Files
m2dev-client-src/src/PackLib/Pack.cpp
2025-09-21 05:28:55 +02:00

72 lines
2.0 KiB
C++

#include "Pack.h"
#include <zstd.h>
bool CPack::Open(const std::string& path, TPackFileMap& entries)
{
std::error_code ec;
m_file.map(path, ec);
if (ec) {
return false;
}
size_t file_size = m_file.size();
if (file_size < sizeof(TPackFileHeader)) {
return false;
}
memcpy(&m_header, m_file.data(), sizeof(TPackFileHeader));
m_decryption.SetKeyWithIV(PACK_KEY.data(), PACK_KEY.size(), m_header.iv, CryptoPP::Camellia::BLOCKSIZE);
if (file_size < sizeof(TPackFileHeader) + m_header.entry_num * sizeof(TPackFileEntry)) {
return false;
}
for (size_t i = 0; i < m_header.entry_num; i++) {
TPackFileEntry entry;
memcpy(&entry, m_file.data() + sizeof(TPackFileHeader) + i * sizeof(TPackFileEntry), sizeof(TPackFileEntry));
m_decryption.ProcessData((CryptoPP::byte*)&entry, (CryptoPP::byte*)&entry, sizeof(TPackFileEntry));
entries[entry.file_name] = std::make_pair(shared_from_this(), entry);
if (file_size < m_header.data_begin + entry.offset + entry.compressed_size) {
return false;
}
}
return true;
}
bool CPack::GetFile(const TPackFileEntry& entry, TPackFile& result)
{
result.resize(entry.file_size);
size_t offset = m_header.data_begin + entry.offset;
switch (entry.encryption)
{
case 0: {
size_t decompressed_size = ZSTD_decompress(result.data(), result.size(), m_file.data() + offset, entry.compressed_size);
if (decompressed_size != entry.file_size) {
return false;
}
} break;
case 1: {
std::vector<uint8_t> compressed_data(entry.compressed_size);
memcpy(compressed_data.data(), m_file.data() + offset, entry.compressed_size);
m_decryption.Resynchronize(entry.iv, sizeof(entry.iv));
m_decryption.ProcessData(compressed_data.data(), compressed_data.data(), entry.compressed_size);
size_t decompressed_size = ZSTD_decompress(result.data(), result.size(), compressed_data.data(), compressed_data.size());
if (decompressed_size != entry.file_size) {
return false;
}
} break;
default: return false;
}
return true;
}