Asymmetric Key Generator

May 26, 2025 ยท View on GitHub

This simple tool can be used to generate an Ed25519 PKCS#8 and RSA key pairs (private and public key).

There's two methods to run the tool, you can either download or build from source code.

Download

Prebuild apps can be found in Releases.

To verify the package's integrity, download both the app and the checksum file to the same directory:

-rw-r--r--@  1 john  staff   156M 18 Nov 17:02 AsymmetricKeyGenerator-0.5.0-universal.dmg
-rw-r--r--@  1 john  staff   102B 18 Nov 19:01 AsymmetricKeyGenerator-0.5.0-universal.dmg.CHECKSUM

Then run sha256 checksum:

sha256sum -c AsymmetricKeyGenerator-0.5.0-universal.dmg.CHECKSUM

If it passes the integrity check, it'll return AsymmetricKeyGenerator-0.5.0-universal.dmg: OK

Build from source code

Obtain the source code locally and go through the following steps:


// install package
npm install

// run locally
npm run start

// build packages locally into the "dist" folder.
npm run dist

Command-Line Tool Usage

This tool can also be executed as a command-line interface (CLI) script. Here's how you can use it:

Installation

  1. Clone the repository or download the source code.

  2. Install the necessary dependencies using npm:

npm install

Key Pair Generation

To generate key pairs, run the following command:

npm run generate -- -k <key-type> -p <passphrase> -n <number-of-keys> -o <output>

Parameters:

  • -k, --key-type <type>: The type of key to generate. Allowed values are:

    • rsa-2048

    • rsa-4096

    • ed25519

  • -p, --passphrase <passphrase>: (Optional) A passphrase to encrypt the private key. If not provided, no passphrase is used.

  • -n, --num-keys <number>: (Optional, default: 1) The number of key pairs to generate.

  • -o, --output <filename>: (Optional) The output tar.gz file. If not provided, a default name is used id_<key-type>-<i>.tar.gz.

Example Usage:

  1. Generate a single RSA-2048 key pair:
npm run generate -- -k rsa-2048 -o id_rsa.tar.gz
  1. Generate 2 Ed25519 key pairs with passphrase:
npm run generate -- -k ed25519 -p mySecretPassphrase -n 2

This will generate:

  • id_rsa.tar.gz consisting of one pair: id_rsa and id_rsa.pub

  • id_ed25519.tar.gz consisting of two pairs id_ed25519-{i} and id_ed25519-{i}.pub

If you do not provide -o option, the default names id_<key-type>-<i> and id_<key-type>-<i>.pub will be used.

UI Usage

  1. Open the app;

  2. Choose the key type; Recommend to keep the default value (Ed25519), then click the button Generate Key Pair;

  3. Below on the left column is the Private Key, which should be stored in a secure location on your local disk (by using the Save button) and must never be shared with anyone;

  4. The right column is the Public Key. Click Save button to save into local disk. This key can be shared with others to verify the Private Key signed data;

Contribution

Contributions are welcome! If you've found a bug within this project, please open an issue to discuss what you would like to change.

License

MIT