How to do on-behalf-of auth in .NET Core (missing BootstrapContext)? - azure-active-directory

I've run the on-behalf-of sample in .NET 4.5:
https://github.com/Azure-Samples/active-directory-dotnet-webapi-onbehalfof
But I need to do the same thing in .NET core. When trying to port the sample service to .NET core everything compiles except for this line:
var bootstrapContext = ClaimsPrincipal.Current.Identities.First().BootstrapContext as System.IdentityModel.Tokens.BootstrapContext;
It won't compile because System.IdentityModel isn't available in .NET Core.
I discovered that if I acquire the user access token and the user name using this code instead it works for users in the same tenant as the service:
System.Security.Claims.ClaimsIdentity identity =
User.Identity as System.Security.Claims.ClaimsIdentity;
string userAccessToken = identity.BootstrapContext as string;
string userName = (User.FindFirst(ClaimTypes.Upn))?.Value;
But for users in a different tenant (multi-tenant authentication), userAccessToken and userName are set to null. What do I need to do differently to get this working for users coming from a different tenant?

I figured out that the reason userAccessToken and userName were coming back as null is because I was missing the SaveSigninToken parameter when calling UseJwtBearerAuthentication in Startup.cs:
app.UseJwtBearerAuthentication(new JwtBearerOptions
{
AutomaticAuthenticate = true,
AutomaticChallenge = true,
Authority = String.Format(CultureInfo.InvariantCulture, Configuration["Authentication:AzureAd:AADInstance"], Configuration["Authentication:AzureAd:Tenant"]),
Audience = Configuration["Authentication:AzureAd:Audience"],
TokenValidationParameters = new TokenValidationParameters { SaveSigninToken = true, ValidateIssuer = false }
});
Without SaveSigninToken = true, the caller's access token and identity doesn't flow through in the case where the caller is from another tenant.

Instead of using the BootstrapContext class to get the access_token, we can use the HttpContext in the controller directly to get the orignal access_token via code below:
var orignalToken = HttpContext.Request.Headers["authorization"][0].Split(' ')[1];

Related

Is there a way to avoid using the redirected form in Spring OAuth2 Authorization server when trying to get Authorization code? [duplicate]

