Add API for resolver

internal/dis/component/auth/scopes/instances.go

@@ -32,7 +32,6 @@ func (*ListInstancesScope) Scope() component.ScopeInfo {
 }
 
 func (lis *ListInstancesScope) HasScope(param string, r *http.Request) (bool, error) {
-	// TODO: at the moment everyone has this permission
-	// this should change in the future!
-	return true, nil
+	_, user, err := lis.Dependencies.Auth.SessionOf(r)
+	return user != nil, err
 }

internal/dis/component/auth/scopes/news.go

@@ -32,6 +32,6 @@ func (*ListNewsScope) Scope() component.ScopeInfo {
 }
 
 func (lns *ListNewsScope) HasScope(param string, r *http.Request) (bool, error) {
-	// TODO: at the moment everyone has this permission
-	return true, nil
+	_, user, err := lns.Dependencies.Auth.SessionOf(r)
+	return user != nil, err
 }

internal/dis/component/auth/scopes/resolver.go

@@ -0,0 +1,37 @@
+package scopes
+
+import (
+	"net/http"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
+)
+
+type ResolverScope struct {
+	component.Base
+	Dependencies struct {
+		Auth *auth.Auth
+	}
+}
+
+var (
+	_ component.ScopeProvider = (*ResolverScope)(nil)
+)
+
+const (
+	ScopeResolver Scope = "url.resolve"
+)
+
+func (*ResolverScope) Scope() component.ScopeInfo {
+	return component.ScopeInfo{
+		Scope:         ScopeResolver,
+		Description:   "resolve a URI to a URL to display it in",
+		DeniedMessage: "",
+		TakesParam:    false,
+	}
+}
+
+func (rs *ResolverScope) HasScope(param string, r *http.Request) (bool, error) {
+	_, user, err := rs.Dependencies.Auth.SessionOf(r)
+	return user != nil, err
+}