Web API 2 OWIN Bearer Token purpose of cookie? - asp.net-mvc-5

I am trying to understand the new OWIN Bearer Token authentication process in the Single Page App template in MVC 5. Please correct me if I'm wrong, for the OAuth password client authentication flow, Bearer Token authentication works by checking the http authorization request header for the Bearer access token code to see if a request is authenticated, it doesn't rely on cookie to check if a particular request is authenticated.
According to this post:
OWIN Bearer Token Authentication with Web API Sample
public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
{
using (IdentityManager identityManager = _identityManagerFactory.CreateStoreManager())
{
if (!await identityManager.Passwords.CheckPasswordAsync(context.UserName, context.Password))
{
context.SetError("invalid_grant", "The user name or password is incorrect.");
return;
}
string userId = await identityManager.Logins.GetUserIdForLocalLoginAsync(context.UserName);
IEnumerable<Claim> claims = await GetClaimsAsync(identityManager, userId);
ClaimsIdentity oAuthIdentity = CreateIdentity(identityManager, claims,
context.Options.AuthenticationType);
ClaimsIdentity cookiesIdentity = CreateIdentity(identityManager, claims,
_cookieOptions.AuthenticationType);
AuthenticationProperties properties = await CreatePropertiesAsync(identityManager, userId);
AuthenticationTicket ticket = new AuthenticationTicket(oAuthIdentity, properties);
context.Validated(ticket);
context.Request.Context.Authentication.SignIn(cookiesIdentity);
}
}
The GrantReourceOwnerCredentials function not only compose the ticket with this line: context.Validated(ticket); but it also compose a cookie identity and set it to the cookie with this line: context.Request.Context.Authentication.SignIn(cookiesIdentity);
So my questions are, what is the exact purpose of the cookie in this function? Shouldn't the AuthenticationTicket be good enough for authentication purpose?

In the SPA template there are actually two separate authentication mechanisms enabled- cookie authentication and token authentication. This enables authentication of both MVC and Web API controller actions, but requires some additional setup.
If you look in the WebApiConfig.Register method you'll see this line of code:
config.SuppressDefaultHostAuthentication();
That tells Web API to ignore cookie authentication, which avoids a host of problems which are explained in the link you posted in your question:
"...the SPA template enables application cookie middleware as active mode as well in order to enable other scenarios like MVC authentication. So Web API will still be authenticated if the request has session cookie but without a bearer token. That’s probably not what you want as you would be venerable to CSRF attacks for your APIs. Another negative impact is that if request is unauthorized, both middleware components will apply challenges to it. The cookie middleware will alter the 401 response to a 302 to redirect to the login page. That is also not what you want in a Web API request."
So now with the call to config.SuppressDefaultHostAuthentication() Web API calls that require authorization will ignore the cookie that is automatically sent along with the request and look for an Authorization header that begins with "Bearer". MVC controllers will continue to use cookie authentication and are ignorant of the token authentication mechanism as it's not a very good fit for web page authentication to begin with.

The existence of the cookie also left me puzzled, since it clearly is not necessary in a bearer token authentication scenario... In this post the author dissects the individual accounts template, and has the following to say about the cookie:
The method also sets an application cookie. I don’t see a good reason for that.
My guess is that the authors of the template wanted to show examples of different kinds of authentication logic, and in this particular case they wanted to show how the authentication information could be stored in both the bearer token authentication JSON payload, as well as in a standard authentication cookie.
The fact that the JSON authentication payload is set to also include an additional (unnecessary) unencrypted property (the user id), in addition to the encrypted ticket, seems to support this theory:
var properties = CreateProperties(user.UserName);
var ticket = new AuthenticationTicket(oAuthIdentity, properties);
It seems that the authors of the template wanted to provide some useful examples, rather than the bare minimum needed to achieve bearer token authentication. This is also mentioned in the linked post above.

The cookie has one important purpose. Its value contains the bearer token which can be extracted by client-side javascript on your pages. This means that if the user hits F5 or refreshes the page, the cookie will typically persist. Your client-side javascript can then grab the bearer token from the cookie when the page reloads.

Related

Nodejs How to bypass the limitation of redirecting without data regarding external auth method?

