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How to create a 'CallBack' action after getting a Code from Authentication Server in OAuth2 in Web Application Controller

I'm Providing an 'OAuthHandler' for Walmart and overriding some OAuthHandler methods to communicate between User Agent (Client) and Remote Authenticate Server.
Below is my controller:
[AllowAnonymous]
public class WalmartLoginController : Controller
{
public async Task<IActionResult> Login([FromForm] string provider)
{
if (string.IsNullOrWhiteSpace(provider))
{
return BadRequest();
}
if (!await HttpContext.IsProviderSupportedAsync(provider))
{
return BadRequest();
}
return Challenge(new AuthenticationProperties { RedirectUri = "/" }, provider);
}
[HttpGet("~/signout")]
[HttpPost("~/signout")]
public IActionResult SignOutCurrentUser()
{
return SignOut(new AuthenticationProperties { RedirectUri = "/" },
CookieAuthenticationDefaults.AuthenticationScheme);
}
}
And I added some classes to handle my requests: [here is the importance of those that overrode from the OAuthHandler class]
public partial class WalmartAuthenticationHandler : OAuthHandler<WalmartAuthenticationOptions>
{
public WalmartAuthenticationHandler(
[NotNull] IOptionsMonitor<WalmartAuthenticationOptions> options,
[NotNull] ILoggerFactory logger,
[NotNull] UrlEncoder encoder,
[NotNull] ISystemClock clock)
: base(options, logger, encoder, clock)
{}
// STEP 1: CREATE CHALLENGE URL
protected override string BuildChallengeUrl([NotNull] AuthenticationProperties properties, [NotNull] string redirectUri)
{
var scopeParameter = properties.GetParameter<ICollection<string>>(OAuthChallengeProperties.ScopeKey);
var scope = scopeParameter != null ? FormatScope(scopeParameter) : FormatScope();
var parameters = new Dictionary<string, string?>
{
["client_id"] = Options.ClientId,
["response_type"] = "code",
["scope"] = scope
};
if (Options.UsePkce)
{
var bytes = BitConverter.GetBytes(256 / 8);
var codeVerifier = WebEncoders.Base64UrlEncode(bytes);
// Store this for use during the code redemption.
properties.Items.Add(OAuthConstants.CodeVerifierKey, codeVerifier);
var challengeBytes = SHA256.HashData(Encoding.UTF8.GetBytes(codeVerifier));
var codeChallenge = WebEncoders.Base64UrlEncode(challengeBytes);
parameters[OAuthConstants.CodeChallengeKey] = codeChallenge;
parameters[OAuthConstants.CodeChallengeMethodKey] = OAuthConstants.CodeChallengeMethodS256;
}
var state = Options.StateDataFormat.Protect(properties);
parameters["redirect_uri"] = QueryHelpers.AddQueryString(redirectUri, "state", state);
return QueryHelpers.AddQueryString(Options.AuthorizationEndpoint, parameters);
}
// STEP 2 : CHANGE CODE WITH ACCESS_TOKEN
protected override async Task<OAuthTokenResponse> ExchangeCodeAsync([NotNull] OAuthCodeExchangeContext context)
{
var tokenRequestParameters = new Dictionary<string, string?>()
{
["client_id"] = Options.ClientId,
["client_secret"] = Options.ClientSecret,
["redirect_uri"] = context.RedirectUri,
["code"] = context.Code,
["grant_type"] = "authorization_code"
};
// Add CodeVerify to tokenRequestParameters
