I'm trying to authenticate a request from my Google Cloud Function to my API on App Engine (Standard environment).
I have something working, but I'm new to OAuth2 and am looking for a sanity check.
In my Cloud Function, I send an authenticated request to my API doing the following:
import { GoogleAuth } from 'google-auth-library';
// Send Request Code:
const auth = new GoogleAuth();
const tokenClient = await auth.getIdTokenClient(`/protectedEndpoint`);
await tokenClient.request({
url: `https://${process.env.GCLOUD_PROJECT}.appspot.com/protectedEndpoint`,
method: 'POST',
});
In the API (on App Engine), I do the following:
import { GoogleAuth } from 'google-auth-library';
// Handle Request Code:
const token = <Bearer token parsed from request headers>
const googleAuth = new GoogleAuth();
const tokenClient = await googleAuth.getIdTokenClient('');
const loginTicket = await tokenClient.verifyIdToken({
idToken: token,
audience: '/protectedEndpoint',
});
if (loginTicket.getUserId() !== process.env.SERVICE_ACCOUNT_ID)) {
throw new Error('Unauthenticated Service Account');
}
return 'Successful Authentication'
Note: In both cases, I'm using Google's default application credentials to initialize the GoogleAuth client. (my Default App Engine service account)
This all works. My function sends a request to my API, and my API is able to parse the bearer token and tell me that it came from my approved service account... but I'm not 100% confident that this is actually secure. Is it possible for someone to spoof my service account without having its credentials?
Thanks in advance!
Is it possible for someone to spoof my service account without having
its credentials?
A precise answer requires the specification of time. Given enough time and processing power, any authentication/authorization/encryption/hashing/signing method can be broken.
A Google service account contains an RSA 2048-bit private key. Current guesstimates are 300 trillion years to break RSA 2048 bit encryption. With the rapid advances in computers, let's assume your data will probably not be of any use/value by the time RSA is broken.
The private key is used to sign a JWT. The Signed JWT is used to request OAuth Access/Identity Tokens.
Spoofing would require signing with the same private key. Therefore, spoofing is not possible with today's technology.
Stealing/leaking the private key or the generated OAuth tokens is the only realistic method today.
Related
I have an ASP.NET 6.0 Web API project. I would like to add authentication and authorization to it, but it must use SSO via Azure.
We already have a SPA application that does this, it uses the Angular MSAL library to redirect the user to an SSO Login page, then returns to the SPA with an access token. The access token is then added to the header of each request to the Web API, which uses it to enforce authentication.
Now we want to share our web API with other teams within our organization, and we would like to have that login process just be another API call, rather than a web page.
Conceptually, a client would hit the /login endpoint of our API, passing in a userID and password. The web API would then get an access token from Azure, then return it as the payload of the login request. It's then up to the client to add that token to subsequent request headers.
I have done this with regular ASP.NET Identity, where all of the user and role data is stored in a SQL database, but since our organization uses SSO via Azure Active Directory, we would rather use that.
I have researched this topic online, and so far all of the examples I have seen use a separate SPA, just like we already have. But as this is a web api, not a front-end, we need to have an API method that does this instead.
Is this even possible? I know Microsoft would rather not have user credentials flow through our own web server, where a dishonest programmer might store them for later misuse. I understand that. But I'm not sure there's a way around this.
Thanks.
I believe you are looking for the Resource Owner Password (ROP) flow. You can use IdentityModel.OidcClient to implement it.
Sample code:
public class Program
{
static async Task Main()
{
// call this in your /login endpoint and return the access token to the client
var response = await RequestTokenAsync("bob", "bob");
if (!response.IsError)
{
var accessToken = response.AccessToken;
Console.WriteLine(accessToken);
}
}
static async Task<TokenResponse> RequestTokenAsync(string userName, string password)
{
var client = new HttpClient();
var disco = await client.GetDiscoveryDocumentAsync(Constants.Authority);
if (disco.IsError) throw new Exception(disco.Error);
var response = await client.RequestPasswordTokenAsync(new PasswordTokenRequest
{
Address = disco.TokenEndpoint,
ClientId = "roclient",
ClientSecret = "secret",
UserName = userName,
Password = password,
Scope = "resource1.scope1 resource2.scope1",
Parameters =
{
{ "acr_values", "tenant:custom_account_store1 foo bar quux" }
}
});
if (response.IsError) throw new Exception(response.Error);
return response;
}
}
Sample taken from IdentityServer4 repository where you can find more ROP flow client examples.
I would recommend that you don't go with this implementation and instead have all clients obtain their access tokens directly from Azure AD like you did with your Angular SPA.
I'm trying to get azure AD authentication working between a Blazor WASM app, and another API that I have running locally but on a different port. I need both applications to use the Azure login, but I only want the user to have to log in once on the Blazor app which should then pass those credentials through to the API.
I've set up app registrations for both apps in the portal, created the redirect url, exposed the API with a scope and I can successfully log into the blazor app and see my name using #context.User.Identity.Name.
When it then tries to call the API though, I get a 401 error back and it doesn't hit any breakpoints in the API (presumably because there is no authentication being passed across in the http request).
