[PATCH V3 3/9] OvmfPkg/IntelTdx: Add SecTdxHelperLib

["Min Xu" <min.m.xu@intel.com>]

From: Min M Xu <min.m.xu@intel.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4243

TdxHelperLib provides below helper functions for a td-guest.
 - TdxHelperProcessTdHob
 - TdxHelperMeasureTdHob
 - TdxHelperMeasureCfvImage
 - TdxHelperBuildGuidHobForTdxMeasurement

SecTdxHelperLib is the SEC instance of TdxHelperLib. It implements 4
functions for tdx in SEC phase:
 - TdxHelperProcessTdHob consumes TdHob to accept un-accepted memories.
   Before the TdHob is consumed, it is first validated.

 - TdxHelperMeasureTdHob measure/extend TdHob and store the measurement
   value in workarea.

 - TdxHelperMeasureCfvImage measure/extend the Configuration FV image and
   store the measurement value in workarea.

 - TdxHelperBuildGuidHobForTdxMeasurement builds GuidHob for tdx
   measurement.

This patch implements TdxHelperMeasureTdHob and TdxHelperMeasureCfvImage.
TdxHelperProcessTdHob and TdxHelperBuildGuidHobForTdxMeasurement will be
implemented in the following patches. Because these 2 functions are to be
moved from other files, such as PlatformInitLib/IntelTdx.c.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c  | 221 ++++++++++++++++++
 .../IntelTdx/TdxHelperLib/SecTdxHelperLib.inf |  52 +++++
 2 files changed, 273 insertions(+)
 create mode 100644 OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
 create mode 100644 OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf

diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
new file mode 100644
index 000000000000..2cb12bd9c7e1
--- /dev/null
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
@@ -0,0 +1,221 @@
+/** @file
+  TdxHelper Functions which are used in SEC phase
+
+  Copyright (c) 2022 - 2023, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <PiPei.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/BaseCryptLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <IndustryStandard/Tdx.h>
+#include <IndustryStandard/IntelTdx.h>
+#include <IndustryStandard/Tpm20.h>
+#include <Library/TdxLib.h>
+#include <Pi/PrePiHob.h>
+#include <WorkArea.h>
+#include <ConfidentialComputingGuestAttr.h>
+#include <Library/TdxHelperLib.h>
+
+/**
+  In Tdx guest, some information need to be passed from host VMM to guest
+  firmware. For example, the memory resource, etc. These information are
+  prepared by host VMM and put in TdHob which is described in TdxMetadata.
+  TDVF processes the TdHob to accept memories.
+
+  @retval   EFI_SUCCESS   Successfully process the TdHob
+  @retval   Others        Other error as indicated
+**/
+EFI_STATUS
+EFIAPI
+TdxHelperProcessTdHob (
+  VOID
+  )
+{
+  return EFI_UNSUPPORTED;
+}
+
+//
+// SHA512_CTX is defined in <openssl/sha.h> and its size is 216 bytes.
+// It can be built successfully with GCC5 compiler but failed with VS2019.
+// The error code showed in VS2019 is that "openssl/sha.h" cannot be found.
+// To overcome this error SHA512_CTX_SIZE is defined.
+//
+#define SHA512_CTX_SIZ  216
+
+/**
+ * Calculate the sha384 of input Data and extend it to RTMR register.
+ *
+ * @param RtmrIndex       Index of the RTMR register
+ * @param DataToHash      Data to be hashed
+ * @param DataToHashLen   Length of the data
+ * @param Digest          Hash value of the input data
+ * @param DigestLen       Length of the hash value
+ *
+ * @retval EFI_SUCCESS    Successfully hash and extend to RTMR
+ * @retval Others         Other errors as indicated
+ */
+STATIC
+EFI_STATUS
+HashAndExtendToRtmr (
+  IN UINT32  RtmrIndex,
+  IN VOID    *DataToHash,
+  IN UINTN   DataToHashLen,
+  OUT UINT8  *Digest,
+  IN  UINTN  DigestLen
+  )
+{
+  EFI_STATUS  Status;
+  UINT8       Sha384Ctx[SHA512_CTX_SIZ];
+
+  if ((DataToHash == NULL) || (DataToHashLen == 0)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((Digest == NULL) || (DigestLen != SHA384_DIGEST_SIZE)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Calculate the sha384 of the data
+  //
+  Sha384Init (Sha384Ctx);
+  Sha384Update (Sha384Ctx, DataToHash, DataToHashLen);
+  Sha384Final (Sha384Ctx, Digest);
+
+  //
+  // Extend to RTMR
+  //
+  Status = TdExtendRtmr (
+             (UINT32 *)Digest,
+             SHA384_DIGEST_SIZE,
+             (UINT8)RtmrIndex
+             );
+
+  ASSERT (!EFI_ERROR (Status));
+  return Status;
+}
+
+/**
+  In Tdx guest, TdHob is passed from host VMM to guest firmware and it contains
+  the information of the memory resource. From the security perspective before
+  it is consumed, it should be measured and extended.
+ *
+ * @retval EFI_SUCCESS Successfully measure the TdHob
+ * @retval Others      Other error as indicated
+ */
+EFI_STATUS
+EFIAPI
+TdxHelperMeasureTdHob (
+  VOID
+  )
+{
+  EFI_PEI_HOB_POINTERS  Hob;
+  EFI_STATUS            Status;
+  UINT8                 Digest[SHA384_DIGEST_SIZE];
+  OVMF_WORK_AREA        *WorkArea;
+  VOID                  *TdHob;
+
+  TdHob   = (VOID *)(UINTN)FixedPcdGet32 (PcdOvmfSecGhcbBase);
+  Hob.Raw = (UINT8 *)TdHob;
+
+  //
+  // Walk thru the TdHob list until end of list.
+  //
+  while (!END_OF_HOB_LIST (Hob)) {
+    Hob.Raw = GET_NEXT_HOB (Hob);
+  }
+
+  Status = HashAndExtendToRtmr (
+             0,
+             (UINT8 *)TdHob,
+             (UINTN)((UINT8 *)Hob.Raw - (UINT8 *)TdHob),
+             Digest,
+             SHA384_DIGEST_SIZE
+             );
+
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // This function is called in SEC phase and at that moment the Hob service
+  // is not available. So the TdHob measurement value is stored in workarea.
+  //
+  WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
+  if (WorkArea == NULL) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.MeasurementsBitmap |= TDX_MEASUREMENT_TDHOB_BITMASK;
+  CopyMem (WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.TdHobHashValue, Digest, SHA384_DIGEST_SIZE);
+
+  return EFI_SUCCESS;
+}
+
+/**
+ * In Tdx guest, Configuration FV (CFV) is treated as external input because it
+ * may contain the data provided by VMM. From the sucurity perspective Cfv image
+ * should be measured before it is consumed.
+ *
+ * @retval EFI_SUCCESS Successfully measure the CFV image
+ * @retval Others      Other error as indicated
+ */
+EFI_STATUS
+EFIAPI
+TdxHelperMeasureCfvImage (
+  VOID
+  )
+{
+  EFI_STATUS      Status;
+  UINT8           Digest[SHA384_DIGEST_SIZE];
+  OVMF_WORK_AREA  *WorkArea;
+
+  Status = HashAndExtendToRtmr (
+             0,
+             (UINT8 *)(UINTN)PcdGet32 (PcdOvmfFlashNvStorageVariableBase),
+             (UINT64)PcdGet32 (PcdCfvRawDataSize),
+             Digest,
+             SHA384_DIGEST_SIZE
+             );
+
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // This function is called in SEC phase and at that moment the Hob service
+  // is not available. So CfvImage measurement value is stored in workarea.
+  //
+  WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
+  if (WorkArea == NULL) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.MeasurementsBitmap |= TDX_MEASUREMENT_CFVIMG_BITMASK;
+  CopyMem (WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.CfvImgHashValue, Digest, SHA384_DIGEST_SIZE);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Build the GuidHob for tdx measurements which were done in SEC phase.
+  The measurement values are stored in WorkArea.
+
+  @retval EFI_SUCCESS  The GuidHob is built successfully
+  @retval Others       Other errors as indicated
+**/
+EFI_STATUS
+EFIAPI
+TdxHelperBuildGuidHobForTdxMeasurement (
+  VOID
+  )
+{
+  return EFI_UNSUPPORTED;
+}
diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
new file mode 100644
index 000000000000..3c6b96f7759a
--- /dev/null
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
@@ -0,0 +1,52 @@
+## @file
+#  TdxHelperLib SEC instance
+#
+#  This module provides Tdx helper functions in SEC phase.
+#  Copyright (c) 2021 - 2023, Intel Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = SecTdxHelperLib
+  FILE_GUID                      = ba69ac6b-0c59-4472-899d-b684590ec1e9
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = TdxHelperLib|SEC
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = X64
+#
+
+[Sources]
+  SecTdxHelper.c
+
+[Packages]
+  CryptoPkg/CryptoPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+  SecurityPkg/SecurityPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  BaseCryptLib
+  DebugLib
+  HobLib
+  PcdLib
+  TdxMailboxLib
+  TdxLib
+
+[FixedPcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase
+  gUefiOvmfPkgTokenSpaceGuid.PcdTdxAcceptPageSize
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBase
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageVariableBase
+  gUefiOvmfPkgTokenSpaceGuid.PcdCfvRawDataSize
+
+[Guids]
+  gCcEventEntryHobGuid
-- 
2.29.2.windows.2