mirror of
https://github.com/Atmosphere-NX/Atmosphere.git
synced 2024-12-25 19:56:03 +00:00
96 lines
3.5 KiB
C++
96 lines
3.5 KiB
C++
/*
|
|
* Copyright (c) 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/>.
|
|
*/
|
|
#include <exosphere.hpp>
|
|
#include "secmon_smc_common.hpp"
|
|
#include "secmon_random_cache.hpp"
|
|
|
|
namespace ams::secmon::smc {
|
|
|
|
namespace {
|
|
|
|
constinit int g_random_offset_low = 0;
|
|
constinit int g_random_offset_high = 0;
|
|
|
|
void FillRandomCache(int offset, int size) {
|
|
/* Get the cache. */
|
|
u8 * const random_cache_loc = GetRandomBytesCache() + offset;
|
|
|
|
/* Flush the region we're about to fill to ensure consistency with the SE. */
|
|
hw::FlushDataCache(random_cache_loc, size);
|
|
hw::DataSynchronizationBarrierInnerShareable();
|
|
|
|
/* Generate random bytes. */
|
|
se::GenerateRandomBytes(random_cache_loc, size);
|
|
hw::DataSynchronizationBarrierInnerShareable();
|
|
|
|
/* Flush to ensure the CPU sees consistent data for the region. */
|
|
hw::FlushDataCache(random_cache_loc, size);
|
|
hw::DataSynchronizationBarrierInnerShareable();
|
|
}
|
|
|
|
}
|
|
|
|
void FillRandomCache() {
|
|
/* Fill the cache. */
|
|
FillRandomCache(0, GetRandomBytesCacheSize());
|
|
|
|
/* Set the extents. */
|
|
g_random_offset_low = 0;
|
|
g_random_offset_high = GetRandomBytesCacheSize() - 1;
|
|
}
|
|
|
|
void RefillRandomCache() {
|
|
/* Check that we need to do any refilling. */
|
|
if (const int used_start = (g_random_offset_high + 1) % GetRandomBytesCacheSize(); used_start != g_random_offset_low) {
|
|
if (used_start < g_random_offset_low) {
|
|
/* The region we need to fill is after used_start but before g_random_offset_low. */
|
|
const auto size = g_random_offset_low - used_start;
|
|
FillRandomCache(used_start, size);
|
|
g_random_offset_high += size;
|
|
} else {
|
|
/* We need to fill the space from high to the end and from low to start. */
|
|
const int high_size = GetRandomBytesCacheSize() - used_start;
|
|
if (high_size > 0) {
|
|
FillRandomCache(used_start, high_size);
|
|
g_random_offset_high += high_size;
|
|
}
|
|
|
|
const int low_size = g_random_offset_low;
|
|
if (low_size > 0) {
|
|
FillRandomCache(0, low_size);
|
|
g_random_offset_high += low_size;
|
|
}
|
|
|
|
}
|
|
|
|
g_random_offset_high %= GetRandomBytesCacheSize();
|
|
}
|
|
}
|
|
|
|
void GetRandomFromCache(void *dst, size_t size) {
|
|
/* Copy out the requested size. */
|
|
std::memcpy(dst, GetRandomBytesCache() + g_random_offset_low, size);
|
|
|
|
/* Advance. */
|
|
g_random_offset_low += size;
|
|
|
|
/* Ensure that at all times g_random_offset_low is not within 0x38 bytes of the end of the pool. */
|
|
if (g_random_offset_low + MaxRandomBytes >= GetRandomBytesCacheSize()) {
|
|
g_random_offset_low = 0;
|
|
}
|
|
}
|
|
|
|
}
|