Programmatic authentication - spring

I am using Spring Security in my application.
I have all the pages secured. But couple of URL needs to be available both for system user and anonymous user.
But anonymous user should not have direct access to the URLs. He gets a link with unique token and gets access to some URLS if this token is valid.
What I want to do is:
In controller check if token in URL is valid
If it is - authenticate user in the system programmatically using some predefined login and password. This user will be configured to have authority to access necessary URLs.
The question is:
Is this a correct approach to perform user authentication programatically with some roles in controller if token is valid? Is this safe approach?

Security is an aspect. An aspect can be decoupled from your main code (controller) to reduce code duplication and improve flexibility. Move authentication code from controller to new filter (be sure that this filter executed after spring security filter chain). You will be able secure new URLs via web.xml (zero lines of code).

I think the better way to do this is:
move the shared operations into service layer
define a controller for those anonymous user and make its authority
as anonymous
check the validity of token in this controller
if valid, call some services method to perform the operations.
render the result in this controller

Related

Securing rest and actuator endpoints using custom token and http session

I have a spring boot app where the API #Controller endpoints are secured using a token that is contained in the http header. The token needs to be extracted from the header and validated against an internal cache to make sure it is valid. If the token is valid then the request can proceed to the controller and if it is not valid then it should return a 401 to the caller.
I also have another requirement to secure some of the actuator end points. When the user tries to use the browser to access the respective actuator endpoint, it will check for a user session if no session exists then the request is redirected to the spring login page. When they login I need to extract the username and password and validate using an external service. If valid a session can be created for the user and they can then use the hawtio endpoint. The session needs to store role based information so that when the user tries to perform JMX operations it will only allow them to perform the appropriate read only / write if they have the requisite role.
Any pointers regarding how you'd try and tackle this would be most welcome. I am unsure whether this is achieved by specifying addFilterBefore or addFilter and I don't understand how having authenticated the user for the actuator I go about creating a session that can be stored in the context and checked later on for subsequent requests.
Thanks

How to access a secured API in the frontend?

There is a lot of good content on the internet that explains how to secure a Spring API with Keycloak: Create a Client that represents the API Service in Keycloak and use a link like the one below to get the access and refresh token:
<Domain>/auth/realms/<realm>/protocol/openid-connect/auth/{some parameters}
This yields both tokens. So far so good.
Now, however, I am not sure how the flow for the frontend accessing the API should look like.
Should the frontend directly access this endpoint and, therefore, obtain the access and refresh token? That would mean that the API can only have the access-type public because there is no way to store the client (the API) secret securely.
Or should there be a third server that somehow stores the refresh token for each user, that the user can call if his access token is no longer valid. This server would then use the client's refresh token (and the client secret that could be stored securely, since it would be in the backend) to get a new access token from Keycloak and would forward it to the user.
I guess the main question that I am asking is, whether the client/user should get the refresh token.
If one needs to implement a logic according to the second option, I would be interested in a link or description of how something like this can be done in Spring.
I think, in either case you need to use the Authorization Code Flow. The implicit flow, which was recommended for SPAs (frontends without a backend server) in former versions of OAuth2 must not be used anymore.
The best option is to have a backend server, so the user retrieves the auth code via redirection and the backend server exchanges this auth code with the access and refresh tokens (and keep them without forwarding them to the frontend).
If there is no backend in place and your frontend needs to retrieve and hold the tokens directly, I would recommend to use the Authorization Code Flow with a public client and the PKCE extension (which - put simply - ensures that the entity asking for the auth code is the same as the entity asking for the tokens and that the auth code was not stolen and used by a foreign entity). There are several sources with more detailed explanations, which might help you, for example: https://auth0.com/docs/flows/authorization-code-flow-with-proof-key-for-code-exchange-pkce
Hope this helps you with your architectural considerations.

Microservices authorization. How to prevent user with valid JWT access other users resources?

I have a number of stateless Microservices behind API Gateway and I want to make sure that a user request containing valid Authorization JWT token cannot access resources of other users.
Currently, my API Gateway only validates if the JWT is not expired and is valid.
To prevent a user request with valid JWT access resources of other users, I was going to use Spring's Method Level Security and check if the principal user id matches the userId in the request URL path. But that means that, in each microservice, I need to add Spring Security, create an authorization filter, and create a security context based on the information I read from JWT. I will need to recreate the Spring Security Context in every single Microservice.
Is it a correct way to do it? If not, what is another way to prevent a user request containing valid JWT to access the resources of other users?
Please advise me.
How you’re handling it is usually the correct approach. In order for each service to remain de-coupled from others it’s important it is able to determine which methods/endpoints care about the user scope and which ones don’t. More rules and logic in the gateway means more restrictions on what individual services can do.
That being said, if you have globally predictable rules that apply to all services you have a case for putting the logic in the gateway. Something like JWT verification is an example of such a rule that is standardized enough that you can make assumptions about what underlying services would want to do with the token upon receiving it (verify it). If you have a rule you can safely apply globally, you can pull it out of the services and put it in the gateway. Otherwise, you’re better off with a bit of duplication so that you don’t create hurdles that would prevent services from handling input differently.

Spring Security Authorize by authentication method

How can I limit the access to a method, base on the authentication method, in Sprint Security?
For example, I want two methods of authentication to my service: basic and LDAP. But for one method in my service I only want access to be allowed if the user authenticated using basic-authirization.
I know I can add Authentication to the method signature and then check if it's an instance of UsernamePasswordAuthenticationToken, but that seems a but ugly and not really using the full power of the framework.
I guess I can do the same with PreAuthorize.
Another ugly way to do this is to add a rule to every authenticated user that tells the authentication method. I can the authorize base on the role. Again, ugly
But is there a more out-of-the-box/Springy way of doing this?

Zend : Block Access via URL

I have in my first ZF1 application two controllers : AuthController et ProductController.
My code for the authentication work perfectly by using Zend_Auth.
But the user still can access in the application in the browser without authentication. For example if the user enter :
http://localhost/apptest/public/product/action
he can access directly. Must I use Zend_Session or Zend_Acl to block access if the user is not login?
Thanks.
Zend_Auth is concerned only with authentication and not with authorization. Authentication is loosely defined as determining whether an entity actually is what it purports to be (i.e., identification), based on some set of credentials. Authorization, the process of deciding whether to allow an entity access to, or to perform operations upon, other entities is outside the scope of Zend_Auth. For more information about authorization and access control with Zend Framework, please see Zend_Acl.

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