zeth.core.utils Namespace Reference

Classes
class	EtherValue

Functions
Any	open_web3 (str url, Optional[str] certificate=None, bool insecure=False)
bytes	encode_single (str type_name, Any data)
bytes	encode_abi (List[str] type_names, List[Any] data)
bytes	eth_address_to_bytes (str eth_addr)
bytes	eth_address_to_bytes32 (str eth_addr)
int	eth_uint256_to_int (str eth_uint256)
str	eth_address_from_private_key (bytes eth_private_key)
Tuple[int, int]	int_and_bytelen_from_hex (str value_hex)
str	int_to_hex (int value, int num_bytes)
bytes	int64_to_bytes (int number)
str	int64_to_hex (int number)
str	hex_digest_to_binary_string (str digest)
str	digest_to_binary_string (bytes digest)
Iterable[int]	hex_to_uint256_list (str hex_str)
List[int]	hex_list_to_uint256_list (Sequence[Union[str, List[str]]] elements)
bytes	extend_32bytes (bytes value)
str	hex_extend_32bytes (str element)
int	to_zeth_units (EtherValue value)
EtherValue	from_zeth_units (int zeth_units)
str	parse_zksnark_arg ()
str	get_zeth_dir ()
str	get_contracts_dir ()
List[str]	string_list_flatten (Sequence[Union[str, List[str]]] str_list)
bytes	message_to_bytes (Any message_list)
str	short_commitment (bytes cm)

Variables
int	WEB3_HTTP_PROVIDER_TIMEOUT_SEC = 60

Function Documentation

digest_to_binary_string()

str zeth.core.utils.digest_to_binary_string

(

bytes

digest

)

Definition at line 168 of file utils.py.

def digest_to_binary_string(digest: bytes) -> str:
    return "".join(["{0:08b}".format(b) for b in digest])
 
 

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encode_abi()

bytes zeth.core.utils.encode_abi	(	List[str]	type_names,
		List[Any]	data
	)

Typed wrapper around eth_abi.encode_abi

Definition at line 97 of file utils.py.

def encode_abi(type_names: List[str], data: List[Any]) -> bytes:
    """
    Typed wrapper around eth_abi.encode_abi
    """
    return eth_abi.encode_abi(type_names, data)  # type: ignore
 
 

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encode_single()

bytes zeth.core.utils.encode_single	(	str	type_name,
		Any	data
	)

Typed wrapper around eth_abi.encode_single

Definition at line 90 of file utils.py.

def encode_single(type_name: str, data: Any) -> bytes:
    """
    Typed wrapper around eth_abi.encode_single
    """
    return eth_abi.encode_single(type_name, data)  # type: ignore
 
 

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eth_address_from_private_key()

str zeth.core.utils.eth_address_from_private_key

(

bytes

eth_private_key

)

Definition at line 129 of file utils.py.

def eth_address_from_private_key(eth_private_key: bytes) -> str:
    pk = eth_keys.keys.PrivateKey(eth_private_key)
    return pk.public_key.to_address()
 
 

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eth_address_to_bytes()

bytes zeth.core.utils.eth_address_to_bytes

(

str

eth_addr

)

Binary encoding of ethereum address to 20 bytes

Definition at line 104 of file utils.py.

def eth_address_to_bytes(eth_addr: str) -> bytes:
    """
    Binary encoding of ethereum address to 20 bytes
    """
    # Strip the leading '0x' and hex-decode.
    assert len(eth_addr) == 42
    assert eth_addr.startswith("0x")
    return bytes.fromhex(eth_addr[2:])
 
 

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eth_address_to_bytes32()

bytes zeth.core.utils.eth_address_to_bytes32

(

str

eth_addr

)

Binary encoding of ethereum address to 32 bytes

Definition at line 114 of file utils.py.

def eth_address_to_bytes32(eth_addr: str) -> bytes:
    """
    Binary encoding of ethereum address to 32 bytes
    """
    return extend_32bytes(eth_address_to_bytes(eth_addr))
 
 

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eth_uint256_to_int()

int zeth.core.utils.eth_uint256_to_int

(

str

eth_uint256

)

Definition at line 121 of file utils.py.

def eth_uint256_to_int(eth_uint256: str) -> int:
    assert isinstance(eth_uint256, str)
    assert eth_uint256.startswith("0x")
    return int.from_bytes(
        bytes.fromhex(hex_extend_32bytes(eth_uint256[2:])),
        byteorder='big')
 
 

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extend_32bytes()

bytes zeth.core.utils.extend_32bytes

(

bytes

value

)

Pad value on the left with zeros, to make 32 bytes.

