Secure generation of cookies with proper SameSite attribute
import play.api.mvc._
def login = Action { implicit request =>
val sessionId = java.util.UUID.randomUUID().toString
Ok("Logged in").withCookies(Cookie("sessionId", sessionId))
}
In the above code, a new session cookie is created for each login request but the SameSite attribute is not set. The
withCookies method is used to add the cookie to the HTTP response.
The SameSite attribute is a security measure that browsers use to restrict how cookies are sent with cross-site requests. If this attribute is not set, the cookie is sent with all requests, including those that originate from a different site. This can lead to Cross-Site Request Forgery (CSRF) attacks, where an attacker tricks a victim into performing an action that the victim did not intend to do.
In this code, an attacker could potentially trick a user into sending a request to the login route of this application from a different site, causing the application to generate a new session cookie and sending it back to the attacker's site. The attacker could then use this session cookie to impersonate the user in subsequent requests to the application.
To fix this vulnerability, the SameSite attribute should be set to 'Strict' or 'Lax' when creating the cookie. This will instruct the browser to only send the cookie with same-site requests, preventing CSRF attacks.
import play.api.mvc._
def login = Action { implicit request =>
val sessionId = java.util.UUID.randomUUID().toString
val cookie = Cookie("sessionId", sessionId, httpOnly = true, secure = true, sameSite = Some(Cookie.SameSite.Strict))
Ok("Logged in").withCookies(cookie)
}
The updated code now includes the
SameSite attribute in the cookie creation process. The
SameSite attribute is set to
Strict, which means the cookie will only be sent in a first-party context, i.e., only to the site that it originated from. This prevents the cookie from being sent along with requests initiated by third party websites, effectively mitigating the risk of cross-site request forgery (CSRF) attacks.
In addition to setting the
SameSite attribute, the
httpOnly attribute is set to
true to prevent the cookie from being accessed through client-side scripts, and the
secure attribute is set to
true to ensure the cookie is only sent over secure (HTTPS) connections.
It's important to note that these settings should be applied to all cookies generated by the application, not just the login cookie, to ensure a consistent level of security across all application features.