fuzz: add target for LocalAddress from string (#227)

* fuzz: add target for `LocalAddress` from string

* docs: add fuzzing into README

Cargo.toml

@@ -1,6 +1,19 @@
 [workspace]
 resolver = "2"
 members = [
+    "florestad",
+    "fuzz",
+    "crates/floresta",
+    "crates/floresta-chain",
+    "crates/floresta-cli",
+    "crates/floresta-common",
+    "crates/floresta-compact-filters",
+    "crates/floresta-electrum",
+    "crates/floresta-watch-only",
+    "crates/floresta-wire",
+]
+
+default-members = [ 
     "florestad",
     "crates/floresta",
     "crates/floresta-chain",

README.md

@@ -13,20 +13,22 @@ If you want to use `libfloresta` to build your own Bitcoin application, you can
 
 ### ToC
 
-- [Community](#community)
 - [Building](#building)
+  - [(Prerequisites)](#prerequisites)
   - [Building with nix](#building-with-nix)
-- [Running](#running)
-  - [Assume Utreexo](#assume-utreexo)
-  - [Compact Filters](#compact-filters)
-  - [Getting help](#getting-help)
-  - [Wallet](#wallet)
-- [Running the tests](#running-the-tests)
-- [Contributing](#contributing)
-- [Using Nix](#using-nix)
-- [License](#license)
-- [Acknowledgments](#acknowledgments)
-- [Consensus implementation](#consensus-implementation)
+  - [Running](#running)
+    - [Assume Utreexo](#assume-utreexo)
+    - [Compact Filters](#compact-filters)
+    - [Getting help](#getting-help)
+    - [Wallet](#wallet)
+  - [Running the tests](#running-the-tests)
+    - [Requirements](#requirements)
+  - [Fuzzing](#fuzzing)
+  - [Contributing](#contributing)
+  - [Using Nix](#using-nix)
+  - [License](#license)
+  - [Acknowledgments](#acknowledgments)
+  - [Consensus implementation](#consensus-implementation)
 
 ### Community
 
@@ -203,6 +205,15 @@ pip3 install -r tests/requirements.txt
 python tests/run_tests.py
 ```
 
+### Fuzzing
+
+This project uses `cargo-fuzz` (libfuzzer) for fuzzing, you can run a fuzz target with:
+```bash
+cargo +nightly fuzz run local_address_str
+```
+
+You can replace `local_address_str` with the name of any other target you want to run.
+
 ### Contributing
 Contributions are welcome, feel free to open an issue or a pull request.
 

fuzz/.gitignore

@@ -0,0 +1,4 @@
+target
+corpus
+artifacts
+coverage

fuzz/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "floresta-fuzz"
+version = "0.0.0"
+publish = false
+edition = "2021"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+libfuzzer-sys = "0.4"
+bitcoin = { version = "0.31", features = ["serde", "std"] }
+floresta-wire = { path = "../crates/floresta-wire" }
+
+[[bin]]
+name = "local_address_str"
+path = "fuzz_targets/local_address_str.rs"
+test = false
+doc = false
+bench = false

fuzz/fuzz_targets/local_address_str.rs

@@ -0,0 +1,14 @@
+#![no_main]
+
+use core::str;
+use std::str::FromStr;
+
+use floresta_wire::address_man::LocalAddress;
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    let _ = match str::from_utf8(data) {
+        Ok(s) => LocalAddress::from_str(s),
+        Err(_) => return,
+    };
+});