ci(x509): smoke test x509 via fuzzing

.github/workflows/x509.yml

@@ -64,3 +64,17 @@ jobs:
           override: true
       - uses: RustCrypto/actions/cargo-hack-install@master
       - run: cargo hack test --feature-powerset
+
+  fuzz:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: nightly
+          override: true
+      - run: cargo install cargo-fuzz
+      - run: cargo fuzz run certreq -- -max_total_time=30 -seed_inputs="fuzz/inputs/rsa2048-csr.der"
+      - run: cargo fuzz run certreqinfo -- -max_total_time=30

x509/fuzz/.gitignore

@@ -0,0 +1,4 @@
+target
+corpus
+artifacts
+Cargo.lock

x509/fuzz/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "x509-fuzz"
+version = "0.0.0"
+authors = ["RustCrypto Developers"]
+publish = false
+edition = "2021"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+libfuzzer-sys = "0.4"
+x509 = { path = ".." }
+
+# Prevents this crate from interfering with the workspace
+[workspace]
+members = ["."]

x509/fuzz/src/bin/certreq.rs

@@ -0,0 +1,8 @@
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+use x509::request::CertReq;
+
+fuzz_target!(|input: &[u8]| {
+    let _ = CertReq::try_from(input);
+});

x509/fuzz/src/bin/certreqinfo.rs

@@ -0,0 +1,8 @@
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+use x509::request::CertReqInfo;
+
+fuzz_target!(|input: &[u8]| {
+    let _ = CertReqInfo::try_from(input);
+});