diff --git a/audit/Poly1305.py b/audit/Poly1305.py deleted file mode 100644 index eb5e0da..0000000 --- a/audit/Poly1305.py +++ /dev/null @@ -1,217 +0,0 @@ -# -*- coding: utf-8 -*- -# -# Hash/Poly1305.py - Implements the Poly1305 MAC -# -# =================================================================== -# 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. -# =================================================================== - -from binascii import unhexlify - -from Crypto.Util.py3compat import bord, tobytes, _copy_bytes - -from Crypto.Hash import BLAKE2s -from Crypto.Random import get_random_bytes -from Crypto.Util._raw_api import (load_pycryptodome_raw_lib, - VoidPointer, SmartPointer, - create_string_buffer, - get_raw_buffer, c_size_t, - c_uint8_ptr) - - -_raw_poly1305 = load_pycryptodome_raw_lib("Crypto.Hash._poly1305", - """ - int poly1305_init(void **state, - const uint8_t *r, - size_t r_len, - const uint8_t *s, - size_t s_len); - int poly1305_destroy(void *state); - int poly1305_update(void *state, - const uint8_t *in, - size_t len); - int poly1305_digest(const void *state, - uint8_t *digest, - size_t len); - """) - - -class Poly1305_MAC(object): - """An Poly1305 MAC object. - Do not instantiate directly. Use the :func:`new` function. - - :ivar digest_size: the size in bytes of the resulting MAC tag - :vartype digest_size: integer - """ - - digest_size = 16 - - def __init__(self, r, s, data): - - if len(r) != 16: - raise ValueError("Parameter r is not 16 bytes long") - if len(s) != 16: - raise ValueError("Parameter s is not 16 bytes long") - - self._mac_tag = None - - state = VoidPointer() - result = _raw_poly1305.poly1305_init(state.address_of(), - c_uint8_ptr(r), - c_size_t(len(r)), - c_uint8_ptr(s), - c_size_t(len(s)) - ) - if result: - raise ValueError("Error %d while instantiating Poly1305" % result) - self._state = SmartPointer(state.get(), - _raw_poly1305.poly1305_destroy) - if data: - self.update(data) - - def update(self, data): - """Authenticate the next chunk of message. - - Args: - data (byte string/byte array/memoryview): The next chunk of data - """ - - if self._mac_tag: - raise TypeError("You can only call 'digest' or 'hexdigest' on this object") - - result = _raw_poly1305.poly1305_update(self._state.get(), - c_uint8_ptr(data), - c_size_t(len(data))) - if result: - raise ValueError("Error %d while hashing Poly1305 data" % result) - return self - - def copy(self): - raise NotImplementedError() - - def digest(self): - """Return the **binary** (non-printable) MAC tag of the message - authenticated so far. - - :return: The MAC tag digest, computed over the data processed so far. - Binary form. - :rtype: byte string - """ - - if self._mac_tag: - return self._mac_tag - - bfr = create_string_buffer(16) - result = _raw_poly1305.poly1305_digest(self._state.get(), - bfr, - c_size_t(len(bfr))) - if result: - raise ValueError("Error %d while creating Poly1305 digest" % result) - - self._mac_tag = get_raw_buffer(bfr) - return self._mac_tag - - def hexdigest(self): - """Return the **printable** MAC tag of the message authenticated so far. - - :return: The MAC tag, computed over the data processed so far. - Hexadecimal encoded. - :rtype: string - """ - - return "".join(["%02x" % bord(x) - for x in tuple(self.digest())]) - - def verify(self, mac_tag): - """Verify that a given **binary** MAC (computed by another party) - is valid. - - Args: - mac_tag (byte string/byte string/memoryview): the expected MAC of the message. - - Raises: - ValueError: if the MAC does not match. It means that the message - has been tampered with or that the MAC key is incorrect. - """ - - secret = get_random_bytes(16) - - mac1 = BLAKE2s.new(digest_bits=160, key=secret, data=mac_tag) - mac2 = BLAKE2s.new(digest_bits=160, key=secret, data=self.digest()) - - if mac1.digest() != mac2.digest(): - raise ValueError("MAC check failed") - - def hexverify(self, hex_mac_tag): - """Verify that a given **printable** MAC (computed by another party) - is valid. - - Args: - hex_mac_tag (string): the expected MAC of the message, - as a hexadecimal string. - - Raises: - ValueError: if the MAC does not match. It means that the message - has been tampered with or that the MAC key is incorrect. - """ - - self.verify(unhexlify(tobytes(hex_mac_tag))) - - - -def new(**kwargs): - """Create a new Poly1305 MAC object. - - Args: - key (bytes/bytearray/memoryview): - The 32-byte key for the Poly1305 object. - cipher (module from ``Crypto.Cipher``): - The cipher algorithm to use for deriving the Poly1305 - key pair *(r, s)*. - It can only be ``Crypto.Cipher.AES`` or ``Crypto.Cipher.ChaCha20``. - nonce (bytes/bytearray/memoryview): - Optional. The non-repeatable value to use for the MAC of this message. - It must be 16 bytes long for ``AES`` and 8 or 12 bytes for ``ChaCha20``. - If not passed, a random nonce is created; you will find it in the - ``nonce`` attribute of the new object. - data (bytes/bytearray/memoryview): - Optional. The very first chunk of the message to authenticate. - It is equivalent to an early call to ``update()``. - - Returns: - A :class:`Poly1305_MAC` object - """ - - cipher = kwargs.pop("cipher", None) - if not hasattr(cipher, '_derive_Poly1305_key_pair'): - raise ValueError("Parameter 'cipher' must be AES or ChaCha20") - - cipher_key = kwargs.pop("key", None) - if cipher_key is None: - raise TypeError("You must pass a parameter 'key'") - - nonce = kwargs.pop("nonce", None) - data = kwargs.pop("data", None) - - if kwargs: - raise TypeError("Unknown parameters: " + str(kwargs)) - - r, s, nonce = cipher._derive_Poly1305_key_pair(cipher_key, nonce) - - new_mac = Poly1305_MAC(r, s, data) - new_mac.nonce = _copy_bytes(None, None, nonce) # nonce may still be just a memoryview - return new_mac