def get_size(cls, curve: ec.EllipticCurve = None):
"""
Returns the size (in bytes) of a KFrag given the curve.
If no curve is provided, it will use the default curve.
"""
curve = curve if curve is not None else default_curve()
bn_size = CurveBN.get_size(curve)
point_size = Point.get_size(curve)
return (bn_size * 4) + (point_size * 2)
def get_size(cls, curve: ec.EllipticCurve = None):
"""
Returns the size (in bytes) of a CorrectnessProof without the metadata.
If no curve is given, it will use the default curve.
"""
curve = curve if curve is not None else default_curve()
bn_size = CurveBN.get_size(curve=curve)
point_size = Point.get_size(curve=curve)
return (bn_size * 3) + (point_size * 4)
def get_size(cls, curve: ec.EllipticCurve = None):
"""
Returns the size (in bytes) of a CapsuleFrag given the curve without
the CorrectnessProof.
If no curve is provided, it will use the default curve.
"""
curve = curve if curve is not None else default_curve()
bn_size = CurveBN.get_size(curve)
point_size = Point.get_size(curve)
return (bn_size * 1) + (point_size * 3)
def from_bytes(cls, data: bytes, curve: ec.EllipticCurve = None):
"""
Instantiate a KFrag object from the serialized data.
"""
curve = curve if curve is not None else default_curve()
bn_size = CurveBN.get_size(curve)
point_size = Point.get_size(curve)
data = BytesIO(data)
# CurveBNs are the keysize in bytes, Points are compressed and the
# keysize + 1 bytes long.
id = data.read(bn_size)
key = CurveBN.from_bytes(data.read(bn_size), curve)
ni = Point.from_bytes(data.read(point_size), curve)
commitment = Point.from_bytes(data.read(point_size), curve)
xcoord = Point.from_bytes(data.read(point_size), curve)
sig1 = CurveBN.from_bytes(data.read(bn_size), curve)
sig2 = CurveBN.from_bytes(data.read(bn_size), curve)
return cls(id, key, ni, commitment, xcoord, sig1, sig2)
def from_bytes(cls, data: bytes, curve: ec.EllipticCurve = None):
"""
Instantiates a CapsuleFrag object from the serialized data.
"""
curve = curve if curve is not None else default_curve()
bn_size = CurveBN.get_size(curve=curve)
point_size = Point.get_size(curve=curve)
data = BytesIO(data)
# CurveBNs are the keysize in bytes, Points are compressed and the
# keysize + 1 bytes long.
e1 = Point.from_bytes(data.read(point_size), curve)
v1 = Point.from_bytes(data.read(point_size), curve)
kfrag_id = data.read(bn_size)
ni = Point.from_bytes(data.read(point_size), curve)
xcoord = Point.from_bytes(data.read(point_size), curve)
proof = data.read() or None
proof = CorrectnessProof.from_bytes(proof, curve) if proof else None
return cls(e1, v1, kfrag_id, ni, xcoord, proof)
def from_bytes(cls, data: bytes, curve: ec.EllipticCurve=None):
"""
Instantiate CorrectnessProof from serialized data.
"""
curve = curve if curve is not None else default_curve()
bn_size = CurveBN.get_size(curve)
point_size = Point.get_size(curve)
data = BytesIO(data)
# CurveBNs are the keysize in bytes, Points are compressed and the
# keysize + 1 bytes long.
e2 = Point.from_bytes(data.read(point_size), curve)
v2 = Point.from_bytes(data.read(point_size), curve)
kfrag_commitment = Point.from_bytes(data.read(point_size), curve)
kfrag_pok = Point.from_bytes(data.read(point_size), curve)
kfrag_sig1 = CurveBN.from_bytes(data.read(bn_size), curve)
kfrag_sig2 = CurveBN.from_bytes(data.read(bn_size), curve)
sig = CurveBN.from_bytes(data.read(bn_size), curve)
metadata = data.read() or None
return cls(e2, v2, kfrag_commitment, kfrag_pok,
kfrag_sig1, kfrag_sig2, sig, metadata=metadata)