1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
#!/usr/bin/env python3
# Copyright (c) 2015-2022 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."""
import struct
import time
import unittest
from .address import (
address_to_scriptpubkey,
key_to_p2sh_p2wpkh,
key_to_p2wpkh,
script_to_p2sh_p2wsh,
script_to_p2wsh,
)
from .messages import (
CBlock,
COIN,
COutPoint,
CTransaction,
CTxIn,
CTxInWitness,
CTxOut,
SEQUENCE_FINAL,
hash256,
ser_uint256,
tx_from_hex,
uint256_from_str,
WITNESS_SCALE_FACTOR,
)
from .script import (
CScript,
CScriptNum,
CScriptOp,
OP_1,
OP_RETURN,
OP_TRUE,
)
from .script_util import (
key_to_p2pk_script,
key_to_p2wpkh_script,
keys_to_multisig_script,
script_to_p2wsh_script,
)
from .util import assert_equal
MAX_BLOCK_SIGOPS = 20000
MAX_BLOCK_SIGOPS_WEIGHT = MAX_BLOCK_SIGOPS * WITNESS_SCALE_FACTOR
MAX_STANDARD_TX_WEIGHT = 400000
# Genesis block time (regtest)
TIME_GENESIS_BLOCK = 1296688602
MAX_FUTURE_BLOCK_TIME = 2 * 60 * 60
# Coinbase transaction outputs can only be spent after this number of new blocks (network rule)
COINBASE_MATURITY = 100
# From BIP141
WITNESS_COMMITMENT_HEADER = b"\xaa\x21\xa9\xed"
NORMAL_GBT_REQUEST_PARAMS = {"rules": ["segwit"]}
VERSIONBITS_LAST_OLD_BLOCK_VERSION = 4
MIN_BLOCKS_TO_KEEP = 288
def create_block(hashprev=None, coinbase=None, ntime=None, *, version=None, tmpl=None, txlist=None):
"""Create a block (with regtest difficulty)."""
block = CBlock()
if tmpl is None:
tmpl = {}
block.nVersion = version or tmpl.get('version') or VERSIONBITS_LAST_OLD_BLOCK_VERSION
block.nTime = ntime or tmpl.get('curtime') or int(time.time() + 600)
block.hashPrevBlock = hashprev or int(tmpl['previousblockhash'], 0x10)
if tmpl and not tmpl.get('bits') is None:
block.nBits = struct.unpack('>I', bytes.fromhex(tmpl['bits']))[0]
else:
block.nBits = 0x207fffff # difficulty retargeting is disabled in REGTEST chainparams
if coinbase is None:
coinbase = create_coinbase(height=tmpl['height'])
block.vtx.append(coinbase)
if txlist:
for tx in txlist:
if not hasattr(tx, 'calc_sha256'):
tx = tx_from_hex(tx)
block.vtx.append(tx)
block.hashMerkleRoot = block.calc_merkle_root()
block.calc_sha256()
return block
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])
def add_witness_commitment(block, nonce=0):
"""Add a witness commitment to the block's coinbase transaction.
According to BIP141, blocks with witness rules active must commit to the
hash of all in-block transactions including witness."""
# 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 script_BIP34_coinbase_height(height):
if height <= 16:
res = CScriptOp.encode_op_n(height)
# Append dummy to increase scriptSig size above 2 (see bad-cb-length consensus rule)
return CScript([res, OP_1])
return CScript([CScriptNum(height)])
def create_coinbase(height, pubkey=None, *, script_pubkey=None, extra_output_script=None, fees=0, nValue=50):
"""Create a coinbase transaction.
If pubkey is passed in, the coinbase output will be a P2PK output;
otherwise an anyone-can-spend output.
