cowac_web v1.1.1

COWAC WEB

Description

COWAC (Climbing Over WebAssembly Arithmetic Capabilities) is a JavaScript library, powered by Wail and inspired by Cojac, that instrument WebAssembly modules in order to add a numerical sniffer. This sniffer is able to track and signal arithmetic anomalies.

Currently, COWAC is able to detect the following anomalies:

• Overflow of integers addition and subtraction
• Overflow of floating point numbers addition and subtraction

Disponibility

Cowac is available as a npm package, and can be install with the following command:

npm i cowac_web

The tools is also available from the JSDeliver CDN:

<script src=" https://cdn.jsdelivr.net/npm/cowac_web@1.0.40/index.min.js "></script>

Use

To use the library, no need to install it ! The script can be used via the plugin Tampermonkey.

First, install the plugin. Then, you can use the userscript available in the project's userscript folder or directly from the npm repositorry. Just add the script to Tampermonkey. The script is configured to target every website. If you want to target only specific websites, you can modify the @match directive script header. You can as well change the Cowac version by modifying the import URL. Don't forget to activate the script.

// ==UserScript==
// @name         Cowac Web
// @namespace    Cowac
// @version      2025-01-26
// @description  Instrument WebAssembly (add a numerical sniffer, find and signal overflow in running time)
// @author       Dimitri Julmy
// @match        ==> CHANGE HERE <==
// @grant        none
// @run-at       document-start
// ==/UserScript==

...
var module
try {
    // ==> CHANGE HERE <==
    module = await import('https://cdn.jsdelivr.net/npm/cowac_web@x.x.x/index.js')
} catch (error) {
    console.error("Failed to load Cowac Web module:", error)
    return
}