jwt/login example CSRF ignored because of Bearer Token

[simasch]

Hi,

I tried the jwt/login example and noticed that the CSRF token is not generated when a Bearer token is present because of BearerTokenRequestMatcher.

The only request without Bearer token would be the auth request with basic authentication, but for this request CSRF is disabled.

Does the example make sense? Or why isn't CSRF disabled at all?

Thank you.

[marcusdacoregio]

Hi @simasch,

CSRF protection is unnecessary in this scenario because we are using stateless authentication. In other words, we are not dealing with Session Cookies, which are added to the request automatically by the browser, this way avoiding the majority of CSRF exploits. When using an Authorization header, we have to add the header manually using JavaScript.

The HTTP Basic authentication mechanism is also stateless, so no need for CSRF protection either.

[simasch]

Hi @marcusdacoregio
That's what I thought :-)

Will https://github.com/spring-projects/spring-security-samples/blob/main/servlet/spring-boot/java/jwt/login/src/main/java/example/RestConfig.java be change accordingly?

[marcusdacoregio]

Hi @simasch,

What changes specifically do you expect to see in the configuration?

[simasch]

csrf(AbstractHttpConfigurer::disable)

instead of

csrf((csrf) -> csrf.ignoringRequestMatchers("/token"))

Because it was very confusing that CSRF is configured but not used and now token was generated.

[marcusdacoregio]

It is a little tricky for sure, but I think keeping .csrf((csrf) -> csrf.ignoringAntMatchers("/token")) makes sense. If the user happens to add some authentication mechanism that relies on a session cookie they do not have to remember to change the CSRF configuration to now include those endpoints.

It is a recommended secure posture to "deny" everything unless they are authorized, it's the same train of thought as spring-projects/spring-security#11958

[simasch]

Makes sense!
Thank you