if (context.Properties.Items.TryGetValue(OAuthConstants.CodeVerifierKey, out var codeVerifier))
{
tokenRequestParameters.Add(OAuthConstants.CodeVerifierKey, codeVerifier);
context.Properties.Items.Remove(OAuthConstants.CodeVerifierKey);
}
var endpoint = QueryHelpers.AddQueryString(Options.TokenEndpoint, tokenRequestParameters);
using var request = new HttpRequestMessage(HttpMethod.Post, Options.TokenEndpoint);
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/x-www-form-urlencoded"));
request.Content = new FormUrlEncodedContent(tokenRequestParameters);
using var response = await Backchannel.SendAsync(request, Context.RequestAborted);
if (!response.IsSuccessStatusCode)
{
// An error occurred while retrieving an OAuth token.
}
var payload = JsonDocument.Parse(await response.Content.ReadAsStringAsync(Context.RequestAborted));
return OAuthTokenResponse.Success(payload);
}
// STEP 3: access to UserInformation with Access Token
protected override async Task<AuthenticationTicket> CreateTicketAsync(
[NotNull] ClaimsIdentity identity,
[NotNull] AuthenticationProperties properties,
[NotNull] OAuthTokenResponse tokens)
{
using var request = new HttpRequestMessage(HttpMethod.Get, Options.UserInformationEndpoint);
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", tokens.AccessToken);
using var response = await Backchannel.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, Context.RequestAborted);
if (!response.IsSuccessStatusCode)
{
// An error occurred while retrieving the user profile.
}
using var payload = JsonDocument.Parse(await response.Content.ReadAsStringAsync(Context.RequestAborted));
var principal = new ClaimsPrincipal(identity);
var context = new OAuthCreatingTicketContext(principal, properties, Context, Scheme, Options, Backchannel, tokens, payload.RootElement.GetProperty("data"));
context.RunClaimActions();
await Events.CreatingTicket(context);
return new AuthenticationTicket(context.Principal!, context.Properties, Scheme.Name);
}
}
As you know, after running https:\\Development-Domain.com\signin by post method (second action), a Challenge is started and will redirect to BuildChallengeUrl() and return a Url with Code and State. The next action would be ExchangeCodeAsync() to change the Code sent by the remote server with an AccessToken.
The question is, which action or method was missed in this process? Will my ExchangeCodeAsync() call automatically after the BuildChallengeUrl() handler, or do I need to put some action to continue to authorize the user?
Update #1: I added a callback action to get info from 'QueryString' in controller to call next method of handler class:
[HttpPost("~/signin-oidc")]
public async Task<IActionResult> Callback([FromForm] string provider)
{
var code = Request.Query["code"];
var state = Request.Query["state"];
if (string.IsNullOrWhiteSpace(code))
{
return BadRequest();
}
if (!await HttpContext.IsProviderSupportedAsync(provider))
{
return BadRequest();
}
return {?};
}
What code must I write in {?} to request for Access Token from TokenEndpoint?

