diff --git a/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf new file mode 100644 index 0000000000..f857290e82 --- /dev/null +++ b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf @@ -0,0 +1,36 @@ +## @file +# Instance of RNG (Random Number Generator) Library. +# +# BaseRng Library that uses the TimerLib to provide reasonably random numbers. +# Do NOT use this on a production system as this uses the system performance +# counter rather than a true source of random in addition to having a weak +# random algorithm. This is provided primarily as a source of entropy for +# OpenSSL for platforms that do not have a good built in RngLib as this +# emulates what was done before (though it isn't perfect). +# +# Copyright (c) Microsoft Corporation. All rights reserved.
+# +# SPDX-License-Identifier: BSD-2-Clause-Patent +# +# +## + +[Defines] + INF_VERSION = 1.27 + BASE_NAME = BaseRngLibTimerLib + MODULE_UNI_FILE = BaseRngLibTimerLib.uni + FILE_GUID = 74950C45-10FC-4AB5-B114-49C87C17409B + MODULE_TYPE = BASE + VERSION_STRING = 1.0 + LIBRARY_CLASS = RngLib + +[Sources] + RngLibTimer.c + +[Packages] + MdePkg/MdePkg.dec + +[LibraryClasses] + BaseLib + DebugLib + TimerLib diff --git a/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni new file mode 100644 index 0000000000..fde24b9f01 --- /dev/null +++ b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni @@ -0,0 +1,15 @@ +// @file +// Instance of RNG (Random Number Generator) Library. +// +// RngLib that uses TimerLib's performance counter to provide random numbers. +// +// Copyright (c) Microsoft Corporation. +// +// SPDX-License-Identifier: BSD-2-Clause-Patent +// + + +#string STR_MODULE_ABSTRACT #language en-US "Instance of RNG Library" + +#string STR_MODULE_DESCRIPTION #language en-US "BaseRng Library that uses the TimerLib to provide low-entropy random numbers" + diff --git a/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c b/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c new file mode 100644 index 0000000000..54d29d96f3 --- /dev/null +++ b/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c @@ -0,0 +1,189 @@ +/** @file + BaseRng Library that uses the TimerLib to provide reasonably random numbers. + Do not use this on a production system. + + Copyright (c) Microsoft Corporation. + SPDX-License-Identifier: BSD-2-Clause-Patent +**/ + +#include +#include +#include +#include + +#define DEFAULT_DELAY_TIME_IN_MICROSECONDS 10 + +/** + Using the TimerLib GetPerformanceCounterProperties() we delay + for enough time for the PerformanceCounter to increment. + + If the return value from GetPerformanceCounterProperties (TimerLib) + is zero, this function will return 10 and attempt to assert. + **/ +STATIC +UINT32 +CalculateMinimumDecentDelayInMicroseconds ( + VOID + ) +{ + UINT64 CounterHz; + + // Get the counter properties + CounterHz = GetPerformanceCounterProperties (NULL, NULL); + // Make sure we won't divide by zero + if (CounterHz == 0) { + ASSERT(CounterHz != 0); // Assert so the developer knows something is wrong + return DEFAULT_DELAY_TIME_IN_MICROSECONDS; + } + // Calculate the minimum delay based on 1.5 microseconds divided by the hertz. + // We calculate the length of a cycle (1/CounterHz) and multiply it by 1.5 microseconds + // This ensures that the performance counter has increased by at least one + return (UINT32)(MAX (DivU64x64Remainder (1500000,CounterHz, NULL), 1)); +} + + +/** + Generates a 16-bit random number. + + if Rand is NULL, then ASSERT(). + + @param[out] Rand Buffer pointer to store the 16-bit random value. + + @retval TRUE Random number generated successfully. + @retval FALSE Failed to generate the random number. + +**/ +BOOLEAN +EFIAPI +GetRandomNumber16 ( + OUT UINT16 *Rand + ) +{ + UINT32 