basicswap/basicswap/interface/dcr/dcr.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright (c) 2024 tecnovert
# Copyright (c) 2024-2025 The Basicswap developers
# Distributed under the MIT software license, see the accompanying
# file LICENSE or http://www.opensource.org/licenses/mit-license.php.

import base64
import hashlib
import json
import logging
import random
import traceback

from basicswap.basicswap_util import getVoutByScriptPubKey, TxLockTypes
from basicswap.chainparams import Coins
from basicswap.contrib.test_framework.script import (
    CScriptNum,
)
from basicswap.interface.base import (
    Secp256k1Interface,
)
from basicswap.interface.btc import (
    extractScriptLockScriptValues,
    extractScriptLockRefundScriptValues,
)
from basicswap.util import (
    ensure,
    b2i,
    i2b,
    i2h,
)
from basicswap.util.address import (
    b58decode,
    b58encode,
)
from basicswap.util.crypto import (
    blake256,
    hash160,
    ripemd160,
)
from basicswap.util.script import (
    SerialiseNumCompact,
)
from basicswap.util.extkey import ExtKeyPair
from basicswap.util.integer import encode_varint
from basicswap.interface.dcr.rpc import make_rpc_func, openrpc
from .messages import (
    COutPoint,
    CTransaction,
    CTxIn,
    CTxOut,
    findOutput,
    SigHashType,
    TxSerializeType,
)
from .script import (
    OP_CHECKMULTISIG,
    OP_CHECKSEQUENCEVERIFY,
    OP_CHECKSIG,
    OP_DROP,
    OP_DUP,
    OP_ELSE,
    OP_ENDIF,
    OP_EQUAL,
    OP_EQUALVERIFY,
    OP_HASH160,
    OP_IF,
    push_script_data,
)
from coincurve.keys import (
    PrivateKey,
    PublicKey,
)
from coincurve.ecdsaotves import (
    ecdsaotves_enc_sign,
    ecdsaotves_enc_verify,
    ecdsaotves_dec_sig,
    ecdsaotves_rec_enc_key,
)


SEQUENCE_LOCKTIME_GRANULARITY = 9  # 512 seconds
SEQUENCE_LOCKTIME_TYPE_FLAG = 1 << 22
SEQUENCE_LOCKTIME_MASK = 0x0000F

SigHashSerializePrefix: int = 1
SigHashSerializeWitness: int = 3


def DCRSignatureHash(
    sign_script: bytes, hash_type: SigHashType, tx: CTransaction, idx: int
) -> bytes:
    masked_hash_type = hash_type & SigHashType.SigHashMask
    if masked_hash_type != SigHashType.SigHashAll:
        raise ValueError("todo")

    # Prefix hash
    sign_tx_in_idx: int = idx
    sign_vins = tx.vin
    if hash_type & SigHashType.SigHashAnyOneCanPay != 0:
        sign_vins = [
            tx.vin[idx],
        ]
        sign_tx_in_idx = 0

    hash_buffer = bytearray()
    version: int = tx.version | (SigHashSerializePrefix << 16)
    hash_buffer += version.to_bytes(4, "little")
    hash_buffer += encode_varint(len(sign_vins))

    for txi_n, txi in enumerate(sign_vins):
        hash_buffer += txi.prevout.hash.to_bytes(32, "little")
        hash_buffer += txi.prevout.n.to_bytes(4, "little")
        hash_buffer += txi.prevout.tree.to_bytes(1, "little")

        # In the case of SigHashNone and SigHashSingle, commit to 0 for everything that is not the input being signed instead.
        if (
            masked_hash_type == SigHashType.SigHashNone
            or masked_hash_type == SigHashType.SigHashSingle
        ) and sign_tx_in_idx != txi_n:
            hash_buffer += (0).to_bytes(4, "little")
        else:
            hash_buffer += txi.sequence.to_bytes(4, "little")

    hash_buffer += encode_varint(len(tx.vout))

    for txo_n, txo in enumerate(tx.vout):
        if masked_hash_type == SigHashType.SigHashSingle and idx != txo_n:
            hash_buffer += (-1).to_bytes(8, "little")
            hash_buffer += txo.version.to_bytes(2, "little")
            hash_buffer += encode_varint(0)
            continue
        hash_buffer += txo.value.to_bytes(8, "little")
        hash_buffer += txo.version.to_bytes(2, "little")
        hash_buffer += encode_varint(len(txo.script_pubkey))
        hash_buffer += txo.script_pubkey

    hash_buffer += tx.locktime.to_bytes(4, "little")
    hash_buffer += tx.expiry.to_bytes(4, "little")

    prefix_hash = blake256(hash_buffer)

    # Witness hash
    hash_buffer.clear()

    version: int = tx.version | (SigHashSerializeWitness << 16)
    hash_buffer += version.to_bytes(4, "little")

    hash_buffer += encode_varint(len(sign_vins))
    for txi_n, txi in enumerate(sign_vins):
        if sign_tx_in_idx != txi_n:
            hash_buffer += encode_varint(0)
            continue
        hash_buffer += encode_varint(len(sign_script))
        hash_buffer += sign_script

    witness_hash = blake256(hash_buffer)

    hash_buffer.clear()
    hash_buffer += hash_type.to_bytes(4, "little")
    hash_buffer += prefix_hash
    hash_buffer += witness_hash

    return blake256(hash_buffer)


def extract_sig_and_pk(sig_script: bytes) -> (bytes, bytes):
    sig = None
    pk = None
    o: int = 0
    num_bytes = sig_script[o]
    o += 1
    sig = sig_script[o : o + num_bytes]
    o += num_bytes
    num_bytes = sig_script[o]
    o += 1
    pk = sig_script[o : o + num_bytes]
    return sig, pk


class DCRInterface(Secp256k1Interface):

    @staticmethod
    def coin_type():
        return Coins.DCR

    @staticmethod
    def exp() -> int:
        return 8

    @staticmethod
    def COIN() -> int:
        return 100000000

    @staticmethod
    def nbk() -> int:
        return 32

    @staticmethod
    def nbK() -> int:  # No. of bytes requires to encode a public key
        return 33

    @staticmethod
    def txVersion() -> int:
        return 2

    @staticmethod
    def txoType():
        return CTxOut

    @staticmethod
    def est_lock_tx_vsize() -> int:
        return 224

    @staticmethod
    def xmr_swap_a_lock_spend_tx_vsize() -> int:
        return 327

    @staticmethod
    def xmr_swap_b_lock_spend_tx_vsize() -> int:
        return 224

    @staticmethod
    def getExpectedSequence(lockType: int, lockVal: int) -> int:
        ensure(lockVal >= 1, "Bad lockVal")
        if lockType == TxLockTypes.SEQUENCE_LOCK_BLOCKS:
            return lockVal
        if lockType == TxLockTypes.SEQUENCE_LOCK_TIME:
            secondsLocked = lockVal
            # Ensure the locked time is never less than lockVal
            if secondsLocked % (1 << SEQUENCE_LOCKTIME_GRANULARITY) != 0:
                secondsLocked += 1 << SEQUENCE_LOCKTIME_GRANULARITY
            secondsLocked >>= SEQUENCE_LOCKTIME_GRANULARITY
            return secondsLocked | SEQUENCE_LOCKTIME_TYPE_FLAG
        raise ValueError("Unknown lock type")

    @staticmethod
    def decodeSequence(lock_value: int) -> int:
        # Return the raw value
        if lock_value & SEQUENCE_LOCKTIME_TYPE_FLAG:
            return (
                lock_value & SEQUENCE_LOCKTIME_MASK
            ) << SEQUENCE_LOCKTIME_GRANULARITY
        return lock_value & SEQUENCE_LOCKTIME_MASK