Except callback action other code are in-line with Authorisation code flow.
In PKCE Authorization code flow, you should match with flow mentioned here, that will help pass security validation / testing post production.
How it works, Authorization Flow
Answer to question,
CallBack action an endpoint action method of callback url should trigger and make post request to token endpoint of authorisation server with code received as query string in CallBack Url with Code Verifier created with Code Challenge and on successful post it will return access-token, refresh-token, id-token, .... based on your configuration. You will need to specify callback url also with client_id and client_secret in configuration.
re-arranging code based on this How it works, Authorization Flow will help.

After figuring out and researching Microsoft .Net Core OAuth libraries, I got the answer and I would like to share it with you:
As you know, we no need to write any code in callback action for running the next method in the WalmartAuthenticationHandler class because all the process is automatic and event-based and all of them are provided in the Microsoft OAuthHandler class. You need to write some code inside the Callback action just for registering User after the authentication process.
Even you can use Microsoft ExternalLogin Identity pages for the registration of an external User.
Also, I decided to create a project on GitHub and I'd like to share it here
OktaProvider, maybe everyone needs to add external authentication for non-famous companies.

I get cookie instead of token with authorization code grant

Summary
I have ASP.NET MVC 5 web app with Identity authentication and I have to develop an API with "grant_type" = "authorization_code". This API will be to provide users data to another "well-known" web service that needs a custom error responses. My IDE is Visual Studio Professional 2017. I use Postman to make requests to my Web API.
Documentation I read
In the OWIN and Katana documentation the OWIN OAuth 2.0 Authorization Server link redirects again to main OWIN and Katana page, but I think that I found the source on GitHub: OWIN OAuth 2.0 Authorization Server. I tried to follow this documentation, but there are no examples about this question.
Problem
I can create a new authorization code in my AuthorizationCodeProvider class (with Create() method) when a user authenticates and authorizes the "well-known" web service client to access user's resources. I store this code in a database. When I request a Token AuthorizationCodeProvider.Receive() method is called and the token is deserialized correctly. Then GrantAuthorizationCode() method is called, Postman receives OK response (200 status code) but without token information in body (.AspNet.ApplicationCookie is in cookies).
Detailed explanation and code
This is the Startup class:
public partial class Startup
{
public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }
public void ConfigureAuth(IAppBuilder app)
{
app.CreatePerOwinContext(ApplicationDbContext.Create);
app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
app.CreatePerOwinContext<ApplicationSignInManager>(ApplicationSignInManager.Create);
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
LoginPath = new PathString("/Account/Login"),
Provider = new CookieAuthenticationProvider
{
OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
validateInterval: TimeSpan.FromMinutes(30),
regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager)),
OnApplyRedirect = (context =>
{
// This code is to return custom error response
string path = null;
if (context.Request.Path.HasValue)
path = context.Request.Path.Value;
if (!(path != null && path.Contains("/api"))) // Don't redirect to login page
context.Response.Redirect(context.RedirectUri);
})
}
});
app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);
app.UseTwoFactorSignInCookie(DefaultAuthenticationTypes.TwoFactorCookie, TimeSpan.FromMinutes(5));
app.UseTwoFactorRememberBrowserCookie(DefaultAuthenticationTypes.TwoFactorRememberBrowserCookie);
this.ConfigureAuthorization(app);
}
private void ConfigureAuthorization(IAppBuilder app)
{
app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);
OAuthOptions = new OAuthAuthorizationServerOptions
{
AllowInsecureHttp = false,
TokenEndpointPath = new PathString("/api/token"),
AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
Provider = new TokenAuthorizationServerProvider(),
AuthorizationCodeProvider = new AuthorizationCodeProvider()
};
