# 🔐 NIP‑49 Key Decrypt Fully Offline Self-Contained HTML

A simple, browser-based tool for decrypting NIP-49 (password-protected) Nostr keys — fully offline.  
It ensures your private key **never leaves your device** and gives users full transparency into what code is running.

---

## ✅ Overview & Motivation

This tool was built to make **secure, offline decryption** of NIP-49 encrypted Nostr keys easy for anyone — without requiring Node.js, servers, or dependencies.

Most web-based cryptography tools fetch external scripts from CDNs each time they run, which can expose users to privacy or supply-chain risks.  
The **NIP-49 Offline Decrypt Tool** avoids this by letting users:

1. Fetch the required libraries **once** while online.
2. Package everything into a **self-contained HTML file**.
3. Disconnect from the internet and safely decrypt their NIP-49 key offline.

---

## ⚙️ How It Works

The app runs entirely in the browser using JavaScript and modern Web APIs:

1. **Library Fetching (Online)**  
   The user downloads the required cryptographic libraries:
   - [`libsodium-wrappers`](https://www.npmjs.com/package/libsodium-wrappers)
   - [`scrypt-js`](https://www.npmjs.com/package/scrypt-js)
   - [`bech32`](https://www.npmjs.com/package/bech32)

   These are loaded into memory, never uploaded anywhere, and stored temporarily for packaging.

2. **Self-Contained Export**  
   The app lets you export a new `nip49-offline.html` file that includes:
   - The libraries (embedded inline)
   - The app logic
   - The interface for decryption

3. **Offline Mode (Decryption)**  
   Once exported, the tool verifies that you are offline and allows decryption of your NIP-49 key locally.

---

## 🚀 Usage Instructions (Step-by-Step)

1. **Open the Online Tool**  
   Visit the hosted version or open the HTML file locally with an internet connection.

2. **Step 1: Download Libraries**  
   - Click **“Download Libraries”**  
   - The tool will fetch and store the required scripts in memory.  
   - You’ll see progress indicators for each library.

3. **Step 2: Export Offline HTML**  
   - Once all libraries are fetched, click **“Export Self-Contained HTML”**.  
   - This creates a new `nip49-offline.html` file with everything embedded.  
   - Save the file to your computer.

4. **Step 3: Go Offline**  
   - Disconnect from the internet.  
   - Open your saved `nip49-offline.html` file in your browser.

5. **Step 4: Decrypt**  
   - Paste your NIP-49 encrypted key and password.  
   - Click “Decrypt.”  
   - Your private key will be displayed (never transmitted anywhere).

---

## 🔐 Security Notes

- All operations happen **entirely in your browser** — no data leaves your device.  
- The exported HTML file contains all logic and dependencies inline.  
- To verify safety, you can inspect the final file contents — everything is human-readable JavaScript and HTML.  
- Always perform decryption **offline** and **with your network fully disabled** for maximum safety.

---

## 🧠 Technical Details

- **Language:** HTML, JavaScript (no build tools required)  
- **Libraries Used:**
  - [`libsodium-wrappers`](https://www.npmjs.com/package/libsodium-wrappers) — cryptographic operations
  - [`scrypt-js`](https://www.npmjs.com/package/scrypt-js) — password-based key derivation
  - [`bech32`](https://www.npmjs.com/package/bech32) — encoding/decoding NIP-49 format
- **Features:**
  - Detects online/offline state dynamically
  - In-memory caching of library source code
  - Self-contained HTML export using `Blob` and `URL.createObjectURL`
  - Minimal UI for clarity and transparency

---


---
---
---


# 🔐 NIP‑49 Key Encrypt/Decrypt & Conversion CLI

A tiny, no-fuss command-line tool / self contained HTML to **encrypt**, **decrypt**, and **convert** Nostr keys — safely and offline.

Built for privacy-conscious users who want a secure and user-friendly way to handle their Nostr keys using [NIP‑49](https://github.com/nostr-protocol/nips/blob/master/49.md).

---

## ✨ Features

- 🔐 **Encrypt / Decrypt** your Nostr `nsec` keys using a password (NIP‑49)
- 🔁 **Convert** private key hex ↔ `nsec` and public key hex ↔ `npub`
- 🧭 Friendly CLI with step-by-step wizard prompts
- ⚙️ Pure Python. No compiling, no GUI — just run and go
- 🔒 Secure: works 100% offline — no network requests

---

## 🍎 macOS CLI Setup

### ✅ 1. Install Python 3 (via Homebrew)

If you don’t already have Python 3:

```bash
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
brew install python
```
Confirm it’s working:
```bash
python3 --version
```
📦 Installation
```bash
📁 1. Clone the repo
git clone https://github.com/btcforplebs/nip49-decrypt.git
```
cd nip49-decrypt
### 🧪 2. Create and activate a virtual environment
```bash
python3 -m venv venv
source venv/bin/activate
```
### 📦 3. Install Python packages
```bash
pip install bech32 cryptography ecdsa pynacl
If pynacl fails, the script will fall back to cryptography for encryption.
```
### ✅ 4. Make it executable
```bash
chmod +x nip-49decrypt
```
▶️ Usage
From the project directory, run:
```bash
./nip-49decrypt
```
You’ll see a friendly menu:
```bash
Choose an action:
  (d) Decrypt an encrypted key with password
  (e) Encrypt a private key with password
  (h) Convert private key hex to nsec
  (p) Convert public key hex to npub
  (q) Quit
  ```
### 🔐 Example: Decrypt a Key
Select (d)
Paste your ncryptsec string
Enter your password (input hidden)
View your decrypted raw private key and corresponding nsec

### 🛠️ Other Features
Convert raw hex → nsec
Choose (h) and enter your private key as 64-character hex.
Convert public key hex → npub
Choose (p) and paste a 66-character (compressed) or 130-character (uncompressed) public key in hex.
Encrypt nsec → ncryptsec
Choose (e) and paste your private key (hex or nsec). You’ll be prompted for a password, and the script will return a password-encrypted ncryptsec.

### 🧼 To Exit
Use (q) or press Ctrl + C at any time.

### 📁 Files
File	Description
nip-49decrypt	Main Python script
README.md	This help file
venv/	Your virtual environment (optional)

### 🧠 FAQ
❓ Is this secure?
✅ Yes. This script never sends anything over the internet.
❓ Can I run it offline?
✅ 100%. Works without an internet connection.

❓ What if a Python package is missing?
🛠️ The script will detect it and print exact instructions for how to install it.

❓ Can I compile this to a single file?
Yes! You can use tools like pyinstaller to build a standalone binary.

### 🤝 Credits
Built with ❤️ by plebs, for plebs. Inspired by NIP‑49 and the Nostr community.
### 🛡️ License
MIT — Free for all. Fork, contribute, share.