fuzz: add a fuzz target for initial_channel

Signed-off-by: Antoine Poinsot <darosior@protonmail.com>

tests/fuzz/Makefile

@@ -7,7 +7,7 @@ FUZZ_TARGETS_SRC := $(wildcard tests/fuzz/fuzz-*.c)
 FUZZ_TARGETS_OBJS := $(FUZZ_TARGETS_SRC:.c=.o)
 FUZZ_TARGETS_BIN := $(FUZZ_TARGETS_SRC:.c=)
 
-FUZZ_COMMON_OBJS :=					\
+FUZZ_COMMON_OBJS := \
 	common/amount.o					\
 	common/addr.o					\
 	common/base32.o					\
@@ -15,18 +15,40 @@ FUZZ_COMMON_OBJS :=					\
 	common/bech32.o					\
 	common/bip32.o					\
 	common/bigsize.o				\
+	common/channel_config.o				\
 	common/close_tx.o				\
 	common/channel_id.o				\
+	common/daemon.o					\
+	common/daemon_conn.o				\
+	common/derive_basepoints.o			\
+	common/fee_states.o				\
+	common/htlc_state.o				\
 	common/permute_tx.o				\
+	common/initial_channel.o			\
+	common/initial_commit_tx.o			\
 	common/json.o					\
 	common/json_stream.o				\
+	common/key_derive.o				\
+	common/keyset.o					\
+	common/msg_queue.o				\
+	common/memleak.o				\
+	common/node_id.o				\
 	common/wireaddr.o				\
 	common/setup.o					\
+	common/status.o					\
+	common/status_wire.o				\
+	common/status_wiregen.o				\
 	common/type_to_string.o				\
 	common/utils.o					\
+	common/version.o				\
 	wire/fromwire.o					\
 	wire/onion_wiregen.o				\
-	wire/towire.o
+	wire/peer_wire.o				\
+	wire/peer_wiregen.o				\
+	wire/towire.o					\
+	wire/wire_io.o					\
+	wire/wire_sync.o
+
 $(FUZZ_TARGETS_OBJS): $(COMMON_HEADERS) $(WIRE_HEADERS) $(COMMON_SRC)
 $(FUZZ_TARGETS_BIN): $(LIBFUZZ_OBJS) $(FUZZ_COMMON_OBJS) $(BITCOIN_OBJS)
 

tests/fuzz/fuzz-initial_channel.c

@@ -0,0 +1,80 @@
+#include <assert.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <tests/fuzz/libfuzz.h>
+
+#include <bitcoin/pubkey.h>
+#include <bitcoin/chainparams.h>
+#include <bitcoin/script.h>
+#include <bitcoin/tx.h>
+#include <ccan/tal/tal.h>
+#include <common/amount.h>
+#include <common/fee_states.h>
+#include <common/initial_channel.h>
+#include <common/setup.h>
+#include <common/status.h>
+#include <common/utils.h>
+#include <stdio.h>
+#include <wire/wire.h>
+
+void init(int *argc, char ***argv)
+{
+	common_setup("fuzzer");
+	int devnull = open("/dev/null", O_WRONLY);
+	status_setup_sync(devnull);
+	chainparams = chainparams_for_network("bitcoin");
+}
+
+void run(const uint8_t *data, size_t size)
+{
+	struct channel_id cid;
+	struct bitcoin_txid funding_txid;
+	u32 funding_txout, minimum_depth;
+	struct amount_sat funding, max;
+	struct amount_msat local_msatoshi;
+	u32 feerate_per_kw;
+	struct channel_config local, remote;
+	struct basepoints local_basepoints, remote_basepoints;
+	struct pubkey local_funding_pubkey, remote_funding_pubkey;
+	bool option_static_remotekey, option_anchor_outputs;
+	struct channel *channel;
+
+	fromwire_channel_id(&data, &size, &cid);
+	fromwire_bitcoin_txid(&data, &size, &funding_txid);
+	funding_txout = fromwire_u32(&data, &size);
+	minimum_depth = fromwire_u32(&data, &size);
+	funding = fromwire_amount_sat(&data, &size);
+	local_msatoshi = fromwire_amount_msat(&data, &size);
+	max = AMOUNT_SAT((u32)WALLY_SATOSHI_PER_BTC * WALLY_BTC_MAX);
+	if (amount_sat_greater(funding, max))
+		funding = max;
+	feerate_per_kw = fromwire_u32(&data, &size);
+	fromwire_channel_config(&data, &size, &local);
+	fromwire_channel_config(&data, &size, &remote);
+	fromwire_basepoints(&data, &size, &local_basepoints);
+	fromwire_basepoints(&data, &size, &remote_basepoints);
+	fromwire_pubkey(&data, &size, &local_funding_pubkey);
+	fromwire_pubkey(&data, &size, &remote_funding_pubkey);
+	option_anchor_outputs = fromwire_bool(&data, &size);
+	option_static_remotekey = option_anchor_outputs || fromwire_bool(&data, &size);
+
+	/* TODO: determine if it makes sense to check at each step for libfuzzer
+	 * to deduce pertinent inputs */
+	if (!data || !size)
+		return;
+
+	for (enum side opener = 0; opener < NUM_SIDES; opener++) {
+		channel = new_initial_channel(tmpctx, &cid, &funding_txid, funding_txout,
+					      minimum_depth, funding, local_msatoshi,
+					      take(new_fee_states(NULL, opener, &feerate_per_kw)),
+					      &local, &remote, &local_basepoints,
+					      &remote_basepoints, &local_funding_pubkey,
+					      &remote_funding_pubkey, option_static_remotekey,
+					      option_anchor_outputs, opener);
+
+		/* TODO: make initial_channel_tx() work with ASAN.. */
+	}
+
+	clean_tmpctx();
+}