    @staticmethod
    def watch_blocks_for_scripts() -> bool:
        return True

    @staticmethod
    def depth_spendable() -> int:
        return 0

    def __init__(self, coin_settings, network, swap_client=None):
        super().__init__(network)
        self._rpc_host = coin_settings.get("rpchost", "127.0.0.1")
        self._rpcport = coin_settings["rpcport"]
        self._rpcauth = coin_settings["rpcauth"]
        self._sc = swap_client
        self._log = self._sc.log if self._sc and self._sc.log else logging
        self.rpc = make_rpc_func(self._rpcport, self._rpcauth, host=self._rpc_host)
        if "walletrpcport" in coin_settings:
            self._walletrpcport = coin_settings["walletrpcport"]
            self.rpc_wallet = make_rpc_func(
                self._walletrpcport, self._rpcauth, host=self._rpc_host
            )
        else:
            self._walletrpcport = None
            self.rpc_wallet = None
        self.blocks_confirmed = coin_settings["blocks_confirmed"]
        self.setConfTarget(coin_settings["conf_target"])

        self._use_segwit = True  # Decred is natively segwit
        self._connection_type = coin_settings["connection_type"]
        self._altruistic = coin_settings.get("altruistic", True)

        if "wallet_name" in coin_settings:
            raise ValueError(f"Invalid setting for {self.coin_name()}: wallet_name")

    def open_rpc(self):
        return openrpc(self._rpcport, self._rpcauth, host=self._rpc_host)

    def json_request(self, rpc_conn, method, params):
        try:
            v = rpc_conn.json_request(method, params)
            r = json.loads(v.decode("utf-8"))
        except Exception as ex:
            traceback.print_exc()
            raise ValueError("RPC Server Error " + str(ex))
        if "error" in r and r["error"] is not None:
            raise ValueError("RPC error " + str(r["error"]))
        return r["result"]

    def close_rpc(self, rpc_conn):
        rpc_conn.close()

    def use_tx_vsize(self) -> bool:
        return False

    def pkh(self, pubkey: bytes) -> bytes:
        return ripemd160(blake256(pubkey))

    def pkh_to_address(self, pkh: bytes) -> str:
        prefix = self.chainparams_network()["pubkey_address"]

        data = prefix.to_bytes(2, "big") + pkh
        checksum = blake256(blake256(data))
        return b58encode(data + checksum[0:4])

    def sh_to_address(self, sh: bytes) -> str:
        assert len(sh) == 20
        prefix = self.chainparams_network()["script_address"]
        data = prefix.to_bytes(2, "big") + sh
        checksum = blake256(blake256(data))
        return b58encode(data + checksum[0:4])

    def decode_address(self, address: str) -> bytes:
        # Different from decodeAddress returns more prefix bytes
        addr_data = b58decode(address)
        if addr_data is None:
            return None
        prefixed_data = addr_data[:-4]
        checksum = addr_data[-4:]
        if blake256(blake256(prefixed_data))[:4] != checksum:
            raise ValueError("Checksum mismatch")
        return prefixed_data

    def decodeAddress(self, address: str) -> bytes:
        return self.decode_address(address)[2:]

    def testDaemonRPC(self, with_wallet=True) -> None:
        if with_wallet:
            self.rpc_wallet("walletislocked")
        else:
            self.rpc("getblockchaininfo")

    def getChainHeight(self) -> int:
        return self.rpc("getblockcount")

    def initialiseWallet(self, key: bytes, restore_time: int = -1) -> None:
        # Load with --create
        pass

    def isWalletEncrypted(self) -> bool:
        return True

    def isWalletLocked(self) -> bool:
        walletislocked = self.rpc_wallet("walletislocked")
        return walletislocked

    def isWalletEncryptedLocked(self) -> (bool, bool):
        walletislocked = self.rpc_wallet("walletislocked")
        return True, walletislocked

    def changeWalletPassword(
        self, old_password: str, new_password: str, check_seed_if_encrypt: bool = True
    ):
        self._log.info("changeWalletPassword - {}".format(self.ticker()))
        if old_password == "":
            # Read initial pwd from settings
            settings = self._sc.getChainClientSettings(self.coin_type())
            old_password = settings["wallet_pwd"]
        self.rpc_wallet("walletpassphrasechange", [old_password, new_password])

        # Lock wallet to match other coins
        self.rpc_wallet("walletlock")

        # Clear initial password
        self._sc.editSettings(self.coin_name().lower(), {"wallet_pwd": ""})

    def unlockWallet(self, password: str, check_seed: bool = True) -> None:
        if password == "":
            return
        self._log.info("unlockWallet - {}".format(self.ticker()))

        # Max timeout value, ~3 years
        self.rpc_wallet("walletpassphrase", [password, 100000000])
        if check_seed:
            self._sc.checkWalletSeed(self.coin_type())

    def lockWallet(self):
        self._log.info("lockWallet - {}".format(self.ticker()))
        self.rpc_wallet("walletlock")

    def getWalletSeedID(self):
        masterpubkey = self.rpc_wallet("getmasterpubkey")
        masterpubkey_data = self.decode_address(masterpubkey)[4:]
        return hash160(masterpubkey_data).hex()

    def checkExpectedSeed(self, expect_seedid) -> bool:
        self._expect_seedid_hex = expect_seedid
        rv: bool = expect_seedid == self.getWalletSeedID()
        self._have_checked_seed = True
        return rv

    def getDaemonVersion(self):
        return self.rpc("getnetworkinfo")["version"]

    def getBlockchainInfo(self):
        bci = self.rpc("getblockchaininfo")

        # Adjust verificationprogress to consider blocks wallet has synced
        wallet_blocks = self.rpc_wallet("getinfo")["blocks"]
        synced_ind = bci["verificationprogress"]
        wallet_synced_ind = wallet_blocks / bci["headers"]
        if wallet_synced_ind < synced_ind:
            bci["verificationprogress"] = wallet_synced_ind

        return bci

    def getWalletInfo(self):
        rv = {}
        rv = self.rpc_wallet("getinfo")
        wi = self.rpc_wallet("walletinfo")
        balances = self.rpc_wallet("getbalance")

        default_account_bal = balances["balances"][0]  # 0 always default?
        rv["balance"] = default_account_bal["spendable"]
        rv["unconfirmed_balance"] = default_account_bal["unconfirmed"]
        rv["immature_balance"] = (
            default_account_bal["immaturecoinbaserewards"]
            + default_account_bal["immaturestakegeneration"]
        )
        rv["encrypted"] = True
        rv["locked"] = True if wi["unlocked"] is False else False

        return rv

    def getSpendableBalance(self) -> int:
        balances = self.rpc_wallet("getbalance")
        default_account_bal = balances["balances"][0]  # 0 always default?
        return self.make_int(default_account_bal["spendable"])

    def getSeedHash(self, seed: bytes, coin_type_id=None) -> bytes:
        # m / purpose' / coin_type' / account' / change / address_index
        # m/44'/coin_type'/0'/0/0

        ek = ExtKeyPair(self.coin_type())
        ek.set_seed(seed)

        coin_type = (
            self.chainparams_network()["bip44"]
            if coin_type_id is None
            else coin_type_id
        )
        ek_purpose = ek.derive(44 | (1 << 31))
        ek_coin = ek_purpose.derive(coin_type | (1 << 31))
        ek_account = ek_coin.derive(0 | (1 << 31))

        return hash160(ek_account.encode_p())

    def decodeKey(self, encoded_key: str) -> (int, bytes):
        key = b58decode(encoded_key)
        checksum = key[-4:]
        key = key[:-4]

        if blake256(key)[:4] != checksum:
            raise ValueError("Checksum mismatch")
        return key[2], key[3:]

    def encodeKey(self, key_bytes: bytes) -> str:
        wif_prefix = self.chainparams_network()["key_prefix"]
        key_type = 0  # STEcdsaSecp256k1
        b = wif_prefix.to_bytes(2, "big") + key_type.to_bytes(1, "big") + key_bytes
        b += blake256(b)[:4]
        return b58encode(b)

