Security Protocol v2.0 Ready

PortGuard: Keep Your Services Invisible to Scanners

PortGuard combines a modified fwknop-based server with a cross-platform client that supports the fwknop SPA protocol. Ports stay closed by default and open temporarily only after a valid AES/GPG-signed packet is verified.

Λήψη τώρα Read Docs

Quick Server Install

Installs the latest open-source package built by GitHub Actions from the PortGuard server repository.

Guide
curl -fsSL https://portguard.net/install.sh | sudo bash
Live Client Preview
Built for fwknop-compatible workflows

Traditional Exposure Mode (Risk)

  • ✕Ports remain open all day and are continuously probed by global scanners.
  • ✕Exposed services face brute-force attempts and exploit attacks directly.
  • ✕Firewall allowlists become complex to maintain and lack dynamic flexibility.

PortGuard Mode (Solution)

  • ✓Default Deny: Ports are completely invisible before authorization (stealth).
  • ✓SPA Auth: Only specially formatted encrypted single packets can trigger access.
  • ✓Dynamic Access: Temporarily allow only the source IP, then close automatically.

Core Features

Core Security Features

Strong defaults for teams that want SSH, admin panels, and private services to disappear until authorization is intentional.

Efficient SPA Communication

Send fwknop-compatible single-packet authorization without TCP handshake overhead, with strong stealth.

AES/GPG + HMAC

Integrated SHA256 integrity checks ensure commands are authentic and untampered.

Full Port Stealth

Default DROP behavior makes services appear unreachable to scanners.

Replay Attack Resistance

Time-window validation plus integrity checks quickly invalidates old packets.

Εκπαιδευτικό Σεμινάριο PortGuard

A cleaner fwknop-compatible client for every device.

PortGuard Client supports the fwknop SPA protocol. Profiles, one-tap SPA, QR import, encrypted export, and activation stay compatible with fwknopd and PortGuard Server workflows.

One-tap SPA Send authorized knocks without command-line friction.
Encrypted profiles Keep local configs protected at rest.
QR import Move profiles between devices quickly.

How It Works

Security Workflow

PortGuard runs at the firewall edge of protected servers. It continuously inspects network traffic for authorization packets without exposing service handshakes externally.

1
Generate Authorization Packet

The client uses keys and a timestamp to generate an encrypted single packet.

2
Handshake-less Delivery

The packet is sent via UDP and similar methods, making handshake-based probing ineffective.

3
Dynamic Open

After validation, the server temporarily allows the source IP and then automatically removes the rule.

PORT_GUARD_DAEMON СТАТУС: СЛУШАЕТ
[INFO] Перехват SPA-пакетов на eth0...
[CMD] Обнаружен пакет от 124.6.x.x
[AUTH] HMAC SHA256 проверен. Метка времени корректна.
[AUTH] Расшифровка payload с помощью AES-256-CBC...
[FIREWALL] Открытие порта 22 для 124.6.x.x на 30 с.
_

Use Cases

SSH Remote Operations

Protect port 22 and make it visible only briefly after an admin sends SPA.

Multi-Cloud Security

Unified access control across AWS/Azure and more to reduce exposure.

IoT Device Management

Protect IoT control interfaces and avoid direct public exposure.

ACL Automation

Combine scripts and rule cycles to automate temporary authorization.

Downloads and Installation

Supports multi-platform clients and server-side packages

Windows Client

portguard-client-2.2.1-x64-setup.exe

Download .EXE Αγοράστε κωδικό ενεργοποίησης

macOS Client

portguard-client-2.2.2-18-macos.dmg

Download .DMG Αγοράστε κωδικό ενεργοποίησης

Apple App Store

iPhone & iPad

Go to Store

Android App

fwknopc_2_6_11.apk

Download APK

Linux Server

Debian, Ubuntu, Rocky, CentOS, OpenWrt

Server Packages
Security Tip: Please verify MD5/SHA256 fingerprints after downloading.

Server Packages

Install PortGuard Server on Debian, Ubuntu, Rocky, CentOS, and OpenWrt

Use the quick installer for supported Linux servers, or download the latest package generated from the open-source GitHub Actions release pipeline.

Quick Install

One command server setup

curl -fsSL https://portguard.net/install.sh | sudo bash

The script detects the operating system, selects the matching package from the GitHub release manifest, verifies SHA256, installs dependencies, and leaves fwknopd ready for configuration export to PortGuard Client.

Installation Guide manifest.tsv

Open Source Release

Packages synced from GitHub

These packages are built automatically by GitHub Actions from the public PortGuard server source code.

Latest Release
GitHub Repo GitHub Actions checksums.txt
System Version Architecture Package Λήψη
Loading packages from GitHub release...

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FAQ и сценарии использования

Последнее обновление:

What is the relationship between PortGuard and fwknop?

