#!/usr/bin/env python3 # Based on spend-p2sh-txout.py from python-bitcoinlib. # Copyright (C) 2017 The Zcash developers # small modifications from zXcat.py to be convenient for ETH xcat import sys if sys.version_info.major < 3: sys.stderr.write('Sorry, Python 3.x required by this example.\n') sys.exit(1) import zcash import zcash.rpc from zcash import SelectParams from zcash.core import b2x, lx, x, b2lx, COIN, COutPoint, CMutableTxOut, CMutableTxIn, CMutableTransaction, Hash160 from zcash.core.script import CScript, OP_DUP, OP_IF, OP_ELSE, OP_ENDIF, OP_HASH160, OP_EQUALVERIFY, OP_CHECKSIG, SignatureHash, SIGHASH_ALL, OP_FALSE, OP_DROP, OP_CHECKLOCKTIMEVERIFY, OP_SHA256, OP_TRUE from zcash.core.scripteval import VerifyScript, SCRIPT_VERIFY_P2SH from zcash.wallet import CBitcoinAddress, CBitcoinSecret, P2SHBitcoinAddress, P2PKHBitcoinAddress import bitcoin from utils import * # SelectParams('testnet') SelectParams('regtest') zcashd = zcash.rpc.Proxy() FEE = 0.001*COIN def get_keys(funder_address, redeemer_address): fundpubkey = CBitcoinAddress(funder_address) redeempubkey = CBitcoinAddress(redeemer_address) # fundpubkey = zcashd.getnewaddress() # redeempubkey = zcashd.getnewaddress() return fundpubkey, redeempubkey def privkey(address): zcashd.dumpprivkey(address) def hashtimelockcontract(funder, redeemer, hash_of_secret, lock_increment): funderAddr = CBitcoinAddress(funder) redeemerAddr = CBitcoinAddress(redeemer) blocknum = zcashd.getblockcount() print("Current blocknum", blocknum) redeemblocknum = blocknum + lock_increment print("REDEEMBLOCKNUM ZCASH", redeemblocknum) zec_redeemScript = CScript([OP_IF, OP_SHA256, hash_of_secret, OP_EQUALVERIFY,OP_DUP, OP_HASH160, redeemerAddr, OP_ELSE, redeemblocknum, OP_CHECKLOCKTIMEVERIFY, OP_DROP, OP_DUP, OP_HASH160, funderAddr, OP_ENDIF,OP_EQUALVERIFY, OP_CHECKSIG]) print("Redeem script for p2sh contract on Zcash blockchain:", b2x(zec_redeemScript)) txin_scriptPubKey = zec_redeemScript.to_p2sh_scriptPubKey() # Convert the P2SH scriptPubKey to a base58 Bitcoin address txin_p2sh_address = CBitcoinAddress.from_scriptPubKey(txin_scriptPubKey) p2sh = str(txin_p2sh_address) # Returning all this to be saved locally in p2sh.json return { 'redeemScript': b2x(zec_redeemScript), 'p2sh': p2sh} def fund_htlc(p2sh, amount): send_amount = float(amount)*COIN fund_txid = zcashd.sendtoaddress(p2sh, send_amount) txid = b2x(lx(b2x(fund_txid))) return txid def check_funds(p2sh): zcashd.importaddress(p2sh, "", False) #Ariel: changed this to true print("Imported address", p2sh) # Get amount in address amount = zcashd.getreceivedbyaddress(p2sh, 0) print("Amount in address", amount) amount = amount/COIN return amount def get_tx_details(txid): fund_txinfo = zcashd.gettransaction(txid) return fund_txinfo['details'][0] def find_transaction_to_address(p2sh): zcashd.importaddress(p2sh, "", False) txs = zcashd.listunspent() for tx in txs: if tx['address'] == CBitcoinAddress(p2sh): print("Found tx to p2sh", p2sh) return tx # def get_tx_details(txid): # # This method is problematic I haven't gotten the type conversions right # print(bytearray.fromhex(txid)) # print(b2x(bytearray.fromhex(txid))) # fund_txinfo = zcashd.gettransaction(bytearray.fromhex(txid)) # print(fund_txinfo) # # return fund_txinfo['details'][0] def find_secret(p2sh,vinid): zcashd.importaddress(p2sh, "", True) # is this working? txs = zcashd.listtransactions() # print("==========================================LISTTT============", txs) # print() # print('LENNNNNNN:', len(txs)) # print('LENNNNNNN2:', len(txs)) for tx in txs: # print("tx addr:", tx['address'], "tx id:", tx['txid']) # print(type(tx['address'])) # print(type(p2sh)) # print('type::',type(tx['txid'])) raw = zcashd.gettransaction(lx(tx['txid']))['hex'] decoded = zcashd.decoderawtransaction(raw) # print("fdsfdfds", decoded['vin'][0]) if('txid' in decoded['vin'][0]): sendid = decoded['vin'][0]['txid'] # print("sendid:", sendid) if (sendid == vinid ): # print(type(tx['txid'])) # print(str.encode(tx['txid'])) return parse_secret(lx(tx['txid'])) print("Redeem transaction with secret not found") return "" def parse_secret(txid): raw = zcashd.gettransaction(txid)['hex'] # print("Raw", raw) decoded = zcashd.decoderawtransaction(raw) scriptSig = decoded['vin'][0]['scriptSig'] print("Decoded", scriptSig) asm = scriptSig['asm'].split(" ") pubkey = asm[1] secret = hex2str(asm[2]) redeemPubkey = P2PKHBitcoinAddress.from_pubkey(x(pubkey)) print('redeemPubkey', redeemPubkey) print(secret) return secret # redeems automatically after buyer has funded tx, by scanning for transaction to the p2sh # i.e., doesn't require buyer telling us fund txid def auto_redeem(p2sh, secret): # How to find redeemScript and redeemblocknum from blockchain? print("Contract in auto redeem", contract.__dict__) p2sh = contract.p2sh #checking there are funds in the address amount = check_funds(p2sh) if(amount == 0): print("address ", p2sh, " not funded") quit() fundtx = find_transaction_to_address(p2sh) amount = fundtx['amount'] / COIN p2sh = P2SHBitcoinAddress(p2sh) if fundtx['address'] == p2sh: print("Found {0} in p2sh {1}, redeeming...".format(amount, p2sh)) # Parsing redeemblocknum from the redeemscript of the p2sh redeemblocknum = find_redeemblocknum(contract) blockcount = zcashd.getblockcount() print("\nCurrent blocknum at time of redeem on Zcash chain:", blockcount) if blockcount < redeemblocknum: redeemPubKey = find_redeemAddr(contract) print('redeemPubKey', redeemPubKey) else: print("nLocktime exceeded, refunding") redeemPubKey = find_refundAddr(contract) print('refundPubKey', redeemPubKey) # redeemPubKey = CBitcoinAddress.from_scriptPubKey(redeemPubKey) # exit() zec_redeemScript = CScript(x(contract.redeemScript)) txin = CMutableTxIn(fundtx['outpoint']) txout = CMutableTxOut(fundtx['amount'] - FEE, redeemPubKey.to_scriptPubKey()) # Create the unsigned raw transaction. tx = CMutableTransaction([txin], [txout]) # nLockTime needs to be at least as large as parameter of CHECKLOCKTIMEVERIFY for script to verify # TODO: these things like redeemblocknum should really be properties of a tx class... # Need: redeemblocknum, zec_redeemScript, secret (for creator...), txid, redeemer... if blockcount >= redeemblocknum: print("\nLocktime exceeded") tx.nLockTime = redeemblocknum sighash = SignatureHash(zec_redeemScript, tx, 0, SIGHASH_ALL) # TODO: figure out how to