# 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. from pypdf._crypt_providers._base import CryptBase from pypdf.errors import DependencyError _DEPENDENCY_ERROR_STR = "cryptography>=3.1 is required for AES algorithm" crypt_provider = ("local_crypt_fallback", "0.0.0") class CryptRC4(CryptBase): def __init__(self, key: bytes) -> None: self.s = bytearray(range(256)) j = 0 for i in range(256): j = (j + self.s[i] + key[i % len(key)]) % 256 self.s[i], self.s[j] = self.s[j], self.s[i] def encrypt(self, data: bytes) -> bytes: s = bytearray(self.s) out = [0 for _ in range(len(data))] i, j = 0, 0 for k in range(len(data)): i = (i + 1) % 256 j = (j + s[i]) % 256 s[i], s[j] = s[j], s[i] x = s[(s[i] + s[j]) % 256] out[k] = data[k] ^ x return bytes(bytearray(out)) def decrypt(self, data: bytes) -> bytes: return self.encrypt(data) class CryptAES(CryptBase): def __init__(self, key: bytes) -> None: pass def encrypt(self, data: bytes) -> bytes: raise DependencyError(_DEPENDENCY_ERROR_STR) def decrypt(self, data: bytes) -> bytes: raise DependencyError(_DEPENDENCY_ERROR_STR) def rc4_encrypt(key: bytes, data: bytes) -> bytes: return CryptRC4(key).encrypt(data) def rc4_decrypt(key: bytes, data: bytes) -> bytes: return CryptRC4(key).decrypt(data) def aes_ecb_encrypt(key: bytes, data: bytes) -> bytes: raise DependencyError(_DEPENDENCY_ERROR_STR) def aes_ecb_decrypt(key: bytes, data: bytes) -> bytes: raise DependencyError(_DEPENDENCY_ERROR_STR) def aes_cbc_encrypt(key: bytes, iv: bytes, data: bytes) -> bytes: raise DependencyError(_DEPENDENCY_ERROR_STR) def aes_cbc_decrypt(key: bytes, iv: bytes, data: bytes) -> bytes: raise DependencyError(_DEPENDENCY_ERROR_STR)