def cli_get_wallet(wallet_name, sync=True): if not os.path.exists(os.path.join('wallets', wallet_name)): wallet = get_wallet_cls()(wallet_name, None, max_mix_depth=options.amtmixdepths) else: while True: try: pwd = get_password("Enter wallet decryption passphrase: ") wallet = get_wallet_cls()(wallet_name, pwd, max_mix_depth=options.amtmixdepths) except WalletError: print("Wrong password, try again.") continue except Exception as e: print("Failed to load wallet, error message: " + repr(e)) sys.exit(0) break if jm_single().config.get("BLOCKCHAIN", "blockchain_source") == "electrum-server": jm_single().bc_interface.synctype = "with-script" if sync: sync_wallet(wallet, fast=options.fastsync) return wallet
def make_wallets(n, wallet_structures=None, mean_amt=1, sdev_amt=0, start_index=0, fixed_seeds=None, test_wallet=False, passwords=None, walletclass=None): '''n: number of wallets to be created wallet_structure: array of n arrays , each subarray specifying the number of addresses to be populated with coins at each depth (for now, this will only populate coins into 'receive' addresses) mean_amt: the number of coins (in btc units) in each address as above sdev_amt: if randomness in amouts is desired, specify here. Returns: a dict of dicts of form {0:{'seed':seed,'wallet':Wallet object},1:..,} Default Wallet constructor is joinmarket.Wallet, else use TestWallet, which takes a password parameter as in the list passwords. ''' if len(wallet_structures) != n: raise Exception("Number of wallets doesn't match wallet structures") if not fixed_seeds: seeds = chunks(binascii.hexlify(os.urandom(15 * n)), 15 * 2) else: seeds = fixed_seeds wallets = {} for i in range(n): if test_wallet: w = TestWallet(seeds[i], max_mix_depth=5, pwd=passwords[i]) else: if walletclass: wc = walletclass else: wc = get_wallet_cls() w = wc(seeds[i], pwd=None, max_mix_depth=5) wallets[i + start_index] = {'seed': seeds[i], 'wallet': w} for j in range(5): for k in range(wallet_structures[i][j]): deviation = sdev_amt * random.random() amt = mean_amt - sdev_amt / 2.0 + deviation if amt < 0: amt = 0.001 amt = float(Decimal(amt).quantize(Decimal(10)**-8)) jm_single().bc_interface.grab_coins( wallets[i + start_index]['wallet'].get_external_addr(j), amt) #reset the index so the coins can be seen if running in same script wallets[i + start_index]['wallet'].index[j][0] -= wallet_structures[i][j] return wallets
def ygmain(ygclass, txfee=1000, cjfee_a=200, cjfee_r=0.002, ordertype='swreloffer', nickserv_password='', minsize=100000, gaplimit=6): import sys parser = OptionParser(usage='usage: %prog [options] [wallet file]') parser.add_option('-o', '--ordertype', action='store', type='string', dest='ordertype', default=ordertype, help='type of order; can be either reloffer or absoffer') parser.add_option('-t', '--txfee', action='store', type='int', dest='txfee', default=txfee, help='minimum miner fee in satoshis') parser.add_option('-c', '--cjfee', action='store', type='string', dest='cjfee', default='', help='requested coinjoin fee in satoshis or proportion') parser.add_option('-p', '--password', action='store', type='string', dest='password', default=nickserv_password, help='irc nickserv password') parser.add_option('-s', '--minsize', action='store', type='int', dest='minsize', default=minsize, help='minimum coinjoin size in satoshis') parser.add_option('-g', '--gap-limit', action='store', type="int", dest='gaplimit', default=gaplimit, help='gap limit for wallet, default=' + str(gaplimit)) parser.add_option('--fast', action='store_true', dest='fastsync', default=False, help=('choose to do fast wallet sync, only for Core and ' 'only for previously synced wallet')) (options, args) = parser.parse_args() if len(args) < 1: parser.error('Needs a wallet') sys.exit(0) wallet_name = args[0] ordertype = options.ordertype txfee = options.txfee if ordertype in ('reloffer', 'swreloffer'): if options.cjfee != '': cjfee_r = options.cjfee # minimum size is such that you always net profit at least 20% #of the miner fee minsize = max(int(1.2 * txfee / float(cjfee_r)), options.minsize) elif ordertype in ('absoffer', 'swabsoffer'): if