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Crypto/Cipher/AES.py

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+# -*- coding: utf-8 -*-
+#
+#  Cipher/AES.py : AES
+#
+# ===================================================================
+# The contents of this file are dedicated to the public domain.  To
+# the extent that dedication to the public domain is not available,
+# everyone is granted a worldwide, perpetual, royalty-free,
+# non-exclusive license to exercise all rights associated with the
+# contents of this file for any purpose whatsoever.
+# No rights are reserved.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# ===================================================================
+"""
+Module's constants for the modes of operation supported with AES:
+
+:var MODE_ECB: :ref:`Electronic Code Book (ECB) <ecb_mode>`
+:var MODE_CBC: :ref:`Cipher-Block Chaining (CBC) <cbc_mode>`
+:var MODE_CFB: :ref:`Cipher FeedBack (CFB) <cfb_mode>`
+:var MODE_OFB: :ref:`Output FeedBack (OFB) <ofb_mode>`
+:var MODE_CTR: :ref:`CounTer Mode (CTR) <ctr_mode>`
+:var MODE_OPENPGP:  :ref:`OpenPGP Mode <openpgp_mode>`
+:var MODE_CCM: :ref:`Counter with CBC-MAC (CCM) Mode <ccm_mode>`
+:var MODE_EAX: :ref:`EAX Mode <eax_mode>`
+:var MODE_GCM: :ref:`Galois Counter Mode (GCM) <gcm_mode>`
+:var MODE_SIV: :ref:`Syntethic Initialization Vector (SIV) <siv_mode>`
+:var MODE_OCB: :ref:`Offset Code Book (OCB) <ocb_mode>`
+"""
+
+import sys
+
+from Crypto.Cipher import _create_cipher
+from Crypto.Util._raw_api import (load_pycryptodome_raw_lib,
+                                  VoidPointer, SmartPointer,
+                                  c_size_t, c_uint8_ptr)
+
+from Crypto.Util import _cpu_features
+from Crypto.Random import get_random_bytes
+
+
+_cproto = """
+        int AES_start_operation(const uint8_t key[],
+                                size_t key_len,
+                                void **pResult);
+        int AES_encrypt(const void *state,
+                        const uint8_t *in,
+                        uint8_t *out,
+                        size_t data_len);
+        int AES_decrypt(const void *state,
+                        const uint8_t *in,
+                        uint8_t *out,
+                        size_t data_len);
+        int AES_stop_operation(void *state);
+        """
+
+
+# Load portable AES
+_raw_aes_lib = load_pycryptodome_raw_lib("Crypto.Cipher._raw_aes",
+                                         _cproto)
+
+# Try to load AES with AES NI instructions
+try:
+    _raw_aesni_lib = None
+    if _cpu_features.have_aes_ni():
+        _raw_aesni_lib = load_pycryptodome_raw_lib("Crypto.Cipher._raw_aesni",
+                                                   _cproto.replace("AES",
+                                                                   "AESNI"))
+# _raw_aesni may not have been compiled in
+except OSError:
+    pass
+
+
+def _create_base_cipher(dict_parameters):
+    """This method instantiates and returns a handle to a low-level
+    base cipher. It will absorb named parameters in the process."""
+
+    use_aesni = dict_parameters.pop("use_aesni", True)
+
+    try:
+        key = dict_parameters.pop("key")
+    except KeyError:
+        raise TypeError("Missing 'key' parameter")
+
+    if len(key) not in key_size:
+        raise ValueError("Incorrect AES key length (%d bytes)" % len(key))
+
+    if use_aesni and _raw_aesni_lib:
+        start_operation = _raw_aesni_lib.AESNI_start_operation
+        stop_operation = _raw_aesni_lib.AESNI_stop_operation
+    else:
+        start_operation = _raw_aes_lib.AES_start_operation
+        stop_operation = _raw_aes_lib.AES_stop_operation
+
+    cipher = VoidPointer()
+    result = start_operation(c_uint8_ptr(key),
+                             c_size_t(len(key)),
+                             cipher.address_of())
+    if result:
+        raise ValueError("Error %X while instantiating the AES cipher"
+                         % result)
+    return SmartPointer(cipher.get(), stop_operation)
+
+
+def _derive_Poly1305_key_pair(key, nonce):
+    """Derive a tuple (r, s, nonce) for a Poly1305 MAC.