My code in the Blazor app sets up a http client with the base address set to the API:
public static async Task Main(string[] args)
{
var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.Services.AddHttpClient("APIClient", client => client.BaseAddress = new Uri("https://localhost:11001"))
.AddHttpMessageHandler<BaseAddressAuthorizationMessageHandler>();
builder.Services.AddScoped(sp => sp.GetRequiredService<IHttpClientFactory>().CreateClient("APIClient"));
builder.Services.AddMsalAuthentication<RemoteAuthenticationState, CustomUserAccount>(options =>
{
builder.Configuration.Bind("AzureAd", options.ProviderOptions.Authentication);
options.ProviderOptions.DefaultAccessTokenScopes.Add("api://d3152e51-9f5e-4ff7-85f2-8df5df5e2b2e/MyAPI");
//options.UserOptions.RoleClaim = "appRole";
});
await builder.Build().RunAsync();
}
In my API, I just have the Authorise attribute set on the class, and eventually will need roles in there too:
[Authorize]
[Route("api/[controller]")]
[ApiController]
public class CarController
Then, in my Blazor component, I then inject the http factory and try to make a request:
#inject IHttpClientFactory _factory
...
private async Task RetrieveCars()
{
var httpClient = _factory.CreateClient("APIClient");
HttpResponseMessage response = await httpClient.GetAsync("https://localhost:11001/api/cars");
var resp = await response.Content.ReadAsStringAsync();
cars = JsonSerializer.Deserialize<List<Car>>(resp);
}
but this returns the 401 error. I've also tried a few different variations like just injecting a http client (#inject HttpClient Http) but nothing seems to be adding my authorisation into the API calls. The options.UserOptions.RoleClaim is also commented out in the AddMsalAuthentication section as I wasn't sure if it was needed, but it doesn't work with or without it in there.
Can anyone explain what I'm doing wrong and what code I should be using?
Common causes.
Most cases ,we tend to forget to grant consent after giving API
permissions in the app registration portal,after exposing the api
which may lead to unauthorized error.
Other thing is when Audience doesn’t match the “aud” claim when we
track the token in jwt.io .Make sure ,Audience=clientId is configured
in the code in authentication scheme or Token validation parameters
by giving ValidAudiences.And also try with and without api:// prefix
in client id parameter.
Sometimes aud claim doesn’t match as we mistakenly send ID token
instead of Access tokens as access tokens are meant to call APIs .So
make sure you check mark both ID Token and access token in portal
while app registration.
While Enabling the authentication by injecting the [Authorize]
attribute to the Razor pages.Also add reference
Microsoft.AspNetCore.Authorization as(#using
Microsoft.AspNetCore.Authorization)
Please see the note in MS docs and some common-errors
If above are not the cases, please provide with additional error details and startup configurations or any link that you are following to investigate further.
I just wanted to know how can we validate the azure ad access token in a backend API in my case i.e. Django rest framework.
Consider that I have a single page app or a native app and a backend API (django rest framework) completely independen of each other. In my case if my single page app/native app wants to access certain data from the backend API, and inorder to access the API, user should be logged in the backend API.
So what my approch is to make use of MSAL library to get the access token from the SPA/native app and then once token is acquired, pass that token to backend API, validate it, get the user info from graph api. If user exists in the DB then login the user and pass the required info. If user info doesn't exist then create the user, login and pass the info from the API.
So my question is when I pass the access token to my backend api, how can I validate that the token that a user/SPA/native app has passed to backend API is valid token or not?
Is it just we need to make an API call to graph API endpoint with accessToken that user/SPA/native passed and if it is able to get the user data with the accessToken then then token is valid or if it fails then the accessToken is invalid.
Is it the general way to validate the token or some better approach is there? Please help
Good day sir, I wanna share some of my ideas here and I know it's not a solution but it's too long for a comment.
I created a SPA before which used msal.js to make users sign in and generate access token to call graph api, you must know here that when you generate the access token you need to set the scope of the target api, for example, you wanna call 'graph.microsoft.com/v1.0/me', you need a token with the scope 'User.Read, User.ReadWrite' and you also need to add delegated api permission to the azure app.
So as the custom api of your own backend program. I created a springboot api which will return 'hello world' if I call 'localhost:8080/hello', if I wanna my api protected by azure ad, I need to add a filter to validate all the request if has a valid access token. So I need to find a jwt library to decode the token in request head and check if it has a token, if the token has expired and whether the token has the correct scope. So here, which scope is the correct scope? It's decided by the api you exposed in azure ad. You can set the scope named like 'AA_Custom_Impression', and then you can add this delegate api permission to the client azure ad app, then you that app to generate an access token with the scope of 'AA_Custom_Impression'. After appending the Bearer token in calling request, it will be filtered by backend code.
I don't know about python, so I can just recommend you this sample, you may try it, it's provided by microsoft.
I've solved the similar issue. I don't found how to directly validate access token, but you can just call graph API on backend with token you've got on client side with MSAL.