app.Use<AuthenticationMiddleware>(); //Customize responses in Token middleware
app.UseOAuthAuthorizationServer(OAuthOptions);
app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
}
}
ConfigureAuthorization() method configures the authorization. It uses classes implemented by me:
AuthenticationMiddleware: the well-known web service wants 401 status responses with custom error JONS instead of the usual 400 status response. It is based on the answer of the question Replace response body using owin middleware.
public class AuthenticationMiddleware : OwinMiddleware
{
public AuthenticationMiddleware(OwinMiddleware next) : base(next) { }
public override async Task Invoke(IOwinContext context)
{
var owinResponse = context.Response;
var owinResponseStream = owinResponse.Body;
var responseBuffer = new MemoryStream();
owinResponse.Body = responseBuffer;
await Next.Invoke(context);
if (context.Response.StatusCode == (int)HttpStatusCode.BadRequest &&
context.Response.Headers.ContainsKey(BearerConstants.CustomUnauthorizedHeaderKey))
{
context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
string headerValue = context.Response.Headers.Get(BearerConstants.CustomUnauthorizedHeaderKey);
context.Response.Headers.Remove(BearerConstants.CustomUnauthorizedHeaderKey);
ErrorMessage errorMessage = new ErrorMessage(headerValue);
string json = JsonConvert.SerializeObject(errorMessage, Formatting.Indented);
var customResponseBody = new StringContent(json);
var customResponseStream = await customResponseBody.ReadAsStreamAsync();
await customResponseStream.CopyToAsync(owinResponseStream);
owinResponse.ContentType = "application/json";
owinResponse.ContentLength = customResponseStream.Length;
owinResponse.Body = owinResponseStream;
}
}
}
When ErrorMessage is serialized to JSON returns an array of errors:
{
"errors":
[
"message": "the error message"
]
}
I set the BearerConstants.CustomUnauthorizedHeaderKey header in TokenAuthorizationServerProvider.ValidateClientAuthentication() method using a extension method:
public static void Rejected(this OAuthValidateClientAuthenticationContext context, string message)
{
Debug.WriteLine($"\t\t{message}");
context.SetError(message);
context.Response.Headers.Add(BearerConstants.CustomUnauthorizedHeaderKey, new string[] { message });
context.Rejected();
}
This is how TokenAuthorizationServerProvider is implemented:
public class TokenAuthorizationServerProvider : OAuthAuthorizationServerProvider
{
public override Task AuthorizeEndpoint(OAuthAuthorizeEndpointContext context)
{
// Only for breakpoint. Never stops.
return base.AuthorizeEndpoint(context);
}
public override async Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
{
// Check if grant_type is authorization_code
string grantType = context.Parameters[BearerConstants.GrantTypeKey];
if (string.IsNullOrEmpty(grantType) || grantType != BearerConstants.GrantTypeAuthorizationCode)
{
context.Rejected("Invalid grant type"); // Sets header for custom response
return;
}
// Check if client_id and client_secret are in the request
string clientId = context.Parameters[BearerConstants.ClientIdKey];
string clientSecret = context.Parameters[BearerConstants.ClientSecretKey];
if (string.IsNullOrEmpty(clientId) || string.IsNullOrEmpty(clientSecret))
{
context.Rejected("Client credentials missing"); // Sets header for custom response
return;
}
//Check if client_id and client_secret are valid
ApiClient client = await (new ApiClientService()).ValidateClient(clientId, clientSecret);
if (client != null)
{
// Client has been verified.
Debug.WriteLine($"\t\tClient has been verified");
context.OwinContext.Set<ApiClient>("oauth:client", client);
context.Validated(clientId);
}
else
{
// Client could not be validated.
context.Rejected("Invalid client"); // Sets header for custom response
}
}
public override async Task GrantAuthorizationCode(OAuthGrantAuthorizationCodeContext context)
{
TokenRequestParameters parameters = await context.Request.GetBodyParameters();
using (IUserService userService = new UserService())
{
ApplicationUser user = await userService.ValidateUser(parameters.Code);
if (user == null)
{
context.Rejected("Invalid code");
return;
}
// Initialization.
var claims = new List<Claim>();
// Setting
claims.Add(new Claim(ClaimTypes.Name, user.UserName));
// Setting Claim Identities for OAUTH 2 protocol.
ClaimsIdentity oAuthClaimIdentity = new ClaimsIdentity(claims, OAuthDefaults.AuthenticationType);
ClaimsIdentity cookiesClaimIdentity = new ClaimsIdentity(claims, CookieAuthenticationDefaults.AuthenticationType);
// Setting user authentication.
