Added output for witness in coinbase txn

output.txt

@@ -1,4 +1,4 @@
-200000000000000000000000000000000000000000000000000000000000000000000000b97612673f1ac935cf09ce4b0b5427ef0d47976230922347bc316438a2ac876b21d612661f00ffff0000bc99
-01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0403951a06ffffffff0177bf4025000000001976a9142c30a6aaac6d96687291475d7d52f4b469f665a688ac00000000
-1c078a0a38861757e7b63af37b8061c7862d7946d9a801d1282042f3b2e1abf7
+200000000000000000000000000000000000000000000000000000000000000000000000415e963e489fb68a4beb66e670655b3a5243f5a069a48f09023cb7479a08f3a7d0ea1266ffff001f00007dd8
+01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0403951a06ffffffff0277bf4025000000001976a9142c30a6aaac6d96687291475d7d52f4b469f665a688ac0000000000000000266a24aa21a9ed645ca51edf54d5cca1ec2f190d5738d86970c506b86310ce835e08c1b92715770120000000000000000000000000000000000000000000000000000000000000000000000000
+86bd466461b021a26c20c8365c0a19e3318fcb6a808cf66f67b2f7ed14f59a8d
 4ab3cc4296fee78153d60d2884323a84260157db0b83a72309272f109ad9dd32

src/block.h

@@ -45,7 +45,7 @@ string getMerkleRoot(vector<string> &txns_included) {
     return hashQ.front();
 }
 
-string genCoinbaseTxn (int64_t reward) {
+string genCoinbaseTxn (int64_t reward, string wTXID_commitment) {
     string coinbase_txn = "";
 
     coinbase_txn += int2bin(1); // Version
@@ -56,11 +56,17 @@ string genCoinbaseTxn (int64_t reward) {
     coinbase_txn += string{(int8_t) 0x04, (int8_t) 0x03, (int8_t) 0x95, (int8_t) 0x1a, (int8_t) 0x06}; // scriptSig
     coinbase_txn += int2bin(0xffffffff); // Sequence
 
-    coinbase_txn += int2compact(1); // Number of outputs
+    coinbase_txn += int2compact(2); // Number of outputs
 
     coinbase_txn += int2bin(reward, IS_INT64_T); // Reward
     coinbase_txn += int2compact(0x19); // Output script length
     coinbase_txn += hexstr2bstr("76a9142c30a6aaac6d96687291475d7d52f4b469f665a688ac"); // Output script
+
+    coinbase_txn += int2bin(0, IS_INT64_T); // Reward
+    coinbase_txn += int2compact(0x26); // Output script length
+    coinbase_txn += hexstr2bstr("6a24aa21a9ed");    // Output script
+    coinbase_txn += wTXID_commitment;               // Output script
+    coinbase_txn += hexstr2bstr("01200000000000000000000000000000000000000000000000000000000000000000");
 
     coinbase_txn += int2bin(0); // Locktime
 
@@ -73,14 +79,12 @@ string genBlockHeader (vector<string> &txns_included) {
     block_header += string(32, (int8_t) 0); // Previous block hash
 
     string merkle_root = getMerkleRoot(txns_included);
-    // reverse(merkle_root.begin(), merkle_root.end());
     block_header += merkle_root;
 
     time_t timestamp = time(nullptr);
     block_header += int2bin(timestamp);
 
     block_header += string{(int8_t) 255, (int8_t) 255, (int8_t) 0, (int8_t) 31}; // Bits
-    // block_header += string{(int8_t) 31, (int8_t) 0, (int8_t) 255, (int8_t) 255}; // Bits
 
     return block_header;
 }

src/main.cpp

@@ -74,7 +74,10 @@ void mine() {
         blockTxnIds.push_back(txid);
     }
 
-    string coinbaseTxn = genCoinbaseTxn(reward);
+    vector<string> wTXIDs = blockTxnIds;
+    wTXIDs.push_back(string(32, 0));
+    string wTXID_commitment = hash256(getMerkleRoot(wTXIDs) + string(32, 0));
+    string coinbaseTxn = genCoinbaseTxn(reward, wTXID_commitment);
     block_size += coinbaseTxn.size();
 
     string coinbaseTxnId = "";
@@ -93,7 +96,6 @@ void mine() {
     block = bstr2hexstr(block, block.length());
     block.push_back('\n');
 
-    cout << bstr2hexstr(coinbaseTxn, coinbaseTxn.length()) << endl;
     block += bstr2hexstr(coinbaseTxn, coinbaseTxn.length());
     block.push_back('\n');
 

src/script.h

@@ -21,6 +21,17 @@ extern set<string> inputs_used;
 string serialized_txn = "", serialized_segwit_1 = "", serialized_segwit_inp = "", serialized_segwit_2 = "";
 
 
+string hash256(string data) {
+    string hash = "";
+    char sha[SHA256_DIGEST_LENGTH];
+    SHA256((unsigned char*) data.c_str(), data.length(), (unsigned char*) sha);
+    SHA256((unsigned char*) sha, SHA256_DIGEST_LENGTH, (unsigned char*) sha);
+    for (int i = 0; i < SHA256_DIGEST_LENGTH; i++)
+        hash.push_back(sha[i]);
+    return hash;
+}
+
+
 std::vector<std::string> getOps(std::string asmScript) {
     std::vector<std::string> ops;