+    
+    If nonce is ``None``, a new 16-byte nonce is generated.
+    """
+
+    if len(key) != 32:
+        raise ValueError("Poly1305 with AES requires a 32-byte key")
+
+    if nonce is None:
+        nonce = get_random_bytes(16)
+    elif len(nonce) != 16:
+        raise ValueError("Poly1305 with AES requires a 16-byte nonce")
+
+    s = new(key[:16], MODE_ECB).encrypt(nonce)
+    return key[16:], s, nonce
+
+
+def new(key, mode, *args, **kwargs):
+    """Create a new AES cipher.
+
+    :param key:
+        The secret key to use in the symmetric cipher.
+
+        It must be 16, 24 or 32 bytes long (respectively for *AES-128*,
+        *AES-192* or *AES-256*).
+
+        For ``MODE_SIV`` only, it doubles to 32, 48, or 64 bytes.
+    :type key: bytes/bytearray/memoryview
+
+    :param mode:
+        The chaining mode to use for encryption or decryption.
+        If in doubt, use ``MODE_EAX``.
+    :type mode: One of the supported ``MODE_*`` constants
+
+    :Keyword Arguments:
+        *   **iv** (*bytes*, *bytearray*, *memoryview*) --
+            (Only applicable for ``MODE_CBC``, ``MODE_CFB``, ``MODE_OFB``,
+            and ``MODE_OPENPGP`` modes).
+
+            The initialization vector to use for encryption or decryption.
+
+            For ``MODE_CBC``, ``MODE_CFB``, and ``MODE_OFB`` it must be 16 bytes long.
+
+            For ``MODE_OPENPGP`` mode only,
+            it must be 16 bytes long for encryption
+            and 18 bytes for decryption (in the latter case, it is
+            actually the *encrypted* IV which was prefixed to the ciphertext).
+
+            If not provided, a random byte string is generated (you must then
+            read its value with the :attr:`iv` attribute).
+
+        *   **nonce** (*bytes*, *bytearray*, *memoryview*) --
+            (Only applicable for ``MODE_CCM``, ``MODE_EAX``, ``MODE_GCM``,
+            ``MODE_SIV``, ``MODE_OCB``, and ``MODE_CTR``).
+
+            A value that must never be reused for any other encryption done
+            with this key (except possibly for ``MODE_SIV``, see below).
+
+            For ``MODE_EAX``, ``MODE_GCM`` and ``MODE_SIV`` there are no
+            restrictions on its length (recommended: **16** bytes).
+
+            For ``MODE_CCM``, its length must be in the range **[7..13]**.
+            Bear in mind that with CCM there is a trade-off between nonce
+            length and maximum message size. Recommendation: **11** bytes.
+
+            For ``MODE_OCB``, its length must be in the range **[1..15]**
+            (recommended: **15**).
+
+            For ``MODE_CTR``, its length must be in the range **[0..15]**
+            (recommended: **8**).
+            
+            For ``MODE_SIV``, the nonce is optional, if it is not specified,
+            then no nonce is being used, which renders the encryption
+            deterministic.
+
+            If not provided, for modes other than ``MODE_SIV```, a random
+            byte string of the recommended length is used (you must then
+            read its value with the :attr:`nonce` attribute).
+
+        *   **segment_size** (*integer*) --
+            (Only ``MODE_CFB``).The number of **bits** the plaintext and ciphertext
+            are segmented in. It must be a multiple of 8.
+            If not specified, it will be assumed to be 8.
+
+        *   **mac_len** : (*integer*) --
+            (Only ``MODE_EAX``, ``MODE_GCM``, ``MODE_OCB``, ``MODE_CCM``)
+            Length of the authentication tag, in bytes.