IDictionary<string, string> data = new Dictionary<string, string>{ { "userName", user.UserName } };
AuthenticationProperties properties = new AuthenticationProperties(data);
AuthenticationTicket ticket = new AuthenticationTicket(oAuthClaimIdentity, properties);
// Grant access to authorize user.
context.Validated(ticket);
context.Request.Context.Authentication.SignIn(cookiesClaimIdentity);
}
}
}
ApiClientService.ValidateClient() checks on database that cliend ID and Secret are correct.
GrantAuthorizationCode() is based on the step 8 from ASP.NET MVC - OAuth 2.0 REST Web API Authorization Using Database First Approach tutorial. But this tutorial for grant_type = password and I think that something is wrong in here.
And the AuthorizationCodeProvider class:
public class AuthorizationCodeProvider : AuthenticationTokenProvider
{
public override void Create(AuthenticationTokenCreateContext context)
{
AuthenticationTicket ticket = context.Ticket;
string serializedTicket = context.SerializeTicket();
context.SetToken(serializedTicket);
}
public override void Receive(AuthenticationTokenReceiveContext context)
{
context.DeserializeTicket(context.Token);
// At this point context.Ticket.Identity.IsAuthenticated is true
}
}
I call to create method from the AuthorizationController that shows the Allow/Deny view. It is decorated with System.Web.Mvc.Authorize attribute, so if the user isn't authenticated he or she has to login using the default login page from MVC template project (/account/login):
[Authorize]
public class AuthorizationController : Controller
{
private const string ServiceScope = "service-name";
[HttpGet]
public async Task<ActionResult> Index(string client_id, string response_type, string redirect_uri, string scope, string state)
{
AuthorizationViewModel vm = new AuthorizationViewModel()
{
ClientId = client_id,
RedirectUri = redirect_uri,
Scope = scope,
State = state
};
if (scope == ServiceScope)
{
var authentication = HttpContext.GetOwinContext().Authentication;
authentication.SignIn(
new AuthenticationProperties { IsPersistent = true, RedirectUri = redirect_uri },
new ClaimsIdentity(new[] { new Claim(ClaimsIdentity.DefaultNameClaimType, User.Identity.Name) },
"Bearer"));
}
return View(vm);
}
[HttpPost]
[ValidateAntiForgeryToken]
[MultiButton(MatchFormKey = "authorization", MatchFormValue = "Allow")]
public async Task<ActionResult> Allow(AuthorizationViewModel vm)
{
if (ModelState.IsValid)
{
string code = await this.SetAuthorizationCode(vm.ClientId, vm.RedirectUri);
if (vm.Scope == ServiceScope)
{
string url = $"{vm.RedirectUri}?code={code}&state={vm.State}";
return Redirect(url);
}
else
{
return Redirect(vm.RedirectUri);
}
}
return View(vm);
}
[HttpPost]
[ValidateAntiForgeryToken]
[MultiButton(MatchFormKey = "authorization", MatchFormValue = "Deny")]
public async Task<ActionResult> Deny(AuthorizationViewModel vm)
{
// Removed for brevity
return View(vm);
}
private async Task<string> SetAuthorizationCode(string clientId, string redirectUri)
{
string userId = User.Identity.GetUserId();
ClaimsIdentity identity = new ClaimsIdentity(new GenericIdentity(clientId, OAuthDefaults.AuthenticationType));
AuthenticationTokenCreateContext authorizeCodeContext = new AuthenticationTokenCreateContext(
HttpContext.GetOwinContext(),
Startup.OAuthOptions.AuthorizationCodeFormat,
new AuthenticationTicket(
identity,
new AuthenticationProperties(new Dictionary<string, string>
{
{ "user_id", userId },
{ "client_id", clientId },
{ "redirect_uri", redirectUri }
})
{
IssuedUtc = DateTimeOffset.UtcNow,
ExpiresUtc = DateTimeOffset.UtcNow.Add(Startup.OAuthOptions.AuthorizationCodeExpireTimeSpan)
}));
Startup.OAuthOptions.AuthorizationCodeProvider.Create(authorizeCodeContext);
string code = authorizeCodeContext.Token;
IUserService userService = new UserService();
await userService.SetAuthorization(userId, true, code); // save to database
userService.Dispose();
return code;
}
}
The authorization code is created in SetAuthorizationCode() method, which is called in Allow() action. This SetAuthorizationCode() method code is based on this answer.
Questions
I now that is very long with a lot of code, but I'm stuck for some days and I didn't find the solution. I don't know the complete flow of the authorization, I think that I'm missing something.
What happens when I call /api/token? I mean, what are the steps in this part of the authentication/authorization flow?
What happens after AuthorizationCodeProvider.GrantAuthorizationCode()?
Why a cookie returned instead of token in the body?

