[edk2-devel] [PATCH v1 2/2] MdePkg: TimerRngLib: Added RngLib that uses TimerLib

[Matthew Carlson]

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.

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/TimerRngLib/TimerRng.c      | 153 ++++++++++++++++++++
 MdePkg/Library/TimerRngLib/TimerRngLib.inf |  37 +++++
 MdePkg/MdePkg.dsc                          |   2 +
 3 files changed, 192 insertions(+)

diff --git a/MdePkg/Library/TimerRngLib/TimerRng.c b/MdePkg/Library/TimerRngLib/TimerRng.c
new file mode 100644
index 000000000000..1b0f7f04c01d
--- /dev/null
+++ b/MdePkg/Library/TimerRngLib/TimerRng.c
@@ -0,0 +1,153 @@
+/** @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 <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/TimerLib.h>
+#include <Uefi.h>
+
+/**
+  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
+  for (Index = 0; Index < 2; Index ++) {
+    *RandPtr = (UINT8) (GetPerformanceCounter () & 0xFF);
+    MicroSecondDelay (4);
+    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
+  for (Index = 0; Index < 4; Index ++) {
+    *RandPtr = (UINT8) (GetPerformanceCounter () & 0xFF);
+    MicroSecondDelay (2);
+    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
+  for (Index = 0; Index < 8; Index ++) {
+    *RandPtr = (UINT8) (GetPerformanceCounter () & 0xFF);
+    MicroSecondDelay (1);
+    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);
+
+  //
+  // Read first 64 bits
+  //
+  if (!GetRandomNumber64 (Rand)) {
+    return FALSE;
+  }
+
+  //
+  // Read second 64 bits
+  //
+  return GetRandomNumber64 (++Rand);
+}
diff --git a/MdePkg/Library/TimerRngLib/TimerRngLib.inf b/MdePkg/Library/TimerRngLib/TimerRngLib.inf
new file mode 100644
index 000000000000..a80a89b77e72
--- /dev/null
+++ b/MdePkg/Library/TimerRngLib/TimerRngLib.inf
@@ -0,0 +1,37 @@
+## @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.
+#
+#  Copyright (c) Microsoft Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = BaseRngLib
+  MODULE_UNI_FILE                = BaseRngLib.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]
+  TimerRng.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  TimerLib
diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
index 472fa3777412..c46a95e52e15 100644
--- a/MdePkg/MdePkg.dsc
+++ b/MdePkg/MdePkg.dsc
@@ -120,6 +120,8 @@
   MdePkg/Library/SmmLibNull/SmmLibNull.inf
   MdePkg/Library/BaseExtractGuidedSectionLib/BaseExtractGuidedSectionLib.inf
 
+  MdePkg/Library/TimerRngLib/TimerRngLib.inf
+
   MdePkg/Library/StandaloneMmDriverEntryPoint/StandaloneMmDriverEntryPoint.inf
   MdePkg/Library/StandaloneMmServicesTableLib/StandaloneMmServicesTableLib.inf
 
-- 
2.27.0.windows.1


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