def _create_apkh2pkh_transaction(cold_storage_key, signing_key, certificate,
unspent, output):
"""Create a ArculaPublicKeyHash2PublicKeyHash transaction."""
certificate, (public_signing_key, identifier) = certificate
script_code = arcula_locking_script(cold_storage_key, identifier)
tx_in, hashed, output_block = _tx_in_boilerplate(unspent, output,
script_code,
construct_output_block)
signature = signing_key.sign(hashed) + b'\x41'
unlocking_script = (int_to_varint(len(signature)) + signature +
int_to_varint(len(certificate)) + certificate +
int_to_varint(len(public_signing_key)) +
public_signing_key)
return _tx_out_boilerplate(tx_in, unlocking_script, output_block)
def create_p2pkh_transaction(private_key,
unspents,
outputs,
custom_pushdata=False):
public_key = private_key.public_key
public_key_len = len(public_key).to_bytes(1, byteorder="little")
scriptCode = private_key.scriptcode
scriptCode_len = int_to_varint(len(scriptCode))
version = VERSION_1
lock_time = LOCK_TIME
# sequence = SEQUENCE
hash_type = HASH_TYPE
input_count = int_to_unknown_bytes(len(unspents), byteorder="little")
output_count = int_to_unknown_bytes(len(outputs), byteorder="little")
output_block = construct_output_block(outputs,
custom_pushdata=custom_pushdata)
# Optimize for speed, not memory, by pre-computing values.
inputs = []
for unspent in unspents:
script = hex_to_bytes(unspent.script)
script_len = int_to_unknown_bytes(len(script), byteorder="little")
txid = hex_to_bytes(unspent.txid)[::-1]
txindex = unspent.txindex.to_bytes(4, byteorder="little")
amount = unspent.amount.to_bytes(8, byteorder="little")
inputs.append(TxIn(script, script_len, txid, txindex, amount))
hashPrevouts = double_sha256(b"".join([i.txid + i.txindex
for i in inputs]))
hashSequence = double_sha256(b"".join([SEQUENCE for i in inputs]))
hashOutputs = double_sha256(output_block)
# scriptCode_len is part of the script.
for i, txin in enumerate(inputs):
to_be_hashed = (version + hashPrevouts + hashSequence + txin.txid +
txin.txindex + scriptCode_len + scriptCode +
txin.amount + SEQUENCE + hashOutputs + lock_time +
hash_type)
hashed = sha256(to_be_hashed) # BIP-143: Used for Bitcoin Cash
# signature = private_key.sign(hashed) + b'\x01'
signature = private_key.sign(hashed) + b"\x41"
script_sig = (len(signature).to_bytes(1, byteorder="little") +
signature + public_key_len + public_key)
inputs[i].script = script_sig
inputs[i].script_len = int_to_unknown_bytes(len(script_sig),
byteorder="little")
return bytes_to_hex(version + input_count + construct_input_block(inputs) +
output_count + output_block + lock_time)
def get_headers_payload(block_locator_hash,
hash_stop="0000000000000000000000000000000000000000000000000000000000000000"):
"""makes a getheaders serialized payload"""
version = struct.pack("i", 70015)
hash_count = ut.int_to_varint(1)
block_locator_hash = ut.hex_to_bytes(ut.flip_hex_byte_order(block_locator_hash))
hash_stop = ut.hex_to_bytes(hash_stop)
payload = version + hash_count + block_locator_hash + hash_stop
return payload
def _tx_in_boilerplate(unspent, output, script_code, construct_output_block_f):
script = hex_to_bytes(unspent.script)
script_len = int_to_unknown_bytes(len(script), byteorder='little')
tx_id = hex_to_bytes(unspent.txid)[::-1]
tx_index = unspent.txindex.to_bytes(4, byteorder='little')
amount = unspent.amount.to_bytes(8, byteorder='little')
tx_in = TxIn(script, script_len, tx_id, tx_index, amount)
hash_previous_outputs = double_sha256(tx_id + tx_index)
hash_sequence = double_sha256(SEQUENCE)
output_block = construct_output_block_f([output])
hash_outputs = double_sha256(output_block)
to_be_hashed = (VERSION_1 + hash_previous_outputs + hash_sequence +
tx_in.txid + tx_in.txindex +
int_to_varint(len(script_code)) + script_code +
tx_in.amount + SEQUENCE + hash_outputs + LOCK_TIME +
HASH_TYPE)
hashed = sha256(to_be_hashed) # BIP-143: Used for Bitcoin Cash
return tx_in, hashed, output_block
def get_op_return_size(message, custom_pushdata=False):
# calculate op_return size for each individual message
if custom_pushdata is False:
op_return_size = (
8 # int64_t amount 0x00000000
+ len(OP_RETURN) # 1 byte
+ len(get_op_pushdata_code(
message)) # 1 byte if <75 bytes, 2 bytes if OP_PUSHDATA1...
+ len(message) # Max 220 bytes at present
)
if custom_pushdata is True:
op_return_size = (
8 # int64_t amount 0x00000000
+ len(OP_RETURN) # 1 byte
+ len(
message
) # Unsure if Max size will be >220 bytes due to extra OP_PUSHDATA codes...
)
# "Var_Int" that preceeds OP_RETURN - 0xdf is max value with current 220 byte limit (so only adds 1 byte)
op_return_size += len(int_to_varint(op_return_size))
return op_return_size
def test_val_more_than_4294967295(self):
assert int_to_varint(
10000000000) == b"\xff\x00\xe4\x0bT\x02\x00\x00\x00"
def test_val_less_than_4294967295(self):
assert int_to_varint(4294967294) == b"\xfe\xfe\xff\xff\xff"
def test_val_less_than_65535(self):
assert int_to_varint(65535) == b"\xfd\xff\xff"
