commit_tx: take raw funding keys instead of wscript.

It now needs the keys for anchor outputs, so have it calculate
the 2 of 2 wscript internally.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

channeld/commit_tx.c

@@ -80,7 +80,8 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 			     const struct bitcoin_txid *funding_txid,
 			     unsigned int funding_txout,
 			     struct amount_sat funding,
-			     const u8 *funding_wscript,
+			     const struct pubkey *local_funding_key,
+			     const struct pubkey *remote_funding_key,
 			     enum side opener,
 			     u16 to_self_delay,
 			     const struct keyset *keyset,
@@ -101,6 +102,10 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 	u32 *cltvs;
 	struct htlc *dummy_to_local = (struct htlc *)0x01,
 		*dummy_to_remote = (struct htlc *)0x02;
+	const u8 *funding_wscript = bitcoin_redeem_2of2(tmpctx,
+							local_funding_key,
+							remote_funding_key);
+
 	if (!amount_msat_add(&total_pay, self_pay, other_pay))
 		abort();
 	assert(!amount_msat_greater_sat(total_pay, funding));

channeld/commit_tx.h

@@ -28,6 +28,7 @@ size_t commit_tx_num_untrimmed(const struct htlc **htlcs,
  * commit_tx: create (unsigned) commitment tx to spend the funding tx output
  * @ctx: context to allocate transaction and @htlc_map from.
  * @funding_txid, @funding_out, @funding: funding outpoint.
+ * @local_funding_key, @remote_funding_key: keys for funding input.
  * @opener: is the LOCAL or REMOTE paying the fee?
  * @keyset: keys derived for this commit tx.
  * @feerate_per_kw: feerate to use
@@ -48,7 +49,8 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 			     const struct bitcoin_txid *funding_txid,
 			     unsigned int funding_txout,
 			     struct amount_sat funding,
-			     const u8 *funding_wscript,
+			     const struct pubkey *local_funding_key,
+			     const struct pubkey *remote_funding_key,
 			     enum side opener,
 			     u16 to_self_delay,
 			     const struct keyset *keyset,

channeld/full_channel.c

@@ -304,7 +304,10 @@ struct bitcoin_tx **channel_txs(const tal_t *ctx,
 	txs = tal_arr(ctx, struct bitcoin_tx *, 1);
 	txs[0] = commit_tx(
 	    ctx, &channel->funding_txid, channel->funding_txout,
-	    channel->funding, cast_const(u8 *, *funding_wscript), channel->opener,
+	    channel->funding,
+	    &channel->funding_pubkey[side],
+	    &channel->funding_pubkey[!side],
+	    channel->opener,
 	    channel->config[!side].to_self_delay, &keyset,
 	    channel_feerate(channel, side),
 	    channel->config[side].dust_limit, channel->view[side].owed[side],

channeld/test/run-commit_tx.c

@@ -746,7 +746,9 @@ int main(int argc, const char *argv[])
 	print_superverbose = true;
 	tx = commit_tx(tmpctx,
 		       &funding_txid, funding_output_index,
-		       funding_amount, wscript,
+		       funding_amount,
+		       &local_funding_pubkey,
+		       &remote_funding_pubkey,
 		       LOCAL, to_self_delay,
 		       &keyset,
 		       feerate_per_kw,
@@ -758,7 +760,9 @@ int main(int argc, const char *argv[])
 	print_superverbose = false;
 	tx2 = commit_tx(tmpctx,
 			&funding_txid, funding_output_index,
-			funding_amount, wscript,
+			funding_amount,
+			&local_funding_pubkey,
+			&remote_funding_pubkey,
 			REMOTE, to_self_delay,
 			&keyset,
 			feerate_per_kw,
@@ -803,7 +807,9 @@ int main(int argc, const char *argv[])
 	print_superverbose = true;
 	tx = commit_tx(tmpctx,
 		       &funding_txid, funding_output_index,
-		       funding_amount, wscript,
+		       funding_amount,
+		       &local_funding_pubkey,
+		       &remote_funding_pubkey,
 		       LOCAL, to_self_delay,
 		       &keyset,
 		       feerate_per_kw,
@@ -815,7 +821,9 @@ int main(int argc, const char *argv[])
 	print_superverbose = false;
 	tx2 = commit_tx(tmpctx,
 			&funding_txid, funding_output_index,
-			funding_amount, wscript,
+			funding_amount,
+			&local_funding_pubkey,
+			&remote_funding_pubkey,
 			REMOTE, to_self_delay,
 			&keyset,
 			feerate_per_kw,
@@ -848,7 +856,9 @@ int main(int argc, const char *argv[])
 		print_superverbose = false;
 		newtx = commit_tx(tmpctx,
 				  &funding_txid, funding_output_index,
-				  funding_amount, wscript,
+				  funding_amount,
+				  &local_funding_pubkey,
+				  &remote_funding_pubkey,
 				  LOCAL, to_self_delay,
 				  &keyset,
 				  feerate_per_kw,
@@ -861,7 +871,9 @@ int main(int argc, const char *argv[])
 		/* This is what it would look like for peer generating it! */
 		tx2 = commit_tx(tmpctx,
 				&funding_txid, funding_output_index,
-				funding_amount, wscript,
+				funding_amount,
+				&local_funding_pubkey,
+				&remote_funding_pubkey,
 				REMOTE, to_self_delay,
 				&keyset,
 				feerate_per_kw,
@@ -893,7 +905,9 @@ int main(int argc, const char *argv[])
 		print_superverbose = true;
 		tx = commit_tx(tmpctx,
 			       &funding_txid, funding_output_index,
-			       funding_amount, wscript,
+			       funding_amount,
+			       &local_funding_pubkey,
+			       &remote_funding_pubkey,
 			       LOCAL, to_self_delay,
 			       &keyset,
 			       feerate_per_kw-1,
@@ -931,7 +945,9 @@ int main(int argc, const char *argv[])
 		print_superverbose = true;
 		newtx = commit_tx(tmpctx,
 				  &funding_txid, funding_output_index,
-				  funding_amount, wscript,
+				  funding_amount,
+				  &local_funding_pubkey,
+				  &remote_funding_pubkey,
 				  LOCAL, to_self_delay,
 				  &keyset,
 				  feerate_per_kw,
@@ -992,7 +1008,9 @@ int main(int argc, const char *argv[])
 		       to_local.millisatoshis, to_remote.millisatoshis, feerate_per_kw);
 		tx = commit_tx(tmpctx,
 			       &funding_txid, funding_output_index,
-			       funding_amount, wscript,
+			       funding_amount,
+			       &local_funding_pubkey,
+			       &remote_funding_pubkey,
 			       LOCAL, to_self_delay,
 			       &keyset,
 			       feerate_per_kw,