I'm trying to create a local Java-based client that interacts with the SurveyMonkey API.
SurveyMonkey requires a long-lived access token using OAuth 2.0, which I'm not very familiar with.
I've been googling this for hours, and I think the answer is no, but I just want to be sure:
Is it possible for me to write a simple Java client that interacts with the SurveyMonkey, without setting up my own redirect server in some cloud?
I feel like having my own online service is mandatory to be able to receive the bearer tokens generated by OAuth 2.0. Is it possible that I can't have SurveyMonkey send bearer tokens directly to my client?
And if I were to set up my own custom Servlet somewhere, and use it as a redirect_uri, then the correct flow would be as follows:
Java-client request bearer token from SurveyMonkey, with
redirect_uri being my own custom servlet URL.
SurveyMonkey sends token to my custom servlet URL.
Java-client polls custom servlet URL until a token is available?
Is this correct?
Yes, it is possible to use OAuth2 without a callback URL.
The RFC6749 introduces several flows. The Implicit and Authorization Code grant types require a redirect URI. However the Resource Owner Password Credentials grant type does not.
Since RFC6749, other specifications have been issued that do not require any redirect URI:
RFC7522: Security Assertion Markup Language (SAML) 2.0 Profile for OAuth 2.0 Client Authentication and Authorization Grants
RFC7523: JSON Web Token (JWT) Profile for OAuth 2.0 Client Authentication and Authorization Grants
RFC8628: OAuth 2.0 Device Authorization Grant
In any case, if the grant types above do not fit on your needs, nothing prevent you from creating a custom grant type.
Not exactly, the whole point of the OAuth flow is that the user (the client you're accessing the data on behalf of) needs to give you permission to access their data.
See the authentication instructions. You need to send the user to the OAuth authorize page:
https://api.surveymonkey.net/oauth/authorize?api_key<your_key>&client_id=<your_client_id>&response_type=code&redirect_uri=<your_redirect_uri>
This will show a page to the user telling them which parts of their account you are requesting access to (ex. see their surveys, see their responses, etc). Once the user approves that by clicking "Authorize" on that page, SurveyMonkey will automatically go to whatever you set as your redirect URI (make sure the one from the url above matches with what you set in the settings for your app) with the code.
So if your redirect URL was https://example.com/surveymonkey/oauth, SurveyMonkey will redirect the user to that URL with a code:
https://example.com/surveymonkey/oauth?code=<auth_code>
You need to take that code and then exchange it for an access token by doing a POST request to https://api.surveymonkey.net/oauth/token?api_key=<your_api_key> with the following post params:
client_secret=<your_secret>
code=<auth_code_you_just_got>
redirect_uri=<same_redirect_uri_as_before>
grant_type=authorization_code
This will return an access token, you can then use that access token to access data on the user's account. You don't give the access token to the user it's for you to use to access the user's account. No need for polling or anything.
If you're just accessing your own account, you can use the access token provided in the settings page of your app. Otherwise there's no way to get an access token for a user without setting up your own redirect server (unless all the users are in the same group as you, i.e. multiple users under the same account; but I won't get into that). SurveyMonkey needs a place to send you the code once the user authorizes, you can't just request one.
You do need to implement something that will act as the redirect_uri, which does not necessarily need to be hosted somewhere else than your client (as you say, in some cloud).
I am not very familiar with Java and Servelets, but if I assume correctly, it would be something that could handle http://localhost:some_port. In that case, the flow that you describe is correct.
I implemented the same flow successfully in C#. Here is the class that implements that flow. I hope it helps.
class OAuth2Negotiator
{
private HttpListener _listener = null;
private string _accessToken = null;
private string _errorResult = null;
private string _apiKey = null;
private string _clientSecret = null;
private string _redirectUri = null;
public OAuth2Negotiator(string apiKey, string address, string clientSecret)
{
_apiKey = apiKey;
_redirectUri = address.TrimEnd('/');
_clientSecret = clientSecret;
_listener = new HttpListener();
_listener.Prefixes.Add(address + "/");
_listener.AuthenticationSchemes = AuthenticationSchemes.Anonymous;
}
public string GetToken()
{
var url = string.Format(#"https://api.surveymonkey.net/oauth/authorize?redirect_uri={0}&client_id=sm_sunsoftdemo&response_type=code&api_key=svtx8maxmjmqavpavdd5sg5p",
HttpUtility.UrlEncode(#"http://localhost:60403"));
System.Diagnostics.Process.Start(url);
_listener.Start();
AsyncContext.Run(() => ListenLoop(_listener));
_listener.Stop();
if (!string.IsNullOrEmpty(_errorResult))
throw new Exception(_errorResult);
return _accessToken;
}
private async void ListenLoop(HttpListener listener)
{
while (true)
{
var context = await listener.GetContextAsync();
var query = context.Request.QueryString;
if (context.Request.Url.ToString().EndsWith("favicon.ico"))
{
context.Response.StatusCode = (int)HttpStatusCode.NotFound;
context.Response.Close();
}
else if (query != null && query.Count > 0)
{
if (!string.IsNullOrEmpty(query["code"]))
{
_accessToken = await SendCodeAsync(query["code"]);
break;
}
else if (!string.IsNullOrEmpty(query["error"]))
{
_errorResult = string.Format("{0}: {1}", query["error"], query["error_description"]);
break;
}
}
}
}
private async Task<string> SendCodeAsync(string code)
{
var GrantType = "authorization_code";
//client_secret, code, redirect_uri and grant_type. The grant type must be set to “authorization_code”
var client = new HttpClient();
client.BaseAddress = new Uri("https://api.surveymonkey.net");
var request = new HttpRequestMessage(HttpMethod.Post, string.Format("/oauth/token?api_key={0}", _apiKey));
var formData = new List<KeyValuePair<string, string>>();
formData.Add(new KeyValuePair<string, string>("client_secret", _clientSecret));
formData.Add(new KeyValuePair<string, string>("code", code));
formData.Add(new KeyValuePair<string, string>("redirect_uri", _redirectUri));
formData.Add(new KeyValuePair<string, string>("grant_type", GrantType));
formData.Add(new KeyValuePair<string, string>("client_id", "sm_sunsoftdemo"));
request.Content = new FormUrlEncodedContent(formData);
var response = await client.SendAsync(request);
if (!response.IsSuccessStatusCode)
{
_errorResult = string.Format("Status {0}: {1}", response.StatusCode.ToString(), response.ReasonPhrase.ToString());
return null;
}
var data = await response.Content.ReadAsStringAsync();
if (data == null)
return null;
Dictionary<string, string> tokenInfo = JsonConvert.DeserializeObject<Dictionary<string, string>>(data);
return(tokenInfo["access_token"]);
}
}

How to update a User Claim after on a active SAML Session in .Net Core?

