safe-eval

    0.4.1 • Public • Published

    safe-eval npm version Build Status

    NOTE

    safe-eval 0.3.0 and below are affected by a sandbox breakout vulnerability - NSP 337, CVE-2017-16088.

    Version 0.4.0 fixes this vulnerability. It is highly recommended to upgrade to the latest version if you are using safe-eval for executing code not generated by yourself. Thanks @kauegimenes for the patch.

    What is this?

    safe-eval lets you execute JavaScript code without having to use the much discouraged and feared upon eval(). safe-eval has access to all the standard APIs of the V8 JavaScript Engine. By default, it does not have access to the Node.js API, but can be given access using a conext object. It is implemented using node's vm module.

    Currently, it works only with Node.js, and the JavaScript code must be an expression (something which evaluates to a value).

    Installation

    npm install safe-eval --save

    Usage

    var safeEval = require('safe-eval')

    safeEval(code, [context], [options])

    code is the JavaScript code you want to execute.

    context is an object of methods and properties, these methods and properties are interpreted as global objects in code. Be careful about the objects you are passing to the context API, because they can completely defeat the purpose of safe-eval.

    options is the options object for the vm executing the code.

    Examples

    // string concatenation
    var code = '"app" + "le"'
    var evaluated = safeEval(code) // "apple"
    // math
    var code = 'Math.floor(22/7)'
    var evaluated = safeEval(code) // 3.142857142857143
    // JSON
    var code = '{name: "Borat", hobbies: ["disco dance", "sunbathing"]}'
    var evaluated = safeEval(code) // {name: "Borat", hobbies: ["disco dance", "sunbathing"]}
    // function expression
    var code = '(function square(b) { return b * b; })(5)'
    var evaluated = safeEval(code) // 25
    // no access to Node.js objects
    var code = 'process'
    safeEval(code) // THROWS!
    // your own context API - access to Node's process object and a custom function
    var code = '{pid: process.pid, apple: a()}'
    var context = {
      process: process,
      a: function () { return 'APPLE' }
    }
    var evaluated = safeEval(code, context) // { pid: 16987, apple: 'APPLE' }
    // pass an options object to the vm
    var code = 'process'
    safeEval(code, {}, { filename: 'myfile.js'}) // myfile.js can be seen in the stacktrace

    License (MIT)

    Copyright (c) 2016 Hage Yaapa

    Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

    Keywords

    none

    Install

    npm i safe-eval

    DownloadsWeekly Downloads

    13,908

    Version

    0.4.1

    License

    MIT

    Unpacked Size

    7.39 kB

    Total Files

    5

    Last publish

    Collaborators

    • avatar