htlc_tx: use keyset abstraction.

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

lightningd/channel.c

@@ -214,11 +214,11 @@ static void add_htlcs(struct bitcoin_tx ***txs,
 
 		if (htlc_owner(htlc) == side) {
 			tx = htlc_timeout_tx(*txs, &txid, i,
-					     htlc,
+					     htlc->msatoshi,
+					     htlc->expiry.locktime,
 					     to_self_delay(channel, side),
-					     &keyset->self_revocation_key,
+					     feerate_per_kw,
-					     &keyset->self_delayed_payment_key,
+					     keyset);
-					     feerate_per_kw);
 			wscript	= bitcoin_wscript_htlc_offer(*wscripts,
 						     &keyset->self_payment_key,
 						     &keyset->other_payment_key,
@@ -226,11 +226,10 @@ static void add_htlcs(struct bitcoin_tx ***txs,
 						     &keyset->self_revocation_key);
 		} else {
 			tx = htlc_success_tx(*txs, &txid, i,
-					     htlc,
+					     htlc->msatoshi,
 					     to_self_delay(channel, side),
-					     &keyset->self_revocation_key,
+					     feerate_per_kw,
-					     &keyset->self_delayed_payment_key,
+					     keyset);
-					     feerate_per_kw);
 			wscript	= bitcoin_wscript_htlc_receive(*wscripts,
 						       &htlc->expiry,
 						       &keyset->self_payment_key,

lightningd/htlc_tx.c

@@ -3,11 +3,12 @@
 #include <bitcoin/tx.h>
 #include <lightningd/commit_tx.h>
 #include <lightningd/htlc_tx.h>
+#include <lightningd/keyset.h>
 
 static struct bitcoin_tx *htlc_tx(const tal_t *ctx,
 				  const struct sha256_double *commit_txid,
 				  unsigned int commit_output_number,
-				  const struct htlc *htlc,
+				  u64 msatoshi,
 				  u16 to_self_delay,
 				  const struct pubkey *revocation_pubkey,
 				  const struct pubkey *local_delayedkey,
@@ -47,7 +48,7 @@ static struct bitcoin_tx *htlc_tx(const tal_t *ctx,
 	tx->input[0].index = commit_output_number;
 
 	/* We need amount for signing. */
-	amount = htlc->msatoshi / 1000;
+	amount = msatoshi / 1000;
 	tx->input[0].amount = tal_dup(tx, u64, &amount);
 
 	/* BOLT #3:
@@ -74,17 +75,18 @@ static struct bitcoin_tx *htlc_tx(const tal_t *ctx,
 struct bitcoin_tx *htlc_success_tx(const tal_t *ctx,
 				   const struct sha256_double *commit_txid,
 				   unsigned int commit_output_number,
-				   const struct htlc *received_htlc,
+				   u64 htlc_msatoshi,
 				   u16 to_self_delay,
-				   const struct pubkey *revocation_pubkey,
+				   u64 feerate_per_kw,
-				   const struct pubkey *local_delayedkey,
+				   const struct keyset *keyset)
-				   u64 feerate_per_kw)
 {
 	/* BOLT #3:
 	 * * locktime: `0` for HTLC-Success, `cltv_expiry` for HTLC-Timeout.
 	 */
-	return htlc_tx(ctx, commit_txid, commit_output_number, received_htlc,
+	return htlc_tx(ctx, commit_txid, commit_output_number, htlc_msatoshi,
-		       to_self_delay, revocation_pubkey, local_delayedkey,
+		       to_self_delay,
+		       &keyset->self_revocation_key,
+		       &keyset->self_delayed_payment_key,
 		       htlc_success_fee(feerate_per_kw), 0);
 }
 
@@ -118,19 +120,21 @@ void htlc_success_tx_add_witness(struct bitcoin_tx *htlc_success,
 struct bitcoin_tx *htlc_timeout_tx(const tal_t *ctx,
 				   const struct sha256_double *commit_txid,
 				   unsigned int commit_output_number,
-				   const struct htlc *offered_htlc,
+				   u64 htlc_msatoshi,
+				   u32 cltv_expiry,
 				   u16 to_self_delay,
-				   const struct pubkey *revocation_pubkey,
+				   u64 feerate_per_kw,
-				   const struct pubkey *local_delayedkey,
+				   const struct keyset *keyset)
-				   u64 feerate_per_kw)
 {
 	/* BOLT #3:
 	 * * locktime: `0` for HTLC-Success, `cltv_expiry` for HTLC-Timeout.
 	 */
-	return htlc_tx(ctx, commit_txid, commit_output_number, offered_htlc,
+	return htlc_tx(ctx, commit_txid, commit_output_number, htlc_msatoshi,
-		       to_self_delay, revocation_pubkey, local_delayedkey,
+		       to_self_delay,
+		       &keyset->self_revocation_key,
+		       &keyset->self_delayed_payment_key,
 		       htlc_timeout_fee(feerate_per_kw),
-		       offered_htlc->expiry.locktime);
+		       cltv_expiry);
 }
 
