highperfocused/bitcoin
1
0
Fork 0
mirror of https://github.com/bitcoin/bitcoin.git synced 2026-06-05 10:42:13 +02:00
Code Issues Packages Projects Releases Wiki Activity

Merge bitcoin/bitcoin#29032: signet: omit commitment for some trivial challenges

Browse Source 
6ee32aaaca test: signet tool genpsbt and solvepsbt commands (Sjors Provoost)
0a99d99fe4 signet: miner skips PSBT step for OP_TRUE (Sjors Provoost)
cdfb70e5a6 signet: split decode_psbt miner helper (Sjors Provoost)

Pull request description:

  [BIP325](https://github.com/bitcoin/bips/blob/master/bip-0325.mediawiki) mentions the following rule:

  > In the special case where an empty solution is valid (ie scriptSig and scriptWitness are both empty) this additional commitment can optionally be left out. This special case is to allow non-signet-aware block generation code to be used to test a custom signet chain where the challenge is trivially true.

  Such a signet can be created using e.g. `-signetchallenge=51` (`OP_TRUE`). However `contrib/signet/miner` won't omit the commitment.

  This PR improves the miner by skipping the PSBT for known trivial scripts (just `OP_TRUE` and trivial pushes for now). This prevents it from appending the 4 byte signet header to the witness commitment, as allowed by the above rule.

  ---

  Previously the script would fail with `PSBT signing failed`, making it difficult to mine. This is no longer the case.

ACKs for top commit:
  achow101:
    ACK 6ee32aaaca
  theStack:
    re-ACK 6ee32aaaca
  danielabrozzoni:
    ACK 6ee32aaaca

Tree-SHA512: e47fbf471f2909286a6c1c073799ea388b9c19551afcce96cf9af45cc48d25c02f1e48e08861a88b604361e2c107a759d5baf393da8a37360de419f31651758a
This commit is contained in:
Ava Chow
2025-06-02 15:24:34 -07:00
parent f999c3775c 6ee32aaaca
commit 2d819fa4df
4 changed files with 160 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
contrib/signet/README.md
View File

@@ -80,3 +80,4 @@ These steps can instead be done explicitly:
This is intended to allow you to replace part of the pipeline for further experimentation (eg, to sign the block with a hardware wallet).
For custom signets with a trivial challenge such as `OP_TRUE` and `OP_2` the walletprocesspsbt step can be skipped.

