How to intercept the Websocket call in Crossbar+Autobahn - websocket

I want to know if it is possible to implement some interceptor to check user authentication in websocket RPC.
My use case is
User registers himself with some token using URI 'com.safe.reg'
Token is validated and cached against the sessionid
For next call to some other URI (say 'com.bus.op1') I want to ensure that the token is still valid and hence want to call something which will check the cached token for the sessionid.
I want this to happen for every business call and also, I don't want to send the session id as parameter in the function call.
This is typically handled in the interceptors in http request-response communication. How can we achieve this in websockets while using crossbar?

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How Save the Client Tokens To use More Times

for example: if i have Asp.net web Api Application and this application get a Token from Client To send Notification for this Client with this Token and every Client have a different Token.
How can I save this Token for each individual Client To every Client use his Special Token more Times from different Computer or From different Browser??
Schould I use cookies or Session or is there something else??
It is worth noting that the Token is sent from the client and used by the server
The WebAPi is a Stateless Project that mean you do not need to manage the state for every client!
For example, if you use JWT token, once the token created by API, client must send the token for every request.
BUT
If you need to save a token for more use!
Four options come to mind :
1-use your primary db(ex:SQL Server) to save the token!and retrieve every time you need!(Not a good idea)
2-save your token to Redis!
3-create a static class with Singleton lifetime, then with dictionary you can save the token for every client to memory!
4-Use In-memory Database link

Spring Boot : Recipe to repeatably get access token based on authorisation header

So I have this situation.
I am coding inside a controller API in spring boot that gets a request with authorisation header.
I need to hit a token endpoint with this header to get the access token.
After this I need to hit an API with this toke to get some information.
Now one way of approaching this is to ,
Create a clients one to get the token .
Create another client to hit the actual API.
Then when my API received the request , then hit these above endpoints in succession to get
the job done. Also, need to take care of caching the token so that we dont end up doing this
every time.
Because this looks like a pattern I want to create a system where i can create one client kind of like the Spring WebCLient and that can take care of hitting the token uri when required.
But all documentation I am reading suggest providing a token url(which I have) and also clientid/secret in the configuration.(These I dont. I only have the incoming auth code).
Is there a programmatic way I can achieve the same with webclient ?

sharing the principal object received from an oauth2 provider between spring and angular

I have stumbled upon a problem with Spring Security and Angular.
On my BE (Spring Boot application), there are defined OAuth2 providers, such as Google, GitHub and Facebook.
My BE works fine with this providers, since I can authenticate on the desired providers.
The problem is when I try to send the principal object to the FE (Angular 6 application).
I get undefined value when i try to subscribe the value from the rest endpoint.
I assume this is due to the Spring Servlet creating a new thread for the login request.
I am doing my login request from the Angular app.
I did watch dozens of tutorials and rad so many articles, but I just can't find the answer. If it's possible for you to share some code on how it is done, or give me a link, since for sure I am making a silly mistake and can't seem to find the answer here.
Thanks for understanding, have a good day.
:)
I am assuming that you are using the Authorization Code flow from your BE to authenticate the user that interacts with your FE Angular application (you in your example). Otherwise, you would be trying to authenticate the BE Client with the Client flow and you wouldn't need to return the "principal object" to the FE application. If my assumptions are correct... read on.
The Authorization Code flow goes as follows:
1) The user somehow selects an Authentication provider (ex: Google) and that selection is returned to some endpoint in the BE as a non-authenticated request..
2) The BE Client receives this request, preferably intercepted by a filter and, since the request is not authenticatedd, redirects the browser to the selected auth provider's authorization endpoint.
3) The user then proceed to authenticate against that provider which, upon succesfull authentication, returns a response that redirects the browser to a BE Client endpoint. That redirect holds a parameter that provides a code that the BE Client will use to get an idToken representing the user. At this point, it is important to note that the browser has not been returned any response for this redirect.
4) The BE Client then proceeds to send a regular HTTP request to the provider's token endpoint along with the received authorization code. The provider then returns the idToken an HTTP response directly to the BE Client. All this is happening while the browser is still waiting for the response to the last redirect.
5) The BE Client then process the idToken (verification, validation, user details, session etc) and only then, will finally send the response to the browser patiently waiting since the code redirect. That response may provide a header or a cookie with a sessionId or token (your choice) that the FE application will be able to read or use for the given purpose.
This flow is relatively easy to implement and requires minimal SS configuration. You must keep the BE Client auth endpoint with permitAll() otherwise, you would not be able to trigger this flow. Also, make sure that, once the FE app. has received the header/cookie, all subsequent calls shall be processed as "authenticated calls". Finally, make sure to document yourself on the perils of stateless sessions as well as cookie security and always use HTTPS.
Jake.

