"""Order utilities for 0x applications.
Some methods require the caller to pass in a `Web3.HTTPProvider` object. For
local testing one may construct such a provider pointing at an instance of
`ganache-cli <https://www.npmjs.com/package/ganache-cli>`_ which has the 0x
contracts deployed on it. For convenience, a docker container is provided for
just this purpose. To start it: ``docker run -d -p 8545:8545 0xorg/ganache-cli
--gasLimit 10000000 --db /snapshot --noVMErrorsOnRPCResponse -p 8545
--networkId 50 -m "concert load couple harbor equip island argue ramp clarify
fence smart topic"``.
"""
from enum import auto, Enum
import json
from typing import Dict, Tuple
from pkg_resources import resource_string
from mypy_extensions import TypedDict
from eth_utils import keccak, to_bytes, to_checksum_address
from web3 import Web3
import web3.exceptions
from web3.providers.base import BaseProvider
from web3.utils import datatypes
from zero_ex.dev_utils.type_assertions import (
assert_is_address,
assert_is_hex_string,
assert_is_provider,
)
from zero_ex.json_schemas import assert_valid
class _Constants:
"""Static data used by order utilities."""
_contract_name_to_abi: Dict[str, Dict] = {} # class data, not instance
@classmethod
def contract_name_to_abi(cls, contract_name: str) -> Dict:
"""Return the ABI for the given contract name.
First tries to get data from the class level storage
`_contract_name_to_abi`. If it's not there, loads it from disk, stores
it in the class data (for the next caller), and then returns it.
"""
try:
return cls._contract_name_to_abi[contract_name]
except KeyError:
cls._contract_name_to_abi[contract_name] = json.loads(
resource_string(
"zero_ex.contract_artifacts",
f"artifacts/{contract_name}.json",
)
)["compilerOutput"]["abi"]
return cls._contract_name_to_abi[contract_name]
network_to_exchange_addr: Dict[str, str] = {
"1": "0x4f833a24e1f95d70f028921e27040ca56e09ab0b",
"3": "0x4530c0483a1633c7a1c97d2c53721caff2caaaaf",
"42": "0x35dd2932454449b14cee11a94d3674a936d5d7b2",
"50": "0x48bacb9266a570d521063ef5dd96e61686dbe788",
}
null_address = "0x0000000000000000000000000000000000000000"
eip191_header = b"\x19\x01"
eip712_domain_separator_schema_hash = keccak(
b"EIP712Domain(string name,string version,address verifyingContract)"
)
eip712_domain_struct_header = (
eip712_domain_separator_schema_hash
+ keccak(b"0x Protocol")
+ keccak(b"2")
)
eip712_order_schema_hash = keccak(
b"Order("
+ b"address makerAddress,"
+ b"address takerAddress,"
+ b"address feeRecipientAddress,"
+ b"address senderAddress,"
+ b"uint256 makerAssetAmount,"
+ b"uint256 takerAssetAmount,"
+ b"uint256 makerFee,"
+ b"uint256 takerFee,"
+ b"uint256 expirationTimeSeconds,"
+ b"uint256 salt,"
+ b"bytes makerAssetData,"
+ b"bytes takerAssetData"
+ b")"
)
class SignatureType(Enum):
"""Enumeration of known signature types."""
ILLEGAL = 0
INVALID = auto()
EIP712 = auto()
ETH_SIGN = auto()
WALLET = auto()
VALIDATOR = auto()
PRE_SIGNED = auto()
N_SIGNATURE_TYPES = auto()
class Order(TypedDict): # pylint: disable=too-many-instance-attributes
"""Object representation of a 0x order."""
makerAddress: str
takerAddress: str
feeRecipientAddress: str
senderAddress: str
makerAssetAmount: str
takerAssetAmount: str
makerFee: str
takerFee: str
expirationTimeSeconds: str
salt: str
makerAssetData: str
takerAssetData: str
exchangeAddress: str
def make_empty_order() -> Order:
"""Construct an empty order.
Initializes all strings to "0x0000000000000000000000000000000000000000"
and all numbers to 0.
"""
return {
"makerAddress": _Constants.null_address,
"takerAddress": _Constants.null_address,
"senderAddress": _Constants.null_address,
"feeRecipientAddress": _Constants.null_address,
"makerAssetData": _Constants.null_address,
"takerAssetData": _Constants.null_address,
"salt": "0",
"makerFee": "0",
"takerFee": "0",
"makerAssetAmount": "0",
"takerAssetAmount": "0",
"expirationTimeSeconds": "0",
"exchangeAddress": _Constants.null_address,
}
def generate_order_hash_hex(order: Order) -> str:
"""Calculate the hash of the given order as a hexadecimal string.