If extra_output_script is given, make a 0-value output to that
script. This is useful to pad block weight/sigops as needed. """
coinbase = CTransaction()
coinbase.vin.append(CTxIn(COutPoint(0, 0xffffffff), script_BIP34_coinbase_height(height), SEQUENCE_FINAL))
coinbaseoutput = CTxOut()
coinbaseoutput.nValue = nValue * COIN
if nValue == 50:
halvings = int(height / 150) # regtest
coinbaseoutput.nValue >>= halvings
coinbaseoutput.nValue += fees
if pubkey is not None:
coinbaseoutput.scriptPubKey = key_to_p2pk_script(pubkey)
elif script_pubkey is not None:
coinbaseoutput.scriptPubKey = script_pubkey
else:
coinbaseoutput.scriptPubKey = CScript([OP_TRUE])
coinbase.vout = [coinbaseoutput]
if extra_output_script is not None:
coinbaseoutput2 = CTxOut()
coinbaseoutput2.nValue = 0
coinbaseoutput2.scriptPubKey = extra_output_script
coinbase.vout.append(coinbaseoutput2)
coinbase.calc_sha256()
return coinbase
def create_tx_with_script(prevtx, n, script_sig=b"", *, amount, output_script=None):
"""Return one-input, one-output transaction object
spending the prevtx's n-th output with the given amount.
Can optionally pass scriptPubKey and scriptSig, default is anyone-can-spend output.
"""
if output_script is None:
output_script = CScript()
tx = CTransaction()
assert n < len(prevtx.vout)
tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), script_sig, SEQUENCE_FINAL))
tx.vout.append(CTxOut(amount, output_script))
tx.calc_sha256()
return tx
def get_legacy_sigopcount_block(block, accurate=True):
count = 0
for tx in block.vtx:
count += get_legacy_sigopcount_tx(tx, accurate)
return count
def get_legacy_sigopcount_tx(tx, accurate=True):
count = 0
for i in tx.vout:
count += i.scriptPubKey.GetSigOpCount(accurate)
for j in tx.vin:
# scriptSig might be of type bytes, so convert to CScript for the moment
count += CScript(j.scriptSig).GetSigOpCount(accurate)
return count
def witness_script(use_p2wsh, pubkey):
"""Create a scriptPubKey for a pay-to-witness TxOut.
This is 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."""
if not use_p2wsh:
# P2WPKH instead
pkscript = key_to_p2wpkh_script(pubkey)
else:
# 1-of-1 multisig
witness_script = keys_to_multisig_script([pubkey])
pkscript = script_to_p2wsh_script(witness_script)
return pkscript.hex()
def create_witness_tx(node, use_p2wsh, utxo, pubkey, encode_p2sh, amount):
"""Return a transaction (in hex) that spends the given utxo to a segwit output.
Optionally wrap the segwit output using P2SH."""
if use_p2wsh:
program = keys_to_multisig_script([pubkey])
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(address_to_scriptpubkey(addr).hex(), witness_script(use_p2wsh, pubkey))
return node.createrawtransaction([utxo], {addr: amount})
def send_to_witness(use_p2wsh, node, utxo, pubkey, encode_p2sh, amount, sign=True, insert_redeem_script=""):
"""Create a transaction spending a given utxo to a segwit output.
The output corresponds 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."""
tx_to_witness = create_witness_tx(node, use_p2wsh, utxo, pubkey, encode_p2sh, amount)
if (sign):
signed = node.signrawtransactionwithwallet(tx_to_witness)
assert "errors" not in signed or len(["errors"]) == 0
return node.sendrawtransaction(signed["hex"])
else:
if (insert_redeem_script):
tx = tx_from_hex(tx_to_witness)
tx.vin[0].scriptSig += CScript([bytes.fromhex(insert_redeem_script)])
tx_to_witness = tx.serialize().hex()
return node.sendrawtransaction(tx_to_witness)
class TestFrameworkBlockTools(unittest.TestCase):
def test_create_coinbase(self):
height = 20
coinbase_tx = create_coinbase(height=height)
assert_equal(CScriptNum.decode(coinbase_tx.vin[0].scriptSig), height)
|
