@crpdo/key/lib/box-key.js

Streamlines key generation, derivation, and management through its simple and intuitive API

const Nacl = require('@crpdo/crypto/nacl')
const BaseKey = require('./base-key')

/**
 * Class representing a BoxKey. 
 * BoxKey is a key used for encryption and decryption.
 * @extends BaseKey
 */
class BoxKey extends BaseKey {
  /**
   * Create a BoxKey.
   * @param {string} seed - The seed used to create the BoxKey.
   */
  constructor(seed) {
    super(Nacl.createBoxKey(seed))
  }

  /**
   * Encrypts data.
   * @param {string} data - The data to be encrypted.
   * @param {string} publicKey - The public key used for encryption. Defaults to the BoxKey's public key if not provided.
   * @param {string} nonce - The nonce used for encryption.
   * @param {boolean} encode - Flag to encode the result. If true, the result is base64 encoded.
   * @returns {string} The encrypted data.
   */
  encrypt(data, publicKey, nonce, encode) {
    return Nacl.boxEncrypt(data, publicKey || this.publicKey, this.privateKey, nonce, encode)
  }

  /**
   * Decrypts data.
   * @param {string} data - The data to be decrypted.
   * @param {string} publicKey - The public key used for decryption. Defaults to the BoxKey's public key if not provided.
   * @param {string} nonce - The nonce used for decryption.
   * @param {boolean} encode - Flag to decode the result. If true, the result is base64 decoded.
   * @returns {string} The decrypted data.
   */
  decrypt(data, publicKey, nonce, encode) {
    return Nacl.boxDecrypt(data, publicKey || this.publicKey, this.privateKey, nonce, encode)
  }

  /**
   * Converts a SignKey to a BoxKey.
   * @param {KeyPair} keyPair - The SignKey to be converted.
   * @returns {BoxKey} The converted BoxKey.
   */
  static fromSignKey(keyPair) {
    const key = Nacl.convertKeyPair(keyPair)
    return new BoxKey(key.privateKey)
  }
}

module.exports = BoxKey