#!/usr/bin/env python3 # Copyright (c) 2015-2016 The Bitcoin Core developers # Distributed under the MIT software license, see the accompanying # file COPYING or http://www.opensource.org/licenses/mit-license.php. """Utilities for manipulating blocks and transactions.""" from .address import ( key_to_p2sh_p2wpkh, key_to_p2sh_p2wpkh, key_to_p2wpkh, script_to_p2sh_p2wsh, script_to_p2wsh, ) from .mininode import * from .script import ( CScript, OP_0, OP_1, OP_CHECKMULTISIG, OP_CHECKSIG, OP_EQUAL, OP_HASH160, OP_RETURN, OP_TRUE, hash160, ) from .util import assert_equal # Create a block (with regtest difficulty) def create_block(hashprev, coinbase, nTime=None): block = CBlock() if nTime is None: import time block.nTime = int(time.time()+600) else: block.nTime = nTime block.hashPrevBlock = hashprev block.nBits = 0x207fffff # Will break after a difficulty adjustment... block.vtx.append(coinbase) block.hashMerkleRoot = block.calc_merkle_root() block.calc_sha256() return block # From BIP141 WITNESS_COMMITMENT_HEADER = b"\xaa\x21\xa9\xed" def get_witness_script(witness_root, witness_nonce): witness_commitment = uint256_from_str(hash256(ser_uint256(witness_root)+ser_uint256(witness_nonce))) output_data = WITNESS_COMMITMENT_HEADER + ser_uint256(witness_commitment) return CScript([OP_RETURN, output_data]) # According to BIP141, blocks with witness rules active must commit to the # hash of all in-block transactions including witness. def add_witness_commitment(block, nonce=0): # First calculate the merkle root of the block's # transactions, with witnesses. witness_nonce = nonce witness_root = block.calc_witness_merkle_root() # witness_nonce should go to coinbase witness. block.vtx[0].wit.vtxinwit = [CTxInWitness()] block.vtx[0].wit.vtxinwit[0].scriptWitness.stack = [ser_uint256(witness_nonce)] # witness commitment is the last OP_RETURN output in coinbase block.vtx[0].vout.append(CTxOut(0, get_witness_script(witness_root, witness_nonce))) block.vtx[0].rehash() block.hashMerkleRoot = block.calc_merkle_root() block.rehash() def serialize_script_num(value): r = bytearray(0) if value == 0: return r neg = value < 0 absvalue = -value if neg else value while (absvalue): r.append(int(absvalue & 0xff)) absvalue >>= 8 if r[-1] & 0x80: r.append(0x80 if neg else 0) elif neg: r[-1] |= 0x80 return r # Create a coinbase transaction, assuming no miner fees. # If pubkey is passed in, the coinbase output will be a P2PK output; # otherwise an anyone-can-spend output. def create_coinbase(height, pubkey = None): coinbase = CTransaction() coinbase.vin.append(CTxIn(COutPoint(0, 0xffffffff), ser_string(serialize_script_num(height)), 0xffffffff)) coinbaseoutput = CTxOut() coinbaseoutput.nValue = 50 * COIN halvings = int(height/150) # regtest coinbaseoutput.nValue >>= halvings if (pubkey != None): coinbaseoutput.scriptPubKey = CScript([pubkey, OP_CHECKSIG]) else: coinbaseoutput.scriptPubKey = CScript([OP_TRUE]) coinbase.vout = [ coinbaseoutput ] coinbase.calc_sha256() return coinbase # Create a transaction. # If the scriptPubKey is not specified, make it anyone-can-spend. def create_transaction(prevtx, n, sig, value, scriptPubKey=CScript()): tx = CTransaction() assert(n < len(prevtx.vout)) tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), sig, 0xffffffff)) tx.vout.append(CTxOut(value, scriptPubKey)) tx.calc_sha256() return tx def get_legacy_sigopcount_block(block, fAccurate=True): count = 0 for tx in block.vtx: count += get_legacy_sigopcount_tx(tx, fAccurate) return count def get_legacy_sigopcount_tx(tx, fAccurate=True): count = 0 for i in tx.vout: count += i.scriptPubKey.GetSigOpCount(fAccurate) for j in tx.vin: # scriptSig might be of type bytes, so convert to CScript for the moment count += CScript(j.scriptSig).GetSigOpCount(fAccurate) return count # Create a scriptPubKey corresponding to either a P2WPKH output for the # given pubkey, or a P2WSH output of a 1-of-1 multisig for the given # pubkey. Returns the hex encoding of the scriptPubKey. def witness_script(use_p2wsh, pubkey): if (use_p2wsh == False): # P2WPKH instead pubkeyhash = hash160(hex_str_to_bytes(pubkey)) pkscript = CScript([OP_0, pubkeyhash]) else: # 1-of-1 multisig witness_program = CScript([OP_1, hex_str_to_bytes(pubkey), OP_1, OP_CHECKMULTISIG]) scripthash = sha256(witness_program) pkscript = CScript([OP_0, scripthash]) return bytes_to_hex_str(pkscript) # Return a transaction (in hex) that spends the given utxo to a segwit output, # optionally wrapping the segwit output using P2SH. def create_witness_tx(node, use_p2wsh, utxo, pubkey, encode_p2sh, amount): if use_p2wsh: program = CScript([OP_1, hex_str_to_bytes(pubkey), OP_1, OP_CHECKMULTISIG]) addr = script_to_p2sh_p2wsh(program) if encode_p2sh else script_to_p2wsh(program) else: addr = key_to_p2sh_p2wpkh(pubkey) if encode_p2sh else key_to_p2wpkh(pubkey) if not encode_p2sh: assert_equal(node.validateaddress(addr)['scriptPubKey'], witness_script(use_p2wsh, pubkey)) return node.createrawtransaction([utxo], {addr: amount}) # Create a transaction spending a given utxo to a segwit output corresponding # to the given pubkey: use_p2wsh determines whether to use P2WPKH or P2WSH; # encode_p2sh determines whether to wrap in P2SH. # sign=True will have the given node sign the transaction. # insert_redeem_script will be added to the scriptSig, if given. def send_to_witness(use_p2wsh, node, utxo, pubkey, encode_p2sh, amount, sign=True, insert_redeem_script=""): tx_to_witness = create_witness_tx(node, use_p2wsh, utxo, pubkey, encode_p2sh, amount) if (sign): signed = node.signrawtransaction(tx_to_witness) assert("errors" not in signed or len(["errors"]) == 0) return node.sendrawtransaction(signed["hex"]) else: if (insert_redeem_script): tx = FromHex(CTransaction(), tx_to_witness) tx.vin[0].scriptSig += CScript([hex_str_to_bytes(insert_redeem_script)]) tx_to_witness = ToHex(tx) return node.sendrawtransaction(tx_to_witness)