py-libp2p/libp2p/crypto/ecc.py
2019-10-24 08:41:10 +02:00

69 lines
2.2 KiB
Python

from fastecdsa import curve as curve_types
from fastecdsa import keys, point
from fastecdsa.encoding.sec1 import SEC1Encoder
from libp2p.crypto.keys import KeyPair, KeyType, PrivateKey, PublicKey
def infer_local_type(curve: str) -> curve_types.Curve:
"""converts a ``str`` representation of some elliptic curve to a
representation understood by the backend of this module."""
if curve == "P-256":
return curve_types.P256
else:
raise NotImplementedError()
class ECCPublicKey(PublicKey):
def __init__(self, impl: point.Point, curve: curve_types.Curve) -> None:
self.impl = impl
self.curve = curve
def to_bytes(self) -> bytes:
return SEC1Encoder.encode_public_key(self.impl, compressed=False)
@classmethod
def from_bytes(cls, data: bytes, curve: str) -> "ECCPublicKey":
curve_type = infer_local_type(curve)
public_key_impl = SEC1Encoder.decode_public_key(data, curve_type)
return cls(public_key_impl, curve_type)
def get_type(self) -> KeyType:
return KeyType.ECC_P256
def verify(self, data: bytes, signature: bytes) -> bool:
raise NotImplementedError
class ECCPrivateKey(PrivateKey):
def __init__(self, impl: int, curve: curve_types.Curve) -> None:
self.impl = impl
self.curve = curve
@classmethod
def new(cls, curve: str) -> "ECCPrivateKey":
curve_type = infer_local_type(curve)
private_key_impl = keys.gen_private_key(curve_type)
return cls(private_key_impl, curve_type)
def to_bytes(self) -> bytes:
return keys.export_key(self.impl, self.curve)
def get_type(self) -> KeyType:
return KeyType.ECC_P256
def sign(self, data: bytes) -> bytes:
raise NotImplementedError
def get_public_key(self) -> PublicKey:
public_key_impl = keys.get_public_key(self.impl, self.curve)
return ECCPublicKey(public_key_impl, self.curve)
def create_new_key_pair(curve: str) -> KeyPair:
"""Return a new ECC keypair with the requested ``curve`` type, e.g.
"P-256"."""
private_key = ECCPrivateKey.new(curve)
public_key = private_key.get_public_key()
return KeyPair(private_key, public_key)