CyberNina

Cross-site request forgery (CSRF) is an attack where the legitimate user trapped by an unauthorized user to perform an unintended task to a website where they are authenticated. Since HTTP is a stateless protocol, cookies are used to validate the request agent. Once the user login to a website, it will not require to type the username and password for each attempt. Hence, for the server to identify the user, the server generates a session identifier and sends it as a set-cookie header to the client browser with the very first response. The cookie set by the server will be saved in the client browser and, the cookie will be sent along with every request made to the server (Where the domain and path are matched). However, the server does not check any other attribute but session identifier. Although the request is made from another client, the website only verifies whether the requesting user is already authenticated or not, using a cookie. For example, if a person logged in...

Double submit cookie is one of the prevention method for Cross-Site Request Forgery ( CSRF ) . Same as the synchronizer token pattern, it is using a cryptographic random value to validate a request agent. However, the implementation is different since the way it is saved is dissimilar. Here, the generated token value is saved in the browser, not on the server. Therefore servers no need to save huge amounts of data. When a user makes a request, the server compared the token value in the form DOM element (in the body) and token in the cookie header of the request.  (Click on the images to view clearly) Source code of the implemented program can be downloaded from here . A login page, index.html has been implemented to enroll users. Once the user entered the credentials, the form data will be submitted to login_handler.php using POST method. If the username and password are correct, the user session is started and the username will be assigned to ...

Synchronizer token pattern is one of the prevention methods for Cross-Site Request Forgery ( CSRF ). It uses a value called CSRF token which is unique for a session identifier. When the user login to a website, the server generates a random value called token for a particular session. The token is saved on the server as well as the browser (after obtained from the server). PHP identifies the session using the session variable ‘PHPSESSID’ which is also stored in the browser as the cookie to identify a particular session. The server validates the user when each request is made, via comparing the token value in the server and token value in the browser. Through this write up how synchronizer token pattern is implemented and how does it works will be described.  (Click on the images to view clearly) Source code of the implemented program can be downloaded from here .  I have implemented a login page called index.html to enroll a user to the server. T...