[PATCH v10 1/5] MdePkg: TimerRngLib: Added RngLib that uses TimerLib

["Matthew Carlson" <matthewfcarlson@gmail.com>]

From: Matthew Carlson <macarl@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: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Signed-off-by: Matthew Carlson <matthewfcarlson@gmail.com>
---
 MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c          | 189 ++++++++++++++++++++
 MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf |  36 ++++
 MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.uni |  15 ++
 MdePkg/MdePkg.dsc                                        |   3 +-
 4 files changed, 242 insertions(+), 1 deletion(-)

diff --git a/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c b/MdePkg/Library/BaseRngLibTimerLib/RngLibTimer.c
new file mode 100644
index 000000000000..54d29d96f3d3
--- /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 <Base.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/TimerLib.h>
+
+#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/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf b/MdePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf
new file mode 100644
index 000000000000..f857290e823b
--- /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.<BR>
+#
+#  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 000000000000..fde24b9f0107
--- /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/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
-- 
2.28.0.windows.1