better protect privkey privkey = zcashd.dumpprivkey(redeemPubKey) sig = privkey.sign(sighash) + bytes([SIGHASH_ALL]) print("SECRET", secret) preimage = secret.encode('utf-8') txin.scriptSig = CScript([sig, privkey.pub, preimage, OP_TRUE, zec_redeemScript]) # exit() # print("txin.scriptSig", b2x(txin.scriptSig)) txin_scriptPubKey = zec_redeemScript.to_p2sh_scriptPubKey() # print('Redeem txhex', b2x(tx.serialize())) VerifyScript(txin.scriptSig, txin_scriptPubKey, tx, 0, (SCRIPT_VERIFY_P2SH,)) print("script verified, sending raw tx") txid = bitcoind.sendrawtransaction(tx) print("Txid of submitted redeem tx: ", b2x(lx(b2x(txid)))) return b2x(lx(b2x(txid))) else: print("No contract for this p2sh found in database", p2sh) def parse_script(script_hex): redeemScript = zcashd.decodescript(script_hex) scriptarray = redeemScript['asm'].split(' ') return scriptarray def find_redeemblocknum(redeemscript): scriptarray = parse_script(redeemScript) redeemblocknum = scriptarray[8] return int(redeemblocknum) def find_redeemAddr(redeemscript): scriptarray = parse_script(redeemScript) redeemer = scriptarray[6] redeemAddr = P2PKHBitcoinAddress.from_bytes(x(redeemer)) return redeemAddr def find_refundAddr(redeemscript): scriptarray = parse_script(redeemScript) funder = scriptarray[13] refundAddr = P2PKHBitcoinAddress.from_bytes(x(funder)) return refundAddr def find_recipient(contract): # make this dependent on actual fund tx to p2sh, not contract txid = contract.fund_tx raw = zcashd.gettransaction(lx(txid), True)['hex'] # print("Raw", raw) decoded = zcashd.decoderawtransaction(raw) scriptSig = decoded['vin'][0]['scriptSig'] print("Decoded", scriptSig) asm = scriptSig['asm'].split(" ") pubkey = asm[1] initiator = CBitcoinAddress(contract.initiator) fulfiller = CBitcoinAddress(contract.fulfiller) print("Initiator", b2x(initiator)) print("Fulfiler", b2x(fulfiller)) print('pubkey', pubkey) redeemPubkey = P2PKHBitcoinAddress.from_pubkey(x(pubkey)) print('redeemPubkey', redeemPubkey) # addr = CBitcoinAddress('tmFRXyju7ANM7A9mg75ZjyhFW1UJEhUPwfQ') # print(addr) # # print(b2x('tmFRXyju7ANM7A9mg75ZjyhFW1UJEhUPwfQ')) # print(b2x(addr)) def new_zcash_addr(): addr = zcashd.getnewaddress() print('new ZEC addr', addr) return addr def generate(num): blocks = zcashd.generate(num) return blocks # redeems funded tx automatically, by scanning for transaction to the p2sh # i.e., doesn't require buyer telling us fund txid # returns false if fund tx doesn't exist or is too small # minamout - the minimal amount your're expecting # assumes your Zcash client has the private key of the legit redeemer def redeem_with_secret(redeemscript,secret,p2sh,minamount): # How to find redeemScript and redeemblocknum from blockchain? # print("Redeeming contract using secret", contract.