options.cjfee != '': cjfee_a = int(options.cjfee) minsize = options.minsize else: parser.error('You specified an incorrect offer type which ' +\ 'can be either swreloffer or swabsoffer') sys.exit(0) nickserv_password = options.password load_program_config() if not os.path.exists(os.path.join('wallets', wallet_name)): wallet = get_wallet_cls()(wallet_name, None, max_mix_depth=MAX_MIX_DEPTH, gaplimit=options.gaplimit) else: while True: try: pwd = get_password("Enter wallet decryption passphrase: ") wallet = get_wallet_cls()(wallet_name, pwd, max_mix_depth=MAX_MIX_DEPTH, gaplimit=options.gaplimit) except WalletError: print("Wrong password, try again.") continue except Exception as e: print("Failed to load wallet, error message: " + repr(e)) sys.exit(0) break if jm_single().config.get("BLOCKCHAIN", "blockchain_source") == "electrum-server": jm_single().bc_interface.synctype = "with-script" sync_wallet(wallet, fast=options.fastsync) maker = ygclass( wallet, [options.txfee, cjfee_a, cjfee_r, options.ordertype, options.minsize]) jlog.info('starting yield generator') clientfactory = JMClientProtocolFactory(maker, proto_type="MAKER") nodaemon = jm_single().config.getint("DAEMON", "no_daemon") daemon = True if nodaemon == 1 else False if jm_single().config.get("BLOCKCHAIN", "network") in ["regtest", "testnet"]: startLogging(sys.stdout) start_reactor(jm_single().config.get("DAEMON", "daemon_host"), jm_single().config.getint("DAEMON", "daemon_port"), clientfactory, daemon=daemon)
def main(): parser = get_sendpayment_parser() (options, args) = parser.parse_args() load_program_config() if options.schedule == '' and len(args) < 3: parser.error('Needs a wallet, amount and destination address') sys.exit(0) #without schedule file option, use the arguments to create a schedule #of a single transaction sweeping = False if options.schedule == '': #note that sendpayment doesn't support fractional amounts, fractions throw #here. amount = int(args[1]) if amount == 0: sweeping = True destaddr = args[2] mixdepth = options.mixdepth addr_valid, errormsg = validate_address(destaddr) if not addr_valid: print('ERROR: Address invalid. ' + errormsg) return schedule = [[ options.mixdepth, amount, options.makercount, destaddr, 0.0, 0 ]] else: result, schedule = get_schedule(options.schedule) if not result: log.info( "Failed to load schedule file, quitting. Check the syntax.") log.info("Error was: " + str(schedule)) sys.exit(0) mixdepth = 0 for s in schedule: if s[1] == 0: sweeping = True #only used for checking the maximum mixdepth required mixdepth = max([mixdepth, s[0]]) wallet_name = args[0] #to allow testing of confirm/unconfirm callback for multiple txs if isinstance(jm_single().bc_interface, RegtestBitcoinCoreInterface): jm_single().bc_interface.tick_forward_chain_interval = 10 jm_single().bc_interface.simulating = True jm_single().maker_timeout_sec = 15 chooseOrdersFunc = None if options.pickorders: chooseOrdersFunc = pick_order if sweeping: print('WARNING: You may have to pick offers multiple times') print('WARNING: due to manual offer picking while sweeping') elif options.choosecheapest: chooseOrdersFunc = cheapest_order_choose else: # choose randomly (weighted) chooseOrdersFunc = weighted_order_choose # Dynamically estimate a realistic fee if it currently is the default value. # At this point we do not know even the number of our own inputs, so # we guess conservatively with 2 inputs and 2 outputs each. if options.txfee == -1: options.txfee = max(options.txfee, estimate_tx_fee(2, 2, txtype="p2sh-p2wpkh")) log.debug("Estimated miner/tx fee for each cj participant: " + str(options.txfee)) assert (options.txfee >= 0) log.debug('starting sendpayment') if not options.userpcwallet: #maxmixdepth in the wallet is actually the *number* of mixdepths (so misnamed); #to ensure we have enough, must be at least (requested index+1) max_mix_depth = max([mixdepth + 1, options.amtmixdepths]) if not os.path.exists(os.path.join('wallets', wallet_name)): wallet = get_wallet_cls()(wallet_name, None, max_mix_depth, options.gaplimit) else: while True: try: pwd = get_password("Enter wallet decryption passphrase: ") wallet = get_wallet_cls()(wallet_name, pwd, max_mix_depth, options.gaplimit) except WalletError: print("Wrong password, try again.") continue except Exception as e: print("Failed to load wallet, error message: " + repr(e)) sys.exit(0) break else: wallet = BitcoinCoreWallet(fromaccount=wallet_name) if jm_single().config.get( "BLOCKCHAIN", "blockchain_source" ) == "electrum-server" and options.makercount != 0: jm_single().bc_interface.synctype = "with-script" #wallet sync will now only occur on reactor start if we're joining. sync_wallet(wallet, fast=options.fastsync) if options.makercount == 0: if isinstance(wallet, BitcoinCoreWallet): raise NotImplementedError( "Direct send only supported for JM wallets") direct_send(wallet, amount, mixdepth, destaddr, options.answeryes) return def filter_orders_callback(orders_fees, cjamount): orders, total_cj_fee = orders_fees log.info("Chose these orders: " + pprint.pformat(orders)) log.info('total cj fee = ' + str(total_cj_fee)) total_fee_pc = 1.0 * total_cj_fee / cjamount log.info('total coinjoin fee = ' + str(float('%.3g' % (100.0 * total_fee_pc))) + '%') WARNING_THRESHOLD = 0.02 # 2% if total_fee_pc > WARNING_THRESHOLD: log.info('\n'.join(['=' * 60] * 3)) log.info('WARNING ' * 6) log.info('\n'.join(['=' * 60] * 1)) log.info( 'OFFERED COINJOIN FEE IS UNUSUALLY HIGH. DOUBLE/TRIPLE CHECK.') log.info('\n'.join(['=' * 60] * 1)) log.info('WARNING ' * 6) log.info('\n'.join(['=' * 60] * 3)) if not options.answeryes: if raw_input('send with these orders? (y/n):')[0] != 'y': return False return True def taker_finished(res, fromtx=False, waittime=0.0, txdetails=None): if fromtx == "unconfirmed": #If final entry, stop *here*, don't wait for confirmation if taker.schedule_index + 1 == len(taker.schedule): reactor.stop() return if fromtx: if res: txd, txid = txdetails taker.wallet.remove_old_utxos(txd) taker.wallet.add_new_utxos(txd, txid) reactor.callLater(waittime * 60, clientfactory.getClient().clientStart) else: #a transaction failed; just stop reactor.stop() else: if not res: log.info("Did not complete successfully, shutting down") #Should usually be unreachable, unless conf received out of order; #because we should stop on 'unconfirmed' for last (see above) else: log.info("All transactions completed correctly") reactor.stop() taker = Taker(wallet, schedule, order_chooser=chooseOrdersFunc, callbacks=(filter_orders_callback, None, taker_finished)) clientfactory = JMClientProtocolFactory(taker) nodaemon = jm_single().config.getint("DAEMON", "no_daemon") daemon = True if nodaemon == 1 else False if jm_single().config.get("BLOCKCHAIN", "network") in ["regtest", "testnet"]: startLogging(sys.stdout) start_reactor(jm_single().config.get("DAEMON", "daemon_host"), jm_single().config.getint("DAEMON", "daemon_port"), clientfactory, daemon=daemon)
def wallet_tool_main(wallet_root_path): """Main wallet tool script function; returned is a string (output or error) """ parser = get_wallettool_parser() (options, args) = parser.parse_args() # if the index_cache stored in wallet.json is longer than the default # then set maxmixdepth to the length of index_cache maxmixdepth_configured = True if not options.maxmixdepth: maxmixdepth_configured = False options.maxmixdepth = 5 noseed_methods = ['generate', 'recover'] methods = ['display', 'displayall', 'summary', 'showseed', 'importprivkey', 'history', 'showutxos'] methods.extend(noseed_methods) noscan_methods = ['showseed', 'importprivkey', 'dumpprivkey', 'signmessage'] if len(args) < 1: parser.error('Needs a wallet file or method') sys.exit(0) if args[0] in noseed_methods: method = args[0] else: seed = args[0] method = ('display' if len(args) == 1 else args[1].lower()) if not os.path.exists(os.path.join(wallet_root_path, seed)): wallet = get_wallet_cls()(seed, None, options.maxmixdepth, options.gaplimit, extend_mixdepth= not maxmixdepth_configured, storepassword=(method == 'importprivkey'), wallet_dir=wallet_root_path) else: while True: try: pwd = get_password("Enter wallet decryption passphrase: ") wallet = get_wallet_cls()(seed, pwd, options.maxmixdepth, options.gaplimit, extend_mixdepth=not