GateBell

SSH Login Detector & Announcer

A Kotech Petacomm Product

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What is GateBell?

GateBell watches your Linux server 24/7. Every time someone connects via SSH, you get an instant email alert with:

• Connecting IP address
• Country, city & ISP — powered by ip-api.com
• Date & time of the login
• Server nickname so you know which server was accessed

No dashboards. No subscriptions. No complexity. One command to install. Two minutes to set up.

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Quick Install

curl -fsSL https://repo.kotechsoft.com/gbi.sh | sudo bash

Then run the setup wizard:

sudo gatebell-setup

The wizard will:

1. Ask for your email address
2. Send you a 6-digit verification code
3. Ask you to give this server a nickname
4. Automatically connect GateBell to SSH

That's it. No config files to edit.

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How It Works

Someone connects via SSH
        │
        ▼
Linux PAM detects the session
        │
        ▼
GateBell captures IP & timestamp
        │
        ▼
Signed HMAC request → Kotech Petacomm API
        │
        ▼
IP analyzed (Country, City, ISP)
        │
        ▼
Email alert sent to your inbox

GateBell uses Linux PAM (Pluggable Authentication Modules) to detect SSH logins at the authentication layer — the most reliable method available.

SSH connections are never delayed or interrupted. The notification runs in the background.

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Security

GateBell was built with security as a first priority:

Feature	Details
Per-user HMAC-SHA256	Every client has a unique secret key — no shared secrets
Replay attack protection	Each request includes a nonce + 5-minute timestamp window
Hashed secrets	Client secrets are stored as SHA-256 hashes, never plaintext
No information leakage	Error responses never reveal whether an email exists
PAM integration	Hooks into the Linux authentication layer directly
TLS everywhere	All communication over HTTPS

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Requirements

• Ubuntu 20.04+ or Debian 11+
• Python 3.8+
• OpenSSH server
• Internet connection
• Root / sudo access

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Manual APT Install

If you prefer to add the repository manually:

# Add GPG key
curl -fsSL https://repo.kotechsoft.com/kotech-petacomm.gpg | \
  sudo gpg --dearmor -o /usr/share/keyrings/kotech-petacomm.gpg

# Add repository
echo "deb [signed-by=/usr/share/keyrings/kotech-petacomm.gpg] \
  https://repo.kotechsoft.com stable main" | \
  sudo tee /etc/apt/sources.list.d/gatebell.list

# Install
sudo apt update && sudo apt install gatebell

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Project Structure

gatebell/
├── app.py              # Flask API server (runs on Kotech Petacomm infrastructure)
├── requirements.txt    # Python dependencies
├── gatebell.service    # systemd service file
├── gatebell-setup      # Client setup wizard
├── gatebell-notify     # PAM notifier script
├── gatebell-pam        # PAM wrapper
└── gbsetup.sh          # One-line installer

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Self-Hosting

Want to run your own GateBell server? The full server code is in app.py.

Requirements:

• Python 3.8+
• Flask, flask-limiter, python-dotenv
• A Brevo (or any SMTP) account for sending emails
• A domain with SSL

See .env.example for configuration options.

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License

GateBell is free and open source software, released under the GNU General Public License v3.0.

See LICENSE for details.

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Support

• Website: kotechsoft.com
• Email: support@kotechsoft.com
• Issues: GitHub Issues

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_{Built with care by Kotech Petacomm — secure tools for everyone.}