BIP39 to SSH Key Generator

A web application for generating and managing SSH keys from BIP39 seed phrases. This application provides web interface that allows you to generate new seed phrases or use existing ones to create Ed25519 SSH key pairs, with support for multiple derivation paths and optional passphrase protection.

Prerequisites

• Node.js (v14 or higher)
• npm (v6 or higher)

Dependencies

• bip39: ^3.1.0 (BIP39 seed phrase generation)
• ed25519: ^2.0.0 (Ed25519 key pair generation)
• express: ^4.18.2 (Web server)
• ejs: ^3.1.9 (Template engine)
• crypto: (Node.js built-in, for cryptographic operations)

Features

Key Generation

• Generate new BIP39 seed phrases (12 or 24 words)
• Use existing BIP39 seed phrases
• Generate multiple SSH key pairs from a single seed
• Optional passphrase protection
• Customizable output directory
• Default output directory: src/generated-keys
• Automatic derivation path management
• Default derivation path: m/44'/60'/0'/0/0 (increments for each key pair)

Key Restoration

• Restore SSH keys from existing seed phrases
• Support for multiple derivation paths
• Maintains original key generation parameters
• Optional passphrase protection
• Customizable output directory
• Default output directory: src/restored-keys
• Default derivation path: m/44'/60'/0'/0/0 (can be customized)

Key Testing

• Verify SSH key pair validity
• Generate and display key fingerprints
• Test both newly generated and existing keys
• Standalone key testing interface

Security Features

Cryptographic Algorithms

• BIP39: For seed phrase generation and management
• PBKDF2: For key derivation with 100,000 iterations
• HMAC-SHA512: For deterministic key material generation
• Ed25519: For SSH key pair generation
• SHA-256: For key fingerprint generation

Security Measures

• Deterministic key generation
• Secure random number generation for new seeds
• Proper key length enforcement (64 bytes for Ed25519)
• Secure key storage with proper file permissions
• Passphrase protection support
• No key material stored in memory longer than necessary

Installation

1. Clone the repository:

git clone https://github.com/yourusername/BIP39toSSH.git
cd BIP39toSSH

2. Install dependencies:

npm install

3. Start the application:

npm start

The application will be available at http://localhost:3000

Usage

Generating New Keys

1. Select "Generate New Seed" or "Use Existing Seed"
2. For new seeds:
   • Choose between 12 or 24 words (24 words recommended for maximum security)
   • Select the number of key pairs to generate (1-10)
   • Optionally add a passphrase (recommended for additional security)
   • Specify output directory (optional, defaults to src/generated-keys)
   • Default derivation paths will be:
     • First key: m/44'/60'/0'/0/0
     • Second key: m/44'/60'/0'/0/1
     • Third key: m/44'/60'/0'/0/2
     • And so on...
3. For existing seeds:
   • Enter your seed phrase (12 or 24 words)
   • Select the number of key pairs to generate
   • Enter the same passphrase used during generation (if any)
   • Specify output directory (optional, defaults to src/generated-keys)
   • Same default derivation paths as above
4. Click "Generate Keys"
5. IMPORTANT: If generating a new seed, write down and securely store the seed phrase

Restoring Keys

1. Enter your seed phrase (12 or 24 words)
2. Enter derivation paths (one per line)
   • Default path: m/44'/60'/0'/0/0
   • For multiple keys, increment the last number:
     • m/44'/60'/0'/0/0
     • m/44'/60'/0'/0/1
     • m/44'/60'/0'/0/2
   • You can use different paths for different purposes
3. Enter passphrase if used during generation
4. Specify output directory (optional, defaults to src/restored-keys)
5. Click "Restore Keys"

Testing Keys

1. Use the "Test Keys" tab
2. Paste your public and private keys
   • Private key: Content of id_ed25519 file
   • Public key: Content of id_ed25519.pub file
3. Click "Test Key Pair"
4. View the verification result and fingerprint

File Structure

Generated keys are saved in the following structure:

output-directory/
├── key-1/
│   ├── id_ed25519        # Private key
│   ├── id_ed25519.pub    # Public key
│   └── derivation.txt    # Derivation path information
├── key-2/
│   ├── id_ed25519
│   ├── id_ed25519.pub
│   └── derivation.txt
└── ...

Security Considerations

1. Seed Phrase Security

   • Store seed phrases securely offline
   • Never share seed phrases
   • Consider using a passphrase for additional security

2. Key Management

   • Keep private keys secure
   • Use appropriate file permissions
   • Back up keys and seed phrases separately

3. Passphrase Usage

   • Use strong passphrases
   • Store passphrases securely
   • Remember that lost passphrases cannot be recovered

Technical Details

Key Derivation Process

1. Seed phrase → BIP39 seed
2. BIP39 seed + passphrase → master seed
3. Master seed + derivation path → private key material
4. Private key material → Ed25519 key pair

File Formats

• Private keys: OpenSSH format
• Public keys: OpenSSH format
• Derivation paths: BIP32 format

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Disclaimer

This tool is provided for educational and practical purposes. Users are responsible for maintaining the security of their keys and seed phrases. You are solely responsible for any loss of funds or data resulting from the use of this tool.

Troubleshooting

Common Issues

1. Key Generation Fails

   • Ensure seed phrase is valid (12 or 24 words)
   • Check that words are from BIP39 word list
   • Verify passphrase if used during generation

2. Key Restoration Fails

   • Verify seed phrase is correct
   • Ensure derivation paths are in correct format
   • Check that passphrase matches original

3. Key Testing Fails

   • Verify key format is correct
   • Ensure private and public keys are from the same pair
   • Check file permissions

Error Messages

• "Invalid seed phrase": Words must be from BIP39 word list
• "Invalid derivation path": Path must follow BIP32 format
• "Key pair verification failed": Keys are not a valid pair
• "File permission error": Check directory permissions