feat(lib): annotate cookies with what rule was passed (#576)

* feat(lib): annotate cookies with what rule was passed

Anubis JWTs now contain a policyRule claim with the cryptographic hash
of the rule that it passed. This is intended to help with a future move
away from proof of work being the default.

Signed-off-by: Xe Iaso <me@xeiaso.net>

* test(lib): fix cookie storage logic

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/http.go

@@ -12,6 +12,7 @@ import (
 	"github.com/TecharoHQ/anubis/lib/policy"
 	"github.com/TecharoHQ/anubis/web"
 	"github.com/a-h/templ"
+	"github.com/golang-jwt/jwt/v5"
 )
 
 func (s *Server) SetCookie(w http.ResponseWriter, name, value, path string) {
@@ -151,3 +152,11 @@ func (s *Server) ServeHTTPNext(w http.ResponseWriter, r *http.Request) {
 		s.next.ServeHTTP(w, r)
 	}
 }
+
+func (s *Server) signJWT(claims jwt.MapClaims) (string, error) {
+	claims["iat"] = time.Now().Unix()
+	claims["nbf"] = time.Now().Add(-1 * time.Minute).Unix()
+	claims["exp"] = time.Now().Add(s.opts.CookieExpiration).Unix()
+
+	return jwt.NewWithClaims(jwt.SigningMethodEdDSA, claims).SignedString(s.priv)
+}