fix(plugin): bundle Python dependencies for standalone deployment

py_modules/cryptography/hazmat/primitives/_modes.py

@@ -0,0 +1,105 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+from __future__ import annotations
+
+import abc
+
+from cryptography import utils
+from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
+from cryptography.hazmat.primitives._cipheralgorithm import (
+    BlockCipherAlgorithm,
+    CipherAlgorithm,
+)
+
+
+class Mode(metaclass=abc.ABCMeta):
+    @property
+    @abc.abstractmethod
+    def name(self) -> str:
+        """
+        A string naming this mode (e.g. "ECB", "CBC").
+        """
+
+    @abc.abstractmethod
+    def validate_for_algorithm(self, algorithm: CipherAlgorithm) -> None:
+        """
+        Checks that all the necessary invariants of this (mode, algorithm)
+        combination are met.
+        """
+
+
+class ModeWithInitializationVector(Mode, metaclass=abc.ABCMeta):
+    @property
+    @abc.abstractmethod
+    def initialization_vector(self) -> utils.Buffer:
+        """
+        The value of the initialization vector for this mode as bytes.
+        """
+
+
+class ModeWithTweak(Mode, metaclass=abc.ABCMeta):
+    @property
+    @abc.abstractmethod
+    def tweak(self) -> utils.Buffer:
+        """
+        The value of the tweak for this mode as bytes.
+        """
+
+
+class ModeWithNonce(Mode, metaclass=abc.ABCMeta):
+    @property
+    @abc.abstractmethod
+    def nonce(self) -> utils.Buffer:
+        """
+        The value of the nonce for this mode as bytes.
+        """
+
+
+class ModeWithAuthenticationTag(Mode, metaclass=abc.ABCMeta):
+    @property
+    @abc.abstractmethod
+    def tag(self) -> bytes | None:
+        """
+        The value of the tag supplied to the constructor of this mode.
+        """
+
+
+def _check_aes_key_length(self: Mode, algorithm: CipherAlgorithm) -> None:
+    if algorithm.key_size > 256 and algorithm.name == "AES":
+        raise ValueError(
+            "Only 128, 192, and 256 bit keys are allowed for this AES mode"
+        )
+
+
+def _check_iv_length(
+    self: ModeWithInitializationVector, algorithm: BlockCipherAlgorithm
+) -> None:
+    iv_len = len(self.initialization_vector)
+    if iv_len * 8 != algorithm.block_size:
+        raise ValueError(f"Invalid IV size ({iv_len}) for {self.name}.")
+
+
+def _check_nonce_length(
+    nonce: utils.Buffer, name: str, algorithm: CipherAlgorithm
+) -> None:
+    if not isinstance(algorithm, BlockCipherAlgorithm):
+        raise UnsupportedAlgorithm(
+            f"{name} requires a block cipher algorithm",
+            _Reasons.UNSUPPORTED_CIPHER,
+        )
+    if len(nonce) * 8 != algorithm.block_size:
+        raise ValueError(f"Invalid nonce size ({len(nonce)}) for {name}.")
+
+
+def _check_iv_and_key_length(
+    self: ModeWithInitializationVector, algorithm: CipherAlgorithm
+) -> None:
+    if not isinstance(algorithm, BlockCipherAlgorithm):
+        raise UnsupportedAlgorithm(
+            f"{self} requires a block cipher algorithm",
+            _Reasons.UNSUPPORTED_CIPHER,
+        )
+    _check_aes_key_length(self, algorithm)
+    _check_iv_length(self, algorithm)