Fuzz Header::read and Header::write

age/src/lib.rs

@@ -116,3 +116,14 @@ pub use protocol::{Decryptor, Encryptor};
 
 #[cfg(feature = "cli-common")]
 pub mod cli_common;
+
+/// Helper for fuzzing the Header parser and serializer.
+#[cfg(fuzzing)]
+pub fn fuzz_header(data: &[u8]) {
+    if let Ok(header) = format::Header::read(data) {
+        let mut buf = Vec::with_capacity(data.len());
+        if let Ok(_) = header.write(&mut buf) {
+            assert_eq!(buf, data);
+        }
+    }
+}

fuzz/Cargo.toml

@@ -18,6 +18,10 @@ git = "https://github.com/rust-fuzz/libfuzzer-sys.git"
 [workspace]
 members = ["."]
 
+[[bin]]
+name = "header"
+path = "fuzz_targets/header.rs"
+
 [[bin]]
 name = "trial_decrypt"
 path = "fuzz_targets/trial_decrypt.rs"

fuzz/fuzz_targets/header.rs

@@ -0,0 +1,6 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    age::fuzz_header(data);
+});