How to implement multiple authentication methods in Spring WebFlux Security? - spring-security

I'd like to provide two ways to authenticate in my application, one is basic auth (users), and the other is some kind of token based (technical users). I understand that I need a custom ReactiveAuthenticationManager but I can't find clues on the big picture. (Actually, there are a very few insights for MVC, and none for WebFlux.)
1) How do I populate the Authentication's name and credentials in the token based approach? If I configure Spring Security to use httpBasic it's already populated. Some kind of filter needed?
2) How do I distinguish in the authentication manager where the credentials are coming from? Do I have to lookup in the userRepository and (if not found) in the technicalUserRepository too?
3) Do I have to override the SecurityContextRepository? All the tutorials do it but I don't see any reason to do so. What is it exactly? This source states that "SecurityContextRepository is similar to userDetailsService provided in regular spring security that compares the username and password of the user." but I think he means ReactiveUserDetailsService (neither UserDetailsService nor ReactiveUserDetailsService does that by the way, it's just for user lookup).

Since i am decent at Webflux and i have worked a lot with oauth2 i'll try and answer some of your questions.
1) How do I populate the Authentication's name and credentials in the
token based approach? If I configure Spring Security to use httpBasic
it's already populated. Some kind of filter needed?
A token never contains credentials. A token is something you get issued after an authentication has been done. So usually you authenticate against an issuing service. After you have authenticated yourself against that service you will be issued a token.
If its an oauth2 token the token itself is just a random string. It contains no data about the user itself. When this token is sent (using the appropriate header) to a service using spring security. Spring security has a token filter that will basically check that the token is valid, usually by sending the token to the issuer and asking "is this token valid?".
If using a jwt, its different, the jwt must contain some information like issuer, scopes, subject etc. etc. but its basically the same thing, there is a built in filter that will validate the jwt by sending it to the issuer (or using a jwk that the service fetches from the issuer so it can verify the integrity of the jwt without doing an extra request).
2) How do I distinguish in the authentication manager where the credentials are coming from? Do I have to lookup in the userRepository and (if not found) in the technicalUserRepository too?
You don't You usually define multiple SecurityWebFilterChains for different url paths. I have not done this in Webflux Spring Security, but thats how you do it in regular Spring Applications, and i don't see any difference here. Unless you are doing something crazy custom.
3) Do I have to override the SecurityContextRepository? All the tutorials do it but I don't see any reason to do so. What is it exactly? This source states that "SecurityContextRepository is similar to userDetailsService provided in regular spring security that compares the username and password of the user." but I think he means ReactiveUserDetailsService (neither UserDetailsService nor ReactiveUserDetailsService does that by the way, it's just for user lookup).
The answer here is probably no. You see Spring security 4 had very bad support for oauth2 and especially JWT. So people got accustomed to writing their own JWT parsers. When spring Security 5 came, Spring implemented a jwt filter that you can configure and use built in. But there are a lot of outdated Spring Security tutorials out there and foremost there are a lot of developers that don't read the official documentation.
They mostly google tutorials and get the wrong information and then work on that.
But easy explained:
SecurityContextRepository
If you have session based authentication (server establishes a session with a client) it will store the SecurityContext (session) in ThreadLocal during a request. But as soon as the request ends, the session will go lost unless we store it somewhere. The SecurityContextPersistenceFilter will use the SecurityContextRepository to extract the session from ThreadLocal and store it, most common is to store it in the HttpSession.
AuthenticationManager
Override this if you want to do a custom authentication process. Example if you want to validate something, call a custom LDAP, database, etc etc. It\s here you perform you authentication. But remember, most standard logins (like ldap, sql-servers, basic login etc.) already have prebuilt configurable managers implemented, when you select what login type like .httpBasic() you will get a pre-implemented AuthenticationManager.
UserDetailsManager
You override this when you want create a custom UserDetails object (also usually called Principal) In the UserDetailsManager you do you database lookup and fetch the user and then build and return a UserDetails object.
Those two interfaces are the most regular custom implementations, and are used if you need to to basic authentication/session based authentication.
If you wish to do token, you have to think about, who is the token issuer? usually the issuer is separate and all services just get tokens and validate them against the issuer.
I hope this explains some of the questions. I have written this on the bus so some things are probably wrong and not 100% correct etc. etc.

Related

How to implement custom 'OAuth2TokenIntrospectionEndpointFilter' in Spring Aauthorization server 1.0.0?