:param order: The order to be hashed. Must conform to `the 0x order JSON schema <https://github.com/0xProject/0x-monorepo/blob/development/packages/json-schemas/schemas/order_schema.json>`_.
:param exchange_address: The address to which the 0x Exchange smart
contract has been deployed.
:rtype: A string, of ASCII hex digits, representing the order hash.
>>> generate_order_hash_hex(
... {
... 'makerAddress': "0x0000000000000000000000000000000000000000",
... 'takerAddress': "0x0000000000000000000000000000000000000000",
... 'feeRecipientAddress': "0x0000000000000000000000000000000000000000",
... 'senderAddress': "0x0000000000000000000000000000000000000000",
... 'makerAssetAmount': "1000000000000000000",
... 'takerAssetAmount': "1000000000000000000",
... 'makerFee': "0",
... 'takerFee': "0",
... 'expirationTimeSeconds': "12345",
... 'salt': "12345",
... 'makerAssetData': "0x0000000000000000000000000000000000000000",
... 'takerAssetData': "0x0000000000000000000000000000000000000000",
... 'exchangeAddress': "0x0000000000000000000000000000000000000000",
... },
... )
'55eaa6ec02f3224d30873577e9ddd069a288c16d6fb407210eecbc501fa76692'
""" # noqa: E501 (line too long)
assert_valid(order, "/orderSchema")
def pad_20_bytes_to_32(twenty_bytes: bytes):
return bytes(12) + twenty_bytes
def int_to_32_big_endian_bytes(i: int):
return i.to_bytes(32, byteorder="big")
eip712_domain_struct_hash = keccak(
_Constants.eip712_domain_struct_header
+ pad_20_bytes_to_32(to_bytes(hexstr=order["exchangeAddress"]))
)
eip712_order_struct_hash = keccak(
_Constants.eip712_order_schema_hash
+ pad_20_bytes_to_32(to_bytes(hexstr=order["makerAddress"]))
+ pad_20_bytes_to_32(to_bytes(hexstr=order["takerAddress"]))
+ pad_20_bytes_to_32(to_bytes(hexstr=order["feeRecipientAddress"]))
+ pad_20_bytes_to_32(to_bytes(hexstr=order["senderAddress"]))
+ int_to_32_big_endian_bytes(int(order["makerAssetAmount"]))
+ int_to_32_big_endian_bytes(int(order["takerAssetAmount"]))
+ int_to_32_big_endian_bytes(int(order["makerFee"]))
+ int_to_32_big_endian_bytes(int(order["takerFee"]))
+ int_to_32_big_endian_bytes(int(order["expirationTimeSeconds"]))
+ int_to_32_big_endian_bytes(int(order["salt"]))
+ keccak(to_bytes(hexstr=order["makerAssetData"]))
+ keccak(to_bytes(hexstr=order["takerAssetData"]))
)
return keccak(
_Constants.eip191_header
+ eip712_domain_struct_hash
+ eip712_order_struct_hash
).hex()
def is_valid_signature(
provider: BaseProvider, data: str, signature: str, signer_address: str
) -> Tuple[bool, str]:
"""Check the validity of the supplied signature.
Check if the supplied ``signature`` corresponds to signing ``data`` with
the private key corresponding to ``signer_address``.
:param provider: A Web3 provider able to access the 0x Exchange contract.
:param data: The hex encoded data signed by the supplied signature.
:param signature: The hex encoded signature.
:param signer_address: The hex encoded address that signed the data to
produce the supplied signature.
:rtype: Tuple consisting of a boolean and a string. Boolean is true if
valid, false otherwise. If false, the string describes the reason.
>>> is_valid_signature(
... Web3.HTTPProvider("http://127.0.0.1:8545"),
... '0x6927e990021d23b1eb7b8789f6a6feaf98fe104bb0cf8259421b79f9a34222b0',
... '0x1B61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc3340349190569279751135161d22529dc25add4f6069af05be04cacbda2ace225403',
... '0x5409ed021d9299bf6814279a6a1411a7e866a631',
... )
(True, '')
""" # noqa: E501 (line too long)
assert_is_provider(provider, "provider")
assert_is_hex_string(data, "data")
assert_is_hex_string(signature, "signature")
assert_is_address(signer_address, "signer_address")
web3_instance = Web3(provider)
# false positive from pylint: disable=no-member
network_id = web3_instance.net.version
contract_address = _Constants.network_to_exchange_addr[network_id]
# false positive from pylint: disable=no-member
contract: datatypes.Contract = web3_instance.eth.contract(
address=to_checksum_address(contract_address),
abi=_Constants.contract_name_to_abi("Exchange"),
)
try:
return (
contract.call().isValidSignature(
data, to_checksum_address(signer_address), signature
),
"",
)
except web3.exceptions.BadFunctionCallOutput as exception:
known_revert_reasons = [
"LENGTH_GREATER_THAN_0_REQUIRED",
"SIGNATURE_ILLEGAL",
"SIGNATURE_UNSUPPORTED",
"LENGTH_0_REQUIRED",
"LENGTH_65_REQUIRED",
]
for known_revert_reason in known_revert_reasons:
if known_revert_reason in str(exception):
return (False, known_revert_reason)
return (False, f"Unknown: {exception}")
class ECSignature(TypedDict):
"""Object representation of an elliptic curve signature's parameters."""
v: int
r: str
s: str
def _parse_signature_hex_as_vrs(signature_hex: str) -> ECSignature:
"""Parse signature hex as a concatentation of EC parameters ordered V, R, S.
