Confused on how to get access tokens from B2C in Blazor App
I have created a sample application with OpenId Connect and Blazor (Server) for you here https://github.com/yberstad/BlazorAuth. It is uses a SameSiteCookie and OpenId Connect.
- In the appsettings.json, fill in your Authority, ClientId and ClientSecret.
- Configure the redirect URi in Azure to http://localhost:62438/signin-oidc/
- Start up the app in debug mode
- Got to http://localhost:62438/api/openidconnect/login
- Login with Azure
- Got to http://localhost:62438/api/openidconnect/user, having a break point in the OpenIdConnectController.GetUser action, there you can see how to getting hold of the access token.
How to get access and refresh token:
var accessToken = await HttpContext.GetTokenAsync("access_token");var refreshToken = await HttpContext.GetTokenAsync("refresh_token");
SameSiteCookie Info:https://brockallen.com/2019/01/11/same-site-cookies-asp-net-core-and-external-authentication-providers/
Getting Access Token:http://docs.identityserver.io/en/latest/quickstarts/5_hybrid_and_api_access.html#using-the-access-token
Having the tokens stored in a SameSiteCookie makes it only visible for the server, hence not saving and exposing it in an unsafe environment on the client. A SameSiteCookie is also safe for XSS.
Hope this helps.
I was able to solve this myself. My AcquireTokenSilent call was failling because there was no users in the cache when I call it, so I had to make sure to add first entry to the cache when my user logs in. I was able to achieve this by configuring my auth as follows:
services.AddAuthentication(sharedOptions => { sharedOptions.DefaultScheme = AzureADB2CDefaults.AuthenticationScheme; sharedOptions.DefaultChallengeScheme = AzureADB2CDefaults.OpenIdScheme; }) .AddAzureADB2C(options => Configuration.Bind("AzureAdB2C", options)) .AddCookie(); services.Configure<OpenIdConnectOptions>(AzureADB2CDefaults.OpenIdScheme, options => { //Configuration.Bind("AzureAdB2C", options); options.ResponseType = Microsoft.IdentityModel.Protocols.OpenIdConnect.OpenIdConnectResponseType.CodeIdToken; options.Scope.Add("offline_access"); options.Scope.Add("https://mytenant.onmicrosoft.com/api/api.read.write"); options.SaveTokens = true; options.GetClaimsFromUserInfoEndpoint = true; options.Events.OnAuthorizationCodeReceived = async context => { AzureADB2COptions opt = new AzureADB2COptions(); Configuration.Bind("AzureAdB2C", opt); // As AcquireTokenByAuthorizationCodeAsync is asynchronous we want to tell ASP.NET core that we are handing the code // even if it's not done yet, so that it does not concurrently call the Token endpoint. (otherwise there will be a // race condition ending-up in an error from Azure AD telling "code already redeemed") context.HandleCodeRedemption(); var code = context.ProtocolMessage.Code; string signedInUserID = context.Principal.FindFirst(ClaimTypes.NameIdentifier).Value; IConfidentialClientApplication cca = ConfidentialClientApplicationBuilder.Create(opt.ClientId) .WithB2CAuthority(opt.Authority) .WithRedirectUri(opt.RedirectUri) .WithClientSecret(opt.ClientSecret) .WithClientName("myWebapp") .WithClientVersion("0.0.0.1") .Build(); new MSALStaticCache(signedInUserID, context.HttpContext).EnablePersistence(cca.UserTokenCache); try { AuthenticationResult result = await cca.AcquireTokenByAuthorizationCode(opt.ApiScopes.Split(' '), code) .ExecuteAsync(); context.HandleCodeRedemption(result.AccessToken, result.IdToken); } catch (Exception) { } }; });