I have a NodeJS application where I let my users to login via an external auth like Github and Google.
In the frontend I open for the client a tab in Github for example which prompts him to authorize GitHub against my application. I also do this with a callback url. Github then redirects the user back to the callback url I've configured.
Currently this callback URL is an API in my server.
The next step is to redirect the user back to my home page. However, I need to provide the user with some credentials like JWT token.
But I'm limited to send some data along with redirection action. What should I do?
I provide the following data with Github:
super({
clientID: configService.get('githubOAuthClientId', { infer: true }),
clientSecret: configService.get('githubOAuthClientSecret', { infer: true }),
callbackURL: configService.get('githubOAuthRedirectUri', { infer: true }),
scope: ['user:email'],
});
The githubOAuthRedirectUri variable holds my backend api route. Then I handle the data I receive from GitHub in this route controller. Now I want to redirect the user back to the home page but he also needs the JWT token and some more user specific data.
After receiving data from Github, you could redirect to an intermediate page, sending data in url query for example, and then the front-end app redirect to the home page.
That's my idea
I assume that the OAuth provider (Google or GitHub) will invoke your callback URL with an authorization code in a URL parameter ?code=.... Your server must then exchange this authorization code for an access token by making a token request to the OAuth provider. The response to that token request will then contain the access token, which is
either a JWT with a sub claim containing (most likely) the user's email address, see https://stackoverflow.com/a/72590693/16462950
or an "opaque" token, which your server must use in an Authorization: Bearer header of a UserInfo request.
Only after these steps do you know who the user is. Your server could put the JWT in a session cookie so that it is sent again (and must be validated again) in all subsequent requests.
If your server receives an opaque token instead of a JWT, this may be only short-lived and hence cannot be used in a session cookie. In this case, your server could construct its own JWT containing the user info.

