#!/usr/bin/env python3 # Copyright (c) 2020-2021 The Bitcoin Core developers # Distributed under the MIT software license, see the accompanying # file COPYING or http://www.opensource.org/licenses/mit-license.php. """A limited-functionality wallet, which may replace a real wallet in tests""" from copy import deepcopy from decimal import Decimal from enum import Enum from random import choice from typing import ( Any, Optional, ) from test_framework.address import ( base58_to_byte, create_deterministic_address_bcrt1_p2tr_op_true, key_to_p2pkh, key_to_p2sh_p2wpkh, key_to_p2wpkh, ) from test_framework.descriptors import descsum_create from test_framework.key import ECKey from test_framework.messages import ( COIN, COutPoint, CTransaction, CTxIn, CTxInWitness, CTxOut, tx_from_hex, ) from test_framework.script import ( CScript, LegacySignatureHash, LEAF_VERSION_TAPSCRIPT, OP_NOP, OP_TRUE, SIGHASH_ALL, ) from test_framework.script_util import ( key_to_p2pk_script, key_to_p2pkh_script, key_to_p2sh_p2wpkh_script, key_to_p2wpkh_script, keyhash_to_p2pkh_script, scripthash_to_p2sh_script, ) from test_framework.util import ( assert_equal, assert_greater_than_or_equal, ) DEFAULT_FEE = Decimal("0.0001") class MiniWalletMode(Enum): """Determines the transaction type the MiniWallet is creating and spending. For most purposes, the default mode ADDRESS_OP_TRUE should be sufficient; it simply uses a fixed bech32m P2TR address whose coins are spent with a witness stack of OP_TRUE, i.e. following an anyone-can-spend policy. However, if the transactions need to be modified by the user (e.g. prepending scriptSig for testing opcodes that are activated by a soft-fork), or the txs should contain an actual signature, the raw modes RAW_OP_TRUE and RAW_P2PK can be useful. Summary of modes: | output | | tx is | can modify | needs mode | description | address | standard | scriptSig | signing ----------------+-------------------+-----------+----------+------------+---------- ADDRESS_OP_TRUE | anyone-can-spend | bech32m | yes | no | no RAW_OP_TRUE | anyone-can-spend | - (raw) | no | yes | no RAW_P2PK | pay-to-public-key | - (raw) | yes | yes | yes """ ADDRESS_OP_TRUE = 1 RAW_OP_TRUE = 2 RAW_P2PK = 3 class MiniWallet: def __init__(self, test_node, *, mode=MiniWalletMode.ADDRESS_OP_TRUE): self._test_node = test_node self._utxos = [] self._priv_key = None self._address = None assert isinstance(mode, MiniWalletMode) if mode == MiniWalletMode.RAW_OP_TRUE: self._scriptPubKey = bytes(CScript([OP_TRUE])) elif mode == MiniWalletMode.RAW_P2PK: # use simple deterministic private key (k=1) self._priv_key = ECKey() self._priv_key.set((1).to_bytes(32, 'big'), True) pub_key = self._priv_key.get_pubkey() self._scriptPubKey = key_to_p2pk_script(pub_key.get_bytes()) elif mode == MiniWalletMode.ADDRESS_OP_TRUE: self._address, self._internal_key = create_deterministic_address_bcrt1_p2tr_op_true() self._scriptPubKey = bytes.fromhex(self._test_node.validateaddress(self._address)['scriptPubKey']) def get_balance(self): return sum(u['value'] for u in self._utxos) def rescan_utxos(self): """Drop all utxos and rescan the utxo set""" self._utxos = [] res = self._test_node.scantxoutset(action="start", scanobjects=[self.get_descriptor()]) assert_equal(True, res['success']) for utxo in res['unspents']: self._utxos.append({'txid': utxo['txid'], 'vout': utxo['vout'], 'value': utxo['amount'], 'height': utxo['height']}) def scan_tx(self, tx): """Scan the tx for self._scriptPubKey outputs and add them to self._utxos""" for out in tx['vout']: if out['scriptPubKey']['hex'] == self._scriptPubKey.hex(): self._utxos.append({'txid': tx['txid'], 'vout': out['n'], 'value': out['value'], 