Helper functions

EIP-712 hashing helper

Hashing utilities for EIP-712 messages.

Copied under the MIT license from https://github.com/ethereum/eth-account/blob/master/eth_account/_utils/structured_data/hashing.py with minor modifications.

evmos.utils.eip_712_hash.encode_data(primary_type: str, types: Mapping[str, Sequence[_FieldT]], data: Any) → bytes

Encode data defined by primary_type.

evmos.utils.eip_712_hash.encode_field(types: Mapping[str, Sequence[_FieldT]], name: str, field_type: str, value: Any) → tuple[str, bytes]

Encode field according to given type.

Parameters

• types – mapping with all known types

• name – field name

• field_type – type of field (must be present in types or be basic type)

• value – value to encode

Returns

tuple of form (result_type, encoded_bytes)

evmos.utils.eip_712_hash.encode_struct(struct_name: str, struct_field_types: Iterable[_FieldT]) → str

Stringify a single struct in 'NAME(type1 name1,type2 name2,...)' format.

evmos.utils.eip_712_hash.encode_type(primary_type: str, types: Mapping[str, Sequence[_FieldT]]) → str

Encode type as concatenation of itself and all dependencies (alphabetical order).

The type of a struct is encoded as

name ‖ "(" ‖ member₁ ‖ "," ‖ member₂ ‖ "," ‖ … ‖ memberₙ ")"

where each member is written as type ‖ " " ‖ name.

evmos.utils.eip_712_hash.field_identifier(field: _FieldT) → str

Stringify a field in 'TYPE NAME' format.

evmos.utils.eip_712_hash.get_array_dimensions(data: Any) → tuple[int | str, ...]

Given an data item, check that it is an array and return the dimensions.

Examples

>>> get_array_dimensions([[1, 2, 3], [4, 5, 6]])
(3, 2)

evmos.utils.eip_712_hash.get_dependencies(primary_type: str, types: Mapping[str, Sequence[_FieldT]]) → tuple[str, ...]

Perform DFS to get all the dependencies of the primary_type.

evmos.utils.eip_712_hash.get_depths_and_dimensions(data: Any, depth: int) → Iterator[tuple[int, int]]

Generate tuples of depth and dimension of each element at that depth.

evmos.utils.eip_712_hash.hash_domain(structured_data: EIPToSign) → bytes

Hash domain part of EIP-712 message.

evmos.utils.eip_712_hash.hash_message(structured_data: EIPToSign) → bytes

Hash message part of EIP-712 message.

evmos.utils.eip_712_hash.hash_struct_type(primary_type: str, types: Mapping[str, Sequence[_FieldT]]) → bytes

Hash string representation of type of struct.

evmos.utils.eip_712_hash.is_array_type(type_: str) → bool

Identify if type such as person[] or person[2] is an array.

Internal utilities

evmos.utils.polyfill.removeprefix(self, prefix, /)

Return a str with the given prefix string removed if present.

If the string starts with the prefix string, return string[len(prefix):]. Otherwise, return a copy of the original string.

evmos.utils.polyfill.removesuffix(self, suffix, /)

Return a str with the given suffix string removed if present.

If the string ends with the suffix string and that suffix is not empty, return string[:-len(suffix)]. Otherwise, return a copy of the original string.