def computeAuxpowWithChainId(block, target, chainid, ok):
"""
Build an auxpow object (serialised as hex string) that solves the
block, for a given chain id.
"""
# Start by building the merge-mining coinbase. The merkle tree
# consists only of the block hash as root.
coinbase = "fabe" + binascii.hexlify("m" * 2)
coinbase += block
coinbase += "01000000" + ("00" * 4)
# Construct "vector" of transaction inputs.
vin = "01"
vin += ("00" * 32) + ("ff" * 4)
vin += ("%02x" % (len(coinbase) / 2)) + coinbase
vin += ("ff" * 4)
# Build up the full coinbase transaction. It consists only
# of the input and has no outputs.
tx = "01000000" + vin + "00" + ("00" * 4)
txHash = auxpow.doubleHashHex(tx)
# Construct the parent block header. It need not be valid, just good
# enough for auxpow purposes.
header = "0100" + chainid + "00"
header += "00" * 32
header += auxpow.reverseHex(txHash)
header += "00" * 4
header += "00" * 4
header += "00" * 4
# Mine the block.
(header, blockhash) = mineScryptBlock(header, target, ok)
# Build the MerkleTx part of the auxpow.
output = tx
output += blockhash
output += "00"
output += "00" * 4
# Extend to full auxpow.
output += "00"
output += "00" * 4
output += header
return output
def computeAuxpowWithChainId (block, target, chainid, ok):
"""
Build an auxpow object (serialised as hex string) that solves the
block, for a given chain id.
"""
# Start by building the merge-mining coinbase. The merkle tree
# consists only of the block hash as root.
coinbase = "fabe" + binascii.hexlify ("m" * 2)
coinbase += block
coinbase += "01000000" + ("00" * 4)
# Construct "vector" of transaction inputs.
vin = "01"
vin += ("00" * 32) + ("ff" * 4)
vin += ("%02x" % (len (coinbase) / 2)) + coinbase
vin += ("ff" * 4)
# Build up the full coinbase transaction. It consists only
# of the input and has no outputs.
tx = "01000000" + vin + "00" + ("00" * 4)
txHash = auxpow.doubleHashHex (tx)
# Construct the parent block header. It need not be valid, just good
# enough for auxpow purposes.
header = "0100" + chainid + "00"
header += "00" * 32
header += auxpow.reverseHex (txHash)
header += "00" * 4
header += "00" * 4
header += "00" * 4
# Mine the block.
(header, blockhash) = mineScryptBlock (header, target, ok)
# Build the MerkleTx part of the auxpow.
output = tx
output += blockhash
output += "00"
output += "00" * 4
# Extend to full auxpow.
output += "00"
output += "00" * 4
output += header
return output
def mineScryptBlock(header, target, ok):
"""
Given a block header, update the nonce until it is ok (or not)
for the given target.
"""
data = bytearray(binascii.unhexlify(header))
while True:
assert data[79] < 255
data[79] += 1
hexData = binascii.hexlify(data)
scrypt = getScryptPoW(hexData)
if (ok and scrypt < target) or ((not ok) and scrypt > target):
break
blockhash = auxpow.doubleHashHex(hexData)
return (hexData, blockhash)
def mineScryptBlock (header, target, ok):
"""
Given a block header, update the nonce until it is ok (or not)
for the given target.
"""
data = bytearray (binascii.unhexlify (header))
while True:
assert data[79] < 255
data[79] += 1
hexData = binascii.hexlify (data)
scrypt = getScryptPoW(hexData)
if (ok and scrypt < target) or ((not ok) and scrypt > target):
break
blockhash = auxpow.doubleHashHex (hexData)
return (hexData, blockhash)