How to pass CSRF token with the RestTemplate

I have two Spring Boot REST applications. One of the applications calls other with Spring RestTemplate. Lets call these applications server and client app.
Server app is sending XSRF-TOKEN token as cookie, this is done for the UI part. However there's no way (None that I know of) for the server to distinguish between the request coming from browser and a request coming from the client app. So I can not selectively send the CSRF token from the server to browser only.
Is there a built in mechanism in Spring which allows RestTemplate to detect CSRF cookie/header and replay the request?
If not how can I do the same manually? Should I wait for the CSRF exception to occur and then read the cookie fro the response and replay it?
If it were to be done once then it would be OK, however to wait for the exception for every RestTemplate call doesn't seem right.
I may try to store the token once and set in from the next time, however how would it deal with the multiple server app scenario (Which I have to implement next). As CSRF token of one server app would be invalid for the other, so I won't be able to store a single token, but I would have to store a map of tokens which would have an entry for every new server app URL.
This all seems too complicated, I would rather have Spring handle it.
Any clues are appreciated.
Thanks
For now I have implemented a REST service without protection in the server app which can be called to get CSRF cookies. I had to allow session to be created always so that CSRF cookie doesn't change in one session and so that I could avoid the error Could not verify the provided CSRF token because your session was not found.
Client app calls CSRF rest service to get the cookies and then sends it with the next service call.
It seems a much to call the CSRF token service for each REST call via RestTemplate however it saves me from implementing complicated logic of storing the session. CSRF token service just delivers the cookies so it's network call doesn't take much time compared to the actual service call.
I was also thinking of using a persistent storage (SQL Database or Redis) to store the CSRF token for the server app and then let the client app directly read it from the persistent storage.
However I couldn't figure out how to associate the Session + Server app + CSRF token together to identify token needed by client. As client doesn't have the session initially, so it can't uniquely find CSRF token for it's token from the database. This method is complicated further by the fact that RestTemplate doesn't store the session for the next call.

Can you help me understand this? "Common REST Mistakes: Sessions are irrelevant"

