new_build_system (#18)

Reviewed-on: #18

support/src/utils/encryption.cpp

@@ -21,34 +21,97 @@
 */
 #include "utils/encryption.hpp"
 
-#if defined(PROJECT_ENABLE_LIBSODIUM)
-namespace repertory::utils::encryption {
-#if defined(PROJECT_ENABLE_BOOST)
-auto decrypt_data(std::string_view password,
-                  std::string_view data) -> data_buffer {
-  auto key = generate_key<hash_256_t>(password);
+#include "utils/collection.hpp"
+#include "utils/encrypting_reader.hpp"
 
-  data_buffer buf{};
-  if (not decrypt_data(key,
-                       reinterpret_cast<const unsigned char *>(data.data()),
-                       data.size(), buf)) {
-    throw std::runtime_error("decryption failed");
+#if defined(PROJECT_ENABLE_LIBSODIUM) && defined(PROJECT_ENABLE_BOOST)
+
+namespace repertory::utils::encryption {
+auto decrypt_file_path(std::string_view encryption_token,
+                       std::string &file_path) -> bool {
+  std::string decrypted_file_path{};
+  for (const auto &part : std::filesystem::path(file_path)) {
+    auto file_name = part.string();
+    if (file_name == "/") {
+      continue;
+    }
+
+    auto res = decrypt_file_name(encryption_token, file_name);
+    if (not res) {
+      return res;
+    }
+
+    decrypted_file_path += '/' + file_name;
   }
 
-  return buf;
+  file_path = decrypted_file_path;
+  return true;
 }
 
-auto encrypt_data(std::string_view password,
-                  std::string_view data) -> data_buffer {
-  auto key = generate_key<hash_256_t>(password);
+auto decrypt_file_name(std::string_view encryption_token,
+                       std::string &file_name) -> bool {
+  data_buffer buffer;
+  if (not utils::collection::from_hex_string(file_name, buffer)) {
+    return false;
+  }
 
-  data_buffer buf{};
-  encrypt_data(key, reinterpret_cast<const unsigned char *>(data.data()),
-               data.size(), buf);
+  file_name.clear();
+  if (not utils::encryption::decrypt_data(encryption_token, buffer,
+                                          file_name)) {
+    return false;
+  }
 
-  return buf;
+  return true;
 }
-#endif // defined(PROJECT_ENABLE_BOOST)
+
+#if defined(PROJECT_ENABLE_CURL)
+auto read_encrypted_range(const http_range &range,
+                          const utils::encryption::hash_256_t &key,
+                          reader_func_t reader_func, std::uint64_t total_size,
+                          data_buffer &data) -> bool {
+  const auto encrypted_chunk_size =
+      utils::encryption::encrypting_reader::get_encrypted_chunk_size();
+  const auto data_chunk_size =
+      utils::encryption::encrypting_reader::get_data_chunk_size();
+
+  const auto start_chunk =
+      static_cast<std::size_t>(range.begin / data_chunk_size);
+  const auto end_chunk = static_cast<std::size_t>(range.end / data_chunk_size);
+  auto remain = range.end - range.begin + 1U;
+  auto source_offset = static_cast<std::size_t>(range.begin % data_chunk_size);
+
+  for (std::size_t chunk = start_chunk; chunk <= end_chunk; chunk++) {
+    data_buffer cypher;
+    const auto start_offset = chunk * encrypted_chunk_size;
+    const auto end_offset = std::min(
+        start_offset + (total_size - (chunk * data_chunk_size)) +
+            encryption_header_size - 1U,
+        static_cast<std::uint64_t>(start_offset + encrypted_chunk_size - 1U));
+
+    if (not reader_func(cypher, start_offset, end_offset)) {
+      return false;
+    }
+
+    data_buffer source_buffer;
+    if (not utils::encryption::decrypt_data(key, cypher, source_buffer)) {
+      return false;
+    }
+    cypher.clear();
+
+    const auto data_size = static_cast<std::size_t>(std::min(
+        remain, static_cast<std::uint64_t>(data_chunk_size - source_offset)));
+    std::copy(std::next(source_buffer.begin(),
+                        static_cast<std::int64_t>(source_offset)),
+              std::next(source_buffer.begin(),
+                        static_cast<std::int64_t>(source_offset + data_size)),
+              std::back_inserter(data));
+    remain -= data_size;
+    source_offset = 0U;
+  }
+
+  return true;
+}
+#endif // defined(PROJECT_ENABLE_CURL)
 } // namespace repertory::utils::encryption
 
-#endif // defined(PROJECT_ENABLE_LIBSODIUM)
+#endif // defined(PROJECT_ENABLE_LIBSODIUM) && defined (PROJECT_ENABLE_BOOST)