I have a default Spring authorization Server implementation. i want to modify it as per my project requirements.
I want to implement customized introspection endpoint in new spring authorization server.
I will be having different kinds of tokens, based on token type I want to validate them differently.
So I found out by default spring authorization server uses 'OAuth2TokenIntrospectionEndpointFilter', is there a way to use this class or we have to write a new class and add it to server configuration?
Thank you.
I tried doing the following.
authorizationServerConfigurer.tokenIntrospectionEndpoint(
t -> t.authenticationProvider(customTokenAuthProvider)
.introspectionResponseHandler(successHandler));
I want to know if this the right way to do or any other method exists.
It seems you have two goals:
Customize a jwt, by adding custom claims.
Obtain those claims via the introspection endpoint from a resource server.
There is actually nothing to code for on the authorization server side to achieve #2, as the introspection endpoint returns all claims for a jwt by default. I’m not clear on what you mean by “validate” here, so I’m assuming you mean validate the token and then obtain claims from it. This is what the introspection endpoint does, no customization required. Do note however that the introspection endpoint is not usually called if the resource server is decoding the jwt locally. This would only happen if the resource server is treating the token as opaque.
In order to achieve #1, simply provide an OAuth2TokenCustomizer #Bean as demonstrated in the reference documentation.
Note: I don’t see a need for a custom AuthenticationProvider. If you feel you do have a need for one, then I think some details of your use case are missing.

OpenID Connect, oAuth2 - Where to start?

I am not sure which approach I should be taking in our implementation and need some guidance.
I have a REST API (api.mysite.com) built in the Yii2 Framework (PHP) that accesses data from mysite.com (database). On mysite.com our users will be able to create Connected Apps that will provision a client id + secret - granting access to their account (full scope?).
Based on my research, the next step seems to be setting up something to actually provide the bearer tokens to be passed to the api - I have been leaning towards oAuth2, but then I read that oAuth2 does not provide authentication. Based on this I think I need OpenID Connect in order to also provide user tokens because my API needs to restrict data based on the user context.
In this approach, it is my understanding that I need to have an Authentication Server - so a few questions:
Is there software I can install to act as an OpenID Connect/oAuth2 authentication server?
Are there specific Amazon Web Services that will act as an OpenID Connect/oAuth2 Authentication Server?
I am assuming the flow will be: App makes a request to the auth server with client id + secret and receives an access token. Access token can be used to make API calls. Where are these tokens stored (I am assuming a database specific to the service/software I am using?)
When making API calls would I pass a bearer token AND a user token?
Any insight is greatly appreciated.
your understanding is not very far from reality.
Imagine you have two servers one for Authentication, this one is responsible for generating the tokens based on a Authorization Basic and base64 encoded CLientID / ClientSecret combo. This is application authentication basically. If you want to add user data as well, simply pass username / password in the post body, authenticate on the server side and then add some more data to the tokens, like the usernames, claims, roles, etc
You can control what you put in these tokens, if you use something like JWT ( Json Web Tokens ) then they are simply json bits of data.
then you have a Resource server, you hit it with a Authorization Bearer and the token you obtained from the Authorization one.
Initially the tokens are not stored anywhere, they are issued for a period of time you control. You can however do something else and store them in a db if you really want to. The expiration is much safer though, even if someone gets their hands on them they won't be available for long! In my case I used 30 minutes for token validity.
Now, you haven't specified what languages/frameworks you are looking into. If you use something like dot net then look into IdentityServer, version 4 is for Dot net core, 3 for anything below.
I also have a pretty long article on this subject if you are interested:
https://eidand.com/2015/03/28/authorization-system-with-owin-web-api-json-web-tokens/
Hopefully all this clarifies some of the questions you have.
-- Added to answer a question in comments.
The tokens contain all the information they need to be authenticated by the resource server correctly, you don't need to store them in a database for that. As I already said, you can store them but in my mind this makes them less secure. Don't forget you control what goes into a token so you can add usernames if that's what you need.
Imagine this scenario, you want to authenticate the application and the user in the same call to the Authorization Server. Do the OAuth2 in the standard way, which means authenticate the application first based on the client id / client secret. If that passes then next do the user authentication. Add the username or userid to the token you generate and any other bits of information you need. What this means that the resource server can safely assume that the username passed to it in the token has already been validated by the authentication server otherwise no token would have been generated in the the first place.
I prefer to keep these two separate myself, meaning let the AS ( Authorization Server) to deal with the application level security. Then on the RS (Resource Server) side you have an endpoint point like ValidateUser for example, which takes care of the user validation, after which you can do whatever you need. Pick whichever feels more appropriate for your project I'd say.
One final point, ALWAYS make sure all your api calls ( both AS and RS are just apis really ) are made over HTTPS and never ever have any important information transmitted via a GET call which means the URL can be intercepted. Both Headers and POST body are encrypted and secure over HTTPS.
This should address both your questions, I believe.