maxmixdepth_configured, storepassword=(method == 'importprivkey'), wallet_dir=wallet_root_path) except WalletError: print("Wrong password, try again.") continue except Exception as e: print("Failed to load wallet, error message: " + repr(e)) sys.exit(0) break if method not in noscan_methods: # if nothing was configured, we override bitcoind's options so that # unconfirmed balance is included in the wallet display by default if 'listunspent_args' not in jm_single().config.options('POLICY'): jm_single().config.set('POLICY','listunspent_args', '[0]') sync_wallet(wallet, fast=options.fastsync) #Now the wallet/data is prepared, execute the script according to the method if method == "display": return wallet_display(wallet, options.gaplimit, options.showprivkey) elif method == "displayall": return wallet_display(wallet, options.gaplimit, options.showprivkey, displayall=True) elif method == "summary": return wallet_display(wallet, options.gaplimit, options.showprivkey, summarized=True) elif method == "history": if not isinstance(jm_single().bc_interface, BitcoinCoreInterface): print('showing history only available when using the Bitcoin Core ' + 'blockchain interface') sys.exit(0) else: return wallet_fetch_history(wallet, options) elif method == "generate": retval = wallet_generate_recover("generate", wallet_root_path) return retval if retval else "Failed" elif method == "recover": retval = wallet_generate_recover("recover", wallet_root_path) return retval if retval else "Failed" elif method == "showutxos": return wallet_showutxos(wallet, options.showprivkey) elif method == "showseed": return wallet_showseed(wallet) elif method == "dumpprivkey": return wallet_dumpprivkey(wallet, options.hd_path) elif method == "importprivkey": #note: must be interactive (security) wallet_importprivkey(wallet, options.mixdepth) return "Key import completed." elif method == "signmessage": return wallet_signmessage(wallet, options.hd_path, args[2])
def main(): tumble_log = get_tumble_log(logsdir) (options, args) = get_tumbler_parser().parse_args() options = vars(options) if len(args) < 1: parser.error('Needs a wallet file') sys.exit(0) load_program_config() #Load the wallet wallet_name = args[0] max_mix_depth = options['mixdepthsrc'] + options['mixdepthcount'] if not os.path.exists(os.path.join('wallets', wallet_name)): wallet = get_wallet_cls()(wallet_name, None, max_mix_depth) else: while True: try: pwd = get_password("Enter wallet decryption passphrase: ") wallet = get_wallet_cls()(wallet_name, pwd, max_mix_depth) except WalletError: print("Wrong password, try again.") continue except Exception as e: print("Failed to load wallet, error message: " + repr(e)) sys.exit(0) break if jm_single().config.get("BLOCKCHAIN", "blockchain_source") == "electrum-server": jm_single().bc_interface.synctype = "with-script" sync_wallet(wallet, fast=options['fastsync']) #Parse options and generate schedule #Output information to log files jm_single().mincjamount = options['mincjamount'] destaddrs = args[1:] print(destaddrs) #If the --restart flag is set we read the schedule #from the file, and filter out entries that are #already complete if options['restart']: res, schedule = get_schedule( os.path.join(logsdir, options['schedulefile'])) if not res: print("Failed to load schedule, name: " + str(options['schedulefile'])) print("Error was: " + str(schedule)) sys.exit(0) #This removes all entries that are marked as done schedule = [s for s in schedule if s[5] != 1] if isinstance(schedule[0][5], str) and len(schedule[0][5]) == 64: #ensure last transaction is confirmed before restart tumble_log.info("WAITING TO RESTART...") txid = schedule[0][5] restart_waiter(txid + ":0") #add 0 index because all have it #remove the already-done entry (this connects to the other TODO, #probably better *not* to truncate the done-already txs from file, #but simplest for now. schedule = schedule[1:] elif schedule[0][5] != 0: print("Error: first schedule entry is invalid.") sys.exit(0) with open(os.path.join(logsdir, options['schedulefile']), "wb") as f: f.write(schedule_to_text(schedule)) tumble_log.info("TUMBLE RESTARTING") else: #Create a new schedule