ptmgr: Add a fuzzer for ptmessage.

crates/tor-ptmgr/fuzz/.gitignore

@@ -0,0 +1,3 @@
+target
+corpus
+artifacts

crates/tor-ptmgr/fuzz/Cargo.toml

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+[package]
+name = "tor-ptmgr-fuzz"
+version = "0.0.0"
+authors = ["Automatically generated"]
+publish = false
+edition = "2018"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+libfuzzer-sys = "0.4"
+
+[dependencies.tor-ptmgr]
+path = ".."
+
+# Prevent this from interfering with workspaces
+[workspace]
+members = ["."]
+
+[[bin]]
+name = "ptmessage"
+path = "fuzz_targets/ptmessage.rs"
+test = false
+doc = false

crates/tor-ptmgr/fuzz/fuzz_targets/ptmessage.rs

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+#![no_main]
+use libfuzzer_sys::fuzz_target;
+use std::str::FromStr;
+use tor_ptmgr::ipc::PtMessage;
+
+fuzz_target!(|data: &str| {
+    let _ = PtMessage::from_str(data);
+});