fuzz: target for commitment_signed

Fuzz the decoding and encoding of commitment_signed.

tests/fuzz/fuzz-wire-commitment_signed.c

@@ -0,0 +1,52 @@
+#include "config.h"
+#include <assert.h>
+#include <ccan/mem/mem.h>
+#include <stdint.h>
+#include <tests/fuzz/libfuzz.h>
+#include <tests/fuzz/wire.h>
+#include <wire/peer_wire.h>
+
+struct commitment_signed {
+	struct channel_id channel_id;
+	secp256k1_ecdsa_signature signature;
+	secp256k1_ecdsa_signature *htlc_signature;
+	struct tlv_commitment_signed_tlvs *tlvs;
+};
+
+static void *encode(const tal_t *ctx, const struct commitment_signed *s)
+{
+	return towire_commitment_signed(ctx, &s->channel_id, &s->signature,
+					s->htlc_signature, s->tlvs);
+}
+
+static struct commitment_signed *decode(const tal_t *ctx, const void *p)
+{
+	struct commitment_signed *s = tal(ctx, struct commitment_signed);
+
+	if (fromwire_commitment_signed(s, p, &s->channel_id, &s->signature,
+				       &s->htlc_signature, &s->tlvs))
+		return s;
+	return tal_free(s);
+}
+
+static bool equal(struct commitment_signed *x, struct commitment_signed *y)
+{
+	size_t upto_htlc_signature =
+	    (uintptr_t)&x->htlc_signature - (uintptr_t)x;
+	if (memcmp(x, y, upto_htlc_signature) != 0)
+		return false;
+
+	if (!memeq(x->htlc_signature, tal_bytelen(x->htlc_signature),
+		   y->htlc_signature, tal_bytelen(y->htlc_signature)))
+		return false;
+
+	assert(x->tlvs && y->tlvs);
+	return memeq(x->tlvs->splice_info, tal_bytelen(x->tlvs->splice_info),
+		     y->tlvs->splice_info, tal_bytelen(y->tlvs->splice_info));
+}
+
+void run(const u8 *data, size_t size)
+{
+	test_decode_encode(data, size, WIRE_COMMITMENT_SIGNED,
+			   struct commitment_signed);
+}