    def loadTx(self, tx_bytes: bytes) -> CTransaction:
        tx = CTransaction()
        tx.deserialize(tx_bytes)
        return tx

    def signTx(
        self,
        key_bytes: bytes,
        tx_bytes: bytes,
        input_n: int,
        prevout_script: bytes,
        prevout_value: int,
    ) -> bytes:
        tx = self.loadTx(tx_bytes)
        sig_hash = DCRSignatureHash(prevout_script, SigHashType.SigHashAll, tx, input_n)

        eck = PrivateKey(key_bytes)
        return eck.sign(sig_hash, hasher=None) + bytes((SigHashType.SigHashAll,))

    def setTxSignatureScript(
        self, tx_bytes: bytes, script: bytes, txi: int = 0
    ) -> bytes:
        tx = self.loadTx(tx_bytes)

        tx.vin[txi].signature_script = script
        return tx.serialize()

    def setTxSignature(self, tx_bytes: bytes, stack, txi: int = 0) -> bytes:
        tx = self.loadTx(tx_bytes)

        script_data = bytearray()
        for data in stack:
            push_script_data(script_data, data)

        tx.vin[txi].signature_script = script_data

        return tx.serialize()

    def stripTxSignature(self, tx_bytes) -> bytes:
        tx = self.loadTx(tx_bytes)
        return tx.serialize(TxSerializeType.NoWitness)

    def getTxSignature(self, tx_hex: str, prevout_data, key_wif: str) -> str:
        sig_type, key = self.decodeKey(key_wif)
        redeem_script = bytes.fromhex(prevout_data["redeemScript"])
        sig = self.signTx(
            key,
            bytes.fromhex(tx_hex),
            0,
            redeem_script,
            self.make_int(prevout_data["amount"]),
        )

        return sig.hex()

    def verifyTxSig(
        self,
        tx_bytes: bytes,
        sig: bytes,
        K: bytes,
        input_n: int,
        prevout_script: bytes,
        prevout_value: int,
    ) -> bool:
        tx = self.loadTx(tx_bytes)

        sig_hash = DCRSignatureHash(prevout_script, SigHashType.SigHashAll, tx, input_n)
        pubkey = PublicKey(K)
        return pubkey.verify(sig[:-1], sig_hash, hasher=None)  # Pop the hashtype byte

    def getTxid(self, tx) -> bytes:
        if isinstance(tx, str):
            tx = bytes.fromhex(tx)
        if isinstance(tx, bytes):
            tx = self.loadTx(tx)
        return tx.TxHash()

    def getScriptDest(self, script: bytes) -> bytes:
        # P2SH
        script_hash = self.pkh(script)
        assert len(script_hash) == 20

        return (
            bytes((OP_HASH160,))
            + bytes((len(script_hash),))
            + script_hash
            + bytes((OP_EQUAL,))
        )

    def encodeScriptDest(self, script_dest: bytes) -> str:
        script_hash = script_dest[2:-1]  # Extract hash from script
        return self.sh_to_address(script_hash)

    def getPubkeyHashDest(self, pkh: bytes) -> bytes:
        # P2PKH
        assert len(pkh) == 20
        return (
            bytes((OP_DUP,))
            + bytes((OP_HASH160,))
            + bytes((len(pkh),))
            + pkh
            + bytes((OP_EQUALVERIFY,))
            + bytes((OP_CHECKSIG,))
        )

    def getPkDest(self, K: bytes) -> bytearray:
        return self.getPubkeyHashDest(self.pkh(K))

    def getSCLockScriptAddress(self, lock_script: bytes) -> str:
        lock_tx_dest = self.getScriptDest(lock_script)
        return self.encodeScriptDest(lock_tx_dest)

    def get_fee_rate(self, conf_target: int = 2) -> (float, str):
        chain_client_settings = self._sc.getChainClientSettings(
            self.coin_type()
        )  # basicswap.json
        override_feerate = chain_client_settings.get("override_feerate", None)
        if override_feerate:
            self._log.debug(
                "Fee rate override used for %s: %f", self.coin_name(), override_feerate
            )
            return override_feerate, "override_feerate"

        min_relay_fee = chain_client_settings.get("min_relay_fee", None)

        def try_get_fee_rate(self, conf_target):
            # TODO: How to estimate required fee?
            try:
                fee_rate: float = self.rpc_wallet("walletinfo")["txfee"]
                assert fee_rate > 0.0, "Non positive feerate"
                return fee_rate, "paytxfee"
            except Exception:
                fee_rate: float = self.rpc("getnetworkinfo")["relayfee"]
                return fee_rate, "relayfee"

        fee_rate, rate_src = try_get_fee_rate(self, conf_target)
        if min_relay_fee and min_relay_fee > fee_rate:
            self._log.warning(
                "Feerate {} ({}) is below min relay fee {} for {}".format(
                    self.format_amount(fee_rate, True, 1),
                    rate_src,
                    self.format_amount(min_relay_fee, True, 1),
                    self.coin_name(),
                )
            )
            return min_relay_fee, "min_relay_fee"
        return fee_rate, rate_src

    def getNewAddress(
        self, use_segwit: bool = True, label: str = "swap_receive"
    ) -> str:
        return self.rpc_wallet("getnewaddress")

    def getWalletTransaction(self, txid: bytes):
        try:
            return bytes.fromhex(self.rpc_wallet("gettransaction", [txid.hex()])["hex"])
        except Exception as e:  # noqa: F841
            # TODO: filter errors
            return None

    def getProofOfFunds(self, amount_for, extra_commit_bytes):
        # TODO: Lock unspent and use same output/s to fund bid

        unspents_by_addr = dict()
        unspents = self.rpc_wallet("listunspent")
        if unspents is None:
            unspents = []
        for u in unspents:
            if u["spendable"] is not True:
                continue
            if u["address"] not in unspents_by_addr:
                unspents_by_addr[u["address"]] = {"total": 0, "utxos": []}
            utxo_amount: int = self.make_int(u["amount"], r=1)
            unspents_by_addr[u["address"]]["total"] += utxo_amount
            unspents_by_addr[u["address"]]["utxos"].append(
                (utxo_amount, u["txid"], u["vout"], u["tree"])
            )

        max_utxos: int = 4

        viable_addrs = []
        for addr, data in unspents_by_addr.items():
            if data["total"] >= amount_for:
                # Sort from largest to smallest amount
                sorted_utxos = sorted(data["utxos"], key=lambda x: x[0])

                # Max outputs required to reach amount_for
                utxos_req: int = 0
                sum_value: int = 0
                for utxo in sorted_utxos:
                    sum_value += utxo[0]
                    utxos_req += 1
                    if sum_value >= amount_for:
                        break

                if utxos_req <= max_utxos:
                    viable_addrs.append(addr)
                    continue

        ensure(
            len(viable_addrs) > 0, "Could not find address with enough funds for proof"
        )

        sign_for_addr: str = random.choice(viable_addrs)
        self._log.debug("sign_for_addr %s", sign_for_addr)

        prove_utxos = []
        sorted_utxos = sorted(
            unspents_by_addr[sign_for_addr]["utxos"], key=lambda x: x[0]
        )

        hasher = hashlib.sha256()
        sum_value: int = 0
        for utxo in sorted_utxos:
            sum_value += utxo[0]
            outpoint = (bytes.fromhex(utxo[1]), utxo[2], utxo[3])
            prove_utxos.append(outpoint)
            hasher.update(outpoint[0])
            hasher.update(outpoint[1].to_bytes(2, "big"))
            hasher.update(outpoint[2].to_bytes(1, "big"))
            if sum_value >= amount_for:
                break
        utxos_hash = hasher.digest()

        signature = self.rpc_wallet(
            "signmessage",
            [
                sign_for_addr,
                sign_for_addr
                + "_swap_proof_"
                + utxos_hash.hex()
                + extra_commit_bytes.hex(),
            ],
        )

