"""Interface to Camellia cipher"""
from __future__ import annotations
import typing
from pyflocker.ciphers.backends import (
Backends,
load_algorithm as _load_algo,
)
if typing.TYPE_CHECKING: # pragma: no cover
import io
from pyflocker.ciphers import base
from pyflocker.ciphers.backends.symmetric import FileCipherWrapper
from pyflocker.ciphers.modes import Modes
[docs]
def supported_modes(backend: Backends) -> set[Modes]:
"""
Lists all modes supported by the cipher. It is limited to backend's
implementation and capability, and hence, varies from backend to backend.
Args:
backend: The backend to inspect.
Returns:
Set of :any:`Modes` supported by the backend.
"""
return _load_algo("Camellia", backend).supported_modes()
[docs]
def new(
encrypting: bool,
key: bytes,
mode: Modes,
iv_or_nonce: bytes,
*,
use_hmac: bool = False,
tag_length: int | None = 16,
digestmod: None | base.BaseHash = None,
file: io.BufferedIOBase | None = None,
backend: Backends = Backends.CRYPTOGRAPHY,
) -> base.BaseAEADCipher | base.BaseNonAEADCipher | FileCipherWrapper:
"""Instantiate a new Camellia cipher object.
Args:
encrypting: True is encryption and False is decryption.
key: The key for the cipher.
mode:
The mode to use for Camellia cipher. All backends may not support
that particular mode.
iv_or_nonce:
The Initialization Vector or Nonce for the cipher. It must not be
repeated with the same key.
Keyword Arguments:
use_hmac:
Should the cipher use HMAC as authentication or not. Default is
False.
tag_length:
Length of HMAC tag. By default, a **16 byte tag** is generated. If
``tag_length`` is ``None``, a **non-truncated** tag is generated.
Length of non-truncated tag depends on the digest size of the
underlying hash algorithm used by HMAC.
digestmod:
The algorithm to use for HMAC. If ``None``, defaults to ``sha256``.
Specifying this value without setting ``use_hmac`` to True has no
effect.
file:
The source file to read from. If ``file`` is specified and the
``mode`` is not an AEAD mode, HMAC is always used.
backend: The backend to use. It must be a value from :any:`Backends`.
Important:
The following arguments are ignored if the mode is an AEAD mode:
- ``use_hmac``
- ``tag_length``
- ``digestmod``
Returns:
Camellia cipher from the appropriate backend module.
Raises:
UnsupportedMode: if backend does not support that mode.
UnsupportedAlgorithm: if the backend does not support Camellia.
Note:
Any other error that is raised is from the backend itself.
"""
return _load_algo("Camellia", backend).new(
encrypting,
key,
mode,
iv_or_nonce,
file=file,
use_hmac=use_hmac,
tag_length=tag_length,
digestmod=digestmod,
)