Definition at line 202 of file utils.py.

def extend_32bytes(value: bytes) -> bytes:
    """
    Pad value on the left with zeros, to make 32 bytes.
    """
    assert len(value) <= 32
    return bytes(32-len(value)) + value
 
 

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from_zeth_units()

EtherValue zeth.core.utils.from_zeth_units

(

int

zeth_units

)

Convert a quantity of ether / token to Zeth units

Definition at line 227 of file utils.py.

def from_zeth_units(zeth_units: int) -> EtherValue:
    """
    Convert a quantity of ether / token to Zeth units
    """
    return EtherValue(zeth_units * constants.ZETH_PUBLIC_UNIT_VALUE, "wei")
 
 

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get_contracts_dir()

str zeth.core.utils.get_contracts_dir

(

)

Definition at line 255 of file utils.py.

def get_contracts_dir() -> str:
    return os.environ.get(
        'ZETH_CONTRACTS_DIR',
        join(get_zeth_dir(), "zeth_contracts", "contracts"))
 
 

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get_zeth_dir()

str zeth.core.utils.get_zeth_dir

(

)

Definition at line 249 of file utils.py.

def get_zeth_dir() -> str:
    return os.environ.get(
        'ZETH',
        normpath(join(dirname(__file__), "..", "..", "..")))
 
 

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hex_digest_to_binary_string()

str zeth.core.utils.hex_digest_to_binary_string

(

str

digest

)

Definition at line 162 of file utils.py.

def hex_digest_to_binary_string(digest: str) -> str:
    if len(digest) % 2 == 1:
        digest = "0" + digest
    return "".join(["{0:04b}".format(int(c, 16)) for c in digest])
 
 

hex_extend_32bytes()

str zeth.core.utils.hex_extend_32bytes

(

str

element

)

Extend a hex string to represent 32 bytes

Definition at line 210 of file utils.py.

def hex_extend_32bytes(element: str) -> str:
    """
    Extend a hex string to represent 32 bytes
    """
    res = str(element)
    if len(res) % 2 != 0:
        res = "0" + res
    return extend_32bytes(bytes.fromhex(res)).hex()
 
 

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hex_list_to_uint256_list()

List[int] zeth.core.utils.hex_list_to_uint256_list

(

Sequence[Union[str, List[str]]]

elements

)

Given an array of hex strings, return an array of int values by converting
each hex string to evm uint256 words, and flattening the final list.

Definition at line 189 of file utils.py.

def hex_list_to_uint256_list(
        elements: Sequence[Union[str, List[str]]]) -> List[int]:
    """
    Given an array of hex strings, return an array of int values by converting
    each hex string to evm uint256 words, and flattening the final list.
    """
    # In reality, we need to cope with lists of lists, to handle all
    # field extension degrees for all curve coordinate types.
    # TODO: Create a new type to describe this safely.
    flat_elements = string_list_flatten(elements)
    return [i for hex_str in flat_elements for i in hex_to_uint256_list(hex_str)]
 
 

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hex_to_uint256_list()

Iterable[int] zeth.core.utils.hex_to_uint256_list

(

str

hex_str

)

Given a hex string of arbitrary size, split into uint256 ints, left padding
with 0s.

Definition at line 172 of file utils.py.

def hex_to_uint256_list(hex_str: str) -> Iterable[int]:
    """
    Given a hex string of arbitrary size, split into uint256 ints, left padding
    with 0s.
    """
    if hex_str.startswith("0x"):
        hex_str = hex_str[2:]
    assert len(hex_str) % 2 == 0
    start_idx = 0
    next_idx = len(hex_str) - int((len(hex_str) - 1) / 64) * 64
    while next_idx <= len(hex_str):
        sub_str = hex_str[start_idx:next_idx]
        yield int(sub_str, 16)
        start_idx = next_idx
        next_idx = next_idx + 64
 
 

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int64_to_bytes()

bytes zeth.core.utils.int64_to_bytes

(

int

number

)

Definition at line 154 of file utils.py.

def int64_to_bytes(number: int) -> bytes:
    return number.to_bytes(8, 'big')
 
 

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int64_to_hex()

str zeth.core.utils.int64_to_hex

(

int

number

)

Definition at line 158 of file utils.py.

def int64_to_hex(number: int) -> str:
    return int64_to_bytes(number).hex()
 
 

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int_and_bytelen_from_hex()

Tuple[int, int] zeth.core.utils.int_and_bytelen_from_hex

(

str

value_hex

)

Decode prefixed / non-prefixed hex string and extract the length in bytes
as well as the value.

Definition at line 134 of file utils.py.

def int_and_bytelen_from_hex(value_hex: str) -> Tuple[int, int]:
    """
    Decode prefixed / non-prefixed hex string and extract the length in bytes
    as well as the value.
    """
    assert len(value_hex) % 2 == 0
    if value_hex.startswith("0x"):
        num_bytes = int((len(value_hex) - 2) / 2)
    else:
        num_bytes = int(len(value_hex) / 2)
    return (int(value_hex, 16), num_bytes)
 
 

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int_to_hex()

str zeth.core.utils.int_to_hex	(	int	value,
		int	num_bytes
	)

Create prefixed hex string enforcing a specific byte-length.

