Initial fuzzer set up. (#478)

fuzz/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "http-fuzz"
+version = "0.0.0"
+authors = ["David Korczynski <david@adalogics.com>"]
+publish = false
+edition = "2018"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+arbitrary = { version = "1",  features = ["derive"] }
+libfuzzer-sys = { version = "0.4.0", features = ["arbitrary-derive"] }
+
+[dependencies.http]
+path = ".."
+
+[[bin]]
+name = "fuzz_http"
+path = "src/fuzz_http.rs"
+
+[workspace]

fuzz/src/fuzz_http.rs

@@ -0,0 +1,27 @@
+#![no_main]
+
+use http::Request;
+use http::Response;
+use http::StatusCode;
+use libfuzzer_sys::arbitrary::Arbitrary;
+use libfuzzer_sys::fuzz_target;
+
+#[derive(Debug, Arbitrary)]
+struct HttpSpec {
+    uri: Vec<u8>,
+    header_name: Vec<u8>,
+    header_value: Vec<u8>,
+    status_codes: Vec<u8>,
+}
+
+fuzz_target!(|inp: HttpSpec| {
+    let _ = Request::builder()
+        .uri(&inp.uri[..])
+        .header(&inp.header_name[..], &inp.header_value[..])
+        .body(());
+
+    let _ = Response::builder()
+        .header(&inp.header_name[..], &inp.header_value[..])
+        .body(());
+    let _ = StatusCode::from_bytes(&inp.status_codes[..]);
+});