Minecraft Launcher by AnjoCaido

Reverse engineering of Minecraft Launcher by AnjoCaido.exe.

Contents

MinecraftSP.jar   original payload jar (copied from the Wine temp dir)
extracted/        48 unpacked .class files
decompiled/       11 readable .java files (CFR 0.152)
cfr.jar           decompiler tool used (from Maven Central)

Decompile again

java -jar cfr.jar extracted/net/minecraft/*.class \
     extracted/anjocaido/console/*.class \
     extracted/anjocaido/minecraftmanager/*.class \
     --outputdir decompiled

Note: CFR refuses the jar archive directly, decompile from the extracted class tree instead.

Codebase

A repack of the 2010-2011 classic Mojang launcher (v12.2 era) with AnjoCaido additions.

• net.minecraft (original Mojang classes)
  • MinecraftLauncher entry point, heap check, relaunches itself with -Xmx1024m
  • LoginForm username only login, no server auth, remembers name in lastlogin (PBE encrypted, hard coded key passwordfile)
  • LauncherFrame main window
  • GameUpdater downloads from http://s3.amazonaws.com/MinecraftDownload/ (long dead Mojang CDN, so updates and force update fail today)
  • Launcher embeds the game applet
  • MinecraftUtil working directory and OS detection
• anjocaido.console
  • OutputConsole game output window
• anjocaido.minecraftmanager
  • MinecraftBackupManager "Backup Manager" button: zips and restores .minecraft saves and game directories
  • BackupUtil, Zipper helpers
• SevenZip/ bundled third party LZMA SDK, not part of the launcher code

Security notes

Decompiled sources contain no suspicious code. Network access is limited to old Mojang endpoints (s3.amazonaws.com, www.minecraft.net) and a link to the author's YouTube channel.