Added example case for taproot key path spending with identical signature

Author: saikiran57

examples/spend_p2tr_default_path_identical_signature.py

@@ -0,0 +1,102 @@
+# Copyright (C) 2018-2024 The python-bitcoin-utils developers
+#
+# This file is part of python-bitcoin-utils
+#
+# It is subject to the license terms in the LICENSE file found in the top-level
+# directory of this distribution.
+#
+# No part of python-bitcoin-utils, including this file, may be copied,
+# modified, propagated, or distributed except according to the terms contained
+# in the LICENSE file.
+
+from binascii import unhexlify
+from bitcoinutils.setup import setup
+from bitcoinutils.utils import to_satoshis
+from bitcoinutils.transactions import Transaction, TxInput, TxOutput, TxWitnessInput
+from bitcoinutils.keys import P2pkhAddress, PrivateKey, P2trAddress
+from bitcoinutils.script import Script
+
+
+def main():
+    try:
+        # always remember to setup the network
+        setup("testnet")
+
+        # the key that corresponds to the P2WPKH address
+        #priv = PrivateKey("cPiTDzdpEfCwotToidTcNjh4WsdTZRLkYYScs1vHXT4Dzncwasdo")
+        priv = PrivateKey(b=unhexlify("3fa9909fad4c01625adc47639626877073d94ead84e9630a66b731776cb66fcf"))
+        print(f"internal priv key: {priv.to_bytes().hex()}")
+
+        pub = priv.get_public_key()
+
+        fromAddress = pub.get_taproot_address()
+        print(fromAddress.to_string())
+
+        # UTXO of fromAddress
+        txid = "bf0dc482d03fd2b57fb97cefd84de42f0bf370930856785e8ec9c019f1fb3aca"
+        vout = 0
+
+        # all amounts are needed to sign a taproot input
+        # (depending on sighash)
+        first_amount = to_satoshis(0.00385004)
+        amounts = [first_amount]
+
+        # all scriptPubKeys are needed to sign a taproot input
+        # (depending on sighash) but always of the spend input
+        first_script_pubkey = fromAddress.to_script_pub_key()
+
+        script_pubkey02 = Script(["OP_1", pub.to_taproot_hex()[0]])
+        print(f"first_script_pubkey: {first_script_pubkey.to_hex()}")
+        print(f"script_pubkey02: {script_pubkey02.to_hex()}")
+
+        # alternatively:
+        # first_script_pubkey = Script(['OP_1', pub.to_taproot_hex()])
+
+        utxos_script_pubkeys = [first_script_pubkey]
+
+        # create transaction input from tx id of UTXO
+        seq = "fdffffff"
+        txin = TxInput(txid, vout, sequence=seq)
+
+        toAddress1 = P2trAddress("tb1pz38c8e54f6fkfpetmw8j7ft0ft54yeqy7cvzyckwxgjany8vv7vssddyfa")
+        toAddress2 = P2trAddress("tb1pdtpkgjvkc77nuzssqh420ulgu3xm88m5vy59wrmgg5ctklkandgqmyh9ah")
+
+        # create transaction output
+        txOut1 = TxOutput(to_satoshis(0.00364261), toAddress1.to_script_pub_key())
+        txOut2 = TxOutput(to_satoshis(0.00005000 ), toAddress2.to_script_pub_key())
+        # create transaction without change output - if at least a single input is
+        # segwit we need to set has_segwit=True
+
+        locktime = "a8643400"
+        tx = Transaction([txin], [txOut1, txOut2], has_segwit=True, locktime=locktime)
+
+        print("\nRaw transaction:\n" + tx.serialize())
+
+        print("\ntxid: " + tx.get_txid())
+        print("\ntxwid: " + tx.get_wtxid())
+
+        # sign taproot input
+        # to create the digest message to sign in taproot we need to
+        # pass all the utxos' scriptPubKeys and their amounts
+        sig = priv.sign_taproot_input(tx, 0, utxos_script_pubkeys, amounts, rand_aux=bytes(32))
+        # print(sig)
+
+        tx.witnesses.append(TxWitnessInput([sig]))
+
+        # print raw signed transaction ready to be broadcasted
+        print("\nRaw signed transaction:\n" + tx.serialize())
+
+        print("\nTxId:", tx.get_txid())
+        print("\nTxwId:", tx.get_wtxid())
+
+        print("\nSize:", tx.get_size())
+        print("\nvSize:", tx.get_vsize())
+    except Exception as e:
+      print('Something went wrong', e)
+    finally:
+      print('The try except is finished')
+
+
+
+if __name__ == "__main__":
+    main()