I found the solution of the problem, it was the AuthenticationMiddleware. Once the body of the response is read, it remains empty and does not reach the client. So you have to rewrite the response body.
public class AuthenticationMiddleware : OwinMiddleware
{
public AuthenticationMiddleware(OwinMiddleware next) : base(next) { }
public override async Task Invoke(IOwinContext context)
{
var owinResponse = context.Response;
var owinResponseStream = owinResponse.Body;
var responseBuffer = new MemoryStream();
owinResponse.Body = responseBuffer;
await Next.Invoke(context);
if (context.Response.StatusCode == (int)HttpStatusCode.BadRequest &&
context.Response.Headers.ContainsKey(BearerConstants.CustomUnauthorizedHeaderKey))
{
// Customize the response
}
else
{
// Set body again with the same content
string body = Encoding.UTF8.GetString(responseBuffer.ToArray());
StringContent customResponseBody = new StringContent(body);
Stream customResponseStream = await customResponseBody.ReadAsStreamAsync();
await customResponseStream.CopyToAsync(owinResponseStream);
}
}
}

Implementing short lived Jwt with Refresh Token with Blazor

We are currently developing a Blazor app which is secured using short lived (10 minute) Jwt with Refresh Tokens.
Currently we have the Jwt implemented and through the Blazor server side web api can login, generate the Jwt and generate the refresh token.
From the client side I have used the following link;
Authentication With client-side Blazor
and extended the ApiAuthenticationStateProvider.cs as follows;
public class ApiAuthenticationStateProvider : AuthenticationStateProvider
{
private readonly HttpClient _httpClient;
private readonly ILocalStorageService _localStorage;
public ApiAuthenticationStateProvider(HttpClient httpClient, ILocalStorageService localStorage)
{
_httpClient = httpClient;
_localStorage = localStorage;
}
public override async Task<AuthenticationState> GetAuthenticationStateAsync()
{
var savedToken = await _localStorage.GetItemAsync<string>("authToken");
var refreshToken = await _localStorage.GetItemAsync<string>("refreshToken");
if (string.IsNullOrWhiteSpace(savedToken) || string.IsNullOrWhiteSpace(refreshToken))
{
return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
}
var userResponse = await _httpClient.GetAsync<UserModel>("api/accounts/user", savedToken);
if(userResponse.HasError)
{
var response = await _httpClient.PostAsync<LoginResponse>("api/login/refreshToken", new RefreshTokenModel { RefreshToken = refreshToken });
//check result now
if (!response.HasError)
{
await _localStorage.SetItemAsync("authToken", response.Result.AccessToken);
await _localStorage.SetItemAsync("refreshToken", response.Result.RefreshToken);
userResponse = await _httpClient.GetAsync<UserModel>("api/accounts/user", response.Result.AccessToken);
}
}
var identity = !userResponse.HasError ? new ClaimsIdentity(new[] { new Claim(ClaimTypes.Name, userResponse.Result.Email) }, "apiauth") : new ClaimsIdentity();
return new AuthenticationState(new ClaimsPrincipal(identity));
}
public void MarkUserAsAuthenticated(string email)
{
var authenticatedUser = new ClaimsPrincipal(new ClaimsIdentity(new[] { new Claim(ClaimTypes.Name, email) }, "apiauth"));
var authState = Task.FromResult(new AuthenticationState(authenticatedUser));
NotifyAuthenticationStateChanged(authState);
}
public void MarkUserAsLoggedOut()
{
var anonymousUser = new ClaimsPrincipal(new ClaimsIdentity());
var authState = Task.FromResult(new AuthenticationState(anonymousUser));
NotifyAuthenticationStateChanged(authState);
}
}
So if the Jwt fails the first time we try to renew with the refresh token.
The code above is working, however the first issue i found is, if I then navigate to the /fetchData test end point (which is protected with the [Authorize] attribute). The page initially runs fine and sends the Jwt in the header. However, if i then f5 and refresh the page I get a 401 unauthorized on the /fecthData endpoint, i.e. on the code;
#code {
WeatherForecast[] forecasts;
protected override async Task OnInitAsync()
{
forecasts = await Http.GetJsonAsync<WeatherForecast[]>("api/SampleData/WeatherForecasts");
}
}
Now if to get around this I can manually add the Jwt form localStorage to the header (in my case I use an extension method);
public static async Task<ServiceResponse<T>> GetAsync<T>(
this HttpClient httpClient, string url, string token)
{
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", token);
var response = await httpClient.GetAsync(url);
return await BuildResponse<T>(response);
}
However, the second issue I have here is that if the Jwt expires during this call I would need to call to use the refresh token to get a new Jwt.
Is there a way I can do this do this with middleware to avoid having to check for a 401 on each call and then renewing the token this way?

