initial commit

Signed-off-by: Kamal Tufekcic <kamal@lo.sh>

fuzz/fuzz_targets/decode_arbitrary.rs

@@ -0,0 +1,26 @@
+//! Fuzzer for `decode_frame` against arbitrary byte input.
+//!
+//! Drives the frame parser and Rice bitstream decoder with random bytes.
+//! The decoder must never panic, allocate unboundedly, or enter an infinite
+//! loop on any input: success is "returns `Ok` with valid samples" or
+//! "returns `Err(DecodeError)`". Nothing else is acceptable.
+//!
+//! Paths exercised:
+//! - Every header validation branch (sync, order range, partition order
+//!   range, truncation at each field boundary, partition count vs. sample
+//!   count mismatch).
+//! - The Rice unary-decode loop with pathological run lengths (the
+//!   `q > 2^26` guard in `rice::rice_decode` is specifically targeted).
+//! - The Q15 predictor accumulator on adversarial coefficient and residual
+//!   values (overflow / wrap-around checks).
+
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    // Only the `Ok` / `Err` result is meaningful; panics are the failure
+    // mode. The returned samples themselves are unchecked here — the
+    // `roundtrip_arbitrary` target verifies encoder/decoder self-consistency.
+    let _ = lac::decode_frame(data);
+});