__dict__) #checking there are funds in the address amount = check_funds(p2sh) if(amount < minamount): print("address ", p2sh, " not sufficiently funded") return false fundtx = find_transaction_to_address(p2sh) amount = fundtx['amount'] / COIN p2sh = P2SHBitcoinAddress(p2sh) if fundtx['address'] == p2sh: print("Found {0} in p2sh {1}, redeeming...".format(amount, p2sh)) redeemPubKey = find_redeemAddr(redeemscript) print('redeemPubKey', redeemPubKey) redeemScriptObject = CScript(x(redeemScript)) txin = CMutableTxIn(fundtx['outpoint']) txout = CMutableTxOut(fundtx['amount'] - FEE, redeemPubKey.to_scriptPubKey()) # Create the unsigned raw transaction. tx = CMutableTransaction([txin], [txout]) sighash = SignatureHash(redeemScriptObject, tx, 0, SIGHASH_ALL) # TODO: figure out how to better protect privkey privkey = zcashd.dumpprivkey(redeemPubKey) sig = privkey.sign(sighash) + bytes([SIGHASH_ALL]) print("SECRET", secret) preimage = secret.encode('utf-8') txin.scriptSig = CScript([sig, privkey.pub, preimage, OP_TRUE, redeemScriptObject]) # exit() # print("txin.scriptSig", b2x(txin.scriptSig)) txin_scriptPubKey = redeemScriptObject.to_p2sh_scriptPubKey() # print('Redeem txhex', b2x(tx.serialize())) VerifyScript(txin.scriptSig, txin_scriptPubKey, tx, 0, (SCRIPT_VERIFY_P2SH,)) print("script verified, sending raw tx") txid = zcashd.sendrawtransaction(tx) print("Txid of submitted redeem tx: ", b2x(lx(b2x(txid)))) return b2x(lx(b2x(txid))) else: print("No contract for this p2sh found in database", p2sh) # given a contract return true or false according to whether the relevant fund tx's timelock is still valid def still_locked(contract): p2sh = contract.p2sh # Parsing redeemblocknum from the redeemscript of the p2sh redeemblocknum = find_redeemblocknum(contract) blockcount = zcashd.getblockcount() return (int(blockcount) < int(redeemblocknum)) def redeem_after_timelock(redeemscript,redeempubkey,p2sh,fund_txid): amount = fundtx['amount'] / COIN if (fundtx['address'].__str__() != p2sh): print("no fund transaction found to the contract p2sh address ",p2sh) quit() # print("Found fundtx:", fundtx) # Parsing redeemblocknum from the redeemscript of the p2sh redeemblocknum = find_redeemblocknum(redeemscript) blockcount = zcashd.getblockcount() print ("Current block:", blockcount, "Can redeem from block:", redeemblocknum) if(still_locked(contract)): print("too early for redeeming with timelock try again at block", redeemblocknum, "or later") return print("Found {0} in p2sh {1}, redeeming...".format(amount, p2sh)) redeemPubKey = find_refundAddr(redeemscript) print('refundPubKey', redeemPubKey) redeemScriptObject = CScript(x(contract.redeemScript)) txin = CMutableTxIn(fundtx['outpoint']) txout = CMutableTxOut(fundtx['amount'] - FEE, redeemPubKey.to_scriptPubKey()) # Create the unsigned raw transaction. txin.nSequence = 0 tx = CMutableTransaction([txin], [txout]) tx.nLockTime = redeemblocknum sighash = SignatureHash(redeemScriptObject, tx, 0, SIGHASH_ALL) # TODO: figure out how to better protect privkey privkey = zcashd.dumpprivkey(redeemPubKey) sig = privkey.sign(sighash) + bytes([SIGHASH_ALL]) txin.scriptSig = CScript([sig, privkey.pub, OP_FALSE, redeemScriptObject]) # exit() # print("txin.scriptSig", b2x(txin.scriptSig)) txin_scriptPubKey = redeemScriptObject.to_p2sh_scriptPubKey() # print('Redeem txhex', b2x(tx.serialize())) VerifyScript(txin.scriptSig, txin_scriptPubKey, tx, 0, (SCRIPT_VERIFY_P2SH,)) print("script verified, sending raw tx") txid = zcashd.sendrawtransaction(tx) print("Txid of submitted redeem tx: ", b2x(lx(b2x(txid)))) return b2x(lx(b2x(txid)))