So often, we are thinking on Blazor as an MVC but it is not. It's more like a desktop app running inside browser. I use JWT and renewing tokens in this way: after login, I have an infinite loop that is pinging backend and keeping the session and renewing the tokens. Simplifying:
class JWTAuthenticationStateProvider : AuthenticationStateProvider
{
private bool IsLogedIn = false;
private CustomCredentials credentials = null;
// private ClaimsPrincipal currentClaimsPrincipal = null; (optinally)
public Task Login( string user, string password )
{
credentials = go_backend_login_service( user, password );
// do stuff with credentials and claims
// I raise event here to notify login
keepSession( );
}
public Task Logout( )
{
go_bakcend_logout_service( credentials );
// do stuff with claims
IsLogedIn = false;
// I raise event here to notify logout
}
public override Task<AuthenticationState> GetAuthenticationStateAsync()
{
// make a response from credentials or currentClaimsPrincipal
}
private async void KeepSession()
{
while(IsLogedIn)
{
credentials = go_backend_renewingJWT_service( credentials );
// do stuff with new credentials: check are ok, update IsLogedIn, ...
// I raise event here if server says logout
await Task.Delay(1000); // sleep for a while.
}
}
}
Remember to register component by DI:
public void ConfigureServices(IServiceCollection services)
{
// ... other services added here ...
// One JWTAuthenticationStateProvider for each connection on server side.
// A singleton for clientside.
services.AddScoped<AuthenticationStateProvider,
JWTAuthenticationStateProvider>();
}
This is just one idea, you should to think about it and adapt it to your own solution.
More about Authentication and Authorization on github SteveSandersonMS/blazor-auth.md

OAuth 2.0 REST Web API and xamarin forms

I make webservice api based on this tutorial https://www.c-sharpcorner.com/article/asp-net-mvc-oauth-2-0-rest-web-api-authorization-using-database-first-approach/ and I need to consume the service form xamarin forms. But I don't know how to authorize client.

Before you try authorizing in code, you should try talking to your API via an api client such as Postman.
You can see in step 11 of the article you reference that the writer is infact doing this.
He is performing the following steps:
Calling the token endpoint (no auth)
Adding the token to his subsequent requests
In order to call an API with authorization, you must first know the auth method (basic, OAuth etc). In this case you're saying it's OAuth:
Take a look at the guide, it shares this picture:
To do this in code you will need to add the following header to your http client. Lets assume you're using vanilla System.Net.Http.HttpClient you would need to implement a class that looks something like this:
public class APIClient
{
private HttpClient _client;
public APIClient()
{
_client = SetupClient();
}
private HttpClient SetupClient()
{
//setup your client here
var client = new HttpClient();
//string oauthToken = TokenService.GetUserToken();
string oauthToken = "eyJhbGciO......."; //Example token
client.DefaultRequestHeaders.Add("Authorization", $"Bearer {oauthToken}");
//more setup here
return client;
}
public async Task<HttpResponseMessage> Get(string endpoint)
{
var request = new HttpRequestMessage(HttpMethod.Get, endpoint);
return await CallAsync(request);
}
private async Task<HttpResponseMessage> CallAsync(HttpRequestMessage request)
{
//do things before?
var result = await _client.SendAsync(request);
//handle result? null? not success code?
return result;
}
}
When you initialise your HttpClient you should add the following header:
Authorization : Bearer {yourtoken}
Now subsequent api requests will have authorization from your api client. How you set this bearer value is up to you. Some people store credentials in the xamarin main App class, and then retrieve the property. Other will persist the data into a plist and have the apiclient read this value (maybe credentials expire every 30 days).
Regardless there are a number of pitfalls that come with talking to api's from a xamarin app. You should always start by calling your api from outside of your app, from within an api client. This will teach you how to configure the requests correctly, without the overhead of worrying if your code/configuration is correct.

Please check my class if help you
`public class ServicesClient
{
private HttpClient httpClient;
private bool _IsConnection { get { return CheckInternet(); } }
public bool IsConnection { get { return _IsConnection; } }
public ServicesClient()
{
httpClient = new HttpClient(new HttpClientHandler());
//You can change the key as you need and add value
httpClient.DefaultRequestHeaders.Add("key", "000000");
}
//Get Method
public async Task<T> GetAsync<T>(string URL) where T : class
{
if (IsConnection)
{
var result = await httpClient.GetStringAsync(URL);
if (!string.IsNullOrEmpty(result))
return JsonConvert.DeserializeObject<T>(result);
else
return null;
}
return null;
}
//Post Method
public async Task<T> PostAsync<T>(string URL, object param) where T : class
{
if (IsConnection)
{
var json = JsonConvert.SerializeObject(param);
var httpContent = new StringContent(json, Encoding.UTF8, "application/json");
var result = await httpClient.PostAsync(URL, httpContent);
if (result.IsSuccessStatusCode)
return JsonConvert.DeserializeObject<T>(result.Content.ReadAsStringAsync().Result);
}
return null;
}
bool CheckInternet()
{
return Connectivity.NetworkAccess == NetworkAccess.Internet;
}
}
}`