from scratch schedule = get_tumble_schedule(options, destaddrs) tumble_log.info("TUMBLE STARTING") with open(os.path.join(logsdir, options['schedulefile']), "wb") as f: f.write(schedule_to_text(schedule)) print("Schedule written to logs/" + options['schedulefile']) tumble_log.info("With this schedule: ") tumble_log.info(pprint.pformat(schedule)) print("Progress logging to logs/TUMBLE.log") def filter_orders_callback(orders_fees, cjamount): """Decide whether to accept fees """ return tumbler_filter_orders_callback(orders_fees, cjamount, taker, options) def taker_finished(res, fromtx=False, waittime=0.0, txdetails=None): """on_finished_callback for tumbler; processing is almost entirely deferred to generic taker_finished in tumbler_support module, except here reactor signalling. """ sfile = os.path.join(logsdir, options['schedulefile']) tumbler_taker_finished_update(taker, sfile, tumble_log, options, res, fromtx, waittime, txdetails) if not fromtx: reactor.stop() elif fromtx != "unconfirmed": reactor.callLater(waittime * 60, clientfactory.getClient().clientStart) #to allow testing of confirm/unconfirm callback for multiple txs if isinstance(jm_single().bc_interface, RegtestBitcoinCoreInterface): jm_single().bc_interface.tick_forward_chain_interval = 10 jm_single().bc_interface.simulating = True jm_single().maker_timeout_sec = 15 #instantiate Taker with given schedule and run taker = Taker(wallet, schedule, order_chooser=weighted_order_choose, callbacks=(filter_orders_callback, None, taker_finished), tdestaddrs=destaddrs) clientfactory = JMClientProtocolFactory(taker) nodaemon = jm_single().config.getint("DAEMON", "no_daemon") daemon = True if nodaemon == 1 else False if jm_single().config.get("BLOCKCHAIN", "network") in ["regtest", "testnet"]: startLogging(sys.stdout) start_reactor(jm_single().config.get("DAEMON", "daemon_host"), jm_single().config.getint("DAEMON", "daemon_port"), clientfactory, daemon=daemon)
def main(): parser = OptionParser( usage= 'usage: %prog [options] [txid:n]', description="Adds one or more utxos to the list that can be used to make " "commitments for anti-snooping. Note that this utxo, and its " "PUBkey, will be revealed to makers, so consider the privacy " "implication. " "It may be useful to those who are having trouble making " "coinjoins due to several unsuccessful attempts (especially " "if your joinmarket wallet is new). " "'Utxo' means unspent transaction output, it must not " "already be spent. " "The options -w, -r and -R offer ways to load these utxos " "from a file or wallet. " "If you enter a single utxo without these options, you will be " "prompted to enter the private key here - it must be in " "WIF compressed format. " "BE CAREFUL about handling private keys! " "Don't do this in insecure environments. " "Also note this ONLY works for standard (p2pkh or p2sh-p2wpkh) utxos." ) parser.add_option( '-r', '--read-from-file', action='store', type='str', dest='in_file', help='name of plain text csv file containing utxos, one per line, format: ' 'txid:N, WIF-compressed-privkey' ) parser.add_option( '-R', '--read-from-json', action='store', type='str', dest='in_json', help='name of json formatted file containing utxos with private keys, as ' 'output from "python wallet-tool.py -p walletname showutxos"' ) parser.add_option( '-w', '--load-wallet', action='store', type='str', dest='loadwallet', help='name of wallet from which to load utxos and use as commitments.' ) parser.add_option( '-g', '--gap-limit', action='store', type='int', dest='gaplimit', default = 6, help='Only to be used with -w; gap limit for Joinmarket wallet, default 6.' ) parser.add_option( '-M', '--max-mixdepth', action='store', type='int', dest='maxmixdepth', default=5, help='Only to be used with -w; number of mixdepths for wallet, default 5.' ) parser.add_option( '-d', '--delete-external', action='store_true', dest='delete_ext', help='deletes the current list of external commitment utxos', default=False ) parser.add_option( '-v', '--validate-utxos', action='store_true', dest='validate', help='validate the utxos and pubkeys provided against the blockchain', default=False ) parser.add_option( '-o', '--validate-only', action='store_true', dest='vonly', help='only validate the provided utxos (file or command line), not add', default=False ) parser.add_option('--fast', action='store_true', dest='fastsync', default=False, help=('choose to do fast wallet sync, only for Core and ' 'only for previously synced wallet')) (options, args) = parser.parse_args() load_program_config() #TODO; sort out "commit file location" global so this script can #run without this hardcoding: utxo_data = [] if options.delete_ext: other = options.in_file or options.in_json or options.loadwallet if len(args) > 0 or other: if raw_input("You have chosen to delete commitments, other arguments " "will be ignored; continue? (y/n)") != 'y': print "Quitting" sys.exit(0) c, e = get_podle_commitments() print pformat(e) if raw_input( "You will remove the above commitments; are you sure? (y/n): ") != 'y': print "Quitting" sys.exit(0) update_commitments(external_to_remove=e) print "Commitments deleted." sys.exit(0) #Three options (-w, -r, -R) for loading utxo and privkey pairs from a wallet, #csv file or json file. if options.loadwallet: while True: pwd = get_password("Enter wallet decryption passphrase: ") try: wallet = get_wallet_cls()(options.loadwallet, pwd, options.maxmixdepth, options.gaplimit) except WalletError: print("Wrong password, try again.") continue except Exception as e: print("Failed to load wallet, error message: " + repr(e)) sys.exit(0) break sync_wallet(wallet, fast=options.fastsync) unsp = {} for u, av in wallet.unspent.iteritems(): addr = av['address'] key = wallet.get_key_from_addr(addr) wifkey = btc.wif_compressed_privkey(key, vbyte=get_p2pk_vbyte()) unsp[u] = {'address': av['address'], 'value': av['value'], 'privkey': wifkey} for u, pva in unsp.iteritems(): utxo_data.append((u, pva['privkey'])) elif options.in_file: with open(options.in_file, "rb") as f: utxo_info = f.readlines() for ul in utxo_info: ul = ul.rstrip() if ul: u, priv = get_utxo_info(ul) if not u: quit(parser, "Failed to parse utxo info: " + str(ul)) utxo_data.append((u, priv)) elif options.in_json: if not os.path.isfile(options.in_json): print "File: " + options.in_json + " not found." sys.exit(0) with open(options.in_json, "rb") as f: try: utxo_json = json.loads(f.read()) except: print "Failed to read json from " + options.in_json sys.exit(0) for u, pva in utxo_json.iteritems(): utxo_data.append((u, pva['privkey'])) elif len(args) == 1: u = args[0] priv = raw_input( 'input private key for ' + u + ', in WIF compressed format : ') u, priv = get_utxo_info(','.join([u, priv])) if not u: quit(parser, "Failed to parse utxo info: " + u) utxo_data.append((u, priv)) else: quit(parser, 'Invalid syntax') if options.validate or options.vonly: sw = False if jm_single().config.get("POLICY", "segwit") == "false" else True if not validate_utxo_data(utxo_data, segwit=sw): quit(parser, "Utxos did not validate, quitting") if options.vonly: sys.exit(0) #We are adding utxos to the external list assert len(utxo_data) add_ext_commitments(utxo_data)
if 'txinwitness' in d['ins'][0]: df['ins'][0]['txinwitness'] = d['ins'][0]['txinwitness'] fulltx = btc.serialize(df) for i, iu in enumerate(input_utxos): priv, inamt = get_privkey_amount_from_utxo(wallet, iu) print("Signing index: ", i + 1, " with privkey: ", priv, " and amount: ", inamt, " for utxo: ", iu) fulltx = btc.sign(fulltx, i + 1, priv, amount=inamt) return (True, fulltx) if __name__ == "__main__": parser = get_parser() (options, args) = parser.parse_args() load_program_config() if get_wallet_cls() != SegwitWallet: print( "Only segwit wallets are supported; remove any setting of `segwit`" " in `POLICY` in joinmarket.cfg. Quitting.") exit(0) #default args causes wallet sync here: wallet = cli_get_wallet(args[0]) if args[1] not in ['make', 'take']: print("Second argument must be 'make' or 'take', see '--help'") exit(0) if args[1] == "make": if len(args) < 3 or not is_utxo(args[2]): print( "You must provide a utxo as third argument; 64 character hex " "txid, followed by ':', followed by the output index. " "Use wallet-tool.py method 'showutxos' to select one")