Next.js Authentication with JWT

I am moving a project from React to Next.js and was wondering if the same authentication process is okay. Basically, the user enters their username and password and this is checked against database credentials via an API (Node.js/Express). So, I am not using Next.js internal api functionality, but a totally decoupled API from my Next.js project.
If the login credentials are correct, a JWT token is sent back to the client. I wanted to store that in local storage and then redirect the user. Any future HTTP requests will send the token in the header and check it is valid via the API. Is this okay to do? I ask because I see a lot of Next.js auth using cookies or sessions and don't know if that is the 'standard' approach which I should rather adopt.
My answer is purely based on my experiences and things I read. Feel free to correct it if I happened to be wrong.
So, my way is to store your token in HttpOnly cookie, and always use that cookie to authorize your requests to the Node API via Authorization header. I happen to also use Node.js API in my own project, so I know what's going on.
Following is an example of how I usually handle authentication with Next.js and Node.js API.
In order to ease up authentication problems, I'm using Next.js's built in getServerSideProps function in a page to build a new reusable higher order component that will take care of authentication. In this case, I will name it isLoggedIn.
// isLoggedIn.jsx
export default (GetServerSidePropsFunction) => async (ctx) => {
// 1. Check if there is a token in cookies. Let's assume that your JWT is stored in 'jwt'.
const token = ctx.req.cookies?.jwt || null;
// 2. Perform an authorized HTTP GET request to the private API to check if the user is genuine.
const { data } = await authenticate(...); // your code here...
// 3. If there is no user, or the user is not authenticated, then redirect to homepage.
if (!data) {
return {
redirect: {
destination: '/',
permanent: false,
},
};
}
// 4. Return your usual 'GetServerSideProps' function.
return await GetServerSidePropsFunction(ctx);
};
getServerSideProps will block rendering until the function has been resolved, so make sure your authentication is fast and does not waste much time.
You can use the higher order component like this. Let's call this one profile.jsx, for one's profile page.
// profile.jsx
export default isLoggedIn(async (ctx) => {
// In this component, do anything with the authorized user. Maybe getting his data?
const token = ctx.req.cookies.jwt;
const { data } = await getUserData(...); // don't forget to pass his token in 'Authorization' header.
return {
props: {
data,
},
},
});
This should be secure, as it is almost impossible to manipulate anything that's on server-side, unless one manages to find a way to breach into your back-end.
If you want to make a POST request, then I usually do it like this.
// profile.jsx
const handleEditProfile = async (e) => {
const apiResponse = await axios.post(API_URL, data, { withCredentials: true });
// do anything...
};
In a POST request, the HttpOnly cookie will also be sent to the server, because of the withCredentials parameter being set to true.
There is also an alternative way of using Next.js's serverless API to send the data to the server. Instead of making a POST request to the API, you'll make a POST request to the 'proxy' Next.js's serverless API, where it will perform another POST request to your API.
there is no standard approach. You should be worried about security. I read this blog post: https://hasura.io/blog/best-practices-of-using-jwt-with-graphql/
This is a long but an awesome blog post. everyhing I post here will be quoted from there:
If a JWT is stolen, then the thief can keep using the JWT. An API
that accepts JWTs does an independent verification without depending
on the JWT source so the API server has no way of knowing if this was
a stolen token! This is why JWTs have an expiry value. And these
values are kept short. Common practice is to keep it around 15
minutes.
When server sends you the token, you have to store the JWT on the client persistently.
Doing so you make your app vulnerable to CSRF & XSS attacks, by
malicious forms or scripts to use or steal your token. We need to save our JWT token somewhere so that we can forward it to our API as a header. You might be tempted to persist it in localstorage; don’t do it! This is prone to XSS attacks.
What about saving it in a cookie?
Creating cookies on the client to save the JWT will also be prone to XSS. If it can be read on the client from Javascript outside of
your app - it can be stolen. You might think an HttpOnly cookie
(created by the server instead of the client) will help, but cookies
are vulnerable to CSRF attacks. It is important to note that HttpOnly
and sensible CORS policies cannot prevent CSRF form-submit attacks and
using cookies requires a proper CSRF mitigation strategy.
Note that a SameSite cookie will make Cookie based approaches safe
from CSRF attacks. It might not be a solution if your Auth and API
servers are hosted on different domains, but it should work really
well otherwise!
Where do we save it then?
The OWASP JWT Cheatsheet and OWASP ASVS (Application Security
Verification Standard) prescribe guidelines for handling and storing
tokens.
The sections that are relevant to this are the Token Storage on Client
Side and Token Sidejacking issues in the JWT Cheatsheet, and chapters
3 (Session Management) and 8 (Data Protection) of ASVS.
From the Cheatsheet, "Issue: Token Storage on the Client Side":
Automatically sent by the browser (Cookie storage).
Retrieved even if the browser is restarted (Use of browser localStorage container).
Retrieved in case of XSS issue (Cookie accessible to JavaScript code or Token stored in browser local/session storage).
"How to Prevent:"
Store the token using the browser sessionStorage container.
Add it as a Bearer HTTP Authentication header with JavaScript when calling services.
Add fingerprint information to the token.
By storing the token in browser sessionStorage container it exposes
the token to being stolen through a XSS attack. However, fingerprints
added to the token prevent reuse of the stolen token by the attacker
on their machine. To close a maximum of exploitation surfaces for an
attacker, add a browser Content Security Policy to harden the
execution context.
"FingerPrint"
Where a fingerprint is the implementation of the following guidelines
from the Token Sidejacking issue: This attack occurs when a token has been intercepted/stolen by an attacker and they use it to gain access to the system using targeted user identity.
"How to Prevent":
A way to prevent it is to add a "user context" in the token. A user context will be composed of the following information:
A random string will be generated during the authentication phase. It will be sent to the client as a hardened cookie (flags: HttpOnly +
Secure + SameSite + cookie prefixes).
A SHA256 hash of the random string will be stored in the token (instead of the raw value) in order to prevent any XSS issues allowing
the attacker to read the random string value and setting the expected
cookie.

Using JSON Web Tokens (JWT) with Azure Functions (WITHOUT using Active Directory)