Spring security based application having both form login and SSO

I have searched enough but I haven't got a clear answer and thus posting this question.
I have an existing application which uses spring security for authentication.
Current implementation uses a custom implementation of UsernamePasswordAuthenticationFilter for doing this.
Thus the flow is something like below(in very simple terms):
inputrequest>DelegatingFilterProxy>LoginUrlAuthenticationEntryPoint>CustomUsernamePasswordAuthenticationFilter>AuthenticationManager>CustomAuthenticationProvider
Now I have a requirement to implement SSO (since the user is already asusmed to be authenticated) in some scenarios.
The requirement states that if I have a specific request parameter present then I need to automatically authenticate the request without bothering about user/password.
So it is same set of resources and I do not have to authenticate user/password if the specific SSO related request parameter is present.
e.g
suppose a resource \test\bus is a secure resource.
if I come from normal way then we need to check if the user is authenticated or nor and force user to put valid user/password
if I come from SSO channel then I need to show the \test\bus resource as the user is already authenticated.
currently all the access restrictions are put through <http> element
e.g the snippet of security-config.xml is as follows:
Query: What options do I have in this case. I can think of below options:
Pre-authenticate the user before spring security framework kicks in. This will mean creating an authentication token and putting in spring context before spring security filter is called. This can be done through another filter which is called before spring security filter chain. I have tested it and it works.
Create another custom security filter which set-up the authentication token. I am not clear if this is correct approach as not sure when do we create multiple custom security filter
Create another custom authentication provider e.g SSOCustomAuthenticationProvider. This provider will be called in the existing current flow as we can have multiple authentication providers to a authentication manager. The only issue is that in order to achieve this I have to change the request url to authentication filter's target url so that spring security doesn't check for authentication.
to explain more,
let's say request uri is /test/bus, I will write a filter which will intercept the request and change it to /test/startlogin. This is currently my CustomUsernamePasswordAuthenticationFilter's target url i.e
<property name="filterProcessesUrl" value="/test/startlogin"/>
The flow will be
inputrequest>DelegatingFilterProxy>LoginUrlAuthenticationEntryPoint>CustomUsernamePasswordAuthenticationFilter>AuthenticationManager>SSOCustomAuthenticationProvider
I have tested this and this works. Is this a valid approach or a hack.
Is there any other viable option available with me.
Thanks for reading this.

How to identify provider for oauth2 redirect_uri callback?

Im trying to undertand how to properly identify which provider a returning authorization request was initiated by. I see three approaches:
Use provider specific redirect_uri callback URIs. /oauth2/<provider-name>/callback etc.
Encode provider id/name in state parameter somehow
Store a pending provider id/name in the web session
Try to verify response with all used providers
I've read parts of the OAuth2 spec but I can't find anything discussing it. Looking at other client implementations it seems as provider specific URIs is the most common solution. Am I missing something?
Clients may not be multi-tenant and are tightly integrated with a single Authorization Server, so there's no need to store a provider identifier because there's only a single fixed one. That may be the reason why there's no obvious solution.
Multi-provider clients like your's should store the provider identifier as part of the state. This is because the state should be protected, and the provider specific redirect_uri is not. One could play an access token for provider A against the callback for provider B and thus defeat the purpose of a provider specific callback.
state can be protected either by reference to server state or to an encrypted cookie, or by value in the form of a self-contained encrypted structured value for the state parameter, and thus can be a safe mechanism to store the provide identifier.

ASP.NET MVC 3 Web API - Securing with token

I'm trying to find the simplest way of implementing token based authentication for a number of ASP.NET MVC actions.
The Api controllers sit alongside a web app, so I need to be able to specify which actions/controllers are subject to Api authentication.
I already have a membership provider that is used for forms authentication so I'd like to reuse this to validate the user and build the returned token.
I've read several articles on implementing OAuth, but most seem really complex. I've seen several examples of using an API key, but I want to request a token and then pass it back as a parameter not necessarily as a value in the HTTP header.
Essentially process needs to be:
User requests token from auth action passing in username and
password.
Service returns enc token
User passes enc token to future calls as a parameter to auth
What's the typical way this is done, does the client (say ajax call) need to compute a hash of the user name/pass in 1)? or plain text ok over TLS/SSL?
Any advice appreciated.
What are you concerned about with what you described?
The process you described seems viable. Typically systems will have an expiration on how long the token will be valid for, after which they need to get a new token. There are many variations for expiration though (fixed time, sliding time, etc..).
To your question regarding the username / password, the client shouldn't hash them. Just make sure they are transmitted via a secure method (SSL).

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