from __future__ import annotations
import json
from typing import NamedTuple, cast
import xeddsa
from .migrations import parse_signed_pre_key_pair_model
from .models import SignedPreKeyPairModel
from .types import JSONObject
__all__ = [
"SignedPreKeyPair"
]
[docs]
class SignedPreKeyPair(NamedTuple):
"""
A signed pre key, i.e. a pre key whose public key was encoded using an application-specific encoding
format, then signed by the identity key, and stored together with a generation timestamp for periodic
rotation.
"""
priv: bytes
sig: bytes
timestamp: int
@property
def pub(self) -> bytes:
"""
Returns:
The public key of this signed pre key.
"""
return xeddsa.priv_to_curve25519_pub(self.priv)
@property
def model(self) -> SignedPreKeyPairModel:
"""
Returns:
The internal state of this :class:`SignedPreKeyPair` as a pydantic model.
"""
return SignedPreKeyPairModel(priv=self.priv, sig=self.sig, timestamp=self.timestamp)
@property
def json(self) -> JSONObject:
"""
Returns:
The internal state of this :class:`SignedPreKeyPair` as a JSON-serializable Python object.
"""
return cast(JSONObject, json.loads(self.model.json()))
[docs]
@staticmethod
def from_model(model: SignedPreKeyPairModel) -> "SignedPreKeyPair":
"""
Args:
model: The pydantic model holding the internal state of a :class:`SignedPreKeyPair`, as produced
by :attr:`model`.
Returns:
A configured instance of :class:`SignedPreKeyPair`, with internal state restored from the model.
Warning:
Migrations are not provided via the :attr:`model`/:meth:`from_model` API. Use
:attr:`json`/:meth:`from_json` instead. Refer to :ref:`serialization_and_migration` in the
documentation for details.
"""
return SignedPreKeyPair(priv=model.priv, sig=model.sig, timestamp=model.timestamp)
[docs]
@staticmethod
def from_json(serialized: JSONObject) -> "SignedPreKeyPair":
"""
Args:
serialized: A JSON-serializable Python object holding the internal state of a
:class:`SignedPreKeyPair`, as produced by :attr:`json`.
Returns:
A configured instance of :class:`SignedPreKeyPair`, with internal state restored from the
serialized data.
"""
return SignedPreKeyPair.from_model(parse_signed_pre_key_pair_model(serialized))