diff options
Diffstat (limited to 'src/core/file_sys/xts_archive.cpp')
| -rw-r--r-- | src/core/file_sys/xts_archive.cpp | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/src/core/file_sys/xts_archive.cpp b/src/core/file_sys/xts_archive.cpp new file mode 100644 index 000000000..552835738 --- /dev/null +++ b/src/core/file_sys/xts_archive.cpp @@ -0,0 +1,169 @@ +// Copyright 2018 yuzu emulator team +// Licensed under GPLv2 or any later version +// Refer to the license.txt file included. + +#include <algorithm> +#include <array> +#include <cstring> +#include <regex> +#include <string> +#include <mbedtls/md.h> +#include <mbedtls/sha256.h> +#include "common/assert.h" +#include "common/hex_util.h" +#include "common/logging/log.h" +#include "core/crypto/aes_util.h" +#include "core/crypto/xts_encryption_layer.h" +#include "core/file_sys/partition_filesystem.h" +#include "core/file_sys/vfs_offset.h" +#include "core/file_sys/xts_archive.h" +#include "core/loader/loader.h" + +namespace FileSys { + +constexpr u64 NAX_HEADER_PADDING_SIZE = 0x4000; + +template <typename SourceData, typename SourceKey, typename Destination> +static bool CalculateHMAC256(Destination* out, const SourceKey* key, size_t key_length, + const SourceData* data, size_t data_length) { + mbedtls_md_context_t context; + mbedtls_md_init(&context); + + const auto key_f = reinterpret_cast<const u8*>(key); + const std::vector<u8> key_v(key_f, key_f + key_length); + + if (mbedtls_md_setup(&context, mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), 1) || + mbedtls_md_hmac_starts(&context, reinterpret_cast<const u8*>(key), key_length) || + mbedtls_md_hmac_update(&context, reinterpret_cast<const u8*>(data), data_length) || + mbedtls_md_hmac_finish(&context, reinterpret_cast<u8*>(out))) { + mbedtls_md_free(&context); + return false; + } + + mbedtls_md_free(&context); + return true; +} + +NAX::NAX(VirtualFile file_) : file(std::move(file_)), header(std::make_unique<NAXHeader>()) { + std::string path = FileUtil::SanitizePath(file->GetFullPath()); + static const std::regex nax_path_regex("/registered/(000000[0-9A-F]{2})/([0-9A-F]{32})\\.nca", + std::regex_constants::ECMAScript | + std::regex_constants::icase); + std::smatch match; + if (!std::regex_search(path, match, nax_path_regex)) { + status = Loader::ResultStatus::ErrorBadNAXFilePath; + return; + } + + std::string two_dir = match[1]; + std::string nca_id = match[2]; + std::transform(two_dir.begin(), two_dir.end(), two_dir.begin(), ::toupper); + std::transform(nca_id.begin(), nca_id.end(), nca_id.begin(), ::tolower); + + status = Parse(fmt::format("/registered/{}/{}.nca", two_dir, nca_id)); +} + +NAX::NAX(VirtualFile file_, std::array<u8, 0x10> nca_id) + : file(std::move(file_)), header(std::make_unique<NAXHeader>()) { + Core::Crypto::SHA256Hash hash{}; + mbedtls_sha256(nca_id.data(), nca_id.size(), hash.data(), 0); + status = Parse(fmt::format("/registered/000000{:02X}/{}.nca", hash[0], + Common::HexArrayToString(nca_id, false))); +} + +Loader::ResultStatus NAX::Parse(std::string_view path) { + if (file->ReadObject(header.get()) != sizeof(NAXHeader)) + return Loader::ResultStatus::ErrorBadNAXHeader; + + if (header->magic != Common::MakeMagic('N', 'A', 'X', '0')) + return Loader::ResultStatus::ErrorBadNAXHeader; + + if (file->GetSize() < NAX_HEADER_PADDING_SIZE + header->file_size) + return Loader::ResultStatus::ErrorIncorrectNAXFileSize; + + keys.DeriveSDSeedLazy(); + std::array<Core::Crypto::Key256, 2> sd_keys{}; + const auto sd_keys_res = Core::Crypto::DeriveSDKeys(sd_keys, keys); + if (sd_keys_res != Loader::ResultStatus::Success) { + return sd_keys_res; + } + + const auto enc_keys = header->key_area; + + size_t i = 0; + for (; i < sd_keys.size(); ++i) { + std::array<Core::Crypto::Key128, 2> nax_keys{}; + if (!CalculateHMAC256(nax_keys.data(), sd_keys[i].data(), 0x10, std::string(path).c_str(), + path.size())) { + return Loader::ResultStatus::ErrorNAXKeyHMACFailed; + } + + for (size_t j = 0; j < nax_keys.size(); ++j) { + Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(nax_keys[j], + Core::Crypto::Mode::ECB); + cipher.Transcode(enc_keys[j].data(), 0x10, header->key_area[j].data(), + Core::Crypto::Op::Decrypt); + } + + Core::Crypto::SHA256Hash validation{}; + if (!CalculateHMAC256(validation.data(), &header->magic, 0x60, sd_keys[i].data() + 0x10, + 0x10)) { + return Loader::ResultStatus::ErrorNAXValidationHMACFailed; + } + if (header->hmac == validation) + break; + } + + if (i == 2) { + return Loader::ResultStatus::ErrorNAXKeyDerivationFailed; + } + + type = static_cast<NAXContentType>(i); + + Core::Crypto::Key256 final_key{}; + std::memcpy(final_key.data(), &header->key_area, final_key.size()); + const auto enc_file = + std::make_shared<OffsetVfsFile>(file, header->file_size, NAX_HEADER_PADDING_SIZE); + dec_file = std::make_shared<Core::Crypto::XTSEncryptionLayer>(enc_file, final_key); + + return Loader::ResultStatus::Success; +} + +Loader::ResultStatus NAX::GetStatus() const { + return status; +} + +VirtualFile NAX::GetDecrypted() const { + return dec_file; +} + +std::shared_ptr<NCA> NAX::AsNCA() const { + if (type == NAXContentType::NCA) + return std::make_shared<NCA>(GetDecrypted()); + return nullptr; +} + +NAXContentType NAX::GetContentType() const { + return type; +} + +std::vector<std::shared_ptr<VfsFile>> NAX::GetFiles() const { + return {dec_file}; +} + +std::vector<std::shared_ptr<VfsDirectory>> NAX::GetSubdirectories() const { + return {}; +} + +std::string NAX::GetName() const { + return file->GetName(); +} + +std::shared_ptr<VfsDirectory> NAX::GetParentDirectory() const { + return file->GetContainingDirectory(); +} + +bool NAX::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) { + return false; +} +} // namespace FileSys |