PortGuard is built around the fwknop SPA protocol. PortGuard Client is a cross-platform client that sends fwknop-compatible SPA packets, while PortGuard Server is a modified server based on the upstream fwknop project. Compared with traditional sequence-based port knocking, this single encrypted packet model is faster, stealthier, and resistant to replay attacks.

Μπορώ να δημιουργήσω ένα προφίλ και να χρησιμοποιήσω ένα knock για να επιτρέψω σε μια συγκεκριμένη IP να έχει πρόσβαση σε κάθε θύρα υπηρεσίας;

Ναι. Διαμορφώστε τη στροφή πρόσβασης διακομιστή με το OPEN_PORTS ANY και χρησιμοποιήστε ένα προφίλ πελάτη με το ACCESS ANY. Το προφίλ μπορεί να δημιουργηθεί και να εισαχθεί μία φορά και στη συνέχεια να επαναχρησιμοποιηθεί. Κάθε έγκυρο χτύπημα δημιουργεί έναν προσωρινό κανόνα πηγής IP που επιτρέπει στην IP που έχει επιλεγεί από το ALLOW_IP να φτάσει σε όλες τις θύρες υπηρεσίας TCP και UDP μέχρι να λήξει το FW_TIMEOUT. Μετά τη λήξη, στείλτε ένα νέο χτύπημα. Αυτή είναι μια λειτουργία υψηλού προνομίου: χρησιμοποιήστε ένα σύντομο χρονικό όριο, προστατέψτε το προφίλ και τα κλειδιά και να θυμάστε ότι εξακολουθούν να ισχύουν τα upstream τείχη προστασίας cloud, οι κανόνες δρομολογητή και ο έλεγχος ταυτότητας υπηρεσίας.

Как fwknop сравнивается с tnock?

Оба решения скрывают сетевые порты, но fwknop — более продвинутая SPA-система. tnock и похожие демоны на последовательностях ищут шаблон попыток подключения по нескольким закрытым портам, что медленнее и уязвимо к replay-атакам. fwknop решает это передачей одного криптографически подписанного пакета с меткой времени. Плюсы: заметно выше безопасность, защита от replay и бесшовная интеграция с современными фаерволами.

Как сделать сайт или приватный сервис доступным только определённым людям?

By default, PortGuard Server, modified from fwknop, configures your server's firewall to block all inbound traffic to your service port. The service appears completely offline to the public. When an authorized user needs access, they use PortGuard Client with their unique cryptographic key to send a fwknop-compatible Single Packet Authorization (SPA) packet. Once verified, the server dynamically whitelists their current IP address for a brief period.

Как обеспечить безопасность и приватность NAS в публичной сети без утечки данных?

Прямое открытие NAS в интернет очень рискованно из-за постоянного сканирования ботнетами и сканерами. Обычно есть два безопасных варианта:

  • Вариант 1: Cloudflare Zero Trust (Tunnels) Трафик NAS проходит через сеть Cloudflare без открытия входящих портов. Плюсы: очень просто настроить, не нужен публичный IP, есть дополнительный слой WAF. Минусы: трафик идёт через третью сторону, значит вы зависите от политики приватности Cloudflare; скорость часто ограничена маршрутизацией бесплатного тарифа, что хуже для потоковой передачи больших медиа.
  • Вариант 2: Собственный публичный IP + fwknop Port Knocking Вы открываете порт на роутере, но защищаете его fwknop (SPA). Порт остаётся невидимым в публичном интернете и открывается только после валидного криптографически подписанного пакета доступа. Плюсы: максимальная приватность без сторонних серверов и максимальная скорость железа за счёт прямого соединения (удобно для видео). Минусы: нужен реальный публичный IP и чуть более техническая первичная настройка.

Снижает ли fwknop PortGuard скорость соединения после открытия порта?

No. The fwknop-compatible PortGuard Server only handles the initial authorization packet. Once the firewall rule is dynamically created and your IP is authorized, your connection via SSH, WireGuard, or directly to your NAS operates directly between your client and the server at full line speed.

Trusted by DevOps and Security Experts Worldwide

"After deploying PortGuard on our bastion hosts, SSH scan noise in logs dropped significantly."
- Старший системный администратор, TechGroup
"SPA's one-way, handshake-less design is highly practical, balancing stealth and operability."
- Исследователь безопасности, @CyberNode
"iptables integration was smooth, and we've rolled it out at scale in production."
- Ведущий DevOps, Fintech Corp

Quick Start Guide

Deploy Tutorial →

Step-by-step installation and configuration on Linux servers.

Quick Start →

Send and verify your first SPA packet in minutes.

Official Contact

Need help with PortGuard?

For purchase recovery, activation issues, deployment questions, or security reports, contact the official PortGuard support mailbox.

[email protected]