added v3

venv/lib/python3.11/site-packages/nacl/bindings/crypto_secretbox.py

@@ -0,0 +1,86 @@
+# Copyright 2013 Donald Stufft and individual contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from nacl import exceptions as exc
+from nacl._sodium import ffi, lib
+from nacl.exceptions import ensure
+
+
+crypto_secretbox_KEYBYTES: int = lib.crypto_secretbox_keybytes()
+crypto_secretbox_NONCEBYTES: int = lib.crypto_secretbox_noncebytes()
+crypto_secretbox_ZEROBYTES: int = lib.crypto_secretbox_zerobytes()
+crypto_secretbox_BOXZEROBYTES: int = lib.crypto_secretbox_boxzerobytes()
+crypto_secretbox_MACBYTES: int = lib.crypto_secretbox_macbytes()
+crypto_secretbox_MESSAGEBYTES_MAX: int = (
+    lib.crypto_secretbox_messagebytes_max()
+)
+
+
+def crypto_secretbox(message: bytes, nonce: bytes, key: bytes) -> bytes:
+    """
+    Encrypts and returns the message ``message`` with the secret ``key`` and
+    the nonce ``nonce``.
+
+    :param message: bytes
+    :param nonce: bytes
+    :param key: bytes
+    :rtype: bytes
+    """
+    if len(key) != crypto_secretbox_KEYBYTES:
+        raise exc.ValueError("Invalid key")
+
+    if len(nonce) != crypto_secretbox_NONCEBYTES:
+        raise exc.ValueError("Invalid nonce")
+
+    padded = b"\x00" * crypto_secretbox_ZEROBYTES + message
+    ciphertext = ffi.new("unsigned char[]", len(padded))
+
+    res = lib.crypto_secretbox(ciphertext, padded, len(padded), nonce, key)
+    ensure(res == 0, "Encryption failed", raising=exc.CryptoError)
+
+    ciphertext = ffi.buffer(ciphertext, len(padded))
+    return ciphertext[crypto_secretbox_BOXZEROBYTES:]
+
+
+def crypto_secretbox_open(
+    ciphertext: bytes, nonce: bytes, key: bytes
+) -> bytes:
+    """
+    Decrypt and returns the encrypted message ``ciphertext`` with the secret
+    ``key`` and the nonce ``nonce``.
+
+    :param ciphertext: bytes
+    :param nonce: bytes
+    :param key: bytes
+    :rtype: bytes
+    """
+    if len(key) != crypto_secretbox_KEYBYTES:
+        raise exc.ValueError("Invalid key")
+
+    if len(nonce) != crypto_secretbox_NONCEBYTES:
+        raise exc.ValueError("Invalid nonce")
+
+    padded = b"\x00" * crypto_secretbox_BOXZEROBYTES + ciphertext
+    plaintext = ffi.new("unsigned char[]", len(padded))
+
+    res = lib.crypto_secretbox_open(plaintext, padded, len(padded), nonce, key)
+    ensure(
+        res == 0,
+        "Decryption failed. Ciphertext failed verification",
+        raising=exc.CryptoError,
+    )
+
+    plaintext = ffi.buffer(plaintext, len(padded))
+    return plaintext[crypto_secretbox_ZEROBYTES:]