Node.js example:
class Microsoft {
get baseUrl() {
return 'https://graph.microsoft.com/v1.0'
}
async getUserProfile(accessToken) {
const response = await got(`${this.baseUrl}/me`, {
headers: {
'x-li-format': 'json',
Authorization: `Bearer ${accessToken}`,
},
json: true,
})
return response.body
}
// `acessToken` - passed from client
async authorize(accessToken) {
try {
const userProfile = await this.getUserProfile(accessToken)
const email = userProfile.userPrincipalName
// Note: not every MS account has email, so additional validation may be required
const user = await db.users.findOne({ email })
if (user) {
// login logic
} else {
// create user logic
}
} catch (error) {
// If request to graph API fails we know that token wrong or not enough permissions. `error` object may be additionally parsed to get relevant error message. See https://learn.microsoft.com/en-us/graph/errors
throw new Error('401 (Unauthorized)')
}
}
}
Yes we can validate the Azure AD Bearer token.
You can fellow up below link,
https://github.com/odwyersoftware/azure-ad-verify-token
https://pypi.org/project/azure-ad-verify-token/
We can use this for both Django and flask.
You can directly install using pip
but I'm not sure in Django. If Django install working failed then try to copy paste the code from GitHub
Validation steps this library makes:
1. Accepts an Azure AD B2C JWT.
Bearer token
2. Extracts `kid` from unverified headers.
kid from **Bearer token**
3. Finds `kid` within Azure JWKS.
KID from list of kid from this link `https://login.microsoftonline.com/{tenantid}/discovery/v2.0/keys`
4. Obtains RSA key from JWK.
5. Calls `jwt.decode` with necessary parameters, which inturn validates:
- Signature
- Expiration
- Audience
- Issuer
- Key
- Algorithm
In a angularjs application, i use adal and adal-angular libraries to authentify user on Azure AD. On backend I use OWIN middleware in my webAPI to add custom claims with :
app.UseWindowsAzureActiveDirectoryBearerAuthentication(new WindowsAzureActiveDirectoryBearerAuthenticationOptions
{
Audience = ConfigurationManager.AppSettings["ida:Audience"],
Tenant = ConfigurationManager.AppSettings["ida:Tenant"],
Provider = new OAuthBearerAuthenticationProvider()
{
OnValidateIdentity = async context =>
{
if(!context.IsValidated)
return;
var userManager = context.OwinContext.Get<UserManager>();
string email = context.Ticket.Identity.GetClaimValue(System.Security.Claims.ClaimTypes.Email);
User user = userManager.GetByEmail(email);
context.Ticket.Identity.AddClaim(new Claim(ClaimTypes.UserId, user.Id.ToString(CultureInfo.InvariantCulture));
}
}
});
It's work for the current request, but how to add the claim in the bearer send by httpinterceptor of adal-angular for the next requests?
To answer your direct question: you cannot modify the access token, period.
It has a digital signature which will no longer be valid if you change anything in the token.
It's a security measure that prevents tampering.
Your OWIN middleware downloads the public keys of the signing key pairs from Azure AD on startup, and uses those to validate tokens.
Now if you stored your internal ids as extension attributes,
it would actually be possible to tell Azure AD to include that in the tokens.
This feature is in preview though, and not recommended for production use: https://learn.microsoft.com/en-us/azure/active-directory/develop/active-directory-optional-claims#configuring-custom-claims-via-directory-extensions.
Here you would set the internal id as an extension on the User entity, and have it included for access tokens to your API.
A pragmatic solution to your issue might be an in-memory cache.
How often do emails change?
I am fairly new to AngularJS
I have a resource that I use for user management which is part of a service following this article.
Once sending the login request to the server I am getting a response with a set-cookie as part of the header.
What is the best practice to add this cookie to every request I am sending to the server?
myApp.factory('UserService', ['$resource', function ($resource) {
var userRes = $resource('http://<MyDomain>/api/v1/user/:param',
{param: '#param'},
{
login: {
method: 'POST'
},
logout: {
method: 'DELETE'
}
});
var user;
return {
signIn: function () {
user = userRes.login({param: 'login'}, {"email": "SomeName#MyDomain.com", "password": "test1"});
userRes.get({param: '1'});
},
userRes.login has set-cookie header in on the response
userRes.get does not send the cookie that was just received.
Cheers
Since your API is in a different domain you can't use cookies in this case. We've tried and we failed to put it simple there is no way, not only it doesn't work with CORS but also it doesn't work if you embed an iframe. The iframe trick fails on safaris mostly but it is not reliable.
What we usually do is to return a JWT (Json Web Token) from the API and attach a header then to every API request as Authorization: Bearer JWT.
This JWT can be decoded using a public key from the front end (and it will contain the user profile) and validad with a private key in the backend.
JWT is simple and there are plenty of libraries for every language/technology.
Auth0 is an authentication broker that can validate with any identity provider or custom databases, and it returns JWTs using standars. It provides a clientID that can be used to decode the profile in the front end and a secret to validate the tokens in the backend as well as client side library to do this.
Disclaimer: I work for auth0.