So I’ve reverse-engineered the naturespace Android APK and the files it downloads are definitely encrypted. They’re zip files (named as .nzp) that are XOR obfuscated with a rotating key every X amount of bytes. I haven’t quite worked out how the key rotates itself but I’m close. If I get it working I’ll put the details here and I can give you a Python script to grab whatever sounds you need.
Interesting, looks like they might be using a completely different file format for iOS versus Android. In any case, I’ve knocked up a script which will extract the track.ogg file from any pack of your choosing. Pasting directly here to see if it works (haven’t tried sharing code on Lemmy).
You can browse available packs using the below URL. If you want to find out a pack name, just copy the banner image URL for it and you’ll see the “com.whatever” name in the URL itself.
Code:
import sys import requests import hashlib import io import zipfile ns_baseurl = "https://s3.amazonaws.com/naturespace/kindle_catalog/" # Encryption key key = b'DE2#We@(# sffsFSHfssfhsSFHSs_+&Gaa s,W.Z./lSFGSDF! NOWG!fjasdflasdkfjSADFKJASdflskgj fdkaG8HS42dncuFFSe=-56a' def decryptNS(content): x = 1025 y = 0 dec = bytearray() for i in range(x,len(content)): if ((i+1024) % 1024) != 0: dec += bytes([content[i] ^ key[y % len(key)]]) y = y+1 return dec if __name__ == '__main__': if len(sys.argv) < 2: print("Please provide a pack/module name (e.g. 'com.HolographicAudioTheater.Naturespace.TheImaginarium')") sys.exit(0) pack = sys.argv[1] json_url = ns_baseurl + pack + "/data.json" size = requests.get(json_url).json()["packageSize"] print(size) hashval = hashlib.sha1((pack + "8DvJx25sXwNwq2p" + size).encode()).hexdigest() dlurl = ns_baseurl + pack + "/" + hashval + "/" + pack + ".nzp" print(dlurl) content = decryptNS(requests.get(dlurl).content) """ with open(pack + ".zip", "wb") as f: f.write(content) """ zipf = io.BytesIO(content) zipfile = zipfile.ZipFile(zipf, 'r') track_nsp = zipfile.read('track.nsp') track_ogg = decryptNS(track_nsp) with open(pack + "_track.ogg", "wb") as f: f.write(track_ogg)