channeld/test/run-full_channel.c

@@ -524,7 +524,9 @@ int main(int argc, const char *argv[])
 
 	raw_tx = commit_tx(tmpctx,
 			   &funding_txid, funding_output_index,
-			   funding_amount, funding_wscript,
+			   funding_amount,
+			   &local_funding_pubkey,
+			   &remote_funding_pubkey,
 			   LOCAL, remote_config->to_self_delay,
 			   &keyset,
 			   feerate_per_kw[LOCAL],
@@ -651,7 +653,10 @@ int main(int argc, const char *argv[])
 
 		raw_tx = commit_tx(
 		    tmpctx, &funding_txid, funding_output_index,
-		    funding_amount, funding_wscript, LOCAL, remote_config->to_self_delay,
+		    funding_amount,
+		    &local_funding_pubkey,
+		    &remote_funding_pubkey,
+		    LOCAL, remote_config->to_self_delay,
 		    &keyset, feerate_per_kw[LOCAL], local_config->dust_limit,
 		    to_local, to_remote, htlcs, &htlc_map, NULL,
 		    0x2bb038521914 ^ 42, LOCAL);

common/initial_channel.c

@@ -98,7 +98,7 @@ struct bitcoin_tx *initial_channel_tx(const tal_t *ctx,
 	init_tx = initial_commit_tx(ctx, &channel->funding_txid,
 				    channel->funding_txout,
 				    channel->funding,
-				    cast_const(u8 *, *wscript),
+				    channel->funding_pubkey,
 				    channel->opener,
 				    /* They specify our to_self_delay and v.v. */
 				    channel->config[!side].to_self_delay,
@@ -152,4 +152,5 @@ static char *fmt_channel(const tal_t *ctx, const struct channel *channel)
 		       fmt_channel_view(ctx, &channel->view[LOCAL]),
 		       fmt_channel_view(ctx, &channel->view[REMOTE]));
 }
+/* Magic comment. */
 REGISTER_TYPE_TO_STRING(channel, fmt_channel);

common/initial_commit_tx.c

@@ -62,7 +62,7 @@ struct bitcoin_tx *initial_commit_tx(const tal_t *ctx,
 				     const struct bitcoin_txid *funding_txid,
 				     unsigned int funding_txout,
 				     struct amount_sat funding,
-				     u8 *funding_wscript,
+				     const struct pubkey funding_key[NUM_SIDES],
 				     enum side opener,
 				     u16 to_self_delay,
 				     const struct keyset *keyset,
@@ -85,6 +85,9 @@ struct bitcoin_tx *initial_commit_tx(const tal_t *ctx,
 	u32 sequence;
 	void *dummy_local = (void *)LOCAL, *dummy_remote = (void *)REMOTE;
 	const void *output_order[NUM_SIDES];
+	const u8 *funding_wscript = bitcoin_redeem_2of2(tmpctx,
+							&funding_key[LOCAL],
+							&funding_key[REMOTE]);
 
 	if (!amount_msat_add(&total_pay, self_pay, other_pay))
 		abort();

common/initial_commit_tx.h

@@ -81,6 +81,7 @@ static inline struct amount_sat commit_tx_base_fee(u32 feerate_per_kw,
  * @ctx: context to allocate transaction and @htlc_map from.
  * @funding_txid, @funding_out, @funding: funding outpoint.
  * @funding_wscript: scriptPubkey of the funding output
+ * @funding_keys: funding bitcoin keys
  * @opener: is the LOCAL or REMOTE paying the fee?
  * @keyset: keys derived for this commit tx.
  * @feerate_per_kw: feerate to use
@@ -102,7 +103,7 @@ struct bitcoin_tx *initial_commit_tx(const tal_t *ctx,
 				     const struct bitcoin_txid *funding_txid,
 				     unsigned int funding_txout,
 				     struct amount_sat funding,
-				     u8 *funding_wscript,
+				     const struct pubkey funding_key[NUM_SIDES],
 				     enum side opener,
 				     u16 to_self_delay,
 				     const struct keyset *keyset,