r"""Order utilities for 0x applications.
Setup
-----
Install the package with pip::
pip install 0x-order-utils
Some methods require the caller to pass in a `Web3.BaseProvider`:code: 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
"""
from enum import auto, Enum
import json
from typing import cast, Tuple, Union
from pkg_resources import resource_string
from mypy_extensions import TypedDict
from eth_typing import HexStr
from eth_utils import keccak, remove_0x_prefix, to_bytes, to_checksum_address
from web3 import Web3
import web3.exceptions
from web3.providers.base import BaseProvider
from web3.contract import Contract
from zero_ex.contract_addresses import chain_to_addresses, ChainId
import zero_ex.contract_artifacts
from zero_ex.contract_wrappers.exchange import Exchange
from zero_ex.contract_wrappers.exchange.types import Order
from zero_ex.contract_wrappers.order_conversions import order_to_jsdict
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."""
null_address = "0x0000000000000000000000000000000000000000"
eip191_header = b"\x19\x01"
eip712_domain_separator_schema_hash = keccak(
b"EIP712Domain("
+ b"string name,"
+ b"string version,"
+ b"uint256 chainId,"
+ b"address verifyingContract"
+ b")"
)
eip712_domain_struct_header = (
eip712_domain_separator_schema_hash
+ keccak(b"0x Protocol")
+ keccak(b"3.0.0")
)
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"bytes makerFeeAssetData,"
+ b"bytes takerFeeAssetData"
+ 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()
[docs]def generate_order_hash_hex(
order: Order, exchange_address: str, chain_id: int
) -> 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.
:returns: A string, of ASCII hex digits, representing the order hash.
Inputs and expected result below were copied from
@0x/order-utils/test/order_hash_test.ts
>>> generate_order_hash_hex(
... Order(
... makerAddress="0x0000000000000000000000000000000000000000",
... takerAddress="0x0000000000000000000000000000000000000000",
... feeRecipientAddress="0x0000000000000000000000000000000000000000",
... senderAddress="0x0000000000000000000000000000000000000000",
... makerAssetAmount="0",
... takerAssetAmount="0",
... makerFee="0",
... takerFee="0",
... expirationTimeSeconds="0",
... salt="0",
... makerAssetData=((0).to_bytes(1, byteorder='big') * 20),
... takerAssetData=((0).to_bytes(1, byteorder='big') * 20),
... makerFeeAssetData=((0).to_bytes(1, byteorder='big') * 20),
... takerFeeAssetData=((0).to_bytes(1, byteorder='big') * 20),
... ),
... exchange_address="0x1dc4c1cefef38a777b15aa20260a54e584b16c48",
... chain_id=1337
... )
'cb36e4fedb36508fb707e2c05e21bffc7a72766ccae93f8ff096693fff7f1714'
""" # noqa: E501 (line too long)
assert_is_address(exchange_address, "exchange_address")
assert_valid(
order_to_jsdict(order, chain_id, exchange_address), "/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
+ int_to_32_big_endian_bytes(int(chain_id))
+ pad_20_bytes_to_32(to_bytes(hexstr=exchange_address))
)
def ensure_bytes(str_or_bytes: Union[str, bytes]) -> bytes:
return (
to_bytes(hexstr=cast(bytes, str_or_bytes))
if isinstance(str_or_bytes, str)
else str_or_bytes
)
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(ensure_bytes(order["makerAssetData"]))
+ keccak(ensure_bytes(order["takerAssetData"]))
+ keccak(ensure_bytes(order["makerFeeAssetData"]))
+ keccak(ensure_bytes(order["takerFeeAssetData"]))
)
return keccak(
_Constants.eip191_header
+ eip712_domain_struct_hash
+ eip712_order_struct_hash
).hex()
[docs]def is_valid_signature(
provider: BaseProvider, data: str, signature: str, signer_address: str
) -> bool:
"""Check the validity of the supplied signature.
Check if the supplied `signature`:code: corresponds to signing `data`:code:
with the private key corresponding to `signer_address`:code:.
: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.
:returns: 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")
return Exchange(
provider,
chain_to_addresses(
ChainId(
int(Web3(provider).eth.chainId) # pylint: disable=no-member
)
).exchange,
).is_valid_hash_signature.call(
bytes.fromhex(remove_0x_prefix(HexStr(data))),
to_checksum_address(signer_address),
bytes.fromhex(remove_0x_prefix(HexStr(signature))),
)
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"]
)
[docs]def sign_hash(
web3_or_provider: Union[Web3, BaseProvider],
signer_address: str,
hash_hex: str,
) -> str:
"""Sign a message with the given hash, and return the signature.
:param web3_or_provider: Either an instance of `web3.Web3`:code: or
`web3.providers.base.BaseProvider`:code:
: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()`:code:.
:returns: A string, of ASCII hex digits, representing the signature.
>>> provider = Web3.HTTPProvider("http://127.0.0.1:8545")
>>> sign_hash(
... provider,
... Web3(provider).geth.personal.listAccounts()[0],
... '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004',
... )
'0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03'
""" # noqa: E501 (line too long)
web3_instance = None
if isinstance(web3_or_provider, BaseProvider):
web3_instance = Web3(web3_or_provider)
elif isinstance(web3_or_provider, Web3):
web3_instance = web3_or_provider
else:
raise TypeError(
"Expected parameter 'web3_or_provider' to be an instance of either"
+ " Web3 or BaseProvider"
)
assert_is_address(signer_address, "signer_address")
assert_is_hex_string(hash_hex, "hash_hex")
# 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(
web3_instance.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(
web3_instance.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. "
+ "Signature was: {signature}"
)
[docs]def sign_hash_to_bytes(
web3_or_provider: Union[Web3, BaseProvider],
signer_address: str,
hash_hex: str,
) -> bytes:
"""Sign a message with the given hash, and return the signature.
>>> provider = Web3.HTTPProvider("http://127.0.0.1:8545")
>>> sign_hash_to_bytes(
... provider,
... Web3(provider).geth.personal.listAccounts()[0],
... '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004',
... ).decode(encoding='utf_8')
'1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03'
""" # noqa: E501 (line too long)
return remove_0x_prefix(
HexStr(sign_hash(web3_or_provider, signer_address, hash_hex))
).encode(encoding="utf_8")