you'll receive an "invalid redirect" error.
AllowedGrantTypes = new List<string> { GrantType.Implicit, GrantType.ClientCredentials },
ClientSecrets = new List<Secret> {
new Secret(_clientSecrets.ExternalIdpSecret.Sha256(), clientID)
},
AllowedScopes = new List<string>
{
"newScopeName"
},
RedirectUris = new List<string>
{
$"http://localhost:<portnumber>"
}
Next, add your custom middleware.
public class QueryStringOAuthBearerMiddleware
{
private readonly RequestDelegate next;
public QueryStringOAuthBearerMiddleware(RequestDelegate next)
{
this.next = next;
}
public async Task Invoke(HttpContext context)
{
this.BeginInvoke(context);
await this.next.Invoke(context);
this.EndInvoke(context);
}
private void BeginInvoke(HttpContext context)
{
if (context.Request.Query.ContainsKey("accesstokenparametername"))
{
var accessToken = context.Request.Query.First(p => p.Key == "accesstokenparametername");
if (!string.IsNullOrEmpty(accessToken.Value))
{
context.Request.Headers.Add("Authorization", "Bearer " + accessToken.Value);
}
}
}
private void EndInvoke(HttpContext context)
{
}
}
And add the middleware to your configuration.
app.UseMiddleware<QueryStringOAuthBearerMiddleware>();
Create your login method.
[HttpGet]
[Authorize]
public async Task<IActionResult> Login2(string userName, string returnURL)
{
await _httpContextWrapper.SignInAsync(userName);
return Redirect(returnURL);
}
Configuration for Client application (IDP):
Your client side code should look like this:
var disco = await DiscoveryClient.GetAsync("http://localhost:<portnumber>");
var tokenClient = new TokenClient(disco.TokenEndpoint, "clientIdentifier", "IUsedAGuidHere");
var tokenResponse = await tokenClient.RequestClientCredentialsAsync("newScopeName");
var redirectURL = string.Format("http://localhost:2228/account/Login2?userName=<UserIDValue>&returnURL={1}&accesstokenparametername={0}",
tokenResponse.AccessToken,
Server.UrlEncode(
string.Format("/connect/authorize/login?client_id={3}&redirect_uri={2}&response_type=id_token%20token&scope=<ImplicitFlowScopes>&state={0}&nonce={1}",
CryptoRandom.CreateUniqueId(),
CryptoRandom.CreateUniqueId(),
Server.UrlEncode("http://localhost:<PortNumber>"),
"ClientIdentifier")));
Response.Redirect(redirectURL, false);
Note: Please understand you won't be able to take this code AS-IS and make it work. I've heavily modified it to protect the security of my resources.
I think I might take care of the Authentication with Application A first, then forward on to the next app...
Application A --> IdentityServer --> Application A --> Application B.
You could include some custom parameters in your returnUrl which Application A could read upon return from IdentityServer that would trigger the redirect to Application B.

MSAL, Azure MobileService and Auto REST calls get 401 Unauthorized

I have an app (currently in UWP) that makes use of MobileServiceClient and AutoRest to an Azure App Service API App. I successfully used the winfbsdk and can authenticate thru that and then get it to login to MobileService.LoginAsync with the FB access token as a JObject. I also take that JObject and send it in the x-zumo-auth header when making calls to the API App via AutoRest within the app.
What I would like to do is be able to authenticate using MicrosoftAccount. If I use MobileService.LoginAsync, I cannot get the proper token and pass it along to AutoRest - it always comes back as 401 Unauthorized.
I tried to used MSAL, but it returns a Bearer token and passing that along also comes back as 401 Unauthorized.
Is there any good way to do this? I started on the route of MSAL since that would support Windows desktop, UWP and Xamarin Forms which will be ideal. I just need info on how to get the proper token from it to pass along to an AutoRest HttpClient that goes back to the Azure App Service API App.
Update:
If I use the following flow, it works with Facebook, but not with MicrosoftAccount.
