diff options
Diffstat (limited to 'python-packages/order_utils/src/zero_ex')
5 files changed, 208 insertions, 13 deletions
diff --git a/python-packages/order_utils/src/zero_ex/dev_utils/__init__.py b/python-packages/order_utils/src/zero_ex/dev_utils/__init__.py new file mode 100644 index 000000000..b6a224d2c --- /dev/null +++ b/python-packages/order_utils/src/zero_ex/dev_utils/__init__.py @@ -0,0 +1 @@ +"""Dev utils to be shared across 0x projects and packages.""" diff --git a/python-packages/order_utils/src/zero_ex/dev_utils/abi_utils.py b/python-packages/order_utils/src/zero_ex/dev_utils/abi_utils.py new file mode 100644 index 000000000..71b6128ca --- /dev/null +++ b/python-packages/order_utils/src/zero_ex/dev_utils/abi_utils.py @@ -0,0 +1,102 @@ +"""Ethereum ABI utilities. + +Builds on the eth-abi package, adding some convenience methods like those found +in npmjs.com/package/ethereumjs-abi. Ideally, all of this code should be +pushed upstream into eth-abi. +""" + +import re +from typing import Any, List + +from mypy_extensions import TypedDict + +from eth_abi import encode_abi +from web3 import Web3 + +from .type_assertions import assert_is_string, assert_is_list + + +class MethodSignature(TypedDict, total=False): + """Object interface to an ABI method signature.""" + + method: str + args: List[str] + + +def parse_signature(signature: str) -> MethodSignature: + """Parse a method signature into its constituent parts. + + >>> parse_signature("ERC20Token(address)") + {'method': 'ERC20Token', 'args': ['address']} + """ + assert_is_string(signature, "signature") + + matches = re.match(r"^(\w+)\((.+)\)$", signature) + if matches is None: + raise ValueError(f"Invalid method signature {signature}") + return {"method": matches[1], "args": matches[2].split(",")} + + +def elementary_name(name: str) -> str: + """Convert from short to canonical names; barely implemented. + + Modeled after ethereumjs-abi's ABI.elementaryName(), but only implemented + to support our particular use case and a few other simple ones. + + >>> elementary_name("address") + 'address' + >>> elementary_name("uint") + 'uint256' + """ + assert_is_string(name, "name") + + return { + "int": "int256", + "uint": "uint256", + "fixed": "fixed128x128", + "ufixed": "ufixed128x128", + }.get(name, name) + + +def event_id(name: str, types: List[str]) -> str: + """Return the Keccak-256 hash of the given method. + + >>> event_id("ERC20Token", ["address"]) + '0xf47261b06eedbfce68afd46d0f3c27c60b03faad319eaf33103611cf8f6456ad' + """ + assert_is_string(name, "name") + assert_is_list(types, "types") + + signature = f"{name}({','.join(list(map(elementary_name, types)))})" + return Web3.sha3(text=signature).hex() + + +def method_id(name: str, types: List[str]) -> str: + """Return the 4-byte method identifier. + + >>> method_id("ERC20Token", ["address"]) + '0xf47261b0' + """ + assert_is_string(name, "name") + assert_is_list(types, "types") + + return event_id(name, types)[0:10] + + +def simple_encode(method: str, *args: Any) -> bytes: + # docstring considered all one line by pylint: disable=line-too-long + r"""Encode a method ABI. + + >>> simple_encode("ERC20Token(address)", "0x1dc4c1cefef38a777b15aa20260a54e584b16c48") + b'\xf4ra\xb0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x1d\xc4\xc1\xce\xfe\xf3\x8aw{\x15\xaa &\nT\xe5\x84\xb1lH' + """ # noqa: E501 (line too long) + assert_is_string(method, "method") + + signature: MethodSignature = parse_signature(method) + + return bytes.fromhex( + ( + method_id(signature["method"], signature["args"]) + + encode_abi(signature["args"], args).hex() + )[2:] + ) diff --git a/python-packages/order_utils/src/zero_ex/dev_utils/type_assertions.py b/python-packages/order_utils/src/zero_ex/dev_utils/type_assertions.py new file mode 100644 index 000000000..745d014e6 --- /dev/null +++ b/python-packages/order_utils/src/zero_ex/dev_utils/type_assertions.py @@ -0,0 +1,33 @@ +"""Assertions for runtime type checking of function arguments.""" + +from typing import Any + + +def assert_is_string(value: Any, name: str) -> None: + """If :param value: isn't of type str, raise a TypeError. + + >>> try: assert_is_string(123, 'var') + ... except TypeError as type_error: print(str(type_error)) + ... + expected variable 'var', with value 123, to have type 'str', not 'int' + """ + if not isinstance(value, str): + raise TypeError( + f"expected variable '{name}', with value {str(value)}, to have" + + f" type 'str', not '{type(value).