From 0ca6c3cc8445e780cca378049d231397b4ae70a6 Mon Sep 17 00:00:00 2001
From: niftynei <niftynei@gmail.com>
Date: Tue, 20 Oct 2020 20:05:16 -0500
Subject: [PATCH] script: break out redeemscript->scriptsig function

We're going to finalze some redeemscripts here shortly, so break out the
ability to render an arbitrary redeemscript -> scriptsig
---
 bitcoin/script.c | 20 ++++++++++++++++----
 bitcoin/script.h |  4 ++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/bitcoin/script.c b/bitcoin/script.c
index 0ba9dcdc3..d69751c24 100644
--- a/bitcoin/script.c
+++ b/bitcoin/script.c
@@ -261,18 +261,30 @@ u8 *bitcoin_redeem_p2sh_p2wpkh(const tal_t *ctx, const struct pubkey *key)
 	return script;
 }
 
-u8 *bitcoin_scriptsig_p2sh_p2wpkh(const tal_t *ctx, const struct pubkey *key)
+u8 *bitcoin_scriptsig_redeem(const tal_t *ctx,
+			     const u8 *redeemscript TAKES)
 {
-	u8 *redeemscript = bitcoin_redeem_p2sh_p2wpkh(ctx, key), *script;
+	u8 *script;
 
 	/* BIP141: The scriptSig must be exactly a push of the BIP16
 	 * redeemScript or validation fails. */
 	script = tal_arr(ctx, u8, 0);
-	script_push_bytes(&script, redeemscript, tal_count(redeemscript));
-	tal_free(redeemscript);
+	script_push_bytes(&script, redeemscript,
+			  tal_count(redeemscript));
+
+	if (taken(redeemscript))
+		tal_free(redeemscript);
+
 	return script;
 }
 
+u8 *bitcoin_scriptsig_p2sh_p2wpkh(const tal_t *ctx, const struct pubkey *key)
+{
+	u8 *redeemscript =
+		bitcoin_redeem_p2sh_p2wpkh(NULL, key);
+	return bitcoin_scriptsig_redeem(ctx, take(redeemscript));
+}
+
 u8 **bitcoin_witness_p2wpkh(const tal_t *ctx,
 			    const struct bitcoin_signature *sig,
 			    const struct pubkey *key)
diff --git a/bitcoin/script.h b/bitcoin/script.h
index 30b4c3f6c..b424f45d7 100644
--- a/bitcoin/script.h
+++ b/bitcoin/script.h
@@ -43,6 +43,10 @@ u8 *bitcoin_redeem_p2pkh(const tal_t *ctx, const struct pubkey *pubkey,
 /* Create the redeemscript for a P2SH + P2WPKH. */
 u8 *bitcoin_redeem_p2sh_p2wpkh(const tal_t *ctx, const struct pubkey *key);
 
+/* Create the scriptsig for a redeemscript */
+u8 *bitcoin_scriptsig_redeem(const tal_t *ctx,
+			     const u8 *redeemscript TAKES);
+
 /* Create scriptsig for p2sh-p2wpkh */
 u8 *bitcoin_scriptsig_p2sh_p2wpkh(const tal_t *ctx, const struct pubkey *key);