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/** @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 <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>
/**
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
InternalBuildGuidHobForTdxMeasurement (
VOID
);
/**
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;
}
/**
* 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;
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
//
if (!Sha384HashAll (DataToHash, DataToHashLen, Digest)) {
return EFI_ABORTED;
}
//
// 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
)
{
#ifdef TDX_PEI_LESS_BOOT
return InternalBuildGuidHobForTdxMeasurement ();
#else
return EFI_UNSUPPORTED;
#endif
}
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