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# Copyright (c) 2023, exiledkingcc
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
# * The name of the author may not be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
import secrets
from cryptography import __version__
from cryptography.hazmat.primitives import padding
from cryptography.hazmat.primitives.ciphers.algorithms import AES
try:
# 43.0.0 - https://cryptography.io/en/latest/changelog/#v43-0-0
from cryptography.hazmat.decrepit.ciphers.algorithms import ARC4
except ImportError:
from cryptography.hazmat.primitives.ciphers.algorithms import ARC4
from cryptography.hazmat.primitives.ciphers.base import Cipher
from cryptography.hazmat.primitives.ciphers.modes import CBC, ECB
from pypdf._crypt_providers._base import CryptBase
crypt_provider = ("cryptography", __version__)
class CryptRC4(CryptBase):
def __init__(self, key: bytes) -> None:
self.cipher = Cipher(ARC4(key), mode=None)
def encrypt(self, data: bytes) -> bytes:
encryptor = self.cipher.encryptor()
return encryptor.update(data) + encryptor.finalize()
def decrypt(self, data: bytes) -> bytes:
decryptor = self.cipher.decryptor()
return decryptor.update(data) + decryptor.finalize()
class CryptAES(CryptBase):
def __init__(self, key: bytes) -> None:
self.alg = AES(key)
def encrypt(self, data: bytes) -> bytes:
iv = secrets.token_bytes(16)
pad = padding.PKCS7(128).padder()
data = pad.update(data) + pad.finalize()
cipher = Cipher(self.alg, CBC(iv))
encryptor = cipher.encryptor()
return iv + encryptor.update(data) + encryptor.finalize()
def decrypt(self, data: bytes) -> bytes:
iv = data[:16]
data = data[16:]
# for empty encrypted data
if not data:
return data
# just for robustness, it does not happen under normal circumstances
if len(data) % 16 != 0:
pad = padding.PKCS7(128).padder()
data = pad.update(data) + pad.finalize()
cipher = Cipher(self.alg, CBC(iv))
decryptor = cipher.decryptor()
d = decryptor.update(data) + decryptor.finalize()
return d[: -d[-1]]
def rc4_encrypt(key: bytes, data: bytes) -> bytes:
encryptor = Cipher(ARC4(key), mode=None).encryptor()
return encryptor.update(data) + encryptor.finalize()
def rc4_decrypt(key: bytes, data: bytes) -> bytes:
decryptor = Cipher(ARC4(key), mode=None).decryptor()
return decryptor.update(data) + decryptor.finalize()
def aes_ecb_encrypt(key: bytes, data: bytes) -> bytes:
encryptor = Cipher(AES(key), mode=ECB()).encryptor()
return encryptor.update(data) + encryptor.finalize()
def aes_ecb_decrypt(key: bytes, data: bytes) -> bytes:
decryptor = Cipher(AES(key), mode=ECB()).decryptor()
return decryptor.update(data) + decryptor.finalize()
def aes_cbc_encrypt(key: bytes, iv: bytes, data: bytes) -> bytes:
encryptor = Cipher(AES(key), mode=CBC(iv)).encryptor()
return encryptor.update(data) + encryptor.finalize()
def aes_cbc_decrypt(key: bytes, iv: bytes, data: bytes) -> bytes:
decryptor = Cipher(AES(key), mode=CBC(iv)).decryptor()
return decryptor.update(data) + decryptor.finalize()
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