I am sure someone out there has already done this, but I have yet to find any documentation with regard to the Microsoft implementation of JWT. The official documentation from Microsoft for their JWT library is basically an empty page, see:
https://learn.microsoft.com/en-us/dotnet/framework/security/json-web-token-handler-api-reference
So, here is what I (and I am sure many others) would like to accomplish:
Definition: User ID = The username or email address used to log into a system.
AUTHENTICATION:
A user logs in. The user fills in web form and the system sends (via HTTPS POST) the users ID and password (hashed) to the server in order to authenticate / validate the user.
Server Authenticates user. The users ID and password are checked against the values saved in the database and if NOT valid, an invalid login response is returned to the caller.
Create a JWT Token - ???? No documentation available!
Return the JWT token to the caller - ???? - I assume in a header? via JSON, not sure -- again - no documentation.
Given the code below, can anyone provide a code example for steps 3 and 4?
[FunctionName( "authenticate" )]
public static async Task<HttpResponseMessage> Run( [HttpTrigger( AuthorizationLevel.Anonymous, "get", "post", Route = null )]HttpRequestMessage req, TraceWriter log )
{
// Step 1 - Get user ID and password from POST data
/*
* Step 2 - Verify user ID and password (compare against DB values)
* If user ID or password is not valid, return Invalid User response
*/
// Step 3 - Create JWT token - ????
// Step 4 - Return JWT token - ????
}
AUTHORIZATION:
Assuming the user was authenticated and now has a JWT token (I am assuming the JWT token is saved in the users session; if someone wants to provide more info, please do):
A POST request is made to an Azure Function to do something (like get a users birth date). The JWT token obtained above is loaded (from the POST data or a header - does it matter?) along with any other data required by the function.
The JWT token is validated - ???? No documentation available!
If the JWT token is NOT valid, a BadRequest response is returned by the function.
If the JWT token is valid, the function uses the data passed to it to process and issue a response.
Given the code below, can anyone provide a code example for steps 1 and 2?
[FunctionName( "do_something" )]
public static async Task<HttpResponseMessage> Run( [HttpTrigger( AuthorizationLevel.Anonymous, "get", "post", Route = null )]HttpRequestMessage req, TraceWriter log )
{
// Step 1 - Get JWT token (from POST data or headers?)
// Step 2 - Validate the JWT token - ???
// Step 3 - If JWT token is not valid, return BadRequest response
// Step 4 - Process the request and return data as JSON
}
Any and all information would really help those of us (me) understand how to use JWT with Azure (anonymous) functions in order to build a "secure" REST API.
Thanks in advance.
Any and all information would really help those of us (me) understand how to use JWT with Azure (anonymous) functions in order to build a "secure" REST API.
Per my understanding, you could use the related library in your azure function code to generate / validate the JWT token. Here are some tutorials, you could refer to them:
Create and Consume JWT Tokens in C#.
Jwt.Net, a JWT (JSON Web Token) implementation for .NET
JWT Authentication for Asp.Net Web Api
Moreover, you could leverage App Service Authentication / Authorization to configure the function app level Authentication / Authorization. You could go to your Function App Settings, click "NETWORKING > Authentication / Authorization" under the Platform features tab. Enable App Service Authentication and choose Allow Anonymous requests (no action) as follows:
You could create a HttpTrigger function with anonymous accessing for user logging and return the JWT token if the user exists. For the protected REST APIs, you could follow the code sample below:
if(System.Security.Claims.ClaimsPrincipal.Current.Identity.IsAuthenticated)
{
//TODO: retrieve the username claim
return req.CreateResponse(HttpStatusCode.OK,(System.Security.Claims.ClaimsPrincipal.Current.Identity as ClaimsIdentity).Claims.Select(c => new { key = c.Type, value = c.Value }),"application/json");
}
else
{
