def encode_intended_validator(validator_address: Union[Address, str],
primitive: bytes = None,
*,
hexstr: str = None,
text: str = None) -> SignableMessage:
"""
Encode a message using the "intended validator" approach (ie~ version 0)
defined in EIP-191_.
Supply the message as exactly one of these three arguments:
bytes as a primitive, a hex string, or a unicode string.
.. WARNING:: Note that this code has not gone through an external audit.
Also, watch for updates to the format, as the EIP is still in DRAFT.
:param validator_address: which on-chain contract is capable of validating this message,
provided as a checksummed address or in native bytes.
:param primitive: the binary message to be signed
:type primitive: bytes or int
:param str hexstr: the message encoded as hex
:param str text: the message as a series of unicode characters (a normal Py3 str)
:returns: The EIP-191 encoded message, ready for signing
.. _EIP-191: https://eips.ethereum.org/EIPS/eip-191
"""
if not is_valid_address(validator_address):
raise ValidationError(
f"Cannot encode message with 'Validator Address': {validator_address}. "
"It must be a checksum address, or an address converted to bytes.")
message_bytes = to_bytes(primitive, hexstr=hexstr, text=text)
return SignableMessage(
b'\x00', # version 0, as defined in EIP-191
to_canonical_address(validator_address),
message_bytes,
)
def is_empty_or_checksum_address(val):
if val in VALID_EMPTY_ADDRESSES:
return True
else:
return is_valid_address(val)