Research Academy Daily Swig
My account Customers Account and subscription management About Blog Careers Legal Contact Resellers

Burp Suite User Forum

Login to post

Run JavaScript code using Jython 2.7

Oleksandr | Last updated: Feb 27, 2023 01:02PM UTC

Hello! I am writing an extension that can move requests from Postman collection to Site map using Python. To move requests python script parse Postman collection JSON file. My script works correctly, but I stacked with a problem: Some requests in Postman contains pre-request scripts which is written using JavaScript. This scripts contains lines like this: const number = (Math.floor(Math.random()*10000)*1); var CustomerName1 = "MPCustomer1" + number; pm.globals.set("CustomerName1", CustomerName1); To build correct CustomerName1 var and set in to the globals environment I must run line which calculate random number. Locally I solved this problem using js2py library, which allowed me run js code using Python 2.7. But this and other libraries does not support by Jython and that is why I can not use them. Another variant that I used is EngineManager from javax. Locally I can use one of such engines from OpenJDK and run js code in the python. But as I understand javax imported from OpenJDK which place inside Burp and this OpenJDK does not contains any engines, because of your configuration. So I can use such solution. Can you help me with this problem? How can I run JavaScript code using Python which used Jython 2.7?

Hannah, PortSwigger Agent | Last updated: Mar 01, 2023 04:07PM UTC

If there is an available Java library for you to easily use, have you considered converting your extension to Java? If you use a build manager like Gradle or Maven, you can easily include your library as a dependency. This would also mean that you can use our new Montoya API, which contains more functionality than the legacy Extender API.

Oleksandr | Last updated: Mar 06, 2023 09:40AM UTC

Because of some requirements I must use python, and that is why I can use only Jython 2.7. And I want to be sure, is there any possibilities to run JavaScript code using Jython 2.7? Or I must use only Java?

Cameron | Last updated: Mar 07, 2023 05:33AM UTC

I also would find it much easier to simply be able to use a module like pyexecjs in Jython. I have nearly the exact same case where I am trying to manually calculate UUIDs using a small piece of JavaScript. Seriously frustrating! I get the error, "Could not find an available JavaScript runtime."

You need to Log in to post a reply. Or register here, for free.