Is it possible to update a User Claim during a active SAML Session without a complete relogging to the application?
I want to change a specific claim (activeSite) that we use for authorization in backend and for filtering in queries.
I'm working with an .Net Core API and a Angular/Ionic frontend.
The code we use is from the TestWebAppCoreAngularApi Project with a little adoption by setting some custom user claims.
[Route("AssertionConsumerService")]
public async Task<IActionResult> AssertionConsumerService()
{
var binding = new Saml2PostBinding();
var saml2AuthnResponse = new Saml2AuthnResponse(config);
binding.ReadSamlResponse(Request.ToGenericHttpRequest(), saml2AuthnResponse);
if (saml2AuthnResponse.Status != Saml2StatusCodes.Success)
{
throw new AuthenticationException($"SAML Response status: {saml2AuthnResponse.Status}");
}
binding.Unbind(Request.ToGenericHttpRequest(), saml2AuthnResponse);
var relayStateQuery = binding.GetRelayStateQuery();
var activeSite = relayStateQuery.ContainsKey(relayStateActiveSite) ? relayStateQuery[relayStateActiveSite] : Url.Content("-1");
AddCustomClaims(saml2AuthnResponse, Int32.Parse(activeSite));
await saml2AuthnResponse.CreateSession(HttpContext, claimsTransform: (claimsPrincipal) => ClaimsTransform.Transform(claimsPrincipal));
var returnUrl = relayStateQuery.ContainsKey(relayStateReturnUrl) ? relayStateQuery[relayStateReturnUrl] : Url.Content("~/");
return Redirect(returnUrl);
}
Is it even possible to update that active claim (activeSite) during a active session?
And if so how can I update the claim in .Net?
I tryed something like removing and adding the claim with new value but this seems not to work correctly.
var principle = (ClaimsIdentity)User.Identity;
principle.RemoveClaim(claim);
principle.AddClaim(claim);
It is NOT possible to change claims after a successfully authentication flow. Changing claims require a re-login.
Hovewer, it is possible to change claims after user login in the authentication flow, by calling the ClaimsTransform.Transform, and the ClaimsTransform class.

Add additional query parameters to the Azure B2C login url

I'm implementing Azure B2C to a .NET MVC app, and I need to add an extra query parameter to the login url.
Here's how I've set it up in the startup.cs
var openIdConnectAuthenticationOptions = new OpenIdConnectAuthenticationOptions
{
// Generate the metadata address using the tenant and policy information
MetadataAddress = String.Format(Globals.WellKnownMetadata, Globals.Tenant, Globals.DefaultPolicy),
// These are standard OpenID Connect parameters, with values pulled from web.config
ClientId = Globals.ClientId,
RedirectUri = Globals.RedirectUri,
PostLogoutRedirectUri = Globals.RedirectUri,
// Specify the callbacks for each type of notifications
Notifications = new OpenIdConnectAuthenticationNotifications
{
RedirectToIdentityProvider = OnRedirectToIdentityProvider,
AuthorizationCodeReceived = OnAuthorizationCodeReceived,
AuthenticationFailed = OnAuthenticationFailed
},
// Specify the claim type that specifies the Name property.
TokenValidationParameters = new TokenValidationParameters
{
NameClaimType = "name",
ValidateIssuer = false
},
// Specify the scope by appending all of the scopes requested into one string (separated by a blank space)
Scope = $"openid",
ResponseType = "id_token",
};
app.UseOpenIdConnectAuthentication(
openIdConnectAuthenticationOptions
);
And when someone tries to visit an [authorized] tagged page, it sends them to this b2c url:
https://mytenant.b2clogin.com/mytenant.onmicrosoft.com/oauth2/v2.0/authorize?p=b2c_custom_signin&client_id=0000-000000-000-00&redirect_uri=https://localhost&response_type=id_token&scope=openid&x-client-SKU=ID_NET461&x-client-ver=5.3.0.0
However, I need to add an extra query parameter onto the end, "&appId=000-000-000", so the resulting login URL is:
https://mytenant.b2clogin.com/mytenant.onmicrosoft.com/oauth2/v2.0/authorize?p=b2c_custom_signin&client_id=0000-000000-000-00&redirect_uri=https://localhost&response_type=id_token&scope=openid&x-client-SKU=ID_NET461&x-client-ver=5.3.0.0 &appId=000-000-000
how would I go about doing this?
I'm afraid you could not add the appId parameter, but I recommend to make use of the state parameter. You could use this parameter to send the value of appid as part of request and it gets returned back in response.
For more details, see here.