Definition at line 147 of file utils.py.

def int_to_hex(value: int, num_bytes: int) -> str:
    """
    Create prefixed hex string enforcing a specific byte-length.
    """
    return "0x" + value.to_bytes(num_bytes, byteorder='big').hex()
 
 

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message_to_bytes()

bytes zeth.core.utils.message_to_bytes

(

Any

message_list

)

Encode a list of variables, or list of lists of variables into a byte
vector

Definition at line 277 of file utils.py.

def message_to_bytes(message_list: Any) -> bytes:
    # message_list: Union[List[str], List[Union[int, str, List[str]]]]) -> bytes:
    """
    Encode a list of variables, or list of lists of variables into a byte
    vector
    """
 
    messages = string_list_flatten(message_list)
 
    data_bytes = bytearray()
    for m in messages:
        # For each element
        m_hex = m
 
        # Convert it into a hex
        if isinstance(m, int):
            m_hex = "{0:0>4X}".format(m)
        elif isinstance(m, str) and (m[1] == "x"):
            m_hex = m[2:]
 
        # [SANITY CHECK] Make sure the hex is 32 byte long
        m_hex = hex_extend_32bytes(m_hex)
 
        # Encode the hex into a byte array and append it to result
        data_bytes += encode_single("bytes32", bytes.fromhex(m_hex))
 
    return data_bytes
 
 

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open_web3()

Any zeth.core.utils.open_web3	(	str	url,
		Optional[str]	certificate = None,
		bool	insecure = False
	)

Create a Web3 context from an http URL.

Definition at line 28 of file utils.py.

def open_web3(
        url: str,
        certificate: Optional[str] = None,
        insecure: bool = False) -> Any:
    """
    Create a Web3 context from an http URL.
    """
    if certificate and not exists(certificate):
        raise FileNotFoundError(f"certificate file not found: {certificate}")
    assert not certificate or exists(certificate)
    request_verify: Union[str, bool, None] = False if insecure else certificate
    request_kwargs = {
        'timeout': WEB3_HTTP_PROVIDER_TIMEOUT_SEC,
        'verify': request_verify,
    }
    return Web3(HTTPProvider(url, request_kwargs=request_kwargs))
 
 

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parse_zksnark_arg()

str zeth.core.utils.parse_zksnark_arg

(

)

Parse the zksnark argument and return its value

Definition at line 234 of file utils.py.

def parse_zksnark_arg() -> str:
    """
    Parse the zksnark argument and return its value
    """
    parser = argparse.ArgumentParser(
        description="Testing Zeth transactions using the specified zkSNARK " +
        "('GROTH16' or 'PGHR13').\nNote that the zkSNARK must match the one " +
        "used on the prover server.")
    parser.add_argument("zksnark", help="Set the zkSNARK to use")
    args = parser.parse_args()
    if args.zksnark not in constants.VALID_ZKSNARKS:
        return sys.exit(errors.SNARK_NOT_SUPPORTED)
    return args.zksnark
 
 

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short_commitment()

str zeth.core.utils.short_commitment

(

bytes

cm

)

Summary of the commitment value, in some standard format.

Definition at line 306 of file utils.py.

def short_commitment(cm: bytes) -> str:
    """
    Summary of the commitment value, in some standard format.
    """
    return cm[0:4].hex()

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string_list_flatten()

List[str] zeth.core.utils.string_list_flatten

(

Sequence[Union[str, List[str]]]

str_list

)

Flatten a list containing strings or lists of strings.

Definition at line 261 of file utils.py.

def string_list_flatten(str_list: Sequence[Union[str, List[str]]]) -> List[str]:
    """
    Flatten a list containing strings or lists of strings.
    """
    if any(isinstance(el, (list, tuple)) for el in str_list):
        strs: List[str] = []
        for el in str_list:
            if isinstance(el, (list, tuple)):
                strs.extend(el)
            else:
                strs.append(cast(str, el))
        return strs
 
    return cast(List[str], str_list)
 
 

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to_zeth_units()

int zeth.core.utils.to_zeth_units

(

EtherValue

value

)

Convert a quantity of ether / token to Zeth units

Definition at line 220 of file utils.py.

def to_zeth_units(value: EtherValue) -> int:
    """
    Convert a quantity of ether / token to Zeth units
    """
    return int(value.wei / constants.ZETH_PUBLIC_UNIT_VALUE)
 
 

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Variable Documentation

WEB3_HTTP_PROVIDER_TIMEOUT_SEC

int zeth.core.utils.WEB3_HTTP_PROVIDER_TIMEOUT_SEC = 60

Definition at line 25 of file utils.py.