        return (sign_for_addr, signature, prove_utxos)

    def withdrawCoin(self, value: float, addr_to: str, subfee: bool = False) -> str:
        if subfee:
            raise ValueError("TODO")
        params = [addr_to, float(value)]
        return self.rpc_wallet("sendtoaddress", params)

    def isAddressMine(self, address: str, or_watch_only: bool = False) -> bool:
        addr_info = self.rpc_wallet("validateaddress", [address])
        return addr_info.get("ismine", False)

    def encodeProofUtxos(self, proof_utxos):
        packed_utxos = bytes()
        for utxo in proof_utxos:
            packed_utxos += (
                utxo[0] + utxo[1].to_bytes(2, "big") + utxo[2].to_bytes(1, "big")
            )
        return packed_utxos

    def decodeProofUtxos(self, msg_utxos):
        proof_utxos = []
        if len(msg_utxos) > 0:
            num_utxos = len(msg_utxos) // 34
            p: int = 0
            for i in range(num_utxos):
                proof_utxos.append(
                    (
                        msg_utxos[p : p + 32],
                        int.from_bytes(msg_utxos[p + 32 : p + 34], "big"),
                        msg_utxos[p + 34],
                    )
                )
                p += 35
        return proof_utxos

    def verifyProofOfFunds(
        self, address: str, signature: bytes, utxos, extra_commit_bytes: bytes
    ):
        hasher = hashlib.sha256()
        sum_value: int = 0
        for outpoint in utxos:
            hasher.update(outpoint[0])
            hasher.update(outpoint[1].to_bytes(2, "big"))
            hasher.update(outpoint[2].to_bytes(1, "big"))
        utxos_hash = hasher.digest()

        passed = self.verifyMessage(
            address,
            address + "_swap_proof_" + utxos_hash.hex() + extra_commit_bytes.hex(),
            signature,
        )
        ensure(passed is True, "Proof of funds signature invalid")

        sum_value: int = 0
        for outpoint in utxos:
            txout = self.rpc("gettxout", [outpoint[0].hex(), outpoint[1], outpoint[2]])
            sum_value += self.make_int(txout["value"])

        return sum_value

    def signCompact(self, k, message):
        message_hash = blake256(bytes(message, "utf-8"))

        privkey = PrivateKey(k)
        return privkey.sign_recoverable(message_hash, hasher=None)[:64]

    def signRecoverable(self, k, message: str) -> bytes:
        message_hash = blake256(bytes(message, "utf-8"))

        privkey = PrivateKey(k)
        return privkey.sign_recoverable(message_hash, hasher=None)

    def verifyCompactSig(self, K, message: str, sig) -> None:
        message_hash = blake256(bytes(message, "utf-8"))
        pubkey = PublicKey(K)
        rv = pubkey.verify_compact(sig, message_hash, hasher=None)
        assert rv is True

    def verifySigAndRecover(self, sig, message: str) -> bytes:
        message_hash = blake256(bytes(message, "utf-8"))
        pubkey = PublicKey.from_signature_and_message(sig, message_hash, hasher=None)
        return pubkey.format()

    def verifyMessage(
        self, address: str, message: str, signature: str, message_magic: str = None
    ) -> bool:
        if message_magic is None:
            message_magic = self.chainparams()["message_magic"]

        message_bytes = (
            SerialiseNumCompact(len(message_magic))
            + bytes(message_magic, "utf-8")
            + SerialiseNumCompact(len(message))
            + bytes(message, "utf-8")
        )
        message_hash = blake256(message_bytes)
        signature_bytes = base64.b64decode(signature)
        rec_id = (signature_bytes[0] - 27) & 3
        signature_bytes = signature_bytes[1:] + bytes((rec_id,))
        try:
            pubkey = PublicKey.from_signature_and_message(
                signature_bytes, message_hash, hasher=None
            )
        except Exception as e:
            self._log.info("verifyMessage failed: " + str(e))
            return False

        address_hash = self.decode_address(address)[2:]
        pubkey_hash = ripemd160(blake256(pubkey.format()))

        return True if address_hash == pubkey_hash else False

    def signTxWithWallet(self, tx) -> bytes:
        return bytes.fromhex(self.rpc_wallet("signrawtransaction", [tx.hex()])["hex"])

    def signTxWithKey(self, tx: bytes, key: bytes) -> bytes:
        key_wif = self.encodeKey(key)
        rv = self.rpc_wallet(
            "signrawtransaction",
            [
                tx.hex(),
                [],
                [
                    key_wif,
                ],
            ],
        )
        return bytes.fromhex(rv["hex"])

    def createRawFundedTransaction(
        self,
        addr_to: str,
        amount: int,
        sub_fee: bool = False,
        lock_unspents: bool = True,
    ) -> str:

        # amount can't be a string, else: Failed to parse request: parameter #2 'amounts' must be type float64 (got string)
        float_amount = float(self.format_amount(amount))
        txn = self.rpc("createrawtransaction", [[], {addr_to: float_amount}])
        fee_rate, fee_src = self.get_fee_rate(self._conf_target)
        self._log.debug(
            f"Fee rate: {fee_rate}, source: {fee_src}, block target: {self._conf_target}"
        )
        options = {
            "lockUnspents": lock_unspents,
            "feeRate": fee_rate,
        }
        if sub_fee:
            options["subtractFeeFromOutputs"] = [
                0,
            ]
        return self.rpc_wallet("fundrawtransaction", [txn, "default", options])["hex"]

    def createRawSignedTransaction(self, addr_to, amount) -> str:
        txn_funded = self.createRawFundedTransaction(addr_to, amount)
        return self.rpc_wallet("signrawtransaction", [txn_funded])["hex"]

    def getLockTxHeight(
        self,
        txid,
        dest_address,
        bid_amount,
        rescan_from,
        find_index: bool = False,
        vout: int = -1,
    ):
        if txid is None:
            self._log.debug("TODO: getLockTxHeight")
            return None

        found_vout = None
        # Search for txo at vout 0 and 1 if vout is not known
        if vout is None:
            test_range = range(2)
        else:
            test_range = (vout,)
        for try_vout in test_range:
            try:
                txout = self.rpc("gettxout", [txid.hex(), try_vout, 0, True])
                addresses = txout["scriptPubKey"]["addresses"]
                if len(addresses) != 1 or addresses[0] != dest_address:
                    continue
                if self.make_int(txout["value"]) != bid_amount:
                    self._log.warning(
                        "getLockTxHeight found txout {} with incorrect amount {}".format(
                            txid.hex(), txout["value"]
                        )
                    )
                    continue
                found_vout = try_vout
                break
            except Exception as e:  # noqa: F841
                # self._log.warning('gettxout {}'.format(e))
                return None

        if found_vout is None:
            return None

        block_height: int = 0
        confirmations: int = (
            0 if "confirmations" not in txout else txout["confirmations"]
        )

