Add support for electron ASAR archives

[pombredanne]

Description

This is the format used by Electron apps.
This is defined here https://github.com/electron/asar
See these Python libs:

• @leovoel https://github.com/leovoel/BeautifulDiscord/blob/master/beautifuldiscord/asar.py
• @as1337 https://github.com/AS1337/asarPy
• @Photonios https://github.com/Photonios/pyasar
• @minitech https://github.com/minitech/as2t

See also libarchive/libarchive#1259

[adityaviki]

on it :)

[adityaviki]

Hi! @pombredanne
Since, neither 7zip nor libarchive supports ASAR archives, we'll probably have to create another extractor. Can you provide any pointer on how to do that?

From what I can think of , we can package official asar libarary into a binary file or use one of its python implementation or maybe create our own python asar library for extraction.

[pombredanne]

@adityaviki the general approach would be to copy something such as any of https://github.com/nexB/scancode-toolkit/blob/develop/src/extractcode/libarchive2.py https://github.com/nexB/scancode-toolkit/blob/develop/src/extractcode/sevenzip.py or https://github.com/nexB/scancode-toolkit/blob/develop/src/extractcode/patch.py ... e.g. a module that has these functions in the same way other modules expose these functions

• def extract(location, target_dir):

This would Extract files from an archive file at `location` in the `target_dir`. Return a list of warning messages if any or an empty list. Raise Exceptions on errors.

• def is_rar(location) that would Return True if the file at location is an ASAR archive.

And optionally:

• def list_entries(location):
  This would Return an archive entries list for the archive file at `location`.

And this would use and invoke the best one of the Python libraries above.

[adityaviki]

@pombredanne I looked at the python ASAR libraries that you linked.
All of them are pretty similar. None of them provide a function to list the content of the archive and don't work on Python 2.7.x

So here's what I can do

• Modify the chosen library to work with python 2.7.x .
• Implement a function to list the content of the archive.
• Create a builtin plugin for the said library (similar to scancode-toolkit/plugins-builtin/extractcode_libarchive-*)
• Create a module similar to libarchive2 containing functions def extract(location, target_dir):, def list_entries(location): and def is_rar(location).

[pombredanne]

Actually having a quick look,https://github.com/leovoel/BeautifulDiscord/blob/master/beautifuldiscord/asar.pyand https://github.com/AS1337/asarPy seem all to be derived from the older https://github.com/Photonios/pyasar

The WTPFL license is not great as a license though so I asked @Photonios for a possible change at Photonios/pyasar#3

[pombredanne]

There is also a possible Go-based util we could reuse (though this would mean a native) https://github.com/layeh/asar/

[mjherzog]

Are we at a point where we can use a Python 3 only solution?

[pombredanne]

@mjherzog re

Are we at a point where we can use a Python 3 only solution?

I would not go there fully yet.

[vk-mittal14]

hi, I am new to open source. I was looking at some good first issues. Can I work on this?

[SidharajYadav]

hi sir,
I am new to open source.
I was looking at some good first issues.
Can I work on this?