feat(reader): add PDF reading support with outline chapters, CLI blocks, and noise filtering (task 7)

app/vendor/pypdf/_crypt_providers/_fallback.py

@@ -0,0 +1,93 @@
+# 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(out)
+
+    def decrypt(self, data: bytes, *, strict: bool = True) -> 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, *, strict: bool = True) -> 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)