        # TODO: Better way?
        if confirmations > 0:
            block_height = self.getChainHeight() - confirmations

        rv = {
            "txid": txid.hex(),
            "depth": confirmations,
            "index": found_vout,
            "height": block_height,
        }

        return rv

    def find_prevout_info(self, txn_hex: str, txn_script: bytes):
        txjs = self.rpc("decoderawtransaction", [txn_hex])
        n = getVoutByScriptPubKey(txjs, self.getScriptDest(txn_script).hex())

        txo = txjs["vout"][n]
        return {
            "txid": txjs["txid"],
            "vout": n,
            "scriptPubKey": txo["scriptPubKey"]["hex"],
            "redeemScript": txn_script.hex(),
            "amount": txo["value"],
        }

    def getHTLCSpendTxVSize(self, redeem: bool = True) -> int:
        tx_vsize = (
            5  # Add a few bytes, sequence in script takes variable amount of bytes
        )
        tx_vsize += 348 if redeem else 316
        return tx_vsize

    def createRedeemTxn(
        self, prevout, output_addr: str, output_value: int, txn_script: bytes = None
    ) -> str:
        tx = CTransaction()
        tx.version = self.txVersion()
        prev_txid = b2i(bytes.fromhex(prevout["txid"]))
        tx.vin.append(CTxIn(COutPoint(prev_txid, prevout["vout"], 0)))
        pkh = self.decode_address(output_addr)[2:]
        script = self.getPubkeyHashDest(pkh)
        tx.vout.append(self.txoType()(output_value, script))
        return tx.serialize().hex()

    def createRefundTxn(
        self,
        prevout,
        output_addr: str,
        output_value: int,
        locktime: int,
        sequence: int,
        txn_script: bytes = None,
    ) -> str:
        tx = CTransaction()
        tx.version = self.txVersion()
        tx.locktime = locktime
        prev_txid = b2i(bytes.fromhex(prevout["txid"]))
        tx.vin.append(
            CTxIn(
                COutPoint(prev_txid, prevout["vout"], 0),
                sequence=sequence,
            )
        )
        pkh = self.decode_address(output_addr)[2:]
        script = self.getPubkeyHashDest(pkh)
        tx.vout.append(self.txoType()(output_value, script))
        return tx.serialize().hex()

    def verifyRawTransaction(self, tx_hex: str, prevouts):
        inputs_valid: bool = True
        validscripts: int = 0

        tx_bytes = bytes.fromhex(tx_hex)
        tx = self.loadTx(bytes.fromhex(tx_hex))

        for i, txi in enumerate(tx.vin):
            prevout_data = prevouts[i]
            redeem_script = bytes.fromhex(prevout_data["redeemScript"])
            prevout_value = self.make_int(prevout_data["amount"])
            sig, pk = extract_sig_and_pk(txi.signature_script)

            if not sig or not pk:
                self._log.warning(
                    f"verifyRawTransaction failed to extract signature for input {i}"
                )
                continue

            if self.verifyTxSig(tx_bytes, sig, pk, i, redeem_script, prevout_value):
                validscripts += 1

        # TODO: validate inputs
        inputs_valid = True

        return {
            "inputs_valid": inputs_valid,
            "validscripts": validscripts,
        }

    def getBlockHeaderFromHeight(self, height):
        block_hash = self.rpc("getblockhash", [height])
        return self.rpc("getblockheader", [block_hash])

    def getBlockHeaderAt(self, time: int, block_after=False):
        blockchaininfo = self.rpc("getblockchaininfo")
        last_block_header = self.rpc(
            "getblockheader", [blockchaininfo["bestblockhash"]]
        )

        max_tries = 15000
        for i in range(max_tries):
            prev_block_header = self.rpc(
                "getblockheader", [last_block_header["previousblockhash"]]
            )
            if prev_block_header["time"] <= time:
                return last_block_header if block_after else prev_block_header

            last_block_header = prev_block_header
        raise ValueError(f"Block header not found at time: {time}")

    def getMempoolTx(self, txid):
        raise ValueError("TODO")

    def getBlockWithTxns(self, block_hash: str):
        block = self.rpc("getblock", [block_hash, True, True])

        return {
            "hash": block["hash"],
            "previousblockhash": block["previousblockhash"],
            "tx": block["rawtx"],
            "confirmations": block["confirmations"],
            "height": block["height"],
            "time": block["time"],
            "version": block["version"],
            "merkleroot": block["merkleroot"],
        }

    def publishTx(self, tx: bytes):
        return self.rpc("sendrawtransaction", [tx.hex()])

    def describeTx(self, tx_hex: str):
        return self.rpc("decoderawtransaction", [tx_hex])

    def fundTx(self, tx: bytes, feerate) -> bytes:
        feerate_str = float(self.format_amount(feerate))
        # TODO: unlock unspents if bid cancelled
        options = {
            "feeRate": feerate_str,
        }
        rv = self.rpc_wallet("fundrawtransaction", [tx.hex(), "default", options])
        tx_bytes = bytes.fromhex(rv["hex"])

        tx_obj = self.loadTx(tx_bytes)
        for txi in tx_obj.vin:
            utxos = [
                {
                    "amount": float(self.format_amount(txi.value_in)),
                    "txid": i2h(txi.prevout.hash),
                    "vout": txi.prevout.n,
                    "tree": txi.prevout.tree,
                }
            ]
            rv = self.rpc_wallet("lockunspent", [False, utxos])

        return tx_bytes

    def createSCLockTx(
        self, value: int, script: bytearray, vkbv: bytes = None
    ) -> bytes:
        tx = CTransaction()
        tx.version = self.txVersion()
        tx.vout.append(self.txoType()(value, self.getScriptDest(script)))
        return tx.serialize()

    def fundSCLockTx(self, tx_bytes, feerate, vkbv=None):
        return self.fundTx(tx_bytes, feerate)

    def genScriptLockRefundTxScript(self, Kal, Kaf, csv_val) -> bytes:

        Kal_enc = Kal if len(Kal) == 33 else self.encodePubkey(Kal)
        Kaf_enc = Kaf if len(Kaf) == 33 else self.encodePubkey(Kaf)

        script = bytearray()
        script += bytes((OP_IF,))
        push_script_data(script, bytes((2,)))
        push_script_data(script, Kal_enc)
        push_script_data(script, Kaf_enc)
        push_script_data(script, bytes((2,)))
        script += bytes((OP_CHECKMULTISIG,))
        script += bytes((OP_ELSE,))
        script += CScriptNum.encode(CScriptNum(csv_val))
        script += bytes((OP_CHECKSEQUENCEVERIFY,))
        script += bytes((OP_DROP,))
        push_script_data(script, Kaf_enc)
        script += bytes((OP_CHECKSIG,))
        script += bytes((OP_ENDIF,))

        return script

    def createSCLockSpendTx(
        self, tx_lock_bytes, script_lock, pkh_dest, tx_fee_rate, vkbv=None, fee_info={}
    ):
        tx_lock = self.loadTx(tx_lock_bytes)
        output_script = self.getScriptDest(script_lock)
        locked_n = findOutput(tx_lock, output_script)
        ensure(locked_n is not None, "Output not found in tx")
        locked_coin = tx_lock.vout[locked_n].value

        tx_lock_id_int = b2i(tx_lock.TxHash())

        tx = CTransaction()
        tx.version = self.txVersion()
        tx.vin.append(CTxIn(COutPoint(tx_lock_id_int, locked_n, 0)))
        tx.vout.append(self.txoType()(locked_coin, self.getPubkeyHashDest(pkh_dest)))

        dummy_witness_stack = self.getScriptLockTxDummyWitness(script_lock)
        size = len(self.setTxSignature(tx.serialize(), dummy_witness_stack))
        pay_fee = round(tx_fee_rate * size / 1000)
        tx.vout[0].value = locked_coin - pay_fee

        fee_info["fee_paid"] = pay_fee
        fee_info["rate_used"] = tx_fee_rate
        fee_info["size"] = size

        self._log.info(
            "createSCLockSpendTx {}{}.".format(
                self._log.id(tx.TxHash()),
                (
                    ""
                    if self._log.safe_logs
                    else f":\n    fee_rate, size, fee: {tx_fee_rate}, {size}, {pay_fee}"
                ),
            )
        )

        return tx.serialize(TxSerializeType.NoWitness)

    def createSCLockRefundTx(
        self,
        tx_lock_bytes,
        script_lock,
        Kal,
        Kaf,
        lock1_value,
        csv_val,
        tx_fee_rate,
        vkbv=None,
    ):
        tx_lock = CTransaction()
        tx_lock = self.loadTx(tx_lock_bytes)

        output_script = self.getScriptDest(script_lock)
        locked_n = findOutput(tx_lock, output_script)
        ensure(locked_n is not None, "Output not found in tx")
        locked_coin = tx_lock.vout[locked_n].value

