the CSRF cookie name
Embed a token into a response *
your CSRF header name
Constructs a middleware that will check for the csrf token presence on both the proper cookie, and header values, if the predicate is not satisfied
Constructs a middleware that will check for the csrf token presence on both the proper cookie, and header values, if the predicate is not satisfied
If it is a valid token, it will then embed a new one, to effectively randomize the complete token while avoiding the generation of a new secure random Id, to guard against [BREACH](http://breachattack.com/)
Middleware to embed a csrf token into routes that do not have one.
Middleware to embed a csrf token into routes that do not have one. *
Middleware to avoid Cross-site request forgery attacks. More info on CSRF at: https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)
This middleware is modeled after the double submit cookie pattern: https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)_Prevention_Cheat_Sheet#Double_Submit_Cookie
When a user authenticates,
embedNew
is used to send a random CSRF value as a cookie. (Alternatively, an authenticating service can be wrapped inwithNewToken
).By default, for requests that are unsafe (PUT, POST, DELETE, PATCH), services protected by the
validated
method in the middleware will check that the csrf token is present in both the headerheaderName
and the cookiecookieName
. Due to the Same-Origin policy, an attacker will be unable to reproduce this value in a custom header, resulting in a401 Unauthorized
response.By default, requests with safe methods (such as GET, OPTIONS, HEAD) will have a new token embedded in them if there isn't one, or will receive a refreshed token based off of the previous token to mitigate the BREACH vulnerability. If a request contains an invalid token, regardless of whether it is a safe method, this middleware will fail it with
401 Unauthorized
. In this situation, your user(s) should clear their cookies for your page, to receive a new token.The default can be overridden by modifying the
predicate
invalidate
. It will, by default, check if the method is safe. Thus, you can provide some whitelisting capability for certain kinds of requests.We'd like to emphasize that you please follow proper design principles in creating endpoints, as to not mutate in what should otherwise be idempotent methods (i.e no dropping your DB in a GET method, or altering user data). Please do not use the CSRF protection from this middleware as a safety net for bad design.