Atmosphere/stratosphere/spl/source/spl_key_slot_cache.hpp
SciresM 81f91803ec
Implement support for parsing/interacting with NCAs. (#942)
* fs: implement support for interacting with ncas.

* spl: extend to use virtual keyslots
2020-05-11 15:04:51 -07:00

139 lines
4.6 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <stratosphere.hpp>
namespace ams::spl {
class KeySlotCacheEntry : public util::IntrusiveListBaseNode<KeySlotCacheEntry> {
NON_COPYABLE(KeySlotCacheEntry);
NON_MOVEABLE(KeySlotCacheEntry);
private:
friend class KeySlotCache;
public:
static constexpr size_t KeySize = crypto::AesDecryptor128::KeySize;
private:
const s32 slot_index;
s32 virtual_slot;
public:
explicit KeySlotCacheEntry(s32 idx) : slot_index(idx), virtual_slot(-1) { /* ... */ }
bool Contains(s32 virtual_slot) const {
return virtual_slot == this->virtual_slot;
}
s32 GetPhysicalKeySlotIndex() const { return this->slot_index; }
s32 GetVirtualKeySlotIndex() const { return this->virtual_slot; }
void SetVirtualSlot(s32 virtual_slot) {
this->virtual_slot = virtual_slot;
}
void ClearVirtualSlot() {
this->virtual_slot = -1;
}
};
class KeySlotCache {
NON_COPYABLE(KeySlotCache);
NON_MOVEABLE(KeySlotCache);
private:
using KeySlotCacheEntryList = util::IntrusiveListBaseTraits<KeySlotCacheEntry>::ListType;
private:
KeySlotCacheEntryList mru_list;
public:
constexpr KeySlotCache() : mru_list() { /* ... */ }
s32 Allocate(s32 virtual_slot) {
return this->AllocateFromLru(virtual_slot);
}
bool Find(s32 *out, s32 virtual_slot) {
for (auto it = this->mru_list.begin(); it != this->mru_list.end(); ++it) {
if (it->Contains(virtual_slot)) {
*out = it->GetPhysicalKeySlotIndex();
this->UpdateMru(it);
return true;
}
}
return false;
}
bool Release(s32 *out, s32 virtual_slot) {
for (auto it = this->mru_list.begin(); it != this->mru_list.end(); ++it) {
if (it->Contains(virtual_slot)) {
*out = it->GetPhysicalKeySlotIndex();
it->ClearVirtualSlot();
this->UpdateLru(it);
return true;
}
}
return false;
}
bool FindPhysical(s32 physical_slot) {
for (auto it = this->mru_list.begin(); it != this->mru_list.end(); ++it) {
if (it->GetPhysicalKeySlotIndex() == physical_slot) {
this->UpdateMru(it);
if (it->GetVirtualKeySlotIndex() == physical_slot) {
return true;
} else {
it->SetVirtualSlot(physical_slot);
return false;
}
}
}
AMS_ABORT();
}
void AddEntry(KeySlotCacheEntry *entry) {
this->mru_list.push_front(*entry);
}
private:
s32 AllocateFromLru(s32 virtual_slot) {
AMS_ASSERT(!this->mru_list.empty());
auto it = this->mru_list.rbegin();
it->SetVirtualSlot(virtual_slot);
auto *entry = std::addressof(*it);
this->mru_list.pop_back();
this->mru_list.push_front(*entry);
return entry->GetPhysicalKeySlotIndex();
}
void UpdateMru(KeySlotCacheEntryList::iterator it) {
auto *entry = std::addressof(*it);
this->mru_list.erase(it);
this->mru_list.push_front(*entry);
}
void UpdateLru(KeySlotCacheEntryList::iterator it) {
auto *entry = std::addressof(*it);
this->mru_list.erase(it);
this->mru_list.push_back(*entry);
}
};
}