84
contrib/signet/miner
View File

@@ -18,7 +18,7 @@ PATH_BASE_CONTRIB_SIGNET = os.path.abspath(os.path.dirname(os.path.realpath(__fi
PATH_BASE_TEST_FUNCTIONAL = os.path.abspath(os.path.join(PATH_BASE_CONTRIB_SIGNET, "..", "..", "test", "functional"))
sys.path.insert(0, PATH_BASE_TEST_FUNCTIONAL)
from test_framework.blocktools import get_witness_script, script_BIP34_coinbase_height # noqa: E402
from test_framework.blocktools import get_witness_script, script_BIP34_coinbase_height, SIGNET_HEADER # noqa: E402
from test_framework.messages import CBlock, CBlockHeader, COutPoint, CTransaction, CTxIn, CTxInWitness, CTxOut, from_binary, from_hex, ser_string, ser_uint256, tx_from_hex, MAX_SEQUENCE_NONFINAL # noqa: E402
from test_framework.psbt import PSBT, PSBTMap, PSBT_GLOBAL_UNSIGNED_TX, PSBT_IN_FINAL_SCRIPTSIG, PSBT_IN_FINAL_SCRIPTWITNESS, PSBT_IN_NON_WITNESS_UTXO, PSBT_IN_SIGHASH_TYPE # noqa: E402
from test_framework.script import CScript, CScriptOp # noqa: E402
@@ -28,7 +28,6 @@ logging.basicConfig(
level=logging.INFO,
datefmt='%Y-%m-%d %H:%M:%S')
SIGNET_HEADER = b"\xec\xc7\xda\xa2"
PSBT_SIGNET_BLOCK = b"\xfc\x06signetb" # proprietary PSBT global field holding the block being signed
RE_MULTIMINER = re.compile(r"^(\d+)(-(\d+))?/(\d+)$")
@@ -66,22 +65,31 @@ def signet_txs(block, challenge):
return spend, to_spend
def decode_psbt(b64psbt):
def decode_challenge_psbt(b64psbt):
psbt = PSBT.from_base64(b64psbt)
assert len(psbt.tx.vin) == 1
assert len(psbt.tx.vout) == 1
assert PSBT_SIGNET_BLOCK in psbt.g.map
return psbt
def get_block_from_psbt(psbt):
return from_binary(CBlock, psbt.g.map[PSBT_SIGNET_BLOCK])
def get_solution_from_psbt(psbt, emptyok=False):
scriptSig = psbt.i[0].map.get(PSBT_IN_FINAL_SCRIPTSIG, b"")
scriptWitness = psbt.i[0].map.get(PSBT_IN_FINAL_SCRIPTWITNESS, b"\x00")
return from_binary(CBlock, psbt.g.map[PSBT_SIGNET_BLOCK]), ser_string(scriptSig) + scriptWitness
if emptyok and len(scriptSig) == 0 and scriptWitness == b"\x00":
return None
return ser_string(scriptSig) + scriptWitness
def finish_block(block, signet_solution, grind_cmd):
block.vtx[0].vout[-1].scriptPubKey += CScriptOp.encode_op_pushdata(SIGNET_HEADER + signet_solution)
block.vtx[0].rehash()
block.hashMerkleRoot = block.calc_merkle_root()
if signet_solution is None:
pass # Don't need to add a signet commitment if there's no signet signature needed
else:
block.vtx[0].vout[-1].scriptPubKey += CScriptOp.encode_op_pushdata(SIGNET_HEADER + signet_solution)
block.vtx[0].rehash()
block.hashMerkleRoot = block.calc_merkle_root()
if grind_cmd is None:
block.solve()
else:
@@ -93,10 +101,7 @@ def finish_block(block, signet_solution, grind_cmd):
block.rehash()
return block
def generate_psbt(tmpl, reward_spk, *, blocktime=None, poolid=None):
signet_spk = tmpl["signet_challenge"]
signet_spk_bin = bytes.fromhex(signet_spk)
def new_block(tmpl, reward_spk, *, blocktime=None, poolid=None):
scriptSig = script_BIP34_coinbase_height(tmpl["height"])
if poolid is not None:
scriptSig = CScript(b"" + scriptSig + CScriptOp.encode_op_pushdata(poolid))
@@ -125,8 +130,14 @@ def generate_psbt(tmpl, reward_spk, *, blocktime=None, poolid=None):
block.vtx[0].wit.vtxinwit = [cbwit]
block.vtx[0].vout.append(CTxOut(0, bytes(get_witness_script(witroot, witnonce))))
signme, spendme = signet_txs(block, signet_spk_bin)
block.vtx[0].rehash()
block.hashMerkleRoot = block.calc_merkle_root()
return block
def generate_psbt(block, signet_spk):
signet_spk_bin = bytes.fromhex(signet_spk)
signme, spendme = signet_txs(block, signet_spk_bin)
psbt = PSBT()
psbt.g = PSBTMap( {PSBT_GLOBAL_UNSIGNED_TX: signme.serialize(),
PSBT_SIGNET_BLOCK: block.serialize()
@@ -175,12 +186,16 @@ def get_reward_addr_spk(args, height):
def do_genpsbt(args):
poolid = get_poolid(args)
tmpl = json.load(sys.stdin)
signet_spk = tmpl["signet_challenge"]
_, reward_spk = get_reward_addr_spk(args, tmpl["height"])
psbt = generate_psbt(tmpl, reward_spk, poolid=poolid)
block = new_block(tmpl, reward_spk, poolid=poolid)
psbt = generate_psbt(block, signet_spk)
print(psbt)
def do_solvepsbt(args):
block, signet_solution = decode_psbt(sys.stdin.read())
psbt = decode_challenge_psbt(sys.stdin.read())
block = get_block_from_psbt(psbt)
signet_solution = get_solution_from_psbt(psbt, emptyok=True)
block = finish_block(block, signet_solution, args.grind_cmd)
print(block.serialize().hex())
@@ -223,6 +238,21 @@ def seconds_to_hms(s):
out = "-" + out
return out
def trivial_challenge(spkhex):
"""
BIP325 allows omitting the signet commitment when scriptSig and
scriptWitness are both empty. This is the case for trivial
challenges such as OP_TRUE or a single data push.
"""
spk = bytes.fromhex(spkhex)
if len(spk) == 1 and 0x51 <= spk[0] <= 0x60:
# OP_TRUE/OP_1...OP_16
return True
elif 2 <= len(spk) <= 76 and spk[0] + 1 == len(spk):
# Single fixed push of 1-75 bytes
return True
return False
class Generate:
INTERVAL = 600.0*2016/2015 # 10 minutes, adjusted for the off-by-one bug
@@ -323,14 +353,22 @@ class Generate:
return tmpl
def mine(self, bcli, grind_cmd, tmpl, reward_spk):
psbt = generate_psbt(tmpl, reward_spk, blocktime=self.mine_time, poolid=self.poolid)
input_stream = os.linesep.join([psbt, "true", "ALL"]).encode('utf8')
psbt_signed = json.loads(bcli("-stdin", "walletprocesspsbt", input=input_stream))
if not psbt_signed.get("complete",False):
logging.debug("Generated PSBT: %s" % (psbt,))
sys.stderr.write("PSBT signing failed\n")
return None
block, signet_solution = decode_psbt(psbt_signed["psbt"])
block = new_block(tmpl, reward_spk, blocktime=self.mine_time, poolid=self.poolid)
signet_spk = tmpl["signet_challenge"]
if trivial_challenge(signet_spk):
signet_solution = None
else:
psbt = generate_psbt(block, signet_spk)
input_stream = os.linesep.join([psbt, "true", "ALL"]).encode('utf8')
psbt_signed = json.loads(bcli("-stdin", "walletprocesspsbt", input=input_stream))
if not psbt_signed.get("complete",False):
logging.debug("Generated PSBT: %s" % (psbt,))
sys.stderr.write("PSBT signing failed\n")
return None
psbt = decode_challenge_psbt(psbt_signed["psbt"])
signet_solution = get_solution_from_psbt(psbt)
return finish_block(block, signet_solution, grind_cmd)
def do_generate(args):