MdeModulePkg: Duplicate BaseRngLibTimerLib to MdeModulePkg

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4504

The BaseRngLibTimerLib allows to generate number based on a timer.
This mechanism allows to have a basic non-secure implementation
for non-production platforms.
To bind and identify Random Number Generators implementations with
a GUID, an unsafe GUID should be added. This GUID cannot be added
to the MdePkg unless it is also added to a specification.

To keep the MdePkg self-contained, copy the BaseRngLibTimerLib to
the MdeModulePkg. This will allow to define an unsafe Rng GUID
in a later patch in the MdeModulePkg.

The MdePkg implementation will be removed later. This allows to give
some time to platform owners to switch to the MdeModulePkg
implementation.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Kun Qin <kun.qin@microsoft.com>

MdeModulePkg/Library/BaseRngLibTimerLib/RngLibTimer.c

@@ -0,0 +1,192 @@
+/** @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);
+}