+
+            It must be even and in the range **[4..16]**.
+            The recommended value (and the default, if not specified) is **16**.
+
+        *   **msg_len** : (*integer*) --
+            (Only ``MODE_CCM``). Length of the message to (de)cipher.
+            If not specified, ``encrypt`` must be called with the entire message.
+            Similarly, ``decrypt`` can only be called once.
+
+        *   **assoc_len** : (*integer*) --
+            (Only ``MODE_CCM``). Length of the associated data.
+            If not specified, all associated data is buffered internally,
+            which may represent a problem for very large messages.
+
+        *   **initial_value** : (*integer* or *bytes/bytearray/memoryview*) --
+            (Only ``MODE_CTR``).
+            The initial value for the counter. If not present, the cipher will
+            start counting from 0. The value is incremented by one for each block.
+            The counter number is encoded in big endian mode.
+
+        *   **counter** : (*object*) --
+            Instance of ``Crypto.Util.Counter``, which allows full customization
+            of the counter block. This parameter is incompatible to both ``nonce``
+            and ``initial_value``.
+
+        *   **use_aesni** : (*boolean*) --
+            Use Intel AES-NI hardware extensions (default: use if available).
+
+    :Return: an AES object, of the applicable mode.
+    """
+
+    kwargs["add_aes_modes"] = True
+    return _create_cipher(sys.modules[__name__], key, mode, *args, **kwargs)
+
+
+MODE_ECB = 1
+MODE_CBC = 2
+MODE_CFB = 3
+MODE_OFB = 5
+MODE_CTR = 6
+MODE_OPENPGP = 7
+MODE_CCM = 8
+MODE_EAX = 9
+MODE_SIV = 10
+MODE_GCM = 11
+MODE_OCB = 12
+
+# Size of a data block (in bytes)
+block_size = 16
+# Size of a key (in bytes)
+key_size = (16, 24, 32)

Crypto/Cipher/AES.pyi

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+from typing import Union, Tuple, Optional, Dict
+
+from Crypto.Cipher._mode_ecb import EcbMode
+from Crypto.Cipher._mode_cbc import CbcMode
+from Crypto.Cipher._mode_cfb import CfbMode
+from Crypto.Cipher._mode_ofb import OfbMode
+from Crypto.Cipher._mode_ctr import CtrMode
+from Crypto.Cipher._mode_openpgp import OpenPgpMode
+from Crypto.Cipher._mode_ccm import CcmMode
+from Crypto.Cipher._mode_eax import EaxMode
+from Crypto.Cipher._mode_gcm import GcmMode
+from Crypto.Cipher._mode_siv import SivMode
+from Crypto.Cipher._mode_ocb import OcbMode
+
+AESMode = int
+
+MODE_ECB: AESMode
+MODE_CBC: AESMode
+MODE_CFB: AESMode
+MODE_OFB: AESMode
+MODE_CTR: AESMode
+MODE_OPENPGP: AESMode
+MODE_CCM: AESMode
+MODE_EAX: AESMode
+MODE_GCM: AESMode
+MODE_SIV: AESMode
+MODE_OCB: AESMode
+
+Buffer = Union[bytes, bytearray, memoryview]
+
+def new(key: Buffer,
+        mode: AESMode,
+        iv : Buffer = ...,
+        IV : Buffer = ...,
+        nonce : Buffer = ...,
+        segment_size : int = ...,
+        mac_len : int = ...,
+        assoc_len : int = ...,
+        initial_value : Union[int, Buffer] = ...,
+        counter : Dict = ...,
+        use_aesni : bool = ...) -> \
+        Union[EcbMode, CbcMode, CfbMode, OfbMode, CtrMode,
+              OpenPgpMode, CcmMode, EaxMode, GcmMode,
+              SivMode, OcbMode]: ...
+
+block_size: int
+key_size: Tuple[int, int, int]