Getting UserId of current user Blazor webassembly - entity-framework

So I am writing a Blazor webassembly application, with asp.ner core Identity. I need to get the ID of the current user, not the username that the methods in Identy give.
The method
Context. User.identity.name
gives the username but I need the ID for a fk in a model/table.
I can't use the username as usernames might change.
I have searched the net, however I keep seeing just the username returned.
Any assistance will be greatly appreciated.

I use this with the boiler plate Identity Server:
#page "/claims"
#inject AuthenticationStateProvider AuthenticationStateProvider
<h3>ClaimsPrincipal Data</h3>
<p>#_authMessage</p>
#if (_claims.Count() > 0)
{
<table class="table">
#foreach (var claim in _claims)
{
<tr>
<td>#claim.Type</td>
<td>#claim.Value</td>
</tr>
}
</table>
}
<p>#_userId</p>
#code {
private string _authMessage;
private string _userId;
private IEnumerable<Claim> _claims = Enumerable.Empty<Claim>();
protected override async Task OnParametersSetAsync()
{
await GetClaimsPrincipalData();
await base.OnParametersSetAsync();
}
private async Task GetClaimsPrincipalData()
{
var authState = await AuthenticationStateProvider.GetAuthenticationStateAsync();
var user = authState.User;
if (user.Identity.IsAuthenticated)
{
_authMessage = $"{user.Identity.Name} is authenticated.";
_claims = user.Claims;
_userId = $"User Id: {user.FindFirst(c => c.Type == "sub")?.Value}";
}
else
{
_authMessage = "The user is NOT authenticated.";
}
}
}

In Startup.cs, add the following line in ConfigureServices
services.AddHttpContextAccessor();
In your Blazor component, add the following lines on the top of the file
#using System.Security.Claims
#inject IHttpContextAccessor HttpContextAccessor
In your method, add the following lines to get the UserId
var principal = HttpContextAccessor.HttpContext.User;
var loggedInUserId = principal.FindFirstValue(ClaimTypes.NameIdentifier);

Not an answer, just a tip on using breakpoints to find the answer. My site is Blazor Server, so it's very possible that things are different-- in my case, Brian Parker's solution didn't work for me, so I did the following:
var user = (await AuthenticationStateProvider.GetAuthenticationStateAsync()).User;
if (true) {} // or any other code here, breakpoint this line
If you set a breakpoint right after retrieving the user, run the app and hover the user variable in the code when it breaks, it will pop up the complete object. By hovering various fields, you can investigate. I found that the claim type strings were big long things like "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier"
So the answer that worked for me was:
var user = (await AuthenticationStateProvider.GetAuthenticationStateAsync()).User;
string userId = user.FindFirst(c => c.Type.Contains("nameidentifier"))?.Value;
My point is that when the docs are complicated, or when the technology is changing fast so that one day's right answer is the next day's wrong lead, you can achieve a lot just by using VS to dig around.
Hope that helps someone. :D

Related

ASP.NET Core, where is FindByID?

I have an ASP.NET Core 2.0 application and I'm trying to attach a user to a model:
var user = _userManager.FindByIdAsync(Model.Author);
var promotion = new Promotion()
{
Title = Model.Title,
User = user //error here,
Created = DateTime.Now
};
The problem with this code is that I can't assign user to promotion.User as user is the result of an async operation. I'd prefer not to use FindByIdAsync but for some reason I can't find FindById.
UserManager contains only async API and FindByIdAsync actually returns Task<User> instead of User. So you need to make your code async also and use FindByIdAsync like this:
var user = await _userManager.FindByIdAsync(Model.Author); // will return the User
Only if it is not possible leave your code synchronous, e.g. by calling Result property of the Task which will cause your thread to block until the result is available
var user = _userManager.FindByIdAsync(Model.Author).Result;

