"""Key type enum."""
from enum import Enum
from typing import NamedTuple, Optional
# Define keys
KeySpec = NamedTuple(
"KeySpec",
[("key_type", str), ("multicodec_name", str), ("multicodec_prefix", int)],
)
[docs]class KeyTypeException(BaseException):
"""Key type exception."""
[docs]class KeyType(Enum):
"""KeyType Enum specifying key types with multicodec name."""
# NOTE: the py_multicodec library is outdated. We use hardcoded prefixes here
# until this PR gets released: https://github.com/multiformats/py-multicodec/pull/14
# multicodec is also not used now, but may be used again if py_multicodec is updated
ED25519 = KeySpec("ed25519", "ed25519-pub", b"\xed\x01")
X25519 = KeySpec("x25519", "x25519-pub", b"\xec\x01")
BLS12381G1 = KeySpec("bls12381g1", "bls12_381-g1-pub", b"\xea\x01")
BLS12381G2 = KeySpec("bls12381g2", "bls12_381-g2-pub", b"\xeb\x01")
BLS12381G1G2 = KeySpec("bls12381g1g2", "bls12_381-g1g2-pub", b"\xee\x01")
@property
def key_type(self) -> str:
"""Getter for key type identifier."""
return self.value.key_type
@property
def multicodec_name(self) -> str:
"""Getter for multicodec name."""
return self.value.multicodec_name
@property
def multicodec_prefix(self) -> bytes:
"""Getter for multicodec prefix."""
return self.value.multicodec_prefix
[docs] @classmethod
def from_multicodec_name(cls, multicodec_name: str) -> Optional["KeyType"]:
"""Get KeyType instance based on multicodec name. Returns None if not found."""
for key_type in KeyType:
if key_type.multicodec_name == multicodec_name:
return key_type
return None
[docs] @classmethod
def from_multicodec_prefix(cls, multicodec_prefix: bytes) -> Optional["KeyType"]:
"""Get KeyType instance based on multicodec prefix. Returns None if not found."""
for key_type in KeyType:
if key_type.multicodec_prefix == multicodec_prefix:
return key_type
return None
[docs] @classmethod
def from_prefixed_bytes(cls, prefixed_bytes: bytes) -> Optional["KeyType"]:
"""Get KeyType instance based on prefix in bytes. Returns None if not found."""
for key_type in KeyType:
if prefixed_bytes.startswith(key_type.multicodec_prefix):
return key_type
return None
[docs] @classmethod
def from_key_type(cls, key_type: str) -> Optional["KeyType"]:
"""Get KeyType instance from the key type identifier."""
for _key_type in KeyType:
if _key_type.key_type == key_type:
return _key_type
return None