Rewrite 2.2.11 and 2.2.12 with CTransaction

Author: jachiang

2.2-taptweak.ipynb

@@ -11,9 +11,9 @@
     "import util\n",
     "from test_framework.address import program_to_witness\n",
     "from test_framework.key import ECKey, ECPubKey, SECP256K1_ORDER, generate_key_pair, generate_schnorr_nonce\n",
-    "from test_framework.messages import CTxInWitness, sha256\n",
+    "from test_framework.messages import COutPoint, CTxIn, CTxInWitness, CTxOut, sha256\n",
     "from test_framework.musig import generate_musig_key, aggregate_schnorr_nonces, sign_musig, aggregate_musig_signatures\n",
-    "from test_framework.script import CTransaction, OP_RETURN, SIGHASH_ALL_TAPROOT, TaprootSignatureHash"
+    "from test_framework.script import CScript, CTransaction, OP_RETURN, SIGHASH_ALL_TAPROOT, TaprootSignatureHash"
    ]
   },
   {
@@ -509,7 +509,7 @@
     "\n",
     "# Fetch the oldest unspent outpoint in the Bitcoin Core wallet\n",
     "unspent_txid = node.listunspent(1)[-1][\"txid\"]\n",
-    "unspent_outpoint = [{\"txid\": unspent_txid, \"vout\": 0}]"
+    "unspent_outpoint = COutPoint(int(unspent_txid,16), 0)"
    ]
   },
   {
@@ -527,15 +527,26 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# Construct the two outputs:\n",
+    "# Construct transaction spending previously generated outpoint\n",
+    "op_return_tx = CTransaction()\n",
+    "op_return_tx.nVersion = 1\n",
+    "op_return_tx.nLockTime = 0\n",
+    "op_return_tx_in = CTxIn(outpoint=unspent_outpoint, nSequence=0)\n",
+    "op_return_tx.vin = [op_return_tx_in]\n",
+    "\n",
     "# Output 0) Alice's destination address\n",
-    "# Output 1) OP_RETURN with Alice's commitment\n",
     "address_alice = node.getnewaddress(address_type=\"bech32\")\n",
-    "outputs = [{address_alice: 1}, {\"data\": commitment_bytes.hex()}] \n",
+    "p2wpkh_output_script = bytes.fromhex(node.getaddressinfo(address_alice)['scriptPubKey'])\n",
+    "p2wpkh_output_amount_sat = 100_000_000\n",
+    "p2wpkh_output = CTxOut(nValue=p2wpkh_output_amount_sat, scriptPubKey=p2wpkh_output_script)\n",
+    "\n",
+    "# Output 1) OP_RETURN with Alice's commitment\n",
+    "op_return_output_script = CScript([OP_RETURN, commitment_bytes])\n",
+    "op_return_output = CTxOut(nValue=0, scriptPubKey=op_return_output_script)\n",
     "\n",
-    "# Construct and sign a transaction with the p2pkh and OP_RETURN outputs\n",
-    "op_return_tx_hex = node.createrawtransaction(inputs=unspent_outpoint, outputs=outputs)\n",
-    "op_return_tx_hex_signed = node.signrawtransactionwithwallet(hexstring=op_return_tx_hex)['hex']\n",
+    "# Populate transaction with p2pkh and OP_RETURN outputs and add valid witness\n",
+    "op_return_tx.vout = [p2wpkh_output, op_return_output]\n",
+    "op_return_tx_hex_signed = node.signrawtransactionwithwallet(hexstring=op_return_tx.serialize().hex())['hex']\n",
     "\n",
     "# Confirm details of the OP_RETURN output\n",
     "op_return_tx_decoded = node.decoderawtransaction(op_return_tx_hex_signed)\n",