Sending an async email without await from a .Net core web service

I have a webservice .Net core2 that has certain methods that send an email. I have it working fine using smtpclient.sendemailasync.
public async Task<bool> SendEmailAsync(MailMessage email)
{
try
{
if (string.IsNullOrWhiteSpace(emailFrom)) email.From = new MailAddress(emailFrom);
using (SmtpClient client = getSMTPClientInstance())
{
await client.SendMailAsync(email);
}
return true;
}
catch (Exception ex)
{
Log.Error(ex, "Error sending email in EmailService.SendEmailAsync");
return false;
}
}
The only issue is that some SMTP servers take a little too long to respond. I want to set up the email, queue it and return without waiting for the result.
Just using an unawaited async is out for 2 reasons;
It is not reliable to continue a method outside a request context in asp
I need access to the database context of my entity framework to write a log
I have to allow for external or internal SMTP (my client specifies), so a collection folder is not a possibility - at least not without a service that manages it.
How could I achieve this? Do I need to write a service that manages this? If so, how would I do that inside my .Net Core App, keeping in mind that the service also needs to access the EF context to write a log
UPDATE
There is plumbing available in .NetCore DI especially for this. Refer to my additional answer below. Use IServiceScopeFactory
You can call the RegisterAsyncTask method on the Page object. That will signal the ASP.NET runtime you want to make sure these are finished before terminating the request context:
Example:
public void Page_Load(object sender, EventArgs e)
{
RegisterAsyncTask(new PageAsyncTask(LoadSomeData));
}
public async Task LoadSomeData()
{
var clientcontacts = Client.DownloadStringTaskAsync("api/contacts");
var clienttemperature = Client.DownloadStringTaskAsync("api/temperature");
var clientlocation = Client.DownloadStringTaskAsync("api/location");
await Task.WhenAll(clientcontacts, clienttemperature, clientlocation);
var contacts = Newtonsoft.Json.JsonConvert.DeserializeObject<List<Contact>>(await clientcontacts);
var location = Newtonsoft.Json.JsonConvert.DeserializeObject<string>(await clientlocation);
var temperature = Newtonsoft.Json.JsonConvert.DeserializeObject<string>(await clienttemperature);
listcontacts.DataSource = contacts;
listcontacts.DataBind();
Temparature.Text = temperature;
Location.Text = location;
}
https://www.hanselman.com/blog/TheMagicOfUsingAsynchronousMethodsInASPNET45PlusAnImportantGotcha.aspx
So, while I have marked an answer, there are a couple of options that are better solutions for my specific example. First is the option to use a library like hangfire to schedule tasks - although that is not technically an answer to the question.
The better solution in .net core is to use IServiceScopeFactory
With IServiceScopeFactory you can rescope a task so it doesnt go out of scope when the request is complete. I did the following directly in a controller (I later moved to using the hangfire approach, but this works). As you can see, the async task is fired off in a new unawaited thread while the controller code continues.
var task = Task.Run(async () =>
{
using (var scope = _serviceScopeFactory.CreateScope())
{
var service = scope.ServiceProvider.GetRequiredService<ApprovalService>();
await service.sendResponseEmailAsync(approvalInfo.ApprovalId, userID, approvalInfo.emailTo, approvalInfo.ccTo);
}
});

