utxo: add scriptSig + scriptPubkey field

Allow the utxo object to bear the scriptSig and scriptPubKey

common/test/run-funding_tx.c

@@ -37,6 +37,13 @@ void fromwire_node_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct n
 /* Generated stub for fromwire_pubkey */
 void fromwire_pubkey(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct pubkey *pubkey UNNEEDED)
 { fprintf(stderr, "fromwire_pubkey called!\n"); abort(); }
+/* Generated stub for fromwire_tal_arrn */
+u8 *fromwire_tal_arrn(const tal_t *ctx UNNEEDED,
+		       const u8 **cursor UNNEEDED, size_t *max UNNEEDED, size_t num UNNEEDED)
+{ fprintf(stderr, "fromwire_tal_arrn called!\n"); abort(); }
+/* Generated stub for fromwire_u16 */
+u16 fromwire_u16(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+{ fprintf(stderr, "fromwire_u16 called!\n"); abort(); }
 /* Generated stub for fromwire_u32 */
 u32 fromwire_u32(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_u32 called!\n"); abort(); }
@@ -58,12 +65,18 @@ void towire_node_id(u8 **pptr UNNEEDED, const struct node_id *id UNNEEDED)
 /* Generated stub for towire_pubkey */
 void towire_pubkey(u8 **pptr UNNEEDED, const struct pubkey *pubkey UNNEEDED)
 { fprintf(stderr, "towire_pubkey called!\n"); abort(); }
+/* Generated stub for towire_u16 */
+void towire_u16(u8 **pptr UNNEEDED, u16 v UNNEEDED)
+{ fprintf(stderr, "towire_u16 called!\n"); abort(); }
 /* Generated stub for towire_u32 */
 void towire_u32(u8 **pptr UNNEEDED, u32 v UNNEEDED)
 { fprintf(stderr, "towire_u32 called!\n"); abort(); }
 /* Generated stub for towire_u64 */
 void towire_u64(u8 **pptr UNNEEDED, u64 v UNNEEDED)
 { fprintf(stderr, "towire_u64 called!\n"); abort(); }
+/* Generated stub for towire_u8_array */
+void towire_u8_array(u8 **pptr UNNEEDED, const u8 *arr UNNEEDED, size_t num UNNEEDED)
+{ fprintf(stderr, "towire_u8_array called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
 #if 0

common/utxo.c

@@ -16,6 +16,11 @@ void towire_utxo(u8 **pptr, const struct utxo *utxo)
 	towire_u32(pptr, utxo->keyindex);
 	towire_bool(pptr, utxo->is_p2sh);
 
+	towire_u16(pptr, tal_count(utxo->scriptPubkey));
+	towire_u8_array(pptr, utxo->scriptPubkey, tal_count(utxo->scriptPubkey));
+	towire_u16(pptr, tal_count(utxo->scriptSig));
+	towire_u8_array(pptr, utxo->scriptSig, tal_count(utxo->scriptSig));
+
 	towire_bool(pptr, is_unilateral_close);
 	if (is_unilateral_close) {
 		towire_u64(pptr, utxo->close_info->channel_id);
@@ -36,9 +41,8 @@ struct utxo *fromwire_utxo(const tal_t *ctx, const u8 **ptr, size_t *max)
 	utxo->keyindex = fromwire_u32(ptr, max);
 	utxo->is_p2sh = fromwire_bool(ptr, max);
 
-	/* No need to tell hsmd about the scriptPubkey, it has all the info to
-	 * derive it from the rest. */
-	utxo->scriptPubkey = NULL;
+	utxo->scriptPubkey = fromwire_tal_arrn(utxo, ptr, max, fromwire_u16(ptr, max));
+	utxo->scriptSig = fromwire_tal_arrn(utxo, ptr, max, fromwire_u16(ptr, max));
 
 	if (fromwire_bool(ptr, max)) {
 		utxo->close_info = tal(utxo, struct unilateral_close_info);

common/utxo.h

@@ -41,6 +41,9 @@ struct utxo {
 
 	/* The scriptPubkey if it is known */
 	u8 *scriptPubkey;
+
+	/* scriptSig. Only for P2SH outputs */
+	u8 *scriptSig;
 };
 
 void towire_utxo(u8 **pptr, const struct utxo *utxo);

wallet/wallet.c

@@ -175,6 +175,7 @@ static struct utxo *wallet_stmt2output(const tal_t *ctx, struct db_stmt *stmt)
 	utxo->blockheight = NULL;
 	utxo->spendheight = NULL;
 	utxo->scriptPubkey = NULL;
+	utxo->scriptSig = NULL;
 
 	if (!db_column_is_null(stmt, 9)) {
 		blockheight = tal(utxo, u32);
@@ -537,6 +538,22 @@ const struct utxo **wallet_select_all(const tal_t *ctx, struct wallet *w,
 	return utxo;
 }
 
+u8 *derive_redeem_scriptsig(const tal_t *ctx, struct wallet *w, u32 keyindex)
+{
+	struct ext_key ext;
+	struct pubkey key;
+
+	if (bip32_key_from_parent(w->bip32_base, keyindex,
+				  BIP32_FLAG_KEY_PUBLIC, &ext) != WALLY_OK) {
+		fatal("Unable to derive pubkey");
+	}
+
+	if (!pubkey_from_der(ext.pub_key, PUBKEY_CMPR_LEN, &key))
+		fatal("Unble to derive pubkey from DER");
+
+	return bitcoin_scriptsig_p2sh_p2wpkh(ctx, &key);
+}
+
 bool wallet_can_spend(struct wallet *w, const u8 *script,
 		      u32 *index, bool *output_is_p2sh)
 {

wallet/wallet.h

@@ -399,6 +399,14 @@ const struct utxo **wallet_select_all(const tal_t *ctx, struct wallet *w,
 				      struct amount_sat *sat,
 				      struct amount_sat *fee_estimate);
 
+/* derive_redeem_scriptsig - Compute the scriptSig for a P2SH-P2WPKH
+ *
+ * @ctx - allocation context
+ * @w - wallet
+ * @keyindex - index of the internal BIP32 key
+ */
+u8 *derive_redeem_scriptsig(const tal_t *ctx, struct wallet *w, u32 keyindex);
+
 /**
  * wallet_select_specific - Select utxos given an array of txids and an array of outputs index
  *