How to obfuscate a Minecraft plugin (free, step by step)
Assume your premium plugin will be decompiled the day it goes on sale. Anyone can open the jar in a decompiler and read your code like the source, including the license check you spent an evening on. Obfuscation won't make that impossible. It turns readable code into a puzzle, so copying your logic or patching out a check takes far more work. The catch: a careless obfuscation pass is the fastest…
How to Safely Obfuscate a Minecraft Plugin: Free Step-by-Step Guide
Obfuscation is a useful technique to protect your premium Minecraft plugin from being decompiled and read by others. However, it's important to note that obfuscation doesn't make your plugin completely secure or prevent sharing. It merely makes it more difficult for someone to understand and modify your code. For sharing, a license key per buyer is still necessary.
The two most effective ways to combine obfuscation with a licensing system are: using a free hosted obfuscator to automatically generate keep rules, or manually performing obfuscation with ProGuard. After obfuscation, a thorough testing checklist should be followed before releasing the plugin for sale.
Quick Way: Free Hosted Obfuscation
1. Sign up for a free SunLicense account using Google, GitHub, Discord, or email.
2. Under Developers, select Java for the Java obfuscation option.
3. Choose Maximum (recommended) as the ProGuard engine for the strongest protection.
4. Upload your built plugin jar (created with Shadow or a similar tool) to the SunLicense platform.
5. Review the automatically generated keep rules and edit them if necessary.
6. Run the obfuscation process and download the obfuscated jar file along with the mapping file and report.
By-hand Way: ProGuard
If you prefer to perform obfuscation manually using ProGuard, follow these steps:
1. Create a configuration file with the necessary keep rules for your plugin.
2. Run ProGuard with the appropriate command-line arguments, including the input jar file, output jar file, and the configuration file.
3. After the obfuscation process, test the resulting jar file in a clean Paper server to ensure it works correctly.
4. Optionally, run Skidfuscator on the obfuscated jar for additional string encryption and control flow scrambling.
Testing Checklist
Before selling your obfuscated plugin, perform the following tests:
1. Verify that the plugin loads correctly on a clean Paper server without any errors in the console.
2. Test all functionality, including tab completion commands and any custom commands or events.
3. Check that the plugin's events are being properly handled and that configuration files are correctly loaded and saved.
4. Confirm that any reflection-based functionality (e.g., using Bukkit API classes) still works as expected.
5. Ensure that any placeholder strings used for license key injection are correctly handled and that the store functionality remains operational.
By following this step-by-step guide, you can effectively obfuscate your Minecraft plugin to protect your hard work while still allowing legitimate users to use and enjoy your plugin.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
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