Merge #2173: [Merge Mining] Fixed missing Merge Mining Tag

The function `append_merge_mining_tag`, the `block` parameter needed to be
mutable.  Ensured miner_tx hash is first hash added to hashes when calculating
root.

applications/tari_merge_mining_proxy/src/main.rs

@@ -242,15 +242,20 @@ fn get_monero_data(data: &[u8], seed: String) -> Option<MoneroData> {
                     let block = deserialize::<Block>(&hex);
                     match block {
                         Ok(block) => {
-                            let mut hashes = block.clone().tx_hashes;
+                            let count = 1 + (block.tx_hashes.len() as u16);
+                            let mut hashes = Vec::with_capacity(count as usize);
+                            let mut proof = Vec::with_capacity(count as usize);
                             hashes.push(block.miner_tx.hash());
-                            let root = tree_hash(hashes);
-                            let mut proof = block.clone().tx_hashes;
                             proof.push(block.miner_tx.hash());
+                            for item in block.clone().tx_hashes {
+                                hashes.push(item);
+                                proof.push(item);
+                            }
+                            let root = tree_hash(hashes);
                             Some(MoneroData {
                                 header: block.header.clone(),
                                 key: seed,
-                                count: (block.tx_hashes.len() as u16) + 1,
+                                count,
                                 transaction_root: from_slice(root.as_slice()),
                                 transaction_hashes: from_hashes(&proof),
                                 coinbase_tx: block.miner_tx,
@@ -393,8 +398,8 @@ fn add_merge_mining_tag(data: &[u8], hash: &[u8]) -> Vec<u8> {
                 Ok(hex) => {
                     let block = deserialize::<Block>(&hex[..]);
                     match block {
-                        Ok(block) => {
-                            let mm_tag = append_merge_mining_tag(&block, Hash(from_slice(hash)));
+                        Ok(mut block) => {
+                            let mm_tag = append_merge_mining_tag(&mut block, Hash(from_slice(hash)));
                             match mm_tag {
                                 Ok(mm_tagged_template) => {
                                     let count = 1 + block.tx_hashes.len() as u16;
@@ -969,9 +974,13 @@ mod test {
         let bytes = hex::decode(hex).unwrap();
         let block = deserialize::<Block>(&bytes[..]).unwrap();
         let header = serialize::<BlockHeader>(&block.header);
-        let mut count = serialize::<VarInt>(&VarInt(1 + block.tx_hashes.len() as u64));
-        let mut hashes = block.clone().tx_hashes;
+        let tx_count = 1 + block.tx_hashes.len() as u64;
+        let mut count = serialize::<VarInt>(&VarInt(tx_count));
+        let mut hashes = Vec::with_capacity(tx_count as usize);
         hashes.push(block.miner_tx.hash());
+        for item in block.clone().tx_hashes {
+            hashes.push(item);
+        }
         let mut root = tree_hash(hashes); // tree_hash.c used by monero
         let mut encode2 = header;
         encode2.append(&mut root);

base_layer/core/src/proof_of_work/monero_rx.rs

@@ -71,7 +71,7 @@ pub struct MoneroData {
 
 // Hash algorithm in monero
 pub fn cn_fast_hash(data: &[u8]) -> Vec<u8> {
-    Hash::hash(data).0.as_bytes().to_vec()
+    Hash::hash(data).0.to_vec()
 }
 
 // Tree hash count in monero
@@ -170,16 +170,15 @@ fn monero_difficulty_calculation(header: &BlockHeader) -> Result<Difficulty, Mer
     Ok(difficulty)
 }
 
-/// Appends merge mining hash to a Monero block and returns the Monero blocktemplate_blob
-pub fn append_merge_mining_tag(block: &MoneroBlock, hash: Hash) -> Result<String, MergeMineError> {
-    let mut monero_block = block.clone();
+/// Appends merge mining hash to a Monero block and returns the encoded Monero blocktemplate_blob
+pub fn append_merge_mining_tag(block: &mut MoneroBlock, hash: Hash) -> Result<String, MergeMineError> {
     let mm_tag = SubField::MergeMining(VarInt(0), hash);
-    monero_block.miner_tx.prefix.extra.0.push(mm_tag);
+    block.miner_tx.prefix.extra.0.push(mm_tag);
     let serialized = serialize::<MoneroBlock>(&block);
     Ok(hex::encode(&serialized).into())
 }
 
-/// Calculates the Monero blockhashing_blob
+/// Calculates the encoded Monero blockhashing_blob
 pub fn create_input_blob(
     header: &MoneroBlockHeader,
     tx_count: &u16,
@@ -191,7 +190,7 @@ pub fn create_input_blob(
     let mut count = serialize::<VarInt>(&VarInt(tx_count.clone() as u64));
     let mut hashes = Vec::new();
     for item in tx_hashes {
-        hashes.push(Hash(from_slice(item.clone().as_bytes())));
+        hashes.push(Hash::from(item.clone()));
     }
     let mut root = tree_hash(hashes);
     let mut encode = header;
@@ -220,7 +219,7 @@ pub fn from_hashes(hashes: &[Hash]) -> Vec<[u8; 32]> {
 fn verify_root(monero_data: &MoneroData) -> Result<(), MergeMineError> {
     let mut hashes = Vec::new();
     for item in &monero_data.transaction_hashes {
-        hashes.push(Hash(from_slice(item.to_vec().as_slice())));
+        hashes.push(Hash::from(item));
     }
     let root = tree_hash(hashes);
 
@@ -235,7 +234,7 @@ fn verify_root(monero_data: &MoneroData) -> Result<(), MergeMineError> {
 fn merged_mining_subfield(header: &BlockHeader) -> SubField {
     let hash = header.merged_mining_hash();
     let depth = 0;
-    SubField::MergeMining(VarInt(depth), Hash::hash(&hash[..32]))
+    SubField::MergeMining(VarInt(depth), Hash::from(from_slice(&hash)))
 }
 
 fn verify_header(header: &BlockHeader, monero_data: &MoneroData) -> Result<(), MergeMineError> {