simple-crypto-signature

A simple abstraction to sign and verify string payloads using NodeJS

Getting Started

Install the module with: npm install simple-crypto-signature

Usage

Require the library and pass the options to the constructor:

// require the library
const SimpleCryptoSignature = require('simple-crypto-signature');
// pass simple options
const defaultOptions = {
    privateKeyPath: path.join(__dirname, 'private.pem'),
    publicKeyPath: path.join(__dirname, 'public.pem'),
    passPhrase: '<your_pass_phrase>'
};
const signatureGenerator = new SimpleCryptoSignature(defaultOptions);

Sign the payload:

// payload to sign
const message = 'test-this-string';

// `signedValue` is the payload signed using your private key
const signedValue = signatureGenerator.sign(message);

Verify the signed value:

// You can verify the `signedValue`
const verifiedValue = signatureGenerator.verify(message, signedValue);
// verifiedValue will be either `true` or `false`

API

SimpleCryptoSignature class takes the following options as part of its constructor:

{
    privateKeyPath, // Path to private key , used for signing {String}
        publicKeyPath, // Path to public key , used for verifying {String}
        privateKey, // You can also pass the private key string value instead of private key path {String}
        publicKey, // You can also pass the public key string value instead of public key path {String}
        passPhrase, // The pass phrase used for the private key, if not passed it assumes the private key does not use a pass phrase {String}
        signatureFormat, // The output of signature format - `hex` | `base64`(default) {String}
        signatureAlgorithm; // Algo to use to sign the payload  - `sha256` (default) | `md5` | `DSA` ... see `crypto.getHashes()` for all the algorithms supported by NodeJS crypto library
}

Generating 2048 bit RSA Keys (with passphrase)

Private Key

The following command will generate a private.pem file that contains your private key.

The command will prompt you for a pass phrase and this pass phrase is required for generating the public key as well.

openssl genrsa -des3 -out private.pem 2048

Public Key

To generate the public key for your private key use the following command and provide the pass phrase you used while generating the private key

openssl rsa -in private.pem -outform PEM -pubout -out public.pem

Generating 2048 bit RSA Keys (without passphrase)

Private Key

The following command will generate a private.pem file that contains your private key.

openssl genrsa -out private.pem 2048

Public Key

To generate the public key for your private key use the following command

openssl rsa -in private.pem -outform PEM -pubout -out public.pem

Contributing

Feel free to add more features and do not forget to add good unit tests for those features.

The repo relies on Jest for unit tests and you can use the following:

• yarn test : to run all the tests
• yarn test:cov : to run all the tests with coverage report
• yarn test:debug : when you want to debug your tests

License

Copyright (c) 2018 Rajat Kumar

Licensed under the MIT license.