__name__}'" + ) + + +def assert_is_list(value: Any, name: str) -> None: + """If :param value: isn't of type list, raise a TypeError. + + >>> try: assert_is_list(123, 'var') + ... except TypeError as type_error: print(str(type_error)) + ... + expected variable 'var', with value 123, to have type 'list', not 'int' + """ + if not isinstance(value, list): + raise TypeError( + f"expected variable '{name}', with value {str(value)}, to have" + + f" type 'list', not '{type(value).__name__}'" + ) diff --git a/python-packages/order_utils/src/zero_ex/order_utils/asset_data_utils.py b/python-packages/order_utils/src/zero_ex/order_utils/asset_data_utils.py new file mode 100644 index 000000000..451de39af --- /dev/null +++ b/python-packages/order_utils/src/zero_ex/order_utils/asset_data_utils.py @@ -0,0 +1,72 @@ +"""Asset data encoding and decoding utilities.""" + +from mypy_extensions import TypedDict + +import eth_abi + +from zero_ex.dev_utils import abi_utils +from zero_ex.dev_utils.type_assertions import assert_is_string + + +ERC20_ASSET_DATA_BYTE_LENGTH = 36 +SELECTOR_LENGTH = 10 + + +class ERC20AssetData(TypedDict): + """Object interface to ERC20 asset data.""" + + asset_proxy_id: str + token_address: str + + +def encode_erc20_asset_data(token_address: str) -> str: + """Encode an ERC20 token address into an asset data string. + + :param token_address: the ERC20 token's contract address. + :rtype: hex encoded asset data string, usable in the makerAssetData or + takerAssetData fields in a 0x order. + + >>> encode_erc20_asset_data('0x1dc4c1cefef38a777b15aa20260a54e584b16c48') + '0xf47261b00000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48' + """ + assert_is_string(token_address, "token_address") + + return ( + "0x" + + abi_utils.simple_encode("ERC20Token(address)", token_address).hex() + ) + + +def decode_erc20_asset_data(asset_data: str) -> ERC20AssetData: + # docstring considered all one line by pylint: disable=line-too-long + """Decode an ERC20 assetData hex string. + + :param asset_data: String produced by prior call to encode_erc20_asset_data() + + >>> decode_erc20_asset_data("0xf47261b00000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48") + {'asset_proxy_id': '0xf47261b0', 'token_address': '0x1dc4c1cefef38a777b15aa20260a54e584b16c48'} + """ # noqa: E501 (line too long) + assert_is_string(asset_data, "asset_data") + + if len(asset_data) < ERC20_ASSET_DATA_BYTE_LENGTH: + raise ValueError( + "Could not decode ERC20 Proxy Data. Expected length of encoded" + + f" data to be at least {str(ERC20_ASSET_DATA_BYTE_LENGTH)}." + + f" Got {str(len(asset_data))}." + ) + + asset_proxy_id: str = asset_data[0:10] + if asset_proxy_id != abi_utils.method_id("ERC20Token", ["address"]): + raise ValueError( + "Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be" + + f" ERC20 ({abi_utils.method_id('ERC20Token', ['address'])})" + + f" but got {asset_proxy_id}." + ) + + # workaround for https://github.com/PyCQA/pylint/issues/1498 + # pylint: disable=unsubscriptable-object + token_address = eth_abi.decode_abi( + ["address"], bytes.fromhex(asset_data[SELECTOR_LENGTH:]) + )[0] + + return {"asset_proxy_id": asset_proxy_id, "token_address": token_address} diff --git a/python-packages/order_utils/src/zero_ex/order_utils/signature_utils.py b/python-packages/order_utils/src/zero_ex/order_utils/signature_utils.py deleted file mode 100644 index 7f4697106..000000000 --- a/python-packages/order_utils/src/zero_ex/order_utils/signature_utils.py +++ /dev/null @@ -1,13 +0,0 @@ -"""Signature utilities.""" - - -def ec_sign_order_hash(): - """Signs an orderHash. - - Returns its elliptic curve signature and signature type. This method - currently supports TestRPC, Geth, and Parity above and below v1.6.6. - - >>> ec_sign_order_hash() - 'stub return value' - """ - return "stub return value" |