index.js

'use strict';

const validators = require('./impl/validators');
const hasher = require('./impl/hasher');
const scrambler = require('./impl/scrambler');

const DEFAULT_CIPHER = 'aes256';

module.exports = {
    /**
     * Hashes and encrypts the given input with bcrypt + selected cipher.

     * @param  {[string]} input        Data to hash & encrypt. bcrypt expects input to be a string.
     * @param  {[string]} password     Password used to encrypt the hashed data. The same password should be used in compare function for verification.
     * @param  {[number]} bcryptRounds Number of key expansion rounds in bcrypt. Bigger values provide better security of encrypted data but also take more time to compute the hash.
     * @param  {[string]} cipherType   One of cipher types available in nodejs's crypto module. By default aes256 is used. Call crypto.getCiphers() to check available ciphers.
     * @return {[Promise]}             On success the returned promise resolves with the hashed and encrypted input.
     */
    encrypt: (input, password, bcryptRounds, cipherType = DEFAULT_CIPHER) => {
        const validateParams = () => validators.validateEncryptionParams(input, password, cipherType);
        const createHash = () => hasher.createBcryptHash(input, bcryptRounds);
        const encryptHash = (hash) => scrambler.encrypt(hash, password, cipherType);

        return validateParams().then(createHash).then(encryptHash);
    },

    /**
     * The function decrypts encryptedHash using the provided password. Decrypted data is then compared with input to see if the hashes match.

     * @param  {[string]} input         Input data to compare with decrypted hash.
     * @param  {[string]} encryptedHash Hash encrypted with password and cipherType.
     * @param  {[string]} password      Password used to decrypt the encryptedHash.
     * @param  {[string]} cipherType    Cipher used to decrypt the encryptedHash. It needs to match the ciperType that was used to encrypt data.
     * @return {[Promise]}              Promise object which, on success, is resolved with a boolean value indicating that the input and encryptedHash match(or not).
     */
    compare: (input, encryptedHash, password, cipherType = DEFAULT_CIPHER) => {
        const validateParams = () => validators.validateDecryptionParams(input, encryptedHash, password, cipherType);
        const decryptHash = () => scrambler.decrypt(encryptedHash, password, cipherType);
        const compareInputWithHash = (hash) => hasher.compareInputWithHash(input, hash);

        return validateParams().then(decryptHash).then(compareInputWithHash);
    }
};