CMYK indexed color to encrypt/decrypt

pypdf/_encryption.py

@@ -79,6 +79,8 @@ def encrypt_object(self, obj: PdfObject) -> PdfObject:
  obj2 = StreamObject()
  obj2.update(obj)
  obj2.set_data(self.stm_crypt.encrypt(b_(obj._data)))
+ for key, value in obj.items():
+ obj2[key] = self.encrypt_object(value)
  obj = obj2
  elif isinstance(obj, DictionaryObject):
  obj2 = DictionaryObject() # type: ignore
@@ -95,6 +97,8 @@ def decrypt_object(self, obj: PdfObject) -> PdfObject:
  obj = create_string_object(data)
  elif isinstance(obj, StreamObject):
  obj._data = self.stm_crypt.decrypt(b_(obj._data))
+ for key, value in obj.items():
+ obj[key] = self.decrypt_object(value)
  elif isinstance(obj, DictionaryObject):
  for key, value in obj.items():
  obj[key] = self.decrypt_object(value)

tests/test_encryption.py

@@ -341,3 +341,30 @@ def test_aes_decrypt_corrupted_data():
  aes = CryptAES(secrets.token_bytes(16))
  for num in [0, 17, 32]:
  aes.decrypt(secrets.token_bytes(num))
+
+
+def test_encrypt_stream_dictionary(pdf_file_path):
+ user_password = secrets.token_urlsafe(10)
+
+ reader = PdfReader(RESOURCE_ROOT / "cmyk_image.pdf")
+ page = reader.pages[0]
+ original_image_obj = reader.get_object(page.images["/I"].indirect_reference)
+
+ writer = PdfWriter()
+ writer.add_page(reader.pages[0])
+ writer.encrypt(
+ user_password=user_password,
+ owner_password=None,
+ algorithm="RC4-128",
+ )
+ with open(pdf_file_path, "wb") as output_stream:
+ writer.write(output_stream)
+
+ reader = PdfReader(pdf_file_path)
+ assert reader.is_encrypted
+ assert reader.decrypt(user_password) == PasswordType.OWNER_PASSWORD
+ page = reader.pages[0]
+ decrypted_image_obj = reader.get_object(page.images["/I"].indirect_reference)
+
+ assert decrypted_image_obj["/ColorSpace"][3] == original_image_obj["/ColorSpace"][3]
+