 /* Fill in the witness for HTLC-timeout tx produced above. */

lightningd/htlc_tx.h

@@ -12,11 +12,10 @@ struct sha256_double;
 struct bitcoin_tx *htlc_success_tx(const tal_t *ctx,
 				   const struct sha256_double *commit_txid,
 				   unsigned int commit_output_number,
-				   const struct htlc *received_htlc,
+				   u64 htlc_msatoshi,
 				   u16 to_self_delay,
-				   const struct pubkey *revocation_pubkey,
+				   u64 feerate_per_kw,
-				   const struct pubkey *local_delayedkey,
+				   const struct keyset *keyset);
-				   u64 feerate_per_kw);
 
 /* Fill in the witness for HTLC-success tx produced above. */
 void htlc_success_tx_add_witness(struct bitcoin_tx *htlc_success,
@@ -33,11 +32,11 @@ void htlc_success_tx_add_witness(struct bitcoin_tx *htlc_success,
 struct bitcoin_tx *htlc_timeout_tx(const tal_t *ctx,
 				   const struct sha256_double *commit_txid,
 				   unsigned int commit_output_number,
-				   const struct htlc *offered_htlc,
+				   u64 htlc_msatoshi,
+				   u32 cltv_expiry,
 				   u16 to_self_delay,
-				   const struct pubkey *revocation_pubkey,
+				   u64 feerate_per_kw,
-				   const struct pubkey *local_delayedkey,
+				   const struct keyset *keyset);
-				   u64 feerate_per_kw);
 
 /* Fill in the witness for HTLC-timeout tx produced above. */
 void htlc_timeout_tx_add_witness(struct bitcoin_tx *htlc_timeout,

lightningd/test/run-commit_tx.c

@@ -208,6 +208,7 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 	struct sha256_double txid;
 	struct bitcoin_tx **htlc_tx;
 	secp256k1_ecdsa_signature *remotesig;
+	struct keyset keyset;
 	u8 **wscript;
 
 	htlc_tx = tal_arrz(tmpctx, struct bitcoin_tx *, tal_count(htlc_map));
@@ -224,6 +225,13 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 
 	printf("num_htlcs: %zu\n", n);
 
+	/* FIXME: naming here is kind of backwards: local revocation key
+	 * is derived from remote revocation basepoint, but it's local */
+	keyset.self_revocation_key = *remote_revocation_key;
+	keyset.self_delayed_payment_key = *local_delayedkey;
+	keyset.self_payment_key = *localkey;
+	keyset.other_payment_key = *remotekey;
+
 	for (i = 0; i < tal_count(htlc_map); i++) {
 		const struct htlc *htlc = htlc_map[i];
 
@@ -232,10 +240,11 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 
 		if (htlc_owner(htlc) == LOCAL) {
 			htlc_tx[i] = htlc_timeout_tx(htlc_tx, &txid, i,
-						     htlc, to_self_delay,
+						     htlc->msatoshi,
-						     remote_revocation_key,
+						     htlc->expiry.locktime,
-						     local_delayedkey,
+						     to_self_delay,
-						     feerate_per_kw);
+						     feerate_per_kw,
+						     &keyset);
 			wscript[i] = bitcoin_wscript_htlc_offer(tmpctx,
 								localkey,
 								remotekey,
@@ -243,10 +252,10 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 								remote_revocation_key);
 		} else {
 			htlc_tx[i] = htlc_success_tx(htlc_tx, &txid, i,
-						     htlc, to_self_delay,
+						     htlc->msatoshi,
-						     remote_revocation_key,
+						     to_self_delay,
-						     local_delayedkey,
+						     feerate_per_kw,
-						     feerate_per_kw);
+						     &keyset);
 			wscript[i] = bitcoin_wscript_htlc_receive(tmpctx,
 								  &htlc->expiry,
 								  localkey,