exception for wrong password (#425)

Author: andiwand

cli/src/meta.cpp

@@ -2,6 +2,8 @@
 
 #include <odr/internal/util/odr_meta_util.hpp>
 
+#include <odr/exceptions.hpp>
+
 #include <iostream>
 #include <string>
 
@@ -19,7 +21,9 @@ int main(int argc, char **argv) {
   DocumentFile document_file{input};
 
   if (document_file.password_encrypted() && has_password) {
-    if (!document_file.decrypt(password)) {
+    try {
+      document_file = document_file.decrypt(password).document_file();
+    } catch (const WrongPasswordError &) {
       std::cerr << "wrong password" << std::endl;
       return 1;
     }

cli/src/server.cpp

@@ -1,3 +1,4 @@
+#include <odr/exceptions.hpp>
 #include <odr/file.hpp>
 #include <odr/html.hpp>
 #include <odr/http_server.hpp>
@@ -26,12 +27,12 @@ int main(int argc, char **argv) {
     return 2;
   }
   if (decoded_file.password_encrypted()) {
-    auto decrypt_result = decoded_file.decrypt(*password);
-    if (!decrypt_result.has_value()) {
+    try {
+      decoded_file = decoded_file.decrypt(*password);
+    } catch (const WrongPasswordError &) {
       std::cerr << "wrong password" << std::endl;
       return 1;
     }
-    decoded_file = std::move(*decrypt_result);
   }
 
   HttpServer::Config server_config;

cli/src/translate.cpp

@@ -1,3 +1,4 @@
+#include <odr/exceptions.hpp>
 #include <odr/file.hpp>
 #include <odr/html.hpp>
 #include <odr/html_service.hpp>
@@ -24,12 +25,12 @@ int main(int argc, char **argv) {
     return 2;
   }
   if (decoded_file.password_encrypted()) {
-    auto decrypt_result = decoded_file.decrypt(*password);
-    if (!decrypt_result.has_value()) {
+    try {
+      decoded_file = decoded_file.decrypt(*password);
+    } catch (const WrongPasswordError &) {
       std::cerr << "wrong password" << std::endl;
       return 1;
     }
-    decoded_file = std::move(*decrypt_result);
   }
 
   HtmlConfig config;

src/odr/exceptions.cpp

@@ -108,4 +108,13 @@ UnsupportedOption::UnsupportedOption(const std::string &message)
 NullPointerError::NullPointerError(const std::string &variable)
     : std::runtime_error("null pointer error: " + variable) {}
 
+WrongPasswordError::WrongPasswordError()
+    : std::runtime_error("wrong password error") {}
+
+DecryptionFailed::DecryptionFailed()
+    : std::runtime_error("decryption failed") {}
+
+NotEncryptedError::NotEncryptedError()
+    : std::runtime_error("not encrypted error") {}
+
 } // namespace odr

src/odr/exceptions.hpp

@@ -192,4 +192,19 @@ struct NullPointerError : public std::runtime_error {
   explicit NullPointerError(const std::string &variable);
 };
 
+/// @brief Wrong password error
+struct WrongPasswordError : public std::runtime_error {
+  explicit WrongPasswordError();
+};
+
+/// @brief Decryption failed
+struct DecryptionFailed : public std::runtime_error {
+  explicit DecryptionFailed();
+};
+
+/// @brief Not encrypted error
+struct NotEncryptedError : public std::runtime_error {
+  explicit NotEncryptedError();
+};
+
 } // namespace odr

src/odr/file.cpp

@@ -127,12 +127,8 @@ EncryptionState DecodedFile::encryption_state() const {
   return m_impl->encryption_state();
 }
 
-std::optional<DecodedFile> DecodedFile::decrypt(const std::string &password) {
-  auto decrypted = m_impl->decrypt(password);
-  if (decrypted == nullptr) {
-    return std::nullopt;
-  }
-  return DecodedFile(decrypted);
+DecodedFile DecodedFile::decrypt(const std::string &password) const {
+  return DecodedFile(m_impl->decrypt(password));
 }
 
 bool DecodedFile::is_text_file() const {

src/odr/file.hpp

@@ -196,7 +196,7 @@ class DecodedFile {
 
   [[nodiscard]] bool password_encrypted() const;
   [[nodiscard]] EncryptionState encryption_state() const;
-  [[nodiscard]] std::optional<DecodedFile> decrypt(const std::string &password);
+  [[nodiscard]] DecodedFile decrypt(const std::string &password) const;
 
   [[nodiscard]] bool is_text_file() const;
   [[nodiscard]] bool is_image_file() const;

src/odr/internal/abstract/file.hpp

@@ -46,7 +46,7 @@ class DecodedFile {
     return EncryptionState::not_encrypted;
   }
   [[nodiscard]] virtual std::shared_ptr<DecodedFile>
-  decrypt(const std::string &password) const noexcept {
+  decrypt(const std::string &password) const {
     (void)password;
     return nullptr;
   }

src/odr/internal/odf/odf_crypto.cpp

@@ -167,7 +167,7 @@ std::shared_ptr<abstract::ReadableFilesystem>
 odf::decrypt(const std::shared_ptr<abstract::ReadableFilesystem> &filesystem,
              const Manifest &manifest, const std::string &password) {
   if (!manifest.encrypted) {
-    return nullptr;
+    throw NotEncryptedError();
   }
 
   if (auto it = manifest.entries.find(common::Path("encrypted-package"));
@@ -183,7 +183,7 @@ odf::decrypt(const std::shared_ptr<abstract::ReadableFilesystem> &filesystem,
           std::make_shared<common::MemoryFile>(std::move(decrypt));
       return zip::ZipFile(memory_file).archive()->filesystem();
     } catch (...) {
-      return nullptr;
+      throw WrongPasswordError();
     }
   }
 
@@ -200,12 +200,12 @@ odf::decrypt(const std::shared_ptr<abstract::ReadableFilesystem> &filesystem,
     const std::string decrypt =
         derive_key_and_decrypt(smallest_file_entry, start_key, input);
     if (!validate_password(smallest_file_entry, decrypt)) {
-      return nullptr;
+      throw WrongPasswordError();
     }
     return std::make_shared<DecryptedFilesystem>(filesystem, manifest,
                                                  start_key);
   } catch (...) {
-    return nullptr;
+    throw DecryptionFailed();
   }
 }
 

src/odr/internal/odf/odf_file.cpp

@@ -63,16 +63,12 @@ EncryptionState OpenDocumentFile::encryption_state() const noexcept {
 }
 
 std::shared_ptr<abstract::DecodedFile>
-OpenDocumentFile::decrypt(const std::string &password) const noexcept {
+OpenDocumentFile::decrypt(const std::string &password) const {
   if (m_encryption_state != EncryptionState::encrypted) {
-    return nullptr;
+    throw NotEncryptedError();
   }
 
   auto decrypted_filesystem = odf::decrypt(m_filesystem, m_manifest, password);
-  if (decrypted_filesystem == nullptr) {
-    return nullptr;
-  }
-
   auto decrypted_file = std::make_shared<OpenDocumentFile>(*this);
   decrypted_file->m_filesystem = std::move(decrypted_filesystem);
   decrypted_file->m_file_meta =