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Diffstat (limited to 'frozen_deps/Cryptodome/Cipher/AES.py')
| -rw-r--r-- | frozen_deps/Cryptodome/Cipher/AES.py | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/frozen_deps/Cryptodome/Cipher/AES.py b/frozen_deps/Cryptodome/Cipher/AES.py new file mode 100644 index 0000000..dd2671a --- /dev/null +++ b/frozen_deps/Cryptodome/Cipher/AES.py @@ -0,0 +1,250 @@ +# -*- 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 Cryptodome.Cipher import _create_cipher +from Cryptodome.Util._raw_api import (load_pycryptodome_raw_lib, + VoidPointer, SmartPointer, + c_size_t, c_uint8_ptr) + +from Cryptodome.Util import _cpu_features +from Cryptodome.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("Cryptodome.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("Cryptodome.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 ``Cryptodome.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) |