return req.CreateResponse(HttpStatusCode.Unauthorized,"Access Denied!");
}
For generating the JWT token used in App Service Authentication, you could follow How to: Use custom authentication for your application and the code under custom API controller CustomAuthController from adrian hall's book about Custom Authentication to create the JWT token.
UPDATE:
For the custom authentication approach under App Service Authentication, I just want op to leverage the authentication / Authorization provided by EasyAuth. I have did some test for this approach and found it could work on my side. Op could send the username and password to the HttpTrigger for authentication, then the HttpTrigger backend need to validate the user info, and use Microsoft.Azure.Mobile.Server.Login package for issuing App Service Authentication token to the client, then the client could retrieve the token from the AuthenticationToken property. The subsequent requests against the protected APIs could look like as follows:
https://<your-funapp-name>.azurewebsites.net/api/<httpTrigger-functionName>
Header: x-zumo-auth:<AuthenticationToken>
NOTE:
For this approach, the related HttpTrigger functions need to allow anonymous accessing and the App Service Authentication also needs to choose Allow Anonymous requests (no action). Otherwise, the App Service Authentication and function level authentication would both validate the request. For the protected APIs, op needs to manually add the System.Security.Claims.ClaimsPrincipal.Current.Identity.IsAuthenticated checking.
Try this: https://liftcodeplay.com/2017/11/25/validating-auth0-jwt-tokens-in-azure-functions-aka-how-to-use-auth0-with-azure-functions/
I successfully made it work using this guide. It took awhile due to nuget versions.
Follow that guide properly and use the following nuget versions
IdentityModel.Protocols (2.1.4)
IdentityModel.Protocols.OpenIdConenct (2.1.4)
IdentityModel.Tokens.Jwt (5.1.4)
Oh and, the guide tells you to write your AUDIENCE as your api link, don't. You'll get unauthorized error. Just write the name of your api, e.g. myapi
If you get error about System.http.formatting not being loaded when running the function, try to reinstall NET.Sdk.Functions and ignore the warning about AspNet.WebApi.Client being restored using .NETFramework. And restart visual studio.
What you're describing is something that you should be able to do yourself by doing a little bit of research. To address your specific questions:
Create a JWT Token - ???? No documentation available!
The link Bruce gave you gives a nice example for how to create a JWT: https://www.codeproject.com/Tips/1208535/Create-And-Consume-JWT-Tokens-in-csharp
Return the JWT token to the caller - ???? - I assume in a header? via JSON, not sure -- again - no documentation.
There's no documentation because you're basically inventing your own protocol. That means how you do it is entirely up to you and your application requirements. If it's a login action, it might make sense to return it as part of the HTTP response payload. Just make sure that you're using HTTPS so that the token stays protected over the wire.
A POST request is made to an Azure Function to do something (like get a users birth date). The JWT token obtained above is loaded (from the POST data or a header - does it matter?) along with any other data required by the function.
How you send the token is, again, entirely up to you. Most platforms use the HTTP Authorization request header, but you don't have to if you don't want to.
The JWT token is validated - ???? No documentation available!
Use the ValidateToken method of the JwtSecurityTokenHandler (see the previous link for how to get the JwtSecurityTokenHandler). Docs here: https://msdn.microsoft.com/en-us/library/dn451155(v=vs.114).aspx.
I created an Azure Functions input binding for JWT Token Validation. You can use this as an extra parameter with the [JwtBinding] attribute. See https://hexmaster.nl/posts/az-func-jwt-validator-binding/ for source and NuGet package information.
Basically Azure Functions built on top of ASP.NET Core. By making some dependency injection tricks you could add your own authentication and policy-based authorization. I created demo solution with JWT authentication just for fun, beware to use it on production.