        tx_lock_id_int = b2i(tx_lock.TxHash())

        refund_script = self.genScriptLockRefundTxScript(Kal, Kaf, csv_val)
        tx = CTransaction()
        tx.version = self.txVersion()
        tx.vin.append(
            CTxIn(COutPoint(tx_lock_id_int, locked_n, 0), sequence=lock1_value)
        )
        tx.vout.append(self.txoType()(locked_coin, self.getScriptDest(refund_script)))

        dummy_witness_stack = self.getScriptLockTxDummyWitness(script_lock)
        size = len(self.setTxSignature(tx.serialize(), dummy_witness_stack))
        pay_fee = round(tx_fee_rate * size / 1000)
        tx.vout[0].value = locked_coin - pay_fee

        self._log.info(
            "createSCLockRefundTx {}{}.".format(
                self._log.id(tx.TxHash()),
                (
                    ""
                    if self._log.safe_logs
                    else f":\n    fee_rate, size, fee: {tx_fee_rate}, {size}, {pay_fee}"
                ),
            )
        )

        return tx.serialize(TxSerializeType.NoWitness), refund_script, tx.vout[0].value

    def createSCLockRefundSpendTx(
        self,
        tx_lock_refund_bytes,
        script_lock_refund,
        pkh_refund_to,
        tx_fee_rate,
        vkbv=None,
    ):
        # Returns the coinA locked coin to the leader
        # The follower will sign the multisig path with a signature encumbered by the leader's coinB spend pubkey
        # If the leader publishes the decrypted signature the leader's coinB spend privatekey will be revealed to the follower

        tx_lock_refund = self.loadTx(tx_lock_refund_bytes)

        output_script = self.getScriptDest(script_lock_refund)
        locked_n = findOutput(tx_lock_refund, output_script)
        ensure(locked_n is not None, "Output not found in tx")
        locked_coin = tx_lock_refund.vout[locked_n].value

        tx_lock_refund_hash_int = b2i(tx_lock_refund.TxHash())

        tx = CTransaction()
        tx.version = self.txVersion()
        tx.vin.append(
            CTxIn(COutPoint(tx_lock_refund_hash_int, locked_n, 0), sequence=0)
        )

        tx.vout.append(
            self.txoType()(locked_coin, self.getPubkeyHashDest(pkh_refund_to))
        )

        dummy_witness_stack = self.getScriptLockRefundSpendTxDummyWitness(
            script_lock_refund
        )
        size = len(self.setTxSignature(tx.serialize(), dummy_witness_stack))
        pay_fee = round(tx_fee_rate * size / 1000)
        tx.vout[0].value = locked_coin - pay_fee

        self._log.info(
            "createSCLockRefundSpendTx {}{}.".format(
                self._log.id(tx.TxHash()),
                (
                    ""
                    if self._log.safe_logs
                    else f":\n    fee_rate, size, fee: {tx_fee_rate}, {size}, {pay_fee}"
                ),
            )
        )

        return tx.serialize(TxSerializeType.NoWitness)

    def verifySCLockTx(
        self,
        tx_bytes,
        script_out,
        swap_value,
        Kal,
        Kaf,
        feerate,
        check_lock_tx_inputs,
        vkbv=None,
    ):
        # Verify:
        #

        # Not necessary to check the lock txn is mineable, as protocol will wait for it to confirm
        # However by checking early we can avoid wasting time processing unmineable txns
        # Check fee is reasonable

        tx = self.loadTx(tx_bytes)
        txid = self.getTxid(tx)
        self._log.info("Verifying lock tx: {}.".format(self._log.id(txid)))

        ensure(tx.version == self.txVersion(), "Bad version")
        ensure(tx.locktime == 0, "Bad locktime")
        ensure(tx.expiry == 0, "Bad expiry")

        script_pk = self.getScriptDest(script_out)
        locked_n = findOutput(tx, script_pk)
        ensure(locked_n is not None, "Lock output not found in tx")
        locked_coin = tx.vout[locked_n].value

        # Check value
        ensure(locked_coin == swap_value, "Bad locked value")

        # Check script
        A, B = extractScriptLockScriptValues(script_out)
        ensure(A == Kal, "Bad script pubkey")
        ensure(B == Kaf, "Bad script pubkey")

        if check_lock_tx_inputs:
            # TODO: Check that inputs are unspent
            # Verify fee rate
            inputs_value = 0
            # add_bytes = 0
            add_witness_bytes = 0
            for pi in tx.vin:
                ptx = self.rpc("getrawtransaction", [i2h(pi.prevout.hash), True])
                prevout = ptx["vout"][pi.prevout.n]
                inputs_value += self.make_int(prevout["value"])
                self._log.info("prevout: {}.".format(prevout))

                """
                prevout_type = prevout['scriptPubKey']['type']
                if prevout_type == 'witness_v0_keyhash':
                    #add_witness_bytes += 107  # sig 72, pk 33 and 2 size bytes
                    #add_witness_bytes += getCompactSizeLen(107)
                else:
                    # Assume P2PKH, TODO more types
                    add_bytes += 107  # OP_PUSH72 <ecdsa_signature> OP_PUSH33 <public_key>
                """

            outputs_value = 0
            for txo in tx.vout:
                outputs_value += txo.nValue
            fee_paid = inputs_value - outputs_value
            assert fee_paid > 0

            size = len(tx.serialize()) + add_witness_bytes
            fee_rate_paid = fee_paid * 1000 // size

            self._log.info(
                "tx amount, size, feerate: %ld, %ld, %ld",
                locked_coin,
                size,
                fee_rate_paid,
            )

            if not self.compareFeeRates(fee_rate_paid, feerate):
                self._log.warning(
                    "feerate paid doesn't match expected: %ld, %ld",
                    fee_rate_paid,
                    feerate,
                )
                # TODO: Display warning to user

        return txid, locked_n

    def verifySCLockSpendTx(
        self, tx_bytes, lock_tx_bytes, lock_tx_script, a_pkhash_f, feerate, vkbv=None
    ):
        # Verify:
        #   Must have only one input with correct prevout (n is always 0) and sequence
        #   Must have only one output with destination and amount

        tx = self.loadTx(tx_bytes)
        txid = self.getTxid(tx)
        self._log.info("Verifying lock spend tx: {}.".format(self._log.id(txid)))

        ensure(tx.version == self.txVersion(), "Bad version")
        ensure(tx.locktime == 0, "Bad locktime")
        ensure(tx.expiry == 0, "Bad expiry")
        ensure(len(tx.vin) == 1, "tx doesn't have one input")

        lock_tx = self.loadTx(lock_tx_bytes)
        lock_tx_id = self.getTxid(lock_tx)

        output_script = self.getScriptDest(lock_tx_script)
        locked_n = findOutput(lock_tx, output_script)
        ensure(locked_n is not None, "Output not found in tx")
        locked_coin = lock_tx.vout[locked_n].value

        ensure(tx.vin[0].sequence == 0, "Bad input nSequence")
        ensure(len(tx.vin[0].signature_script) == 0, "Input sig not empty")
        ensure(
            i2b(tx.vin[0].prevout.hash) == lock_tx_id
            and tx.vin[0].prevout.n == locked_n,
            "Input prevout mismatch",
        )

        ensure(len(tx.vout) == 1, "tx doesn't have one output")
        p2wpkh = self.getPubkeyHashDest(a_pkhash_f)
        ensure(tx.vout[0].script_pubkey == p2wpkh, "Bad output destination")

