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)