Auth0 authentication of single-page-app on a different domain than the api

I'm trying add Auth0 authentication to my single-page-app. My app is running under a domain, say app.mycompany.com, whereas the api used by this app is running under a different domain, say api.mycompany.com.
I'm aware of this thread:
Single Sign On (SSO) solution/architecture for Single Page App (SPA)
and the auth0 articles and github repositories linked by here. But I have a feeling that my scenario is slightly simpler, as I don't necessarily want to have single-sign-on between several different single-page-apps. For a start I just want the seperation between the API and the app.
Here is what I have tried already:
I already started from the article React Login With Auth0 and downloaded the starter project. I can surely login without problems and it will leave me with an id_token in my localStorage containing a JWS issued by Auth0.
I can also login directly on api.mycompany.com (my FeathersJS API application) and I can see that during the OAuth redirecting process, the id_token token is magically translated to a feathers-jwt token issued by my Feathers application containing the internal ID of the user-object matching the auth0-ID. I also have implemented the logic used to map from the Auth0-ID to my internal ID. Furthermore all my Feathers hooks such as validation of token and population of the user are working.
What I cannot figure out is how to alter the react-application running under app.mycompany.com with an Auth0-token in localStorage, so that this token is translated to a feathers-jwt token by api.mycompany.com, in such a way that all succeeding API-calls automatically has the feathers-jwt token included so the API can validate the user and return the right data.
Any suggestions on how to proceed will be greatly appreciated.
A couple of more background details:
The api is built on node.js and featherjs (which basically is an extension of Express)
The single-page-app is built on ReactJS and is served by a simple Express server, but it could be served by any server that can serve static files over http. The single-page-app makes http-requests to the api to read data and perform operations.
The api has the following lines of code taking care of the authentication:
const authentication = require('feathers-authentication');
const Auth0Strategy = require('passport-auth0').Strategy;
app.configure(authentication({
local:false,
token: {
secret: 'mysecret',
payload: ['email', 'auth0Nickname'],
issuer: 'mycompany'
},
idField: 'id',
shouldSetupSuccessRoute: false,
auth0: {
strategy: Auth0Strategy,
domain: 'mycompany.eu.auth0.com',
'clientID': 'xxx',
'clientSecret': 'yyy'
}
}));
I had exactly the same problem as you, I wanted to authenticate a user from a single page application, calling the API located on an other server.
The official auth0 example is a classic Express web application that does authentication and renders html page, but it's not a SPA connected to an API hosted on an other domain.
Let's break up what happens when the user authenticates in this example:
The user makes a request calling /auth/auth0 route
The user is automatically redirected to the Auth0 authentication process (Auth0 login form to choose the provider and then the provider login screen)
The user is redirected to /auth/success route
/auth/success route redirects to the static html page public/success.html, also sending a jwt-token cookie that contains the user's token
Client-side, when public/success.html loads, Feathers client authenticate() method reads the token from the cookie and saves it in the local storage.
From now, the Feathers client will authenticate the user reading the cookie from the local storage.
I tried to adapt this scenario to a single-page application architecture, implementing the following process:
From the SPA, call the authentication API with a source query string parameter that contains the SPA URL. For example: http://my-api.com/auth/auth0?source=http://my-spa.com
Server-side, in /auth/auth0 route handler, create a cookie to store that URL
After a successful login, read the source cookie to redirect the user back to the SPA, sending the JWT token in a cookie.
But the last step didn't work because you can't set a cookie on a given domain (the API server domain) and redirect the user to an other domain! (more on this here on Stackoverflow)
So actually I solved the problem by:
server-side: sending the token back to the client using the URL hash.
client-side: create a new html page that reads the token from the URL hash
Server-side code:
// Add a middleware to write in a cookie where the user comes from
// This cookie will be used later to redirect the user to the SPA
app.get('/auth/auth0', (req, res, next) => {
const { origin } = req.query
if (origin) {
res.cookie(WEB_CLIENT_COOKIE, origin)
} else {
res.clearCookie(WEB_CLIENT_COOKIE)
}
next()
})
// Route called after a successful login
// Redirect the user to the single-page application "forwarding" the auth token
app.get('/auth/success', (req, res) => {
const origin = req.cookies[WEB_CLIENT_COOKIE]
if (origin) {
// if there is a cookie that contains the URL source, redirect the user to this URL
// and send the user's token in the URL hash
const token = req.cookies['feathers-jwt']
const redirectUrl = `${origin}/auth0.html#${token}`
res.redirect(redirectUrl)
} else {
// otherwise send the static page on the same domain.
res.sendFile(path.resolve(process.cwd(), 'public', 'success.html'))
}
})
Client-side, auth0.html page in the SPA
In the SPA, I created a new html page I called auth0.html that does 3 things:
it reads the token from the hash
it saves it in the local storage (to mimic what the Feathers client does)
it redirects the user to the SPA main page index.html
html code:
<html>
<body>
<script>
function init() {
const token = getToken()
if (!token) {
console.error('No auth token found in the URL hash!')
}
// Save the token in the local storage
window.localStorage.setItem('feathers-jwt', token)
// Redirect to the single-page application
window.location.href = '/'
}
// Read the token from the URL hash
function getToken() {
const hash = self.location.hash
const array = /#(.*)/.exec(hash)
if (!array) return
return array[1]
}
init()
</script>
</body>
</html>
And now in the SPA I can use the Feathers client, reading the token from the local storage when the app starts.
Let me know if it makes sense, thank you!
If you haven't done so, you should follow this article (React Login with Auth0) to implement the authentication on your React application. If you already tried to follow it, update your question with specific issues you faced.
Even though you currently not need SSO, the actual implementation of the authentication in your application will not vary much. By using Auth0 enabling SSO across your apps is mostly enabling configuration switches.
Finally for a full reference with all the theory behind the security related aspects of your exact scenario check:
Auth0 Architecture Scenarios: SPA + API
Update:
The full scenario I linked too covers the most comprehensive scenarios where an API is accessed by a multitude of client applications that may even be developed by third-parties that do not own the protected API, but want to access the data behind it.
It does this by leveraging recent features that are currently only available in the US region and that at a very high level can be described as an OAuth 2.0 authorization server delivered as a service.
Your particular scenario is simpler, both the API and client application are under control of the same entity, so you have another option.
Option 1 - Leverage the API authorization through Auth0 US region only (for now)
In this situation your client application, at authentication time, would receive an id_token that would be used to know the currently authenticated user and would also receive an access_token that could be used to call the API on behalf of the authenticated user.
This makes a clear separation between the client application and the API; the id_token is for client application usage and the access_token for API usage.
It has the benefit that authorization is clearly separated from authentication and you can have a very fine-grained control over authorization decisions by controlling the scopes included in the access token.
Option 2 - Authenticate in client application and API in the same way
You can deploy your client application and API separately, but still treat them from a conceptual perspective as the same application (you would have one client configured in Auth0 representing both client-side and API).
This has the benefit that you could use the id_token that is obtained after authentication completes to know who the user was on the client-side and also as the mechanism to authenticate each API request.
You would have to configure feathers API to validate the Auth0 id_token as an accepted token for accessing the API. This means that you don't use any feathers based on authentication on the API, that is, you just accept tokens issued by Auth0 to your application as the way to validate the access.