Implement Custom Authentication In Windows Azure Mobile Services

Windows Azure Mobile Services currently doesn't have an option for custom authentication and looking at the feature request
http://feedback.azure.com/forums/216254-mobile-services/suggestions/3313778-custom-user-auth
It isn't coming anytime soon.
With a .NET backend and a .NET application how do you implement custom authentication, so that you don't have to use Facebook, Google or any of their other current providers?
There are plenty of partially completed tutorials on how this this is done with a JS backend and iOS and Android but where are the .NET examples?
I finally worked through the solution, with some help of the articles listed below, some intellisense and some trial and error.
How WAMS Works
First I wanted to describe what WAMS is in a very simple form as this part confused me for a while until it finally clicked. WAMS is just a collection of pre-existing technologies packaged up for rapid deployment. What you need to know for this scenario is:
As you can see WAMS is really just a container for a WebAPI and other things, which I won't go into detail here. When you create a new Mobile Service in Azure you get to download a project that contains the WebAPI. The example they use is the TodoItem, so you will see code for this scenario through the project.
Below is where you download this example from (I was just doing a Windows Phone 8 app)
I could go on further about this but this tutorial will get you started:
http://azure.microsoft.com/en-us/documentation/articles/mobile-services-dotnet-backend-windows-store-dotnet-get-started/
Setup WAMS Project
You will need your MasterKey and ApplicationKey. You can get them from the Azure Portal, clicking on your Mobile Services App and pressing Manage Keys at the bottom
The project you just downloaded, in the Controllers folder I just created a new controller called AccountController.cs and inside I put
public HttpResponseMessage GetLogin(String username, String password)
{
String masterKey = "[enter your master key here]";
bool isValidated = true;
if (isValidated)
return new HttpResponseMessage() { StatusCode = HttpStatusCode.OK, Content = new StringContent("{ 'UserId' : 'F907F58C-09FE-4F25-A26B-3248CD30F835', 'token' : '" + GetSecurityToken(new TimeSpan(1,0, 0), String.Empty, "F907F58C-09FE-4F25-A26B-3248CD30F835", masterKey) + "' }") };
else
return Request.CreateErrorResponse(HttpStatusCode.Unauthorized, "Username and password are incorrect");
}
private static string GetSecurityToken(TimeSpan periodBeforeExpires, string aud, string userId, string masterKey)
{
var now = DateTime.UtcNow;
var utc0 = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
var payload = new
{
exp = (int)now.Add(periodBeforeExpires).Subtract(utc0).TotalSeconds,
iss = "urn:microsoft:windows-azure:zumo",
ver = 2,
aud = "urn:microsoft:windows-azure:zumo",
uid = userId
};
var keyBytes = Encoding.UTF8.GetBytes(masterKey + "JWTSig");
var segments = new List<string>();
//kid changed to a string
var header = new { alg = "HS256", typ = "JWT", kid = "0" };
byte[] headerBytes = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(header, Formatting.None));
byte[] payloadBytes = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(payload, Formatting.None));
segments.Add(Base64UrlEncode(headerBytes));
segments.Add(Base64UrlEncode(payloadBytes));
var stringToSign = string.Join(".", segments.ToArray());
var bytesToSign = Encoding.UTF8.GetBytes(stringToSign);
SHA256Managed hash = new SHA256Managed();
byte[] signingBytes = hash.ComputeHash(keyBytes);
var sha = new HMACSHA256(signingBytes);
byte[] signature = sha.ComputeHash(bytesToSign);
segments.Add(Base64UrlEncode(signature));
return string.Join(".", segments.ToArray());
}
// from JWT spec
private static string Base64UrlEncode(byte[] input)
{
var output = Convert.ToBase64String(input);
output = output.Split('=')[0]; // Remove any trailing '='s
output = output.Replace('+', '-'); // 62nd char of encoding
output = output.Replace('/', '_'); // 63rd char of encoding
return output;
}
You can replace what is in GetLogin, with your own validation code. Once validated, it will return a security token (JWT) that is needed.
If you are testing on you localhost, remember to go into your web.config file and fill in the following keys
<add key="MS_MasterKey" value="Overridden by portal settings" />
<add key="MS_ApplicationKey" value="Overridden by portal settings" />
You need to enter in your Master and Application Keys here. They will be overridden when you upload them but they need to be entered if you are running everything locally.
At the top of the TodoItemController add the AuthorizeLevel attribute as shown below
[AuthorizeLevel(AuthorizationLevel.User)]
public class TodoItemController : TableController<TodoItem>
You will need to modify most of the functions in your TodoItemController but here is an example of the Get All function.
public IQueryable<TodoItem> GetAllTodoItems()
{
var currentUser = User as ServiceUser;
Guid id = new Guid(currentUser.Id);
return Query().Where(todo => todo.UserId == id);
}
Just a side note I am using UserId as Guid (uniqueidentifier) and you need to add this to the todo model definition. You can make the UserId as any type you want, e.g. Int32
Windows Phone/Store App
Please note that this is just an example and you should clean the code up in your main application once you have it working.
On your Client App
Install NuGet Package: Windows Azure Mobile Services
Go into App.xaml.cs and add this to the top
public static MobileServiceClient MobileService = new MobileServiceClient(
"http://localhost:50527/",
"[enter application key here]"
);
In the MainPage.xaml.cs I created
public class Token
{
public Guid UserId { get; set; }
public String token { get; set; }
}
In the main class add an Authenticate function
private bool Authenticate(String username, String password)
{
HttpClient client = new HttpClient();
// Enter your own localhost settings here
client.BaseAddress = new Uri("http://localhost:50527/");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage response = client.GetAsync(String.Format("api/Account/Login?username={0}&password={1}", username, password)).Result;
if (response.StatusCode == System.Net.HttpStatusCode.OK)
{
var token = Newtonsoft.Json.JsonConvert.DeserializeObject<Token>(response.Content.ReadAsStringAsync().Result);
App.MobileService.CurrentUser = new MobileServiceUser(token.UserId.ToString());
App.MobileService.CurrentUser.MobileServiceAuthenticationToken = token.token;
return true;
}
else
{
//Something has gone wrong, handle it here
return false;
}
}
Then in the Main_Loaded function
private void MainPage_Loaded(object sender, RoutedEventArgs e)
{
Authenticate("test", "test");
RefreshTodoItems();
}
If you have break points in the WebAPI, you will see it come in, get the token, then come back to the ToDoItemController and the currentUser will be filled with the UserId and token.
You will need to create your own login page as with this method you can't use the automatically created one with the other identity providers. However I much prefer creating my own login screen anyway.
Any other questions let me know in the comments and I will help if I can.
Security Note
Remember to use SSL.
References
[] http://www.thejoyofcode.com/Exploring_custom_identity_in_Mobile_Services_Day_12_.aspx
[] http://www.contentmaster.com/azure/creating-a-jwt-token-to-access-windows-azure-mobile-services/
[] http://chrisrisner.com/Custom-Authentication-with-Azure-Mobile-Services-and-LensRocket
This is exactly how you do it. This man needs 10 stars and a 5 crates of beer!
One thing, I used the mobile Service LoginResult for login like:
var token = Newtonsoft.Json.JsonConvert.DeserializeObject(response.Content.ReadAsStringAsync().Result);
Hope to get this into Android now!

