🦀 rustfuscator

Rustfuscator is an obfuscation-first CLI and library for Rust codebases. It rewrites source code and exposes macros for string literals, numeric literals, control-flow noise, logging literals, identifier renaming, and derive-based encrypted fields.

Obfuscation is pragmatic: it does not make software invulnerable, but it can raise the cost of casual static analysis and reverse engineering when it is scoped and tested carefully.

Features

• CLI for files, folders, or Cargo projects.
• .obfuscate.toml configuration with include/exclude and per-file control-flow selection.
• Compile-time string literal obfuscation:
• obfuscate_string!("...") returns ObfStr
• obfuscate_str!("...") returns &'static str
• Lightweight integer literal obfuscation with obfuscate_num!(...).
• Control-flow injection with obfuscate_flow!.
• Optional dummy branch injection with obfuscate_dummy_branch! and CLI dummy_branches.
• Logging macro literal rewriting for println!, eprintln!, log::*, and tracing::*.
• Identifier renaming strategies: suffix, hash, and confuse.
• #[derive(Obfuscate)] for structs with String, bool, and Rust integer primitive fields.
• Optional secure_zeroize feature for supported clear values and temporary clear buffers.
• Optional verify_literals feature for debug-only literal round-trip assertions.

How It Works

The CLI does not obfuscate compiled binaries directly. It parses Rust source, rewrites selected constructs, and emits Rust code that uses the library macros.

The macro layer then performs the runtime behavior needed by the transformed source, such as decrypting string literals on demand or injecting flow noise. After running the CLI, build the transformed project with Cargo as usual.

Installation

cargo install rust_code_obfuscator

Or from a local checkout:

git clone https://github.com/GianIac/rustfuscator
cd rustfuscator
cargo install --path obfuscator_cli

CLI Usage

Obfuscate a single Rust file:

obfuscator_cli --input ./src/main.rs --output ./obf

Obfuscate a source folder:

obfuscator_cli --input ./src --output ./obf_src

Obfuscate a Cargo project:

obfuscator_cli \
  --input ./my_project \
  --output ./my_project_obf \
  --as-project \
  --format

Generate a default config:

obfuscator_cli --input ./my_project --init

Useful review flags:

obfuscator_cli --input ./src --output ./obf_src --dry-run --diff
obfuscator_cli --input ./src --output ./obf_src --verbose

Configuration

Example .obfuscate.toml:

[obfuscation]
strings = true
min_string_length = 4
ignore_strings = ["DEBUG", "LOG"]
control_flow = true
control_flow_files = ["**/*.rs"]
dummy_branches = false
obfuscate_logging = true
skip_files = ["src/main.rs"]
skip_attributes = true

[identifiers]
rename = false
strategy = "suffix" # suffix | hash | confuse
preserve = ["main"]

[include]
files = ["**/*.rs"]
exclude = ["target/**", "tests/**"]

[logging_macros]
enabled = [
  "println",
  "eprintln",
  "log::info",
  "log::warn",
  "log::error",
  "tracing::info",
  "tracing::warn",
]
ignore_messages = ["DEBUG", "TRACE", "startup ok"]

Library Usage

Add the library:

[dependencies]
rust_code_obfuscator = "0.3.1"

Use macros directly:

use rust_code_obfuscator::{
    obfuscate_dummy_branch, obfuscate_flow, obfuscate_num, obfuscate_str, obfuscate_string,
};

fn main() {
    let secret = obfuscate_string!("hidden string");
    let role = obfuscate_str!("admin");
    let threshold = obfuscate_num!(1337u32);

    obfuscate_flow!();
    obfuscate_dummy_branch!();

    println!("{secret} {role} {threshold}");
}

Derive Usage

use rust_code_obfuscator::Obfuscate;

#[derive(Debug, PartialEq, Obfuscate)]
struct MyData {
    name: String,
    enabled: bool,
    age: u32,
}

fn main() {
    let obfuscated = ObfuscatedMyData::new_clear("Alice", true, 42);
    let clear = obfuscated.get_clear();

    assert_eq!(clear.age, 42);
}

Supported derive field types are String, bool, and Rust integer primitives. Floats, containers, and custom types are intentionally out of scope.

Examples

Run the advanced macro example:

cargo run --example advanced_macro_usage

Other examples under examples/ cover basic string obfuscation, control-flow injection, derive usage, and CLI transformation targets.

Benchmarks

Benchmarks use Criterion and compare baseline code against macro-assisted code:

cargo bench --bench macro_overhead

The benchmark suite currently covers:

• normal arithmetic vs obfuscate_flow!
• plain string literal access vs obfuscate_string!
• plain integer literal access vs obfuscate_num!

Benchmark results are workload-specific; use them to estimate overhead for your own threat model and performance budget.

Feature Flags

[dependencies]
rust_code_obfuscator = { version = "0.3.1", features = ["secure_zeroize", "verify_literals"] }

• secure_zeroize: zeroizes supported clear values and temporary clear buffers.
• verify_literals: enables debug-only round-trip assertions inside string literal macros.

Project Layout

rustfuscator/
├── src/                         # Public facade crate
├── rust_code_obfuscator_core/    # Core macros and crypto helpers
├── obfuscator_derive/            # #[derive(Obfuscate)]
├── obfuscator_cli/               # CLI source rewriter
├── examples/                     # Runnable examples
├── benches/                      # Criterion benchmarks
└── tests/                        # Integration tests

Disclaimer

Rustfuscator is an obfuscation tool, not a guarantee of secrecy. Combine it with normal release hardening where appropriate:

RUSTFLAGS="-C strip=debuginfo -C opt-level=z -C panic=abort" cargo build --release

Author Note

The first commits signed by user <user@local> are authored by Gianfranco Iaculo.

License

MIT License © 2025 Gianfranco Iaculo