fix: enable double slashes for optional path variables

Closes #754

This implementation is flawed, it's making the pass-challenge route
return 404s. I'm not entirely sure why this is happening, but I'm
pushing this for now in case there's some low hanging fruit.

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

lib/anubis.go

@@ -18,6 +18,7 @@ import (
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/google/cel-go/common/types"
 	"github.com/google/uuid"
+	"github.com/gorilla/mux"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -68,7 +69,7 @@ var (
 
 type Server struct {
 	next        http.Handler
-	mux         *http.ServeMux
+	mux         *mux.Router
 	policy      *policy.ParsedConfig
 	OGTags      *ogtags.OGTagCache
 	ed25519Priv ed25519.PrivateKey

lib/challenge/interface.go

@@ -10,6 +10,7 @@ import (
 	"github.com/TecharoHQ/anubis/lib/policy/config"
 	"github.com/TecharoHQ/anubis/lib/store"
 	"github.com/a-h/templ"
+	"github.com/gorilla/mux"
 )
 
 var (
@@ -58,7 +59,7 @@ type ValidateInput struct {
 
 type Impl interface {
 	// Setup registers any additional routes with the Impl for assets or API routes.
-	Setup(mux *http.ServeMux)
+	Setup(r *mux.Router)
 
 	// Issue a new challenge to the user, called by the Anubis.
 	Issue(r *http.Request, lg *slog.Logger, in *IssueInput) (templ.Component, error)

lib/challenge/metarefresh/metarefresh.go

@@ -11,6 +11,7 @@ import (
 	"github.com/TecharoHQ/anubis/lib/localization"
 	"github.com/TecharoHQ/anubis/web"
 	"github.com/a-h/templ"
+	"github.com/gorilla/mux"
 )
 
 //go:generate go tool github.com/a-h/templ/cmd/templ generate
@@ -21,7 +22,7 @@ func init() {
 
 type Impl struct{}
 
-func (i *Impl) Setup(mux *http.ServeMux) {}
+func (i *Impl) Setup(r *mux.Router) {}
 
 func (i *Impl) Issue(r *http.Request, lg *slog.Logger, in *challenge.IssueInput) (templ.Component, error) {
 	u, err := r.URL.Parse(anubis.BasePrefix + "/.within.website/x/cmd/anubis/api/pass-challenge")

lib/challenge/proofofwork/proofofwork.go

@@ -13,6 +13,7 @@ import (
 	"github.com/TecharoHQ/anubis/lib/localization"
 	"github.com/TecharoHQ/anubis/web"
 	"github.com/a-h/templ"
+	"github.com/gorilla/mux"
 )
 
 func init() {
@@ -24,7 +25,7 @@ type Impl struct {
 	Algorithm string
 }
 
-func (i *Impl) Setup(mux *http.ServeMux) {
+func (i *Impl) Setup(r *mux.Router) {
 	/* no implementation required */
 }
 

lib/challenge/proofofwork/proofofwork_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/TecharoHQ/anubis/lib/challenge"
 	"github.com/TecharoHQ/anubis/lib/policy"
 	"github.com/TecharoHQ/anubis/lib/policy/config"
+	"github.com/gorilla/mux"
 )
 
 func mkRequest(t *testing.T, values map[string]string) *http.Request {
@@ -124,7 +125,7 @@ func TestBasic(t *testing.T) {
 		t.Run(cs.name, func(t *testing.T) {
 			lg := slog.With()
 
-			i.Setup(http.NewServeMux())
+			i.Setup(mux.NewRouter())
 
 			inp := &challenge.IssueInput{
 				Rule: bot,

lib/config.go

@@ -24,6 +24,7 @@ import (
 	"github.com/TecharoHQ/anubis/web"
 	"github.com/TecharoHQ/anubis/xess"
 	"github.com/a-h/templ"
+	"github.com/gorilla/mux"
 )
 
 type Options struct {
@@ -110,25 +111,33 @@ func New(opts Options) (*Server, error) {
 		store:       opts.Policy.Store,
 	}
 
-	mux := http.NewServeMux()
-	xess.Mount(mux)
+	r := mux.NewRouter()
+	xess.Mount(r)
 
 	// Helper to add global prefix
 	registerWithPrefix := func(pattern string, handler http.Handler, method string) {
-		if method != "" {
-			method = method + " " // methods must end with a space to register with them
-		}
-
 		// Ensure there's no double slash when concatenating BasePrefix and pattern
 		basePrefix := strings.TrimSuffix(anubis.BasePrefix, "/")
-		prefix := method + basePrefix
 
 		// If pattern doesn't start with a slash, add one
 		if !strings.HasPrefix(pattern, "/") {
 			pattern = "/" + pattern
 		}
 
-		mux.Handle(prefix+pattern, handler)
+		var route *mux.Route
+
+		switch strings.HasSuffix(pattern, "/") {
+		case true:
+			route = r.PathPrefix(basePrefix + pattern)
+		case false:
+			route = r.Path(basePrefix + pattern)
+		}
+
+		if method != "" {
+			route = route.Methods(method)
+		}
+
+		route.Handler(handler)
 	}
 
 	// Ensure there's no double slash when concatenating BasePrefix and StaticPath
@@ -164,10 +173,10 @@ func New(opts Options) (*Server, error) {
 
 	for _, implKind := range challenge.Methods() {
 		impl, _ := challenge.Get(implKind)
-		impl.Setup(mux)
+		impl.Setup(r)
 	}
 
-	result.mux = mux
+	result.mux = r
 
 	return result, nil
 }