[edk2-devel] [PATCH v5 1/5] MdePkg: TimerRngLib: Added RngLib that uses TimerLib
Matthew Carlson
matthewfcarlson at gmail.com
Wed Aug 12 02:21:23 UTC 2020
From: Matthew Carlson <macarl at microsoft.com>
Added a new RngLib that provides random numbers from the TimerLib
using the performance counter. This is meant to be used for OpenSSL
to replicate past behavior. This should not be used in production as
a real source of entropy.
Ref: https://github.com/tianocore/edk2/pull/845
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1871
Cc: Michael D Kinney <michael.d.kinney at intel.com>
Cc: Liming Gao <liming.gao at intel.com>
Cc: Zhiguang Liu <zhiguang.liu at intel.com>
Signed-off-by: Matthew Carlson <matthewfcarlson at gmail.com>
---
MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c | 187 ++++++++++++++++++++
MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf | 40 +++++
MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni | 17 ++
MdePkg/MdePkg.dsc | 3 +-
4 files changed, 246 insertions(+), 1 deletion(-)
diff --git a/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c b/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c
new file mode 100644
index 000000000000..915382fb9278
--- /dev/null
+++ b/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c
@@ -0,0 +1,187 @@
+/** @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 <Base.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/TimerLib.h>
+
+/**
+ * Using the TimerLib GetPerformanceCounterProperties() we delay
+ * for enough time for the PerformanceCounter to increment.
+ * Depending on your system
+ *
+ * If the return value from GetPerformanceCounterProperties (TimerLib)
+ * is zero, this function will not delay and attempt to assert.
+ */
+VOID
+EFIAPI
+DecentDelay(
+ VOID
+ )
+{
+ UINT64 StartValue;
+ UINT64 EndValue;
+ UINT64 CounterHz;
+ UINT64 MinumumDelayInMicroSeconds;
+ // Get the counter properties
+ CounterHz = GetPerformanceCounterProperties(&StartValue, &EndValue);
+ // Make sure we won't divide by zero
+ if (CounterHz == 0) {
+ ASSERT(FALSE); // Assert so the developer knows something is wrong
+ return;
+ }
+ // 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
+ MinumumDelayInMicroSeconds = 1500000 / CounterHz;
+
+ MicroSecondDelay(MinumumDelayInMicroSeconds);
+}
+
+
+/**
+ 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;
+
+ ASSERT (Rand != NULL);
+
+ if (NULL == Rand) {
+ return FALSE;
+ }
+
+ RandPtr = (UINT8 *) Rand;
+ // Get 2 bytes of random ish data
+ // This should take around 10us
+ for (Index = 0; Index < 2; Index ++) {
+ *RandPtr = (UINT8) (GetPerformanceCounter () & 0xFF);
+ DecentDelay (); // delay to give chance for performance counter to catch up
+ 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;
+
+ ASSERT (Rand != NULL);
+
+ if (NULL == Rand) {
+ return FALSE;
+ }
+
+ RandPtr = (UINT8 *) Rand;
+ // Get 4 bytes of random ish data
+ // This should take around 20ms
+ for (Index = 0; Index < 4; Index ++) {
+ *RandPtr = (UINT8) (GetPerformanceCounter () & 0xFF);
+ DecentDelay (); // delay to give chance for performance counter to catch up
+ 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;
+
+ ASSERT (Rand != NULL);
+
+ if (NULL == Rand) {
+ return FALSE;
+ }
+
+ RandPtr = (UINT8 *) Rand;
+ // Get 8 bytes of random ish data
+ // This should take around 40ms
+ for (Index = 0; Index < 8; Index ++) {
+ *RandPtr = (UINT8) (GetPerformanceCounter () & 0xFF);
+ DecentDelay (); // delay to give chance for performance counter to catch up
+ 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/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
new file mode 100644
index 000000000000..34dea0152497
--- /dev/null
+++ b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
@@ -0,0 +1,40 @@
+## @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.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
+ 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
+ CONSTRUCTOR = BaseRngLibConstructor
+
+#
+# VALID_ARCHITECTURES = IA32 X64
+#
+
+[Sources]
+ RngLibTimer.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ BaseLib
+ TimerLib
diff --git a/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni
new file mode 100644
index 000000000000..766a8e0ddf97
--- /dev/null
+++ b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni
@@ -0,0 +1,17 @@
+// /** @file
+// Instance of RNG (Random Number Generator) Library.
+//
+// BaseRng Library 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/MdePkg.dsc b/MdePkg/MdePkg.dsc
index 472fa3777412..d7ba3a730909 100644
--- a/MdePkg/MdePkg.dsc
+++ b/MdePkg/MdePkg.dsc
@@ -62,6 +62,8 @@
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
@@ -69,7 +71,6 @@
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
--
2.27.0.windows.1
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#64035): https://edk2.groups.io/g/devel/message/64035
Mute This Topic: https://groups.io/mt/76140303/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-
More information about the edk2-devel-archive
mailing list