Disclaimer: I'm new to the REST school of thought, and I'm trying to wrap my mind around it.
So, I'm reading this page, Common REST Mistakes, and I've found I'm completely baffled by the section on sessions being irrelevant. This is what the page says:
There should be no need for a client
to "login" or "start a connection."
HTTP authentication is done
automatically on every message. Client
applications are consumers of
resources, not services. Therefore
there is nothing to log in to! Let's
say that you are booking a flight on a
REST web service. You don't create a
new "session" connection to the
service. Rather you ask the "itinerary
creator object" to create you a new
itinerary. You can start filling in
the blanks but then get some totally
different component elsewhere on the
web to fill in some other blanks.
There is no session so there is no
problem of migrating session state
between clients. There is also no
issue of "session affinity" in the
server (though there are still load
balancing issues to continue).
Okay, I get that HTTP authentication is done automatically on every message - but how? Is the username/password sent with every request? Doesn't that just increase attack surface area? I feel like I'm missing part of the puzzle.
Would it be bad to have a REST service, say, /session, that accepts a GET request, where you'd pass in a username/password as part of the request, and returns a session token if the authentication was successful, that could be then passed along with subsequent requests? Does that make sense from a REST point of view, or is that missing the point?
To be RESTful, each HTTP request should carry enough information by itself for its recipient to process it to be in complete harmony with the stateless nature of HTTP.
Okay, I get that HTTP authentication
is done automatically on every message
- but how?
Yes, the username and password is sent with every request. The common methods to do so are basic access authentication and digest access authentication. And yes, an eavesdropper can capture the user's credentials. One would thus encrypt all data sent and received using Transport Layer Security (TLS).
Would it be bad to have a REST
service, say, /session, that accepts a
GET request, where you'd pass in a
username/password as part of the
request, and returns a session token
if the authentication was successful,
that could be then passed along with
subsequent requests? Does that make
sense from a REST point of view, or is
that missing the point?
This would not be RESTful since it carries state but it is however quite common since it's a convenience for users; a user does not have to login each time.
What you describe in a "session token" is commonly referred to as a login cookie. For instance, if you try to login to your Yahoo! account there's a checkbox that says "keep me logged in for 2 weeks". This is essentially saying (in your words) "keep my session token alive for 2 weeks if I login successfully." Web browsers will send such login cookies (and possibly others) with each HTTP request you ask it to make for you.
It is not uncommon for a REST service to require authentication for every HTTP request. For example, Amazon S3 requires that every request have a signature that is derived from the user credentials, the exact request to perform, and the current time. This signature is easy to calculate on the client side, can be quickly verified by the server, and is of limited use to an attacker who intercepts it (since it is based on the current time).
Many people don't understand REST principales very clearly, using a session token doesn't mean always you're stateful, the reason to send username/password with each request is only for authentication and the same for sending a token (generated by login process) just to decide if the client has permission to request data or not, you only violate REST convetions when you use weither username/password or session tokens to decide what data to show !
instead you have to use them only for athentication (to show data or not to show data)
in your case i say YES this is RESTy, but try avoiding using native php sessions in your REST API and start generating your own hashed tokens that expire in determined periode of time!
No, it doesn't miss the point. Google's ClientLogin works in exactly this way with the notable exception that the client is instructed to go to the "/session" using a HTTP 401 response. But this doesn't create a session, it only creates a way for clients to (temporarily) authenticate themselves without passing the credentials in the clear, and for the server to control the validity of these temporary credentials as it sees fit.
Okay, I get that HTTP authentication
is done automatically on every message
- but how?
"Authorization:" HTTP header send by client. Either basic (plain text) or digest.
Would it be bad to have a REST
service, say, /session, that accepts a
GET request, where you'd pass in a
username/password as part of the
request, and returns a session token
if the authentication was successful,
that could be then passed along with
subsequent requests? Does that make
sense from a REST point of view, or is
that missing the point?
The whole idea of session is to make stateful applications using stateless protocol (HTTP) and dumb client (web browser), by maintaining the state on server's side. One of the REST principles is "Every resource is uniquely addressable using a universal syntax for use in hypermedia links". Session variables are something that cannot be accessed via URI. Truly RESTful application would maintain state on client's side, sending all the necessary variables over by HTTP, preferably in the URI.
Example: search with pagination. You'd have URL in form
http://server/search/urlencoded-search-terms/page_num
It's has a lot in common with bookmarkable URLs
I think your suggestion is OK, if you want to control the client session life time. I think that RESTful architecture encourages you to develop stateless applications. As #2pence wrote "each HTTP request should carry enough information by itself for its recipient to process it to be in complete harmony with the stateless nature of HTTP" .
However, not always that is the case, sometimes the application needs to tell when client logs-in or logs-out and to maintain resources such as locks or licenses based on this information. See my follow up question for an example of such case.

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