Token based authentication with flask-security extension

I am currently looking for a way to secure a REST API using token based authentication. I am developing the API in Python using Flask and have discovered the flask-security extension which seems to have a lot of interesting features.
One of the features mentioned in the documentation is Token Authentication.
According to the documentation:
Token based authentication is enabled by retrieving the user auth
token by performing an HTTP POST with the authentication details as
JSON data against the authentication endpoint. A successful call to
this endpoint will return the user’s ID and their authentication
token. This token can be used in subsequent requests to protected
resources.
I am however still a bit confused on how to implement this feature using flask-security.
Some online research has led me to using things such as #auth_token_required but I am having some trouble to put everything together. The flask-security documentation itself is not very helpful.
For example, how can a user get an authentication token? what is the authentication endpoints?
It would be great if you could lead me in the right direction. Code examples would be awesome too :-)
Endpoint is /login, you post your credentials as json request body:
{'email':'john#smit.com', 'password':'1234'}
However for this to work you need to disable the csrf tokens in your flask app (thanks Mandar Vaze):
app.config['WTF_CSRF_ENABLED'] = False
Then you do each request with the token in the HTTP headers:
Authentication-Token:WyI1NTE1MjhmNDMxY2Q3NTEwOTQxY2ZhYTgiLCI2Yjc4NTA4MzBlYzM0Y2NhZTdjZjIxNzlmZjhiNTA5ZSJd.B_bF8g.t1oUMxHr_fQfRUAF4aLpn2zjja0
Or as query string:
http://localhost:5000/protected?auth_token=WyI1NTE1MjhmNDMxY2Q3NTEwOTQxY2ZhYTgiLCI2Yjc4NTA4MzBlYzM0Y2NhZTdjZjIxNzlmZjhiNTA5ZSJd.B_bF8g.t1oUMxHr_fQfRUAF4aLpn2zjja0
Client example in python 3:
import requests
import json
#do the login
r = requests.post('http://localhost:5000/login',
data=json.dumps({'email':'john#smit.com', 'password':'1234'}),
headers={'content-type': 'application/json'})
response = r.json()
print(response) #check response
token = response['response']['user']['authentication_token'] #set token value
#Now you can do authorised calls
r = requests.get('http://localhost:5000/protected',
headers={'Authentication-Token': token})
print(r.text)
Angular example snippet to obtain the token:
$http.post('/login', {"email": $scope.formdata.login,"password":$scope.formdata.password}).
success(function(results) {
$window.sessionStorage.token = results.response.user.authentication_token;
});
Angular example snippet to visit protected pages:
if ($window.sessionStorage.getItem('token')) {
config.headers['Authentication-Token'] = $window.sessionStorage.getItem('token');
}
I found Flask-Security's token-based not a good candidate for my project. I recommend using JWT token instead.
The problems with Flask-Security's token based authentication.
Need to disable CSRF globally, this is not good when you also have a traditional web application in which CSRF token is desirable
No easy way to renew the token ( without submitting password again )
Can not control the payload of the token, there's no API to put/get data to/from the token
That token, by design, only works with one Flask app. So if your frontend app needs to talk with multiple restful apis, this wont work well
Check out JWT (pyjwt or flask-jwt) token, it solves all the above problems and more.
Authentication endpoint is /login
Look at the code of flask-security here specifically views.py: _render_json()
login() calls _render_json which in turn calls get_auth_token() - and returns the auth token.
Problem (for me) is to get this to work.
For me request.json seems empty (hence this does not work)
{"email": "test#example.com", "password": "test123"}
Hopefully this helps you move forward a little.

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