test/functional/test_framework/blocktools.py

   1 #!/usr/bin/env python3
   2 # Copyright (c) 2015-2016 The Bitcoin Core developers
   3 # Distributed under the MIT software license, see the accompanying
   4 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5 """Utilities for manipulating blocks and transactions."""
   6
   7 from .mininode import *
   8 from .script import CScript, OP_TRUE, OP_CHECKSIG, OP_RETURN
   9
  10 # Create a block (with regtest difficulty)
  11 def create_block(hashprev, coinbase, nTime=None):
  12     block = CBlock()
  13     if nTime is None:
  14         import time
  15         block.nTime = int(time.time()+600)
  16     else:
  17         block.nTime = nTime
  18     block.hashPrevBlock = hashprev
  19     block.nBits = 0x207fffff # Will break after a difficulty adjustment...
  20     block.vtx.append(coinbase)
  21     block.hashMerkleRoot = block.calc_merkle_root()
  22     block.calc_sha256()
  23     return block
  24
  25 # From BIP141
  26 WITNESS_COMMITMENT_HEADER = b"\xaa\x21\xa9\xed"
  27
  28
  29 def get_witness_script(witness_root, witness_nonce):
  30     witness_commitment = uint256_from_str(hash256(ser_uint256(witness_root)+ser_uint256(witness_nonce)))
  31     output_data = WITNESS_COMMITMENT_HEADER + ser_uint256(witness_commitment)
  32     return CScript([OP_RETURN, output_data])
  33
  34
  35 # According to BIP141, blocks with witness rules active must commit to the
  36 # hash of all in-block transactions including witness.
  37 def add_witness_commitment(block, nonce=0):
  38     # First calculate the merkle root of the block's
  39     # transactions, with witnesses.
  40     witness_nonce = nonce
  41     witness_root = block.calc_witness_merkle_root()
  42     # witness_nonce should go to coinbase witness.
  43     block.vtx[0].wit.vtxinwit = [CTxInWitness()]
  44     block.vtx[0].wit.vtxinwit[0].scriptWitness.stack = [ser_uint256(witness_nonce)]
  45
  46     # witness commitment is the last OP_RETURN output in coinbase
  47     block.vtx[0].vout.append(CTxOut(0, get_witness_script(witness_root, witness_nonce)))
  48     block.vtx[0].rehash()
  49     block.hashMerkleRoot = block.calc_merkle_root()
  50     block.rehash()
  51
  52
  53 def serialize_script_num(value):
  54     r = bytearray(0)
  55     if value == 0:
  56         return r
  57     neg = value < 0
  58     absvalue = -value if neg else value
  59     while (absvalue):
  60         r.append(int(absvalue & 0xff))
  61         absvalue >>= 8
  62     if r[-1] & 0x80:
  63         r.append(0x80 if neg else 0)
  64     elif neg:
  65         r[-1] |= 0x80
  66     return r
  67
  68 # Create a coinbase transaction, assuming no miner fees.
  69 # If pubkey is passed in, the coinbase output will be a P2PK output;
  70 # otherwise an anyone-can-spend output.
  71 def create_coinbase(height, pubkey = None):
  72     coinbase = CTransaction()
  73     coinbase.vin.append(CTxIn(COutPoint(0, 0xffffffff),
  74                 ser_string(serialize_script_num(height)), 0xffffffff))
  75     coinbaseoutput = CTxOut()
  76     coinbaseoutput.nValue = 50 * COIN
  77     halvings = int(height/150) # regtest
  78     coinbaseoutput.nValue >>= halvings
  79     if (pubkey != None):
  80         coinbaseoutput.scriptPubKey = CScript([pubkey, OP_CHECKSIG])
  81     else:
  82         coinbaseoutput.scriptPubKey = CScript([OP_TRUE])
  83     coinbase.vout = [ coinbaseoutput ]
  84     coinbase.calc_sha256()
  85     return coinbase
  86
  87 # Create a transaction.
  88 # If the scriptPubKey is not specified, make it anyone-can-spend.
  89 def create_transaction(prevtx, n, sig, value, scriptPubKey=CScript()):
  90     tx = CTransaction()
  91     assert(n < len(prevtx.vout))
  92     tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), sig, 0xffffffff))
  93     tx.vout.append(CTxOut(value, scriptPubKey))
  94     tx.calc_sha256()
  95     return tx
  96
  97 def get_legacy_sigopcount_block(block, fAccurate=True):
  98     count = 0
  99     for tx in block.vtx:
 100         count += get_legacy_sigopcount_tx(tx, fAccurate)
 101     return count
 102
 103 def get_legacy_sigopcount_tx(tx, fAccurate=True):
 104     count = 0
 105     for i in tx.vout:
 106         count += i.scriptPubKey.GetSigOpCount(fAccurate)
 107     for j in tx.vin:
 108         # scriptSig might be of type bytes, so convert to CScript for the moment
 109         count += CScript(j.scriptSig).GetSigOpCount(fAccurate)
 110     return count