From 234252016da8c40afe37e26b7162a45180719939 Mon Sep 17 00:00:00 2001
From: Christian Decker <decker.christian@gmail.com>
Date: Sat, 25 Jan 2020 13:14:34 +0100
Subject: [PATCH] cleanup: Remove block header fields we don't use

---
 bitcoin/block.c | 33 ++++++++++++++++-----------------
 bitcoin/block.h | 11 -----------
 2 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/bitcoin/block.c b/bitcoin/block.c
index de652dfc3..424f4f52b 100644
--- a/bitcoin/block.c
+++ b/bitcoin/block.c
@@ -94,9 +94,10 @@ bitcoin_block_from_hex(const tal_t *ctx, const struct chainparams *chainparams,
 	struct bitcoin_block *b;
 	u8 *linear_tx;
 	const u8 *p;
-	size_t len, i, num;
+	size_t len, i, num, templen;
 	struct sha256_ctx shactx;
 	bool is_dynafed;
+	u32 height;
 
 	if (hexlen && hex[hexlen-1] == '\n')
 		hexlen--;
@@ -127,26 +128,24 @@ bitcoin_block_from_hex(const tal_t *ctx, const struct chainparams *chainparams,
 	if (is_elements(chainparams)) {
 		/* A dynafed block is signalled by setting the MSB of the version. */
 		is_dynafed = (b->hdr.version >> 31 == 1);
-		b->elements_hdr = tal(b, struct elements_block_hdr);
-		b->elements_hdr->block_height = pull_le32(&p, &len);
-		sha256_le32(&shactx, b->elements_hdr->block_height);
+
+		/* elements_header.height */
+		height = pull_le32(&p, &len);
+		sha256_le32(&shactx, height);
 
 		if (is_dynafed) {
 			bitcoin_block_pull_dynafed_details(&p, &len, &shactx);
 		} else {
-			size_t challenge_len = pull_varint(&p, &len);
-			sha256_varint(&shactx, challenge_len);
-			sha256_update(&shactx, p, challenge_len);
-			b->elements_hdr->proof.challenge =
-			    tal_arr(b->elements_hdr, u8, challenge_len);
-			pull(&p, &len, b->elements_hdr->proof.challenge,
-			     challenge_len);
-
-			size_t solution_len = pull_varint(&p, &len);
-			b->elements_hdr->proof.solution =
-			    tal_arr(b->elements_hdr, u8, solution_len);
-			pull(&p, &len, b->elements_hdr->proof.solution,
-			     solution_len);
+			/* elemens_header.challenge */
+			templen = pull_varint(&p, &len);
+			sha256_varint(&shactx, templen);
+			sha256_update(&shactx, p, templen);
+			pull(&p, &len, NULL, templen);
+
+			/* elements_header.solution. Not hashed since it'd be
+			 * a circular dependency. */
+			templen = pull_varint(&p, &len);
+			pull(&p, &len, NULL, templen);
 		}
 
 	} else {
diff --git a/bitcoin/block.h b/bitcoin/block.h
index 8654ed5a1..7f82b8aa5 100644
--- a/bitcoin/block.h
+++ b/bitcoin/block.h
@@ -32,19 +32,8 @@ struct bitcoin_block_hdr {
 	struct bitcoin_blkid hash;
 };
 
-struct elements_block_proof {
-	u8 *challenge;
-	u8 *solution;
-};
-
-struct elements_block_hdr {
-	u32 block_height;
-	struct elements_block_proof proof;
-};
-
 struct bitcoin_block {
 	struct bitcoin_block_hdr hdr;
-	struct elements_block_hdr *elements_hdr;
 	/* tal_count shows now many */
 	struct bitcoin_tx **tx;
 };