mirror of
https://github.com/Atmosphere-NX/Atmosphere
synced 2024-11-14 00:56:35 +00:00
77 lines
2.8 KiB
C++
77 lines
2.8 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_error.hpp"
|
|
#include "secmon_smc_random.hpp"
|
|
#include "secmon_random_cache.hpp"
|
|
#include "secmon_smc_se_lock.hpp"
|
|
|
|
namespace ams::secmon::smc {
|
|
|
|
namespace {
|
|
|
|
SmcResult GenerateRandomBytesImpl(SmcArguments &args) {
|
|
/* Validate the input size. */
|
|
const size_t size = args.r[1];
|
|
SMC_R_UNLESS(size <= MaxRandomBytes, InvalidArgument);
|
|
|
|
/* Create a buffer that the se can generate bytes into. */
|
|
util::AlignedBuffer<hw::DataCacheLineSize, MaxRandomBytes> buffer;
|
|
hw::FlushDataCache(buffer, size);
|
|
hw::DataSynchronizationBarrierInnerShareable();
|
|
|
|
/* Generate random bytes into the buffer. */
|
|
se::GenerateRandomBytes(buffer, size);
|
|
|
|
/* Ensure that the cpu sees consistent data. */
|
|
hw::DataSynchronizationBarrierInnerShareable();
|
|
hw::FlushDataCache(buffer, size);
|
|
hw::DataSynchronizationBarrierInnerShareable();
|
|
|
|
/* Copy the bytes to output. */
|
|
std::memcpy(std::addressof(args.r[1]), buffer, size);
|
|
return SmcResult::Success;
|
|
}
|
|
|
|
}
|
|
|
|
SmcResult SmcGenerateRandomBytes(SmcArguments &args) {
|
|
return LockSecurityEngineAndInvoke(args, GenerateRandomBytesImpl);
|
|
}
|
|
|
|
SmcResult SmcGenerateRandomBytesNonBlocking(SmcArguments &args) {
|
|
/* Try to lock the security engine, so that we can call the standard impl. */
|
|
if (TryLockSecurityEngine()) {
|
|
/* Ensure we unlock the security engine when done. */
|
|
ON_SCOPE_EXIT { UnlockSecurityEngine(); };
|
|
|
|
/* Take advantage of our lock to refill lthe random cache. */
|
|
ON_SCOPE_EXIT { RefillRandomCache(); };
|
|
|
|
/* If we lock it successfully, we can just call the blocking impl. */
|
|
return GenerateRandomBytesImpl(args);
|
|
} else {
|
|
/* Otherwise, we'll retrieve some bytes from the cache. */
|
|
const size_t size = args.r[1];
|
|
SMC_R_UNLESS(size <= MaxRandomBytes, InvalidArgument);
|
|
|
|
/* Get random bytes from the cache. */
|
|
GetRandomFromCache(std::addressof(args.r[1]), size);
|
|
return SmcResult::Success;
|
|
}
|
|
}
|
|
|
|
}
|