'height': 0}) def sign_tx(self, tx, fixed_length=True): """Sign tx that has been created by MiniWallet in P2PK mode""" assert self._priv_key is not None (sighash, err) = LegacySignatureHash(CScript(self._scriptPubKey), tx, 0, SIGHASH_ALL) assert err is None # for exact fee calculation, create only signatures with fixed size by default (>49.89% probability): # 65 bytes: high-R val (33 bytes) + low-S val (32 bytes) # with the DER header/skeleton data of 6 bytes added, this leads to a target size of 71 bytes der_sig = b'' while not len(der_sig) == 71: der_sig = self._priv_key.sign_ecdsa(sighash) if not fixed_length: break tx.vin[0].scriptSig = CScript([der_sig + bytes(bytearray([SIGHASH_ALL]))]) def generate(self, num_blocks, **kwargs): """Generate blocks with coinbase outputs to the internal address, and append the outputs to the internal list""" blocks = self._test_node.generatetodescriptor(num_blocks, self.get_descriptor(), **kwargs) for b in blocks: block_info = self._test_node.getblock(blockhash=b, verbosity=2) cb_tx = block_info['tx'][0] self._utxos.append({'txid': cb_tx['txid'], 'vout': 0, 'value': cb_tx['vout'][0]['value'], 'height': block_info['height']}) return blocks def get_scriptPubKey(self): return self._scriptPubKey def get_descriptor(self): return descsum_create(f'raw({self._scriptPubKey.hex()})') def get_address(self): return self._address def get_utxo(self, *, txid: str = '', vout: Optional[int] = None, mark_as_spent=True): """ Returns a utxo and marks it as spent (pops it from the internal list) Args: txid: get the first utxo we find from a specific transaction """ self._utxos = sorted(self._utxos, key=lambda k: (k['value'], -k['height'])) # Put the largest utxo last if txid: utxo_filter: Any = filter(lambda utxo: txid == utxo['txid'], self._utxos) else: utxo_filter = reversed(self._utxos) # By default the largest utxo if vout is not None: utxo_filter = filter(lambda utxo: vout == utxo['vout'], utxo_filter) index = self._utxos.index(next(utxo_filter)) if mark_as_spent: return self._utxos.pop(index) else: return self._utxos[index] def send_self_transfer(self, **kwargs): """Create and send a tx with the specified fee_rate. Fee may be exact or at most one satoshi higher than needed.""" tx = self.create_self_transfer(**kwargs) self.sendrawtransaction(from_node=kwargs['from_node'], tx_hex=tx['hex']) return tx def send_to(self, *, from_node, scriptPubKey, amount, fee=1000): """ Create and send a tx with an output to a given scriptPubKey/amount, plus a change output to our internal address. To keep things simple, a fixed fee given in Satoshi is used. Note that this method fails if there is no single internal utxo available that can cover the cost for the amount and the fixed fee (the utxo with the largest value is taken). Returns a tuple (txid, n) referring to the created external utxo outpoint. """ tx = self.create_self_transfer(from_node=from_node, fee_rate=0, mempool_valid=False)['tx'] assert_greater_than_or_equal(tx.vout[0].nValue, amount + fee) tx.vout[0].nValue -= (amount + fee) # change output -> MiniWallet tx.vout.append(CTxOut(amount, scriptPubKey)) # arbitrary output -> to be returned txid = self.sendrawtransaction(from_node=from_node, tx_hex=tx.serialize().hex()) return txid, 1 def send_self_transfer_multi(self, **kwargs): """ Create and send a transaction that spends the given UTXOs and creates a certain number of outputs with equal amounts. Returns a dictionary with - txid - serialized transaction in hex format - transaction as CTransaction instance - list of newly created UTXOs, ordered by vout index """ tx = self.create_self_transfer_multi(**kwargs) txid = self.sendrawtransaction(from_node=kwargs['from_node'], tx_hex=tx.serialize().hex()) return {'new_utxos': [self.get_utxo(txid=txid, vout=vout) for vout in range(len(tx.vout))], 'txid': txid, 'hex': tx.serialize().hex(), 'tx': tx} def create_self_transfer_multi(self, *, from_node, utxos_to_spend=None, num_outputs=1, fee_per_output=1000): """ Create and return a transaction that spends the given UTXOs and creates a certain number of outputs with equal amounts. """ utxos_to_spend = utxos_to_spend or [self.get_utxo()] # create simple tx template (1 input, 1 output) tx = self.create_self_transfer(fee_rate=0, from_node=from_node, utxo_to_spend=utxos_to_spend[0], mempool_valid=False)['tx'] # duplicate inputs, witnesses and outputs tx.vin = [deepcopy(tx.vin[0]) for _ in range(len(utxos_to_spend))] tx.wit.vtxinwit = [deepcopy(tx.wit.vtxinwit[0]) for _ in range(len(utxos_to_spend))] tx.vout = [deepcopy(tx.vout[0]) for _ in range(num_outputs)] # adapt input prevouts for i, utxo in enumerate(utxos_to_spend): tx.vin[i] = CTxIn(COutPoint(int(utxo['txid'], 16), utxo['vout'])) # adapt output amounts (use fixed fee per output) inputs_value_total = sum([int(COIN * utxo['value']) for utxo in utxos_to_spend]) outputs_value_total = inputs_value_total - fee_per_output * num_outputs for o in tx.vout: o.nValue = outputs_value_total // num_outputs return tx def create_self_transfer(self, *, fee_rate=Decimal("0.003"), from_node=None, utxo_to_spend=None, mempool_valid=True, locktime=0, sequence=0): """Create and return a tx with the specified fee_rate. Fee may be exact or at most one satoshi higher than needed.""" from_node = from_node or self._test_node utxo_to_spend = utxo_to_spend or self.get_utxo() if self._priv_key is None: vsize = Decimal(104) # anyone-can-spend else: vsize = Decimal(168) # P2PK (73 bytes scriptSig + 35 bytes scriptPubKey + 60 bytes other) send_value = int(COIN * (utxo_to_spend['value'] - fee_rate * (vsize / 1000))) assert send_value > 0 tx = CTransaction() tx.vin = [CTxIn(COutPoint(int(utxo_to_spend['txid'], 16), utxo_to_spend['vout']), nSequence=sequence)] tx.vout = [CTxOut(send_value, self._scriptPubKey)] tx.nLockTime = locktime if not self._address: # raw script if self._priv_key is not None: # P2PK, need to sign self.sign_tx(tx) else: # anyone-can-spend tx.vin[0].scriptSig = CScript([OP_NOP] * 43) # pad to identical size else: tx.wit.vtxinwit = [CTxInWitness()] tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE]), bytes([LEAF_VERSION_TAPSCRIPT]) + self._internal_key] tx_hex = tx.serialize().hex() tx_info = from_node.testmempoolaccept([tx_hex])[0] assert_equal(mempool_valid, tx_info['allowed']) if mempool_valid: assert_equal(tx_info['vsize'], vsize) assert_equal(tx_info['fees']['base'], utxo_to_spend['value'] - Decimal(send_value) / COIN) return {'txid': tx_info['txid'], 'wtxid': tx_info['wtxid'], 'hex': tx_hex, 'tx': tx} def sendrawtransaction(self, *, from_node, tx_hex, **kwargs): txid = from_node.sendrawtransaction(hexstring=tx_hex, **kwargs) self.scan_tx(from_node.decoderawtransaction(tx_hex)) return txid def getnewdestination(address_type='bech32'): """Generate a random destination of the specified type and return the corresponding public key, scriptPubKey and address. Supported types are 'legacy', 'p2sh-segwit' and 'bech32'. Can be used when a random destination is needed, but no compiled wallet is available (e.g. as replacement to the getnewaddress/getaddressinfo RPCs).""" key = ECKey() key.generate() pubkey = key.get_pubkey().get_bytes() if address_type == 'legacy': scriptpubkey = key_to_p2pkh_script(pubkey) address = key_to_p2pkh(pubkey) elif address_type == 'p2sh-segwit': scriptpubkey = key_to_p2sh_p2wpkh_script(pubkey) address = key_to_p2sh_p2wpkh(pubkey) elif address_type == 'bech32': scriptpubkey = key_to_p2wpkh_script(pubkey) address = key_to_p2wpkh(pubkey) # TODO: also support bech32m (need to generate x-only-pubkey) else: assert False return pubkey, scriptpubkey, address def address_to_scriptpubkey(address): """Converts a given address to the corresponding output script (scriptPubKey).""" payload, version = base58_to_byte(address) if version == 111: # testnet pubkey hash return keyhash_to_p2pkh_script(payload) elif version == 196: # testnet script hash return scripthash_to_p2sh_script(payload) # TODO: also support other address formats else: assert False def make_chain(node, address, privkeys, parent_txid, parent_value, n=0, parent_locking_script=None, fee=DEFAULT_FEE): """Build a transaction that spends parent_txid.vout[n] and produces one output with amount = parent_value with a fee deducted. Return tuple (CTransaction object, raw hex, nValue, scriptPubKey of the output created). """ inputs = [{"txid": parent_txid, "vout": n}] my_value = parent_value - fee outputs = {address : my_value} rawtx = node.createrawtransaction(inputs, outputs) prevtxs = [{ "txid": parent_txid, "vout": n, "scriptPubKey": parent_locking_script, "amount": parent_value, }] if parent_locking_script else None signedtx = node.signrawtransactionwithkey(hexstring=rawtx, privkeys=privkeys, prevtxs=prevtxs) assert signedtx["complete"] tx = tx_from_hex(signedtx["hex"]) return (tx, signedtx["hex"], my_value, tx.vout[0].scriptPubKey.hex()) def create_child_with_parents(node, address, privkeys, parents_tx, values, locking_scripts, fee=DEFAULT_FEE): """Creates a transaction that spends the first output of each parent in parents_tx.""" num_parents = len(parents_tx) total_value = sum(values) inputs = [{"txid": tx.rehash(), "vout": 0} for tx in parents_tx] outputs = {address : total_value - fee} rawtx_child = node.createrawtransaction(inputs, outputs) prevtxs = [] for i in range(num_parents): prevtxs.append({"txid": parents_tx[i].rehash(), "vout": 0, "scriptPubKey": locking_scripts[i], "amount": values[i]}) signedtx_child = node.signrawtransactionwithkey(hexstring=rawtx_child, privkeys=privkeys, prevtxs=prevtxs) assert signedtx_child["complete"] return signedtx_child["hex"] def create_raw_chain(node, first_coin, address, privkeys, chain_length=25): """Helper function: create a "chain" of chain_length transactions. The nth transaction in the chain is a child of the n-1th transaction and parent of the n+1th transaction. """ parent_locking_script = None txid = first_coin["txid"] chain_hex = [] chain_txns = [] value = first_coin["amount"] for _ in range(chain_length): (tx, txhex, value, parent_locking_script) = make_chain(node, address, privkeys, txid, value, 0, parent_locking_script) txid = tx.rehash() chain_hex.append(txhex) chain_txns.append(tx) return (chain_hex, chain_txns) def bulk_transaction(tx, node, target_weight, privkeys, prevtxs=None): """Pad a transaction with extra outputs until it reaches a target weight (or higher). returns CTransaction object """ tx_heavy = deepcopy(tx) assert_greater_than_or_equal(target_weight, tx_heavy.get_weight()) while tx_heavy.get_weight() < target_weight: random_spk = "6a4d0200" # OP_RETURN OP_PUSH2 512 bytes for _ in range(512*2): random_spk += choice("0123456789ABCDEF") tx_heavy.vout.append(CTxOut(0, bytes.fromhex(random_spk))) # Re-sign the transaction if privkeys: signed = node.signrawtransactionwithkey(tx_heavy.serialize().hex(), privkeys, prevtxs) return tx_from_hex(signed["hex"]) # OP_TRUE tx_heavy.wit.vtxinwit = [CTxInWitness()] tx_heavy.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE])] return tx_heavy