        # The value of the lock tx output should already be verified, if the fee is as expected the difference will be the correct amount
        fee_paid = locked_coin - tx.vout[0].value
        assert fee_paid > 0

        dummy_witness_stack = self.getScriptLockTxDummyWitness(lock_tx_script)
        size = len(self.setTxSignature(tx.serialize(), dummy_witness_stack))
        fee_rate_paid = fee_paid * 1000 // size

        self._log.info(
            "tx amount, size, feerate: %ld, %ld, %ld",
            tx.vout[0].value,
            size,
            fee_rate_paid,
        )

        if not self.compareFeeRates(fee_rate_paid, feerate):
            raise ValueError("Bad fee rate, expected: {}".format(feerate))

        return True

    def verifySCLockRefundTx(
        self,
        tx_bytes,
        lock_tx_bytes,
        script_out,
        prevout_id,
        prevout_n,
        prevout_seq,
        prevout_script,
        Kal,
        Kaf,
        csv_val_expect,
        swap_value,
        feerate,
        vkbv=None,
    ):
        # Verify:
        #   Must have only one input with correct prevout and sequence
        #   Must have only one output to the p2wsh of the lock refund script
        #   Output value must be locked_coin - lock tx fee

        tx = self.loadTx(tx_bytes)
        txid = self.getTxid(tx)
        self._log.info("Verifying lock refund tx: {}.".format(self._log.id(txid)))

        ensure(tx.version == self.txVersion(), "Bad version")
        ensure(tx.locktime == 0, "locktime not 0")
        ensure(tx.expiry == 0, "Bad expiry")
        ensure(len(tx.vin) == 1, "tx doesn't have one input")

        ensure(tx.vin[0].sequence == prevout_seq, "Bad input sequence")
        ensure(
            i2b(tx.vin[0].prevout.hash) == prevout_id
            and tx.vin[0].prevout.n == prevout_n
            and tx.vin[0].prevout.tree == 0,
            "Input prevout mismatch",
        )
        ensure(len(tx.vin[0].signature_script) == 0, "Input sig not empty")

        ensure(len(tx.vout) == 1, "tx doesn't have one output")

        script_pk = self.getScriptDest(script_out)
        locked_n = findOutput(tx, script_pk)
        ensure(locked_n is not None, "Output not found in tx")
        locked_coin = tx.vout[locked_n].value

        # Check script and values
        A, B, csv_val, C = extractScriptLockRefundScriptValues(script_out)
        ensure(A == Kal, "Bad script pubkey")
        ensure(B == Kaf, "Bad script pubkey")
        ensure(csv_val == csv_val_expect, "Bad script csv value")
        ensure(C == Kaf, "Bad script pubkey")

        fee_paid = swap_value - locked_coin
        assert fee_paid > 0

        dummy_witness_stack = self.getScriptLockTxDummyWitness(prevout_script)
        size = len(self.setTxSignature(tx.serialize(), dummy_witness_stack))
        fee_rate_paid = fee_paid * 1000 // size

        self._log.info(
            "tx amount, size, feerate: %ld, %ld, %ld", locked_coin, size, fee_rate_paid
        )

        if not self.compareFeeRates(fee_rate_paid, feerate):
            raise ValueError("Bad fee rate, expected: {}".format(feerate))

        return txid, locked_coin, locked_n

    def verifySCLockRefundSpendTx(
        self,
        tx_bytes,
        lock_refund_tx_bytes,
        lock_refund_tx_id,
        prevout_script,
        Kal,
        prevout_n,
        prevout_value,
        feerate,
        vkbv=None,
    ):
        # Verify:
        #   Must have only one input with correct prevout (n is always 0) and sequence
        #   Must have only one output sending lock refund tx value - fee to leader's address, TODO: follower shouldn't need to verify destination addr
        tx = self.loadTx(tx_bytes)
        txid = self.getTxid(tx)
        self._log.info("Verifying lock refund spend tx: {}.".format(self._log.id(txid)))

        ensure(tx.version == self.txVersion(), "Bad version")
        ensure(tx.locktime == 0, "locktime not 0")
        ensure(tx.expiry == 0, "Bad expiry")
        ensure(len(tx.vin) == 1, "tx doesn't have one input")

        ensure(tx.vin[0].sequence == 0, "Bad input sequence")
        ensure(len(tx.vin[0].signature_script) == 0, "Input sig not empty")
        ensure(
            i2b(tx.vin[0].prevout.hash) == lock_refund_tx_id
            and tx.vin[0].prevout.n == 0
            and tx.vin[0].prevout.tree == 0,
            "Input prevout mismatch",
        )

        ensure(len(tx.vout) == 1, "tx doesn't have one output")

        # Destination doesn't matter to the follower
        """
        p2wpkh = CScript([OP_0, hash160(Kal)])
        locked_n = findOutput(tx, p2wpkh)
        ensure(locked_n is not None, 'Output not found in lock refund spend tx')
        """
        tx_value = tx.vout[0].value

        fee_paid = prevout_value - tx_value
        assert fee_paid > 0

        dummy_witness_stack = self.getScriptLockRefundSpendTxDummyWitness(
            prevout_script
        )
        size = len(self.setTxSignature(tx.serialize(), dummy_witness_stack))
        fee_rate_paid = fee_paid * 1000 // size

        self._log.info(
            "tx amount, size, feerate: %ld, %ld, %ld", tx_value, size, fee_rate_paid
        )

        if not self.compareFeeRates(fee_rate_paid, feerate):
            raise ValueError("Bad fee rate, expected: {}".format(feerate))

        return True

    def createSCLockRefundSpendToFTx(
        self,
        tx_lock_refund_bytes,
        script_lock_refund,
        pkh_dest,
        tx_fee_rate,
        vkbv=None,
        kbsf=None,
    ):
        # lock refund swipe tx
        # Sends the coinA locked coin to the follower

        tx_lock_refund = self.loadTx(tx_lock_refund_bytes)

        output_script = self.getScriptDest(script_lock_refund)
        locked_n = findOutput(tx_lock_refund, output_script)
        ensure(locked_n is not None, "Output not found in tx")
        locked_amount = tx_lock_refund.vout[locked_n].value

        A, B, lock2_value, C = extractScriptLockRefundScriptValues(script_lock_refund)

        tx_lock_refund_hash_int = b2i(tx_lock_refund.TxHash())

        tx = CTransaction()
        tx.version = self.txVersion()
        tx.vin.append(
            CTxIn(
                COutPoint(tx_lock_refund_hash_int, locked_n, 0),
                sequence=lock2_value,
            )
        )

        tx.vout.append(self.txoType()(locked_amount, self.getPubkeyHashDest(pkh_dest)))

        dummy_witness_stack = self.getScriptLockRefundSwipeTxDummyWitness(
            script_lock_refund
        )
        size = len(self.setTxSignature(tx.serialize(), dummy_witness_stack))
        pay_fee = round(tx_fee_rate * size / 1000)
        tx.vout[0].value = locked_amount - pay_fee

        self._log.info(
            "createSCLockRefundSpendToFTx {}{}.".format(
                self._log.id(tx.TxHash()),
                (
                    ""
                    if self._log.safe_logs
                    else f":\n    fee_rate, size, fee: {tx_fee_rate}, {size}, {pay_fee}"
                ),
            )
        )

        return tx.serialize(TxSerializeType.NoWitness)

    def signTxOtVES(
        self,
        key_sign: bytes,
        pubkey_encrypt: bytes,
        tx_bytes: bytes,
        input_n: int,
        prevout_script: bytes,
        prevout_value: int,
    ) -> bytes:
        tx = self.loadTx(tx_bytes)
        sig_hash = DCRSignatureHash(prevout_script, SigHashType.SigHashAll, tx, input_n)

        return ecdsaotves_enc_sign(key_sign, pubkey_encrypt, sig_hash)

    def verifyTxOtVES(
        self,
        tx_bytes: bytes,
        ct: bytes,
        Ks: bytes,
        Ke: bytes,
        input_n: int,
        prevout_script: bytes,
        prevout_value,
    ):
        tx = self.loadTx(tx_bytes)
        sig_hash = DCRSignatureHash(prevout_script, SigHashType.SigHashAll, tx, input_n)
        return ecdsaotves_enc_verify(Ks, Ke, sig_hash, ct)