How to Read Parameters sent to an Action Method (WebAPI) within a DelegatingHandler

I am using IHttpClientFactory for sending requests and receiving HTTP responses from an external APIs using Net Core 2.2.
I have implemented a DelegatingHandler to "intercept" my http request and add the Authorization header (Token). if token is not valid, It gets a new token and retry one more time.
Likewise, when I get a new token for the first time, I cache the token in-memory for further references. For caching the token I have created a dictionary that requires an accountID and the token.
The problem I have got is that the DelegatingHandler is registered in the Startup.cs class, but at that moment I do not have the accountID, I get the accountID as a parameter in the ActionMethod of the Controller. That action method is the one calling SendAsync and getting the token from the DelegatingHandler and so on.
I do not know, how I can inject that accountID into the DelegatingHandler after a request has been received in the controller.
I was trying creating a IClientCredentials interface and an implementation of that interface that can be instantiated in the controller and injected into the DelegatingHandler.
My Code looks like this:
The DelegatingHandler:
public class AuthenticationDelegatingHandler : DelegatingHandler
{
private readonly AccessTokenManager _accessTokenManager;
private readonly IClientCredentials _clientCredentials;
public AuthenticationDelegatingHandler(IHttpClientFactory httpClientFactory,
IOptions<AppSettings> appSettings, IClientCredentials clientCredentials)
{
_accessTokenManager = new AccessTokenManager(httpClientFactory, appSettings);
_clientCredentials = clientCredentials;
}
protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
var clientCredentials = _clientCredentials.GetClientCredentials();
var accessToken = _accessTokenManager.GetToken(clientCredentials._accountID);
if (accessToken == null) {
accessToken = await _accessTokenManager.GetAccessTokenAsync(clientCredentials._accountID);
_accessTokenManager.AddOrUpdateToken(clientCredentials._accountID, accessToken);
}
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken.access_token);
var response = await base.SendAsync(request, cancellationToken);
if (response.StatusCode == HttpStatusCode.Unauthorized || response.StatusCode == HttpStatusCode.Forbidden)
{
var token = await _accessTokenManager.GetAccessTokenAsync(clientCredentials._accountID);
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token.access_token);
response = await base.SendAsync(request, cancellationToken);
}
return response;
}
}
Startup.cs like that:
services.AddScoped<IClientCredentials>(_ => new
ClientCredentials("au","123"));
services.AddHttpClient("myClient")
.AddHttpMessageHandler<AuthenticationDelegatingHandler>();
And The controller:
[HttpPost("{siteName}/{accountID}")]
public async Task<ActionResult<AirRequest>> Post(AirModel model, string
siteName, string accountID)
{
....
SetClientCredentials(siteName, accountID);
var clientJAAPI =
_httpClientFactory.CreateClient("myClient");
var responseclientJAAPI = await
clientJAAPI.SendAsync(request);
.....
}
private ClientCredentials SetClientCredentials(string siteName, string
accountID) =>
new ClientCredentials(siteName, accountID);

You can use HttpContext.Items to pass the data.
(Not tested, sent from mobile).
In controller:
this.HttpContext.Items["accountId"] = accountId;
In your Handler inject IHttpContextAccessor
var accountId = _httpContextAccessor.HttpContext.Items["accountId"];
IHttpContextAccessor not registered by default, but can be registered by one of components you are using. If you get an exception, register it explicetly in DI:
services.AddHttpContextAccessor();
If IHttpContextAccessor type is missing add Microsoft.AspNetCore.Http nuget.
The data will sit there untill end of the request.