Facebook c# sdk get users email

I have a site which is using facebook for auth. I want to gather some basic info when a user signs up including their email address.
The code i have for the login is standard:
public ActionResult Login(string returnUrl)
{
var oAuthClient = new FacebookOAuthClient();
oAuthClient.AppId = AppSettings.GetConfigurationString("appId");
oAuthClient.RedirectUri = new Uri(AppSettings.GetConfigurationString("redirectUrl"));
var loginUri = oAuthClient.GetLoginUrl(new Dictionary<string, object> { { "state", returnUrl } });
return Redirect(loginUri.AbsoluteUri);
}
How do i add the request to access permissions in that? Or do i do it another way?
You need to use the email permission (the full list is here: http://developers.facebook.com/docs/authentication/permissions/ )
The way to add permissions to the authorization is by appending a comma separated list to &scope= , e.g.:
https://www.facebook.com/dialog/oauth?client_id=YOUR_APP_ID&redirect_uri=YOUR_URL&scope=email,read_stream
Update: As you marked, the parameters are passed to the GetLoginUrl() method, although in the codeplex forum they also used ExchangeCodeForAccessToken(), which you might want to take a look at also.
A couple of examples using the C# SDK:
http://blog.prabir.me/post/Facebook-CSharp-SDK-Writing-your-first-Facebook-Application.aspx
Facebook .NET SDK: How to authenticate with ASP.NET MVC 2
http://facebooksdk.codeplex.com/discussions/244568
A snoop at the sdk code and i came up wiht:
public ActionResult Login(string returnUrl)
{
var oAuthClient = new FacebookOAuthClient();
oAuthClient.AppId = AppSettings.GetConfigurationString("appId");
oAuthClient.RedirectUri = new Uri(AppSettings.GetConfigurationString("redirectUrl"));
var parameters = new Dictionary<string, object>();
parameters["state"] = returnUrl;
parameters["scope"] = "email";
var loginUri = oAuthClient.GetLoginUrl(parameters);
return Redirect(loginUri.AbsoluteUri);
}
not tested it yet and the missus is shouting at me for working late so will have to test tomoz :)

How to get the complete request that calls my MVC2 controller?

Newbie question … sorry ;-)
I have to write and to integrate a new website in a complex web application.
My new (MVC2) website will be hosted on a separate server and only called when the user clicks on a link in the already existing, complex website.
Means I(!) define the URL which calls my(!) new website.
But “they” (the calling, already existing, complex web application/website) will add an attribute to the url. This attribute is the sessionID.
Ok, I think I understand already that this calls my (MVC2) controller.
But how can I get in my (MVC2) controller the “calling URL” (which include the added sessionID)?
Hopefully that someone understand what I ask ;-)
Thanks in advance!
I want just share my little parser - hopefully it helps someone. ;-)
Also requests like
(Request.Url.Query =) "?sessionID=12345678901234567890123456789012&argumentWithoutValue&x=1&y&z=3"
will be well parsed.
Here my code:
Hashtable attributes = new Hashtable();
string query = Request.Url.Query;
string[] arrPairs = query.Split('&'); // ...?x=1&y=2
if (arrPairs != null)
{
foreach(string s in arrPairs)
{
if (!String.IsNullOrEmpty(s))
{
string onePair = s.Replace("?", "").Replace("&", "");
if (onePair.Contains("="))
{
string[] arr = onePair.Split('=');
if (arr != null)
{
if (arr.Count() == 2)
{
attributes.Add(arr[0], arr[1]);
}
}
}
else
{
// onePair does not contain a pair!
attributes.Add(onePair, "");
}
}
}
You really should set your URL and Route to be more MVC-Like. The URL you are calling should be:
newapp/controller/action/sessionId
Then set your route up:
routes.MapRoute(
"sessionId",
"{controller}/{action}/{sessionId}",
new { controller = "controller", action = "action", sessionId = 0 });
Then in your controller:
public ActionResult Action(int sessionId)
{
}
In your controller you still have direct access to the Request object, so you can use Request.Url, etc.
Does that answer your question, or is it something else that you need?