Azure AD v2.0-specific optional claims missing from ID Token

I'm trying to add optional claims using Microsoft Identity Web - NuGet for user authentication in NET Core 3.1 WebApp. Reading the MS Docs, it seems that the only steps needed are to declare the optional claims within the App Registration Manifest file in Azure. But when testing the login process using two different apps (my own code and an MS project example) it looks like the optional claims are not being added to the ID Token when returned from Azure following a successful login i.e they're not present at all when viweing the token details in Debug.
I'm not sure how to diagnose this and where to trace the issue i.e am I missing any required steps in Azure setup?
Side Note: Just to confirm it is the jwt ID Token I want to receive the additional claims, NOT the jwt access token used for calling the graph or another Web API endpoint.
MS Docs reference: v2.0-specific optional claims set
Below is the extract from the Manifest file: (note I've even declared the "accessTokenAcceptedVersion": 2, given that optional claims I'm using are not available in ver.1, which if the above was left at default 'null' value then Azure will assume we're using legacy ver.1 - a possible gotcha)
"accessTokenAcceptedVersion": 2,
"optionalClaims": {
"idToken": [
{
"name": "given_name",
"source": "user",
"essential": false,
"additionalProperties": []
},
{
"name": "family_name",
"source": "user",
"essential": false,
"additionalProperties": []
}
],
"accessToken": [],
"saml2Token": []
},
Extract from startup class:
public void ConfigureServices(IServiceCollection services)
{
// Added to original .net core template.
// ASP.NET Core apps access the HttpContext through the IHttpContextAccessor interface and
// its default implementation HttpContextAccessor. It's only necessary to use IHttpContextAccessor
// when you need access to the HttpContext inside a service.
// Example usage - we're using this to retrieve the details of the currrently logged in user in page model actions.
services.AddHttpContextAccessor();
// DO NOT DELETE (for now...)
// This 'Microsoft.AspNetCore.Authentication.AzureAD.UI' library was originally used for Azure Ad authentication
// before we implemented the newer Microsoft.Identity.Web and Microsoft.Identity.Web.UI NuGet packages.
// Note after implememting the newer library for authetication, we had to modify the _LoginPartial.cshtml file.
//services.AddAuthentication(AzureADDefaults.AuthenticationScheme)
// .AddAzureAD(options => Configuration.Bind("AzureAd", options));
///////////////////////////////////
// Add services required for using options.
// e.g used for calling Graph Api from WebOptions class, from config file.
services.AddOptions();
// Add service for MS Graph API Service Client.
services.AddTransient<OidcConnectEvents>();
// Sign-in users with the Microsoft identity platform
services.AddSignIn(Configuration);
// Token acquisition service based on MSAL.NET
// and chosen token cache implementation
services.AddWebAppCallsProtectedWebApi(Configuration, new string[] { Constants.ScopeUserRead })
.AddInMemoryTokenCaches();
// Add the MS Graph SDK Client as a service for Dependancy Injection.
services.AddGraphService(Configuration);
///////////////////////////////////
// The following lines code instruct the asp.net core middleware to use the data in the "roles" claim in the Authorize attribute and User.IsInrole()
// See https://learn.microsoft.com/aspnet/core/security/authorization/roles?view=aspnetcore-2.2 for more info.
services.Configure<OpenIdConnectOptions>(OpenIdConnectDefaults.AuthenticationScheme, options =>
{
// The claim in the Jwt token where App roles are available.
options.TokenValidationParameters.RoleClaimType = "roles";
});
// Adding authorization policies that enforce authorization using Azure AD roles. Polices defined in seperate classes.
services.AddAuthorization(options =>
{
options.AddPolicy(AuthorizationPolicies.AssignmentToViewLogsRoleRequired, policy => policy.RequireRole(AppRole.ViewLogs));
});
///////////////////////////////////
services.AddRazorPages().AddMvcOptions(options =>
{
var policy = new AuthorizationPolicyBuilder()
.RequireAuthenticatedUser()
.Build();
options.Filters.Add(new AuthorizeFilter(policy));
}).AddMicrosoftIdentityUI();
// Adds the service for creating the Jwt Token used for calling microservices.
// Note we are using our independant bearer token issuer service here, NOT Azure AD
services.AddScoped<JwtService>();
}
Sample Razor PageModel method:
public void OnGet()
{
var username = HttpContext.User.Identity.Name;
var forename = HttpContext.User.Claims.FirstOrDefault(c => c.Type == "given_name")?.Value;
var surname = HttpContext.User.Claims.FirstOrDefault(c => c.Type == "family_name")?.Value;
_logger.LogInformation("" + username + " requested the Index page");
}
UPDATE
Getting closer to a solution but not quite there yet. Couple of issues resolved:
I originally created the Tenant in Azure to use B2C AD, even though I was no longer using B2C and had switched to Azure AD. It wasn't until I deleted the tenant and created a new one before I started to see the optional claims come through to the webapp correctly. After creating the new tenant and assigning the tenant type to use Azure AD, I then found that the 'Token Configuration' menu was now available for configuring the optional claims through the UI, it seems that modifying the App manifest is still required as well, as shown above.
I had to add the 'profile' scope as type 'delegated' to the webapp API Permissions in Azure.
The final issue still unresolved is that although I can see the claims present during Debug, I cant figure out how to retrieve the claim values.
In the method below, I can see the required claims when using Debug, but can't figure out how to retrieve the values:
public void OnGet()
{
var username = HttpContext.User.Identity.Name;
var forename = HttpContext.User.Claims.FirstOrDefault(c => c.Type == "given_name")?.Value;
var surname = HttpContext.User.Claims.FirstOrDefault(c => c.Type == "family_name")?.Value;
_logger.LogInformation("" + username + " requested the Index page");
}
Debug Screenshots shows the given_name & family_name are present:
I've tried different code examples using the claims principal to try and get the values out, but nothing is working for me. Hoping this final riddle is fairly simple to someone who knows the required syntax, as said we now have the required optional claims present, its just not knowing how to actually get the values out.
Big thanks to 'Dhivya G - MSFT Identity' for their assistance (see comments below my original question) method below now allows me to access the required claim values from the Token ID returned from Azure following successful login.
public void OnGet()
{
var username = HttpContext.User.Identity.Name;
var forename = HttpContext.User.Claims.FirstOrDefault(c => c.Type == ClaimTypes.GivenName)?.Value;
var surname = HttpContext.User.Claims.FirstOrDefault(c => c.Type == ClaimTypes.Surname)?.Value;
_logger.LogInformation("" + username + " requested the Index page");
}

