Release: v0.1.0-alpha

internal/security/sizelimit.go

@@ -0,0 +1,30 @@
+// Keywarden - Centralized SSH Key Management and Deployment
+// Copyright (C) 2026 Patrick Asmus (scriptos)
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+package security
+
+import (
+	"net/http"
+)
+
+// SizeLimitMiddleware returns middleware that limits the size of incoming
+// request bodies to maxBytes. This prevents denial-of-service attacks via
+// excessively large uploads. A value of 0 disables the limit.
+//
+// The limit is enforced with http.MaxBytesReader which causes the server
+// to return 413 Request Entity Too Large if the body exceeds the limit.
+func SizeLimitMiddleware(maxBytes int64) func(http.Handler) http.Handler {
+	if maxBytes <= 0 {
+		return func(next http.Handler) http.Handler { return next }
+	}
+
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.Body != nil && r.ContentLength != 0 {
+				r.Body = http.MaxBytesReader(w, r.Body, maxBytes)
+			}
+			next.ServeHTTP(w, r)
+		})
+	}
+}