    def decryptOtVES(self, k: bytes, esig: bytes) -> bytes:
        return ecdsaotves_dec_sig(k, esig) + bytes((SigHashType.SigHashAll,))

    def recoverEncKey(self, esig, sig, K):
        return ecdsaotves_rec_enc_key(K, esig, sig[:-1])  # Strip sighash type

    def getTxOutputPos(self, tx, script):
        if isinstance(tx, bytes):
            tx = self.loadTx(tx)
        script_pk = self.getScriptDest(script)
        return findOutput(tx, script_pk)

    def getScriptLockTxDummyWitness(self, script: bytes):
        return [bytes(72), bytes(72), bytes(len(script))]

    def getScriptLockRefundSpendTxDummyWitness(self, script: bytes):
        return [bytes(72), bytes(72), bytes((1,)), bytes(len(script))]

    def extractLeaderSig(self, tx_bytes: bytes) -> bytes:
        tx = self.loadTx(tx_bytes)

        sig_len = tx.vin[0].signature_script[0]
        return tx.vin[0].signature_script[1 : 1 + sig_len]

    def extractFollowerSig(self, tx_bytes: bytes) -> bytes:
        tx = self.loadTx(tx_bytes)

        sig_len = tx.vin[0].signature_script[0]
        ofs = 1 + sig_len
        sig_len = tx.vin[0].signature_script[ofs]
        ofs += 1
        return tx.vin[0].signature_script[ofs : ofs + sig_len]

    def listInputs(self, tx_bytes: bytes):
        tx = self.loadTx(tx_bytes)

        all_locked = self.rpc_wallet("listlockunspent")
        inputs = []
        for txi in tx.vin:
            txid_hex = i2h(txi.prevout.hash)
            islocked = any(
                [
                    txid_hex == a["txid"] and txi.prevout.n == a["vout"]
                    for a in all_locked
                ]
            )
            inputs.append(
                {"txid": txid_hex, "vout": txi.prevout.n, "islocked": islocked}
            )
        return inputs

    def unlockInputs(self, tx_bytes):
        tx = self.loadTx(tx_bytes)

        inputs = []
        for txi in tx.vin:
            inputs.append(
                {
                    "amount": float(self.format_amount(txi.value_in)),
                    "txid": i2h(txi.prevout.hash),
                    "vout": txi.prevout.n,
                    "tree": txi.prevout.tree,
                }
            )
        self.rpc_wallet("lockunspent", [True, inputs])

    def getWalletRestoreHeight(self) -> int:
        start_time = self.rpc_wallet("getinfo")["keypoololdest"]

        blockchaininfo = self.getBlockchainInfo()
        best_block = blockchaininfo["bestblockhash"]

        chain_synced = round(blockchaininfo["verificationprogress"], 3)
        if chain_synced < 1.0:
            raise ValueError("{} chain isn't synced.".format(self.coin_name()))

        if start_time == 0:
            self._log.debug(
                "Using genesis block for restore height as keypoololdest is 0."
            )
            return 0

        self._log.info(
            "Finding block at time: {} for restore height.".format(start_time)
        )

        blocks_searched: int = 0
        rpc_conn = self.open_rpc()
        try:
            block_hash = best_block
            while True:
                block_header = self.json_request(
                    rpc_conn, "getblockheader", [block_hash]
                )
                if block_header["time"] < start_time:
                    return block_header["height"]
                # genesis block
                if (
                    block_header["previousblockhash"]
                    == "0000000000000000000000000000000000000000000000000000000000000000"
                ):
                    return block_header["height"]

                block_hash = block_header["previousblockhash"]
                blocks_searched += 1
                if blocks_searched % 10000 == 0:
                    self._log.debug(
                        "Still finding restore height, block at height {} has time {}.".format(
                            block_header["height"], block_header["time"]
                        )
                    )
        finally:
            self.close_rpc(rpc_conn)
        raise ValueError("{} wallet restore height not found.".format(self.coin_name()))

    def createBLockTx(self, Kbs, output_amount, vkbv=None) -> bytes:
        tx = CTransaction()
        tx.version = self.txVersion()
        script_pk = self.getPkDest(Kbs)
        tx.vout.append(self.txoType()(output_amount, script_pk))
        return tx.serialize()

    def publishBLockTx(
        self, kbv, Kbs, output_amount, feerate, unlock_time: int = 0
    ) -> bytes:
        b_lock_tx = self.createBLockTx(Kbs, output_amount)

        b_lock_tx = self.fundTx(b_lock_tx, feerate)
        b_lock_tx = self.signTxWithWallet(b_lock_tx)

        return bytes.fromhex(self.publishTx(b_lock_tx))

    def getBLockSpendTxFee(self, tx, fee_rate: int) -> int:
        witness_bytes = 115
        size = len(tx.serialize()) + witness_bytes
        pay_fee = round(fee_rate * size / 1000)
        self._log.info_s(
            f"BLockSpendTx fee_rate, vsize, fee: {fee_rate}, {size}, {pay_fee}."
        )
        return pay_fee

    def spendBLockTx(
        self,
        chain_b_lock_txid: bytes,
        address_to: str,
        kbv: bytes,
        kbs: bytes,
        cb_swap_value: int,
        b_fee: int,
        restore_height: int,
        spend_actual_balance: bool = False,
        lock_tx_vout=None,
    ) -> bytes:
        self._log.info("spendBLockTx %s:\n", chain_b_lock_txid.hex())
        locked_n = lock_tx_vout

        Kbs = self.getPubkey(kbs)
        script_pk = self.getPkDest(Kbs)

        if locked_n is None:
            self._log.debug(
                f"Unknown lock vout, searching tx: {chain_b_lock_txid.hex()}"
            )
            # When refunding a lock tx, it should be in the wallet as a sent tx
            wtx = self.rpc_wallet(
                "gettransaction",
                [
                    chain_b_lock_txid.hex(),
                ],
            )
            lock_tx = self.loadTx(bytes.fromhex(wtx["hex"]))
            locked_n = findOutput(lock_tx, script_pk)

        ensure(locked_n is not None, "Output not found in tx")
        pkh_to = self.decodeAddress(address_to)

        tx = CTransaction()
        tx.version = self.txVersion()

        chain_b_lock_txid_int = b2i(chain_b_lock_txid)

        tx.vin.append(CTxIn(COutPoint(chain_b_lock_txid_int, locked_n, 0), sequence=0))
        tx.vout.append(self.txoType()(cb_swap_value, self.getPubkeyHashDest(pkh_to)))

        pay_fee = self.getBLockSpendTxFee(tx, b_fee)
        tx.vout[0].value = cb_swap_value - pay_fee

        b_lock_spend_tx = tx.serialize()
        b_lock_spend_tx = self.signTxWithKey(b_lock_spend_tx, kbs)

        return bytes.fromhex(self.publishTx(b_lock_spend_tx))

    def findTxnByHash(self, txid_hex: str):
        try:
            txout = self.rpc("gettxout", [txid_hex, 0, 0, True])
        except Exception as e:  # noqa: F841
            # self._log.warning('gettxout {}'.format(e))
            return None

        confirmations: int = (
            0 if "confirmations" not in txout else txout["confirmations"]
        )
        if confirmations >= self.blocks_confirmed:
            block_height = self.getChainHeight() - confirmations  # TODO: Better way?
            return {"txid": txid_hex, "amount": 0, "height": block_height}
        return None

    def encodeSharedAddress(self, Kbv, Kbs):
        return self.pkh_to_address(self.pkh(Kbs))

    def isTxExistsError(self, err_str: str) -> bool:
        return (
            "transaction already exists" in err_str
            or "already have transaction" in err_str
        )

    def isTxNonFinalError(self, err_str: str) -> bool:
        return "locks on inputs not met" in err_str