forerunnerdb/js/lib/PersistCrypto.js

A NoSQL document store database for browsers and Node.js.

"use strict";

var Shared = require('./Shared'),
	CryptoJS = require('crypto-js');

var Plugin = function () {
	this.init.apply(this, arguments);
};

Plugin.prototype.init = function (options) {
	// Ensure at least a password is passed in options
	if (!options || !options.pass) {
		throw('Cannot initialise persistent storage encryption without a passphrase provided in the passed options object as the "pass" field.');
	}

	this._algo = options.algo || 'AES';
	this._pass = options.pass;
};

Shared.mixin(Plugin.prototype, 'Mixin.Common');

/**
 * Gets / sets the current pass-phrase being used to encrypt / decrypt
 * data with the plugin.
 */
Shared.synthesize(Plugin.prototype, 'pass');

Plugin.prototype.stringify = function (cipherParams) {
	// create json object with ciphertext
	var jsonObj = {
		ct: cipherParams.ciphertext.toString(CryptoJS.enc.Base64)
	};

	// optionally add iv and salt
	if (cipherParams.iv) {
		jsonObj.iv = cipherParams.iv.toString();
	}
	if (cipherParams.salt) {
		jsonObj.s = cipherParams.salt.toString();
	}

	// stringify json object
	return this.jStringify(jsonObj);
};

Plugin.prototype.parse = function (jsonStr) {
	// parse json string
	var jsonObj = this.jParse(jsonStr);

	// extract ciphertext from json object, and create cipher params object
	var cipherParams = CryptoJS.lib.CipherParams.create({
		ciphertext: CryptoJS.enc.Base64.parse(jsonObj.ct)
	});

	// optionally extract iv and salt
	if (jsonObj.iv) {
		cipherParams.iv = CryptoJS.enc.Hex.parse(jsonObj.iv);
	}
	if (jsonObj.s) {
		cipherParams.salt = CryptoJS.enc.Hex.parse(jsonObj.s);
	}

	return cipherParams;
};

Plugin.prototype.encode = function (val, meta, finished) {
	var self = this,
		wrapper = {
			type: 'fdbCrypto'
		},
		encryptedVal;

	// Encrypt the data
	encryptedVal = CryptoJS[this._algo].encrypt(val, this._pass, {
		format: {
			stringify: function () { return self.stringify.apply(self, arguments); },
			parse: function () { return self.parse.apply(self, arguments); }
		}
	});

	wrapper.data = encryptedVal.toString();
	wrapper.enabled = true;

	meta.encryption = {
		enabled: wrapper.enabled
	};

	if (finished) {
		finished(false, this.jStringify(wrapper), meta);
	}
};

Plugin.prototype.decode = function (wrapper, meta, finished) {
	var self = this,
		data;

	if (wrapper) {
		wrapper = this.jParse(wrapper);

		data = CryptoJS[this._algo].decrypt(wrapper.data, this._pass, {
			format: {
				stringify: function () { return self.stringify.apply(self, arguments); },
				parse: function () { return self.parse.apply(self, arguments); }
			}
		}).toString(CryptoJS.enc.Utf8);

		if (finished) {
			finished(false, data, meta);
		}
	} else {
		if (finished) {
			finished(false, wrapper, meta);
		}
	}
};

// Register this plugin with the persistent storage class
Shared.plugins.FdbCrypto = Plugin;

module.exports = Plugin;