-Azure AppService with WebAPI (and swagger for testing via a browser)-Security setup through the Azure Dashboard on the service and configured to allow Facebook or MicrosoftAccount
1. On my UWP app, using winfbsdk, I login with Facebook, then grab the FBSession.AccessTokenData.AccessToken and insert that into a JObject:
JObject token = JObject.FromObject
(new{access_token = fbSession.AccessTokenData.AccessToken});
2. Login to MobileServiceClient
user = await App.MobileService.LoginAsync
(MobileServiceAuthenticationProvider.Facebook, token);
Login to API App with HttpClient and retrieve the token to use in X-ZUMO-AUTH
using (var client = new HttpClient())
{
client.BaseAddress = App.MobileService.MobileAppUri;
var jsonToPost = token;
var contentToPost = new StringContent(
JsonConvert.SerializeObject(jsonToPost),
Encoding.UTF8, "application/json");
var asyncResult = await client.PostAsync(
"/.auth/login/" + provider.ToString(),
contentToPost);
if (asyncResult.Content == null)
{
throw new InvalidOperationException("Result from call was null.");
return false;
}
else
{
if (asyncResult.StatusCode == System.Net.HttpStatusCode.OK)
{
var resultContentAsString = asyncResult.Content.AsString();
var converter = new ExpandoObjectConverter();
dynamic responseContentAsObject = JsonConvert.DeserializeObject<ExpandoObject>(
resultContentAsString, converter);
var applicationToken = responseContentAsObject.authenticationToken;
ApiAppClient.UpdateXZUMOAUTHToken(applicationToken);
}
}
}
ApiAppClient.UpdateXZUMOAUTH call just does the following:
if (this.HttpClient.DefaultRequestHeaders.Contains("x-zumo-auth") == true)
{
this.HttpClient.DefaultRequestHeaders.Remove("x-zumo-auth");
}
this.HttpClient.DefaultRequestHeaders.Add("x-zumo-auth", applicationToken);
Any subsequent calls using the ApiAppClient (created with AutoRest from the swagger json of my Azure AppService WebAPI) contain the x-zumo-auth header and are properly authenticated.
The problem occurs when trying to use MicrosoftAccount. I cannot seem to obtain the proper token to use in x-zumo-auth from either MSAL or LoginWithMicrosoftAsync.
For #1 above, when trying for MicrosoftAccount, I used MSAL as follows:
AuthenticationResult result = await MSAuthentication_AcquireToken();
JObject token = JObject.FromObject(new{access_token = result.Token});
And MSAuthentication_AcquireToken is defined below, using interfaces and classes as suggested in the Azure samples: https://github.com/Azure-Samples/active-directory-xamarin-native-v2
private async Task<AuthenticationResult> MSAuthentication_AcquireToken()
{
IMSAcquireToken at = new MSAcquireToken();
try
{
AuthenticationResult res;
res = await at.AcquireTokenAsync(App.MsalPublicClient, App.Scopes);
return res;
}
}
Update - ok with MobileServiceClient, but still not working with MSAL
I got it working with MobileServiceClient as follows:
1. Use MobileService.LoginAsync
2. Take the returned User.MobileServiceAuthenticationToken
3. Set the X-ZUMO-AUTH header to contain the User.MobileServiceAuthenticationToken
user = await App.MobileService.LoginAsync(MobileServiceAuthenticationProvider.MicrosoftAccount);
applicationToken = user.MobileServiceAuthenticationToken;
ApiAppClient.UpdateAppAuthenticationToken(applicationToken);
MSAL still not working!
So the original question still remains, what part of the token returned from MSAL do we need to pass on to X-ZUMO-AUTH or some other header so that calls to the Azure AppService WebAPI app will authenticate?
I have an app (currently in UWP) that makes use of MobileServiceClient and AutoRest to an Azure App Service API App. I successfully used the winfbsdk and can authenticate thru that and then get it to login to MobileService.LoginAsync with the FB access token as a JObject. I also take that JObject and send it in the x-zumo-auth header when making calls to the API App via AutoRest within the app.
