[PATCH 14/18] UefiPayloadPkg: Add RNG support

["Sean Rhodes" <sean@starlabs.systems>]

From: Patrick Rudolph <patrick.rudolph@9elements.com>

Uses the RDRAND instruction if available and install EfiRngProtocol.
The protocol may be used by iPXE or the Linux kernel to gather entropy.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
---
 UefiPayloadPkg/Library/BaseRngLib/BaseRng.c   | 199 ++++++++++++++++++
 .../Library/BaseRngLib/BaseRngLib.inf         |  32 +++
 .../Library/BaseRngLib/BaseRngLib.uni         |  17 ++
 UefiPayloadPkg/UefiPayloadPkg.dsc             |   8 +
 UefiPayloadPkg/UefiPayloadPkg.fdf             |   4 +
 5 files changed, 260 insertions(+)
 create mode 100644 UefiPayloadPkg/Library/BaseRngLib/BaseRng.c
 create mode 100644 UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf
 create mode 100644 UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni

diff --git a/UefiPayloadPkg/Library/BaseRngLib/BaseRng.c b/UefiPayloadPkg/Library/BaseRngLib/BaseRng.c
new file mode 100644
index 0000000000..c21e713cb0
--- /dev/null
+++ b/UefiPayloadPkg/Library/BaseRngLib/BaseRng.c
@@ -0,0 +1,199 @@
+/** @file
+  Random number generator services that uses RdRand instruction access
+  to provide high-quality random numbers.
+
+Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Register/Intel/Cpuid.h>
+
+STATIC BOOLEAN  mHasRdRand;
+
+//
+// Bit mask used to determine if RdRand instruction is supported.
+//
+#define RDRAND_MASK  BIT30
+
+//
+// Limited retry number when valid random data is returned.
+// Uses the recommended value defined in Section 7.3.17 of "Intel 64 and IA-32
+// Architectures Software Developer's Mannual".
+//
+#define RDRAND_RETRY_LIMIT  10
+
+/**
+  The constructor function checks whether or not RDRAND instruction is supported
+  by the host hardware.
+
+  The constructor function checks whether or not RDRAND instruction is supported.
+  It will always return RETURN_SUCCESS.
+
+  @retval RETURN_SUCCESS   The constructor always returns EFI_SUCCESS.
+
+**/
+RETURN_STATUS
+EFIAPI
+BaseRngLibConstructor (
+  VOID
+  )
+{
+  UINT32  RegEax;
+  UINT32  RegEcx;
+
+  AsmCpuid (CPUID_SIGNATURE, &RegEax, NULL, NULL, NULL);
+  if (RegEax < 1) {
+    mHasRdRand = FALSE;
+    return RETURN_SUCCESS;
+  }
+
+  //
+  // Determine RDRAND support by examining bit 30 of the ECX register returned by
+  // CPUID. A value of 1 indicates that processor support RDRAND instruction.
+  //
+  AsmCpuid (CPUID_VERSION_INFO, 0, 0, &RegEcx, 0);
+
+  mHasRdRand = ((RegEcx & RDRAND_MASK) == RDRAND_MASK);
+
+  return RETURN_SUCCESS;
+}
+
+/**
+  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;
+
+  ASSERT (Rand != NULL);
+
+  if (mHasRdRand) {
+    //
+    // A loop to fetch a 16 bit random value with a retry count limit.
+    //
+    for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {
+      if (AsmRdRand16 (Rand)) {
+        return TRUE;
+      }
+    }
+  }
+
+  return FALSE;
+}
+
+/**
+  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;
+
+  ASSERT (Rand != NULL);
+
+  if (mHasRdRand) {
+    //
+    // A loop to fetch a 32 bit random value with a retry count limit.
+    //
+    for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {
+      if (AsmRdRand32 (Rand)) {
+        return TRUE;
+      }
+    }
+  }
+
+  return FALSE;
+}
+
+/**
+  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;
+
+  ASSERT (Rand != NULL);
+
+  if (mHasRdRand) {
+    //
+    // A loop to fetch a 64 bit random value with a retry count limit.
+    //
+    for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {
+      if (AsmRdRand64 (Rand)) {
+        return TRUE;
+      }
+    }
+  }
+
+  return FALSE;
+}
+
+/**
+  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/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf
new file mode 100644
index 0000000000..67a91ccfff
--- /dev/null
+++ b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf
@@ -0,0 +1,32 @@
+## @file
+#  Instance of RNG (Random Number Generator) Library.
+#
+#  Copyright (c) 2020 9elements Agency GmbH.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = BaseRngLib
+  MODULE_UNI_FILE                = BaseRngLib.uni
+  FILE_GUID                      = 05C48431-DE18-4550-931A-3350E8551498
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = RngLib
+  CONSTRUCTOR                    = BaseRngLibConstructor
+
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources.Ia32, Sources.X64]
+  BaseRng.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
diff --git a/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni
new file mode 100644
index 0000000000..f3ed954c52
--- /dev/null
+++ b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni
@@ -0,0 +1,17 @@
+// /** @file
+// Instance of RNG (Random Number Generator) Library.
+//
+// BaseRng Library that uses CPU RdRand instruction access to provide
+// high-quality random numbers.
+//
+// Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+//
+// 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 CPU RdRand instruction access to provide high-quality random numbers"
+
diff --git a/UefiPayloadPkg/UefiPayloadPkg.dsc b/UefiPayloadPkg/UefiPayloadPkg.dsc
index 7b57310dfd..c8562d592b 100644
--- a/UefiPayloadPkg/UefiPayloadPkg.dsc
+++ b/UefiPayloadPkg/UefiPayloadPkg.dsc
@@ -723,6 +723,14 @@
   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.inf
 !endif
 
+  #
+  # Random Number Generator
+  #
+  SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf {
+      <LibraryClasses>
+      RngLib|UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf
+  }
+
   #------------------------------
   #  Build the shell
   #------------------------------
diff --git a/UefiPayloadPkg/UefiPayloadPkg.fdf b/UefiPayloadPkg/UefiPayloadPkg.fdf
index a71d655687..3462eded64 100644
--- a/UefiPayloadPkg/UefiPayloadPkg.fdf
+++ b/UefiPayloadPkg/UefiPayloadPkg.fdf
@@ -232,6 +232,10 @@ INF MdeModulePkg/Bus/Usb/UsbMouseDxe/UsbMouseDxe.inf
 #
 INF  MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableDxe.inf
 
+# Random Number Generator
+#
+INF SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf
+
 #
 # UEFI network modules
 #
-- 
2.32.0