Index; + UINT8 *RandPtr; + UINT32 DelayInMicroSeconds; + + ASSERT (Rand != NULL); + + if (Rand == NULL) { + return FALSE; + } + DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds (); + RandPtr = (UINT8*)Rand; + // Get 2 bytes of random ish data + for (Index = 0; Index < sizeof(UINT16); Index ++) { + *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF); + // Delay to give the performance counter a chance to change + MicroSecondDelay (DelayInMicroSeconds); + RandPtr++; + } + return TRUE; +} + +/** + Generates a 32-bit random number. + + if Rand is NULL, then ASSERT(). + + @param[out] Rand Buffer pointer to store the 32-bit random value. + + @retval TRUE Random number generated successfully. + @retval FALSE Failed to generate the random number. + +**/ +BOOLEAN +EFIAPI +GetRandomNumber32 ( + OUT UINT32 *Rand + ) +{ + UINT32 Index; + UINT8 *RandPtr; + UINT32 DelayInMicroSeconds; + + ASSERT (Rand != NULL); + + if (NULL == Rand) { + return FALSE; + } + + RandPtr = (UINT8 *) Rand; + DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds (); + // Get 4 bytes of random ish data + for (Index = 0; Index < sizeof(UINT32); Index ++) { + *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF); + // Delay to give the performance counter a chance to change + MicroSecondDelay (DelayInMicroSeconds); + RandPtr++; + } + return TRUE; +} + +/** + Generates a 64-bit random number. + + if Rand is NULL, then ASSERT(). + + @param[out] Rand Buffer pointer to store the 64-bit random value. + + @retval TRUE Random number generated successfully. + @retval FALSE Failed to generate the random number. + +**/ +BOOLEAN +EFIAPI +GetRandomNumber64 ( + OUT UINT64 *Rand + ) +{ + UINT32 Index; + UINT8 *RandPtr; + UINT32 DelayInMicroSeconds; + + ASSERT (Rand != NULL); + + if (NULL == Rand) { + return FALSE; + } + + RandPtr = (UINT8 *)Rand; + DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds (); + // Get 8 bytes of random ish data + for (Index = 0; Index < sizeof(UINT64); Index ++) { + *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF); + // Delay to give the performance counter a chance to change + MicroSecondDelay (DelayInMicroSeconds); + RandPtr++; + } + + return TRUE; +} + +/** + Generates a 128-bit random number. + + if Rand is NULL, then ASSERT(). + + @param[out] Rand Buffer pointer to store the 128-bit random value. + + @retval TRUE Random number generated successfully. + @retval FALSE Failed to generate the random number. + +**/ +BOOLEAN +EFIAPI +GetRandomNumber128 ( + OUT UINT64 *Rand + ) +{ + ASSERT (Rand != NULL); + // This should take around 80ms + + // Read first 64 bits + if (!GetRandomNumber64 (Rand)) { + return FALSE; + } + + // Read second 64 bits + return GetRandomNumber64 (++Rand); +} diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc index e3af828d21..bd5b186739 100644 --- a/MdePkg/MdePkg.dsc +++ b/MdePkg/MdePkg.dsc @@ -60,6 +60,8 @@ MdePkg/Library/BasePostCodeLibPort80/BasePostCodeLibPort80.inf MdePkg/Library/BasePrintLib/BasePrintLib.inf MdePkg/Library/BaseReportStatusCodeLibNull/BaseReportStatusCodeLibNull.inf + MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf + MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf MdePkg/Library/BaseSerialPortLibNull/BaseSerialPortLibNull.inf MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf MdePkg/Library/BaseTimerLibNullTemplate/BaseTimerLibNullTemplate.inf @@ -67,7 +69,6 @@ MdePkg/Library/BaseUefiDecompressLib/BaseUefiTianoCustomDecompressLib.inf MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.inf MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf - MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf MdePkg/Library/DxeCoreEntryPoint/DxeCoreEntryPoint.inf MdePkg/Library/DxeCoreHobLib/DxeCoreHobLib.inf