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https://git.eden-emu.dev/eden-emu/eden
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41e15e95b1
AES Updates: Replaced heap churn with stack scratch buffers tail handling now stays in-place, no more recursive transcode detours. CTR/XTS modes read in larger, aligned chunks and still handle odd offsets cleanly. XTS prefetches a few sectors ahead to reduce extra reads. AesCtrStorage writer now uses the pooled buffer properly one stack slab, chunk forward, bump counter, repeat. Result: less malloc noise, fewer watchdog spikes at startup (though mbedtls still sets the pace). This should make the loading speed slightly better than before. Make sure to test. Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2782 Reviewed-by: MaranBr <maranbr@eden-emu.dev> Reviewed-by: crueter <crueter@eden-emu.dev> Co-authored-by: godpow <thesaviorsrule@yahoo.com> Co-committed-by: godpow <thesaviorsrule@yahoo.com>
69 lines
2.5 KiB
C++
69 lines
2.5 KiB
C++
// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
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// SPDX-License-Identifier: GPL-3.0-or-later
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// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
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// SPDX-License-Identifier: GPL-2.0-or-later
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#include <algorithm>
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#include <array>
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#include <cstring>
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#include "core/crypto/xts_encryption_layer.h"
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namespace Core::Crypto {
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constexpr std::size_t XTS_SECTOR_SIZE = 0x4000;
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XTSEncryptionLayer::XTSEncryptionLayer(FileSys::VirtualFile base_, Key256 key_)
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: EncryptionLayer(std::move(base_)), cipher(key_, Mode::XTS) {}
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std::size_t XTSEncryptionLayer::Read(u8* data, std::size_t length, std::size_t offset) const {
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if (length == 0)
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return 0;
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constexpr std::size_t PrefetchSectors = 4;
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auto* out = data;
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std::size_t remaining = length;
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std::size_t current_offset = offset;
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std::size_t total_read = 0;
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std::array<u8, XTS_SECTOR_SIZE> sector{};
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while (remaining > 0) {
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const std::size_t sector_index = current_offset / XTS_SECTOR_SIZE;
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const std::size_t sector_offset = current_offset % XTS_SECTOR_SIZE;
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const std::size_t sectors_to_read = std::min<std::size_t>(PrefetchSectors,
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(remaining + sector_offset +
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XTS_SECTOR_SIZE - 1) /
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XTS_SECTOR_SIZE);
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for (std::size_t s = 0; s < sectors_to_read && remaining > 0; ++s) {
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const std::size_t index = sector_index + s;
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const std::size_t read_offset = index * XTS_SECTOR_SIZE;
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const std::size_t got = base->Read(sector.data(), XTS_SECTOR_SIZE, read_offset);
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if (got == 0)
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return total_read;
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if (got < XTS_SECTOR_SIZE)
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std::memset(sector.data() + got, 0, XTS_SECTOR_SIZE - got);
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cipher.XTSTranscode(sector.data(), XTS_SECTOR_SIZE, sector.data(), index, XTS_SECTOR_SIZE,
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Op::Decrypt);
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const std::size_t local_offset = (s == 0) ? sector_offset : 0;
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const std::size_t available = XTS_SECTOR_SIZE - local_offset;
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const std::size_t to_copy = std::min<std::size_t>(available, remaining);
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std::memcpy(out, sector.data() + local_offset, to_copy);
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out += to_copy;
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current_offset += to_copy;
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remaining -= to_copy;
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total_read += to_copy;
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}
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}
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return total_read;
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}
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} // namespace Core::Crypto
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