Compiling with script encryption key

The export dialog gives you the option to encrypt your scripts with a 256-bit AES key when releasing your project. This will make sure your scripts are not stored in plain text and can not easily be ripped by some script kiddie.

Of course, the key needs to be stored in the binary, but if it’s compiled, optimized and without symbols, it would take some effort to find it.

For this to work, you need to build the export templates from source, with that same key.

Warning

This will not work if you use official, precompiled export templates. It is absolutely required to compile your own export templates to use PCK encryption.

Step by step

  1. Generate a 256-bit AES key in hexadecimal format. You can use the aes-256-cbc variant from this service.

    Alternatively, you can generate it yourself using OpenSSL command-line tools:

    1. openssl rand -hex 32 > godot.gdkey

    The output in godot.gdkey should be similar to:

    1. # NOTE: Do not use the key below! Generate your own key instead.
    2. aeb1bc56aaf580cc31784e9c41551e9ed976ecba10d315db591e749f3f64890f

    You can generate the key without redirecting the output to a file, but that way you can minimize the risk of exposing the key.

  2. Set this key as environment variable in the console that you will use to compile Godot, like this:

    Linux/macOSWindows (cmd)Windows (PowerShell)

    1. export SCRIPT_AES256_ENCRYPTION_KEY="your_generated_key"
    1. set SCRIPT_AES256_ENCRYPTION_KEY=your_generated_key
    1. $env:SCRIPT_AES256_ENCRYPTION_KEY="your_generated_key"

  3. Compile Godot export templates and set them as custom export templates in the export preset options.

  4. Set the encryption key in the Script tab of the export preset:

    ../../_images/script_encryption_key.png

  5. Export the project. The game should run with encrypted scripts now.

Troubleshooting

If you get an error like below, it means the key wasn’t properly included in your Godot build. Godot is encrypting the scripts during export, but can’t read them at runtime.

  1. ERROR: open_and_parse: Condition "String::md5(md5.digest) != String::md5(md5d)" is true. Returning: ERR_FILE_CORRUPT
  2.    At: core/io/file_access_encrypted.cpp:103
  3. ERROR: load_byte_code: Condition ' err ' is true. returned: err
  4.    At: modules/gdscript/gdscript.cpp:755
  5. ERROR: load: Condition ' err != OK ' is true. returned: RES()
  6.    At: modules/gdscript/gdscript.cpp:2135
  7. ERROR: Failed loading resource: res://Node2D.gde
  8.    At: core/io/resource_loader.cpp:279
  9. ERROR: poll: res://Node2D.tscn:3 - Parse Error: [ext_resource] referenced nonexistent resource at: res://Node2D.gd
  10.    At: scene/resources/scene_format_text.cpp:439
  11. ERROR: load: Condition ' err != OK ' is true. returned: RES()
  12.    At: core/io/resource_loader.cpp:202
  13. ERROR: Failed loading resource: res://Node2D.tscn
  14.    At: core/io/resource_loader.cpp:279
  15. ERROR: Failed loading scene: res://Node2D.tscn
  16.    At: main/main.cpp:1727
  17. WARNING: cleanup: ObjectDB Instances still exist!
  18.      At: core/object.cpp:2081
  19. ERROR: clear: Resources Still in use at Exit!
  20.    At: core/resource.cpp:425