>>> _parse_signature_hex_as_vrs('0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03')
{'v': 27, 'r': '117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d87287113', 's': '7feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b'}
""" # noqa: E501 (line too long)
signature: ECSignature = {
"v": int(signature_hex[2:4], 16),
"r": signature_hex[4:68],
"s": signature_hex[68:132],
}
if signature["v"] == 0 or signature["v"] == 1:
signature["v"] = signature["v"] + 27
return signature
def _parse_signature_hex_as_rsv(signature_hex: str) -> ECSignature:
"""Parse signature hex as a concatentation of EC parameters ordered R, S, V.
>>> _parse_signature_hex_as_rsv('0x117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b00')
{'r': '117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d87287113', 's': '7feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b', 'v': 27}
""" # noqa: E501 (line too long)
signature: ECSignature = {
"r": signature_hex[2:66],
"s": signature_hex[66:130],
"v": int(signature_hex[130:132], 16),
}
if signature["v"] == 0 or signature["v"] == 1:
signature["v"] = signature["v"] + 27
return signature
def _convert_ec_signature_to_vrs_hex(signature: ECSignature) -> str:
"""Convert elliptic curve signature object to hex hash string.
>>> _convert_ec_signature_to_vrs_hex(
... {
... 'r': '117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d87287113',
... 's': '7feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b',
... 'v': 27
... }
... )
'0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b'
""" # noqa: E501 (line too long)
return (
"0x"
+ signature["v"].to_bytes(1, byteorder="big").hex()
+ signature["r"]
+ signature["s"]
)
def sign_hash(
provider: BaseProvider, signer_address: str, hash_hex: str
) -> str:
"""Sign a message with the given hash, and return the signature.
:param provider: A Web3 provider.
:param signer_address: The address of the signing account.
:param hash_hex: A hex string representing the hash, like that returned
from `generate_order_hash_hex()`.
:rtype: A string, of ASCII hex digits, representing the signature.
>>> provider = Web3.HTTPProvider("http://127.0.0.1:8545")
>>> sign_hash(
... provider,
... Web3(provider).personal.listAccounts[0],
... '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004',
... )
'0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03'
""" # noqa: E501 (line too long)
assert_is_provider(provider, "provider")
assert_is_address(signer_address, "signer_address")
assert_is_hex_string(hash_hex, "hash_hex")
web3_instance = Web3(provider)
# false positive from pylint: disable=no-member
signature = web3_instance.eth.sign( # type: ignore
signer_address, hexstr=hash_hex.replace("0x", "")
).hex()
valid_v_param_values = [27, 28]
# HACK: There is no consensus on whether the signatureHex string should be
# formatted as v + r + s OR r + s + v, and different clients (even
# different versions of the same client) return the signature params in
# different orders. In order to support all client implementations, we
# parse the signature in both ways, and evaluate if either one is a valid
# signature. r + s + v is the most prevalent format from eth_sign, so we
# attempt this first.
ec_signature = _parse_signature_hex_as_rsv(signature)
if ec_signature["v"] in valid_v_param_values:
signature_as_vrst_hex = (
_convert_ec_signature_to_vrs_hex(ec_signature)
+ _Constants.SignatureType.ETH_SIGN.value.to_bytes(
1, byteorder="big"
).hex()
)
(valid, _) = is_valid_signature(
provider, hash_hex, signature_as_vrst_hex, signer_address
)
if valid is True:
return signature_as_vrst_hex
ec_signature = _parse_signature_hex_as_vrs(signature)
if ec_signature["v"] in valid_v_param_values:
signature_as_vrst_hex = (
_convert_ec_signature_to_vrs_hex(ec_signature)
+ _Constants.SignatureType.ETH_SIGN.value.to_bytes(
1, byteorder="big"
).hex()
)
(valid, _) = is_valid_signature(
provider, hash_hex, signature_as_vrst_hex, signer_address
)
if valid is True:
return signature_as_vrst_hex
raise RuntimeError(
"Signature returned from web3 provider is in an unknown format."
+ " Attempted to parse as RSV and as VRS."
)
