From 62ffb42908df4785b3274c7a838c61cdf00d20b6 Mon Sep 17 00:00:00 2001
From: Matt Morehouse <mattmorehouse@gmail.com>
Date: Mon, 21 Aug 2023 15:50:28 -0500
Subject: [PATCH] fuzz: target for open_channel

Fuzz the decoding and encoding of open_channel.
---
 tests/fuzz/fuzz-wire-open_channel.c | 84 +++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 tests/fuzz/fuzz-wire-open_channel.c

diff --git a/tests/fuzz/fuzz-wire-open_channel.c b/tests/fuzz/fuzz-wire-open_channel.c
new file mode 100644
index 000000000..91deed56b
--- /dev/null
+++ b/tests/fuzz/fuzz-wire-open_channel.c
@@ -0,0 +1,84 @@
+#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 open_channel {
+	struct bitcoin_blkid chain_hash;
+	struct channel_id temporary_channel_id;
+	struct amount_sat funding_satoshis;
+	struct amount_msat push_msat;
+	struct amount_sat dust_limit_satoshis;
+	struct amount_msat max_htlc_value_in_flight_msat;
+	struct amount_sat channel_reserve_satoshis;
+	struct amount_msat htlc_minimum_msat;
+	u32 feerate_per_kw;
+	u16 to_self_delay;
+	u16 max_accepted_htlcs;
+	struct pubkey funding_pubkey;
+	struct pubkey revocation_basepoint;
+	struct pubkey payment_basepoint;
+	struct pubkey delayed_payment_basepoint;
+	struct pubkey htlc_basepoint;
+	struct pubkey first_per_commitment_point;
+	u8 channel_flags;
+	struct tlv_open_channel_tlvs *tlvs;
+};
+
+static void *encode(const tal_t *ctx, const struct open_channel *s)
+{
+	return towire_open_channel(
+	    ctx, &s->chain_hash, &s->temporary_channel_id, s->funding_satoshis,
+	    s->push_msat, s->dust_limit_satoshis,
+	    s->max_htlc_value_in_flight_msat, s->channel_reserve_satoshis,
+	    s->htlc_minimum_msat, s->feerate_per_kw, s->to_self_delay,
+	    s->max_accepted_htlcs, &s->funding_pubkey, &s->revocation_basepoint,
+	    &s->payment_basepoint, &s->delayed_payment_basepoint,
+	    &s->htlc_basepoint, &s->first_per_commitment_point,
+	    s->channel_flags, s->tlvs);
+}
+
+static struct open_channel *decode(const tal_t *ctx, const void *p)
+{
+	struct open_channel *s = tal(ctx, struct open_channel);
+
+	if (fromwire_open_channel(
+		s, p, &s->chain_hash, &s->temporary_channel_id,
+		&s->funding_satoshis, &s->push_msat, &s->dust_limit_satoshis,
+		&s->max_htlc_value_in_flight_msat, &s->channel_reserve_satoshis,
+		&s->htlc_minimum_msat, &s->feerate_per_kw, &s->to_self_delay,
+		&s->max_accepted_htlcs, &s->funding_pubkey,
+		&s->revocation_basepoint, &s->payment_basepoint,
+		&s->delayed_payment_basepoint, &s->htlc_basepoint,
+		&s->first_per_commitment_point, &s->channel_flags, &s->tlvs))
+		return s;
+	return tal_free(s);
+}
+
+static bool equal(const struct open_channel *x, const struct open_channel *y)
+{
+	size_t upto_channel_flags = (uintptr_t)&x->channel_flags - (uintptr_t)x;
+	if (memcmp(x, y, upto_channel_flags) != 0)
+		return false;
+	if (x->channel_flags != y->channel_flags)
+		return false;
+
+	assert(x->tlvs && y->tlvs);
+
+	if (!memeq(x->tlvs->upfront_shutdown_script,
+		   tal_bytelen(x->tlvs->upfront_shutdown_script),
+		   y->tlvs->upfront_shutdown_script,
+		   tal_bytelen(y->tlvs->upfront_shutdown_script)))
+		return false;
+
+	return memeq(x->tlvs->channel_type, tal_bytelen(x->tlvs->channel_type),
+		     y->tlvs->channel_type, tal_bytelen(y->tlvs->channel_type));
+}
+
+void run(const u8 *data, size_t size)
+{
+	test_decode_encode(data, size, WIRE_OPEN_CHANNEL, struct open_channel);
+}