According to your description, I assumed that you are using Client-managed authentication. You directly contact the identity provider and then provide the token during the login with your mobile back-end, then you could leverage MobileServiceClient.InvokeApiAsync to call your API APP, which would add the X-ZUMO-AUTH header with the value authenticationToken after you invoke MobileServiceClient.LoginAsync(MobileServiceAuthenticationProvider.Facebook, token);
What I would like to do is be able to authenticate using MicrosoftAccount. If I use MobileService.LoginAsync, I cannot get the proper token and pass it along to AutoRest - it always comes back as 401 Unauthorized. I tried to used MSAL, but it returns a Bearer token and passing that along also comes back as 401 Unauthorized. Is there any good way to do this?
AFAIK, for the client-flow authentication patterns (AAD, Facebook, Google), the token parameter for LoginAsync would look like {"access_token":"{the_access_token}"}.
For the client-flow authentication (Microsoft Account), you could leverage MobileServiceClient.LoginWithMicrosoftAccountAsync("{Live-SDK-session-authentication-token}"), also you could use LoginAsync with the token parameter of the value {"access_token":"{the_access_token}"} or {"authenticationToken":"{Live-SDK-session-authentication-token}"}. I have tested LoginAsync with the access_token from MSA and retrieve the logged info as follows:
In summary, when you retrieve the authentionToken after you have logged with your mobile back-end, you could add the X-ZUMO-AUTH header to each of your API APP requests with the authentionToken.
For more details, you could refer to this official document about authentication works in App Service.
UPDATE
I have checked this https://github.com/Azure-Samples/active-directory-xamarin-native-v2 and used fiddler to capture the network packages when authenticating the user and get an access token. I found that MSAL is working against Microsoft Graph and REST and when the user is logged, you could only retrieve the access_token and id_token, and both of them could not be used for single sign-on with your mobile back-end.
While the official code sample about Client-managed authentication for Azure Mobile Apps with MSA is using the Live SDK. As the Live SDK REST API mentioned about signing users, you could get an access token and an authentication token which is used for single sign-on scenario. Also, I have checked the Server-managed authentication and found that app service authentication / authorization for MSA also uses the Live SDK REST API.
In summary, you could not use MSAL for client-managed authentication with MSA, for client-managed authentication, you need to leverage Live SDK to retrieve the authentication_token then invoke MobileServiceClient.LoginWithMicrosoftAccountAsync("{Live-SDK-session-authentication-token}") to retrieve the authenticationToken from your mobile backend. Or you could just leverage server-managed authentication for MSA. For more details about Live SDK, you could refer to LiveSDK.

Mobile Services Authentication with Facebook always gives Unauthorized error

I've been trying to create unity application and connect it with mobile services. I'm trying to do FB authentication and here's what I've done on my checklist :
Registered my FB App Id and App secret properly on mobile services.
For testing I use FB tools to generate access token for now.
Here's my code to login to FB using Restsharp :
// token is hardcoded with access token from FB tools for test
AuthenticationToken authToken = CreateToken(provider, token);
_LoginAsyncCallback = callback;
var path = "/login/" + provider.ToString().ToLower();
var baseClient = new RestClient(_baseEndPoint);
var request = new RestRequest(path, Method.POST);
var json = SerializeObject(authToken);
request.RequestFormat = DataFormat.Json;
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", json, ParameterType.RequestBody);
var handle = baseClient.ExecuteAsync<MobileServiceUser>(request, LoginAsyncHandler);
provider is facebook and my post is "access_token":"XXXXXXXX" so this should be correct right?
I always get this error :
Rest Response:{"code":401,"error":"Error: The Facebook Graph API access token authorization request failed with HTTP status code 400"}
I've tried many FB app settings and generate new access tokens from FB tools, etc but nothing seems to work. I'm at my wits end on this