Identity server claims asp.net API

I'm currently writing an angular application that first authenticates against think texture identityserver3.
This works fine, and I receive the bearer token without any issues.
When I use my token on an call to my API, I'm authenticated. I can see my userid, but have lost my claims (username, roles,...).
What do I have to do for transferring my claims with my token, or getting the roles from the identityserver?
You can tell Identity Server to include specific claims in an access token by adding that claim to your API's Scope.
Example:
var apiScope = new Scope {
Name = "myApi",
DisplayName = "My API",
Type = ScopeType.Resource,
Claims = new List<ScopeClaim> {
new ScopeClaim("myClaimType")
}
};
You can also use the AlwaysIncludeInIdToken property of ScopeClaim to include the claims in identity tokens as well as access tokens.
See https://identityserver.github.io/Documentation/docsv2/configuration/scopesAndClaims.html for more info.
We are doing something very similar using MS Web API 2 and a Thinktecture Identity Server v3.
To verify the user's claims we created an Authentication Filter, and then called the Identity server directly to get the user's claims. The bearer token only grants authentication and it is up to the API to get the claims separately.
protected override bool IsAuthorized(HttpActionContext actionContext)
{
string identityServerUrl = WebConfigurationManager.AppSettings.Get("IdentityServerUrl") + "/connect/userinfo";
using (var httpClient = new HttpClient())
{
httpClient.DefaultRequestHeaders.Authorization = actionContext.Request.Headers.Authorization;
var response = httpClient.GetAsync(identityServerUrl).Result;
if (response.IsSuccessStatusCode)
{
string responseString = response.Content.ReadAsStringAsync().Result;
Dictionary<string, string> claims = JsonConvert.DeserializeObject<Dictionary<string, string>>(responseString.ToLower());
... Do stuff with your claims here ...
}
}
}

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