Hi! as the topic we going to discuss.. i have able to obtain Minecraft Windows 10 encrypted Marketplace textures. The textures is obtained by grabbing token using Wireshark. Anyway, we're not gonna talk about "how to obtain" but the main topic is.. how we can decrypt minecraft encrypted packs?
Its really common, Marketplace prices is mostly over-charged for over simple things.. from Skinpacks, Worlds, and even Persona Skin Cosmetics especially anything regarding the skins.
Problematic
Minecraft Windows 10 using JWT or Json Web Token based with HS256 Algorithm. They used this new algorithm recently in 1.16 updates.. i suppose? Minecraft no longer using .zipe algorithm but rather they using JWT and verify the packs using signatures.json that also being encrypted. From the cache folder, you cant really see the content even though its on .png or .json format. The cache file is located at : %USERPROFILE%\AppData\Local\Packages\*Microsoft*Minecraft*\LocalState\PremiumCache
Inside the Premium Cache, there's going to be 3 folders inside. 1. Persona, 2. Skinpacks, 3. Resources (Texture Pack). If you look closely, every-single one of them have "signatures.json" even on resources pack. Enough the roots, lets get into the main idea. Since i have been able to pick on of their textures assets, we probably can do some search for in-game decrypter function or even using hash file to get the key-algorithm they used? Here im going to provide both textures. 1 is encrypted, and another is decrypted readable png that can be read by any photo viewer/editor or etc. I also going to provide some "Minecraft.Windows.exe" from the retail version 1.16, hoping to get some in-depth area.
As because they used JWT, the token can be readed here : https:https://jwt.io/ . I can achieve the token is more likely easier to decipher since its a free marketplace content that yet also encrypted. The assets i was able to get is Persona Pumpkin piece from Headware section from Persona Skin Editor / Profile.
[Encrypted Asset]
Image 1 : https://drive.google.com/file/d/1kNAtUO2j1n_nibe4254LblDnjqIneHwX/view?usp=sharing
Image 2 : https://drive.google.com/file/d/146Yni2XrneL0G2DVx4vhxUuxjq-x98U4/view?usp=sharing
[Decrypted Asset]
Image 1 : https://drive.google.com/file/d/1-4SR32NJFilBHalpDPCJuzmc7R2l1Pju/view?usp=sharing
Image 2 : https://drive.google.com/file/d/1GYhLs9LjVxeKrcpgEGnRA55Q-IU5ekzE/view?usp=sharing
[MC Retail Exe] : https://drive.google.com/file/d/1bA2u7ihT8eBRWLxH6BRxKy4RHp19BqZQ/view?usp=sharing
[Data Set] : https://drive.google.com/drive/folders/1z6hkNumx3RSmpCdr13i8Y7YCIf6BF-CW?usp=sharing