Writing a Custom Config

Prometheus accepts a Lua config file via --config.

prometheus-lua --config ./prometheus.config.lua ./input.lua

File format

The config file must be executable Lua code that returns a table:

return {
  LuaVersion = "Lua51",
  PrettyPrint = false,
  VarNamePrefix = "",
  NameGenerator = "MangledShuffled",
  Seed = 0,
  Steps = {
    { Name = "EncryptStrings", Settings = {} },
    { Name = "Cff", Settings = {} },
    { Name = "WrapInFunction", Settings = { Iterations = 1 } },
  }
}

Step ordering matters

Steps are applied in order. The same step can appear multiple times.

Cff performs control flow flattening. ControlFlowFlattening is also accepted as an alias for Cff. Vmify compiles the AST into register instructions and data tables, then emits Lua code with an interpreter for that data.

If an existing config used Name = "Vmify" for the former control flow flattening behavior, change it to Name = "Cff" to keep that behavior. The same Vmify key now selects the register VM. The standalone Cff and Vmify presets are available with --preset Cff and --preset Vmify.

Name generator values

Supported string values (from src/prometheus/namegenerators.lua):

• Mangled
• MangledShuffled
• Il
• Number
• Confuse

Reproducibility

• Seed > 0: deterministic RNG seed
• Seed <= 0: randomized seed (OpenSSL if available, else current time)

Common mistakes

• Misspelled step names in Name
• wrong setting types (for example string instead of number)
• invalid VarNamePrefix for the selected Lua version