HashLibTdx.c

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#include <PiPei.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/PcdLib.h>
#include <Library/HashLib.h>
#include <Library/TdxLib.h>
#include <Protocol/CcMeasurement.h>
 
EFI_GUID  mSha384Guid = HASH_ALGORITHM_SHA384_GUID;
 
//
// Currently TDX supports SHA384.
//
HASH_INTERFACE  mHashInterface =  {
  { 0 }, NULL, NULL, NULL
};
 
UINTN  mHashInterfaceCount = 0;
 
EFI_STATUS
EFIAPI
HashStart (
  OUT HASH_HANDLE  *HashHandle
  )
{
  HASH_HANDLE  HashCtx;
 
  if (mHashInterfaceCount == 0) {
    ASSERT (FALSE);
    return EFI_UNSUPPORTED;
  }
 
  HashCtx = 0;
  mHashInterface.HashInit (&HashCtx);
 
  *HashHandle = HashCtx;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
HashUpdate (
  IN HASH_HANDLE  HashHandle,
  IN VOID         *DataToHash,
  IN UINTN        DataToHashLen
  )
{
  if (mHashInterfaceCount == 0) {
    ASSERT (FALSE);
    return EFI_UNSUPPORTED;
  }
 
  mHashInterface.HashUpdate (HashHandle, DataToHash, DataToHashLen);
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
HashCompleteAndExtend (
  IN HASH_HANDLE          HashHandle,
  IN TPMI_DH_PCR          PcrIndex,
  IN VOID                 *DataToHash,
  IN UINTN                DataToHashLen,
  OUT TPML_DIGEST_VALUES  *DigestList
  )
{
  TPML_DIGEST_VALUES  Digest;
  EFI_STATUS          Status;
 
  if (mHashInterfaceCount == 0) {
    ASSERT (FALSE);
    return EFI_UNSUPPORTED;
  }
 
  ZeroMem (DigestList, sizeof (*DigestList));
 
  mHashInterface.HashUpdate (HashHandle, DataToHash, DataToHashLen);
  mHashInterface.HashFinal (HashHandle, &Digest);
 
  CopyMem (
    &DigestList->digests[0],
    &Digest.digests[0],
    sizeof (Digest.digests[0])
    );
  DigestList->count++;
 
  ASSERT (DigestList->count == 1 && DigestList->digests[0].hashAlg == TPM_ALG_SHA384);
 
  Status = TdExtendRtmr (
             (UINT32 *)DigestList->digests[0].digest.sha384,
             SHA384_DIGEST_SIZE,
             (UINT8)PcrIndex
             );
 
  ASSERT (!EFI_ERROR (Status));
  return Status;
}
 
EFI_STATUS
EFIAPI
HashAndExtend (
  IN TPMI_DH_PCR          PcrIndex,
  IN VOID                 *DataToHash,
  IN UINTN                DataToHashLen,
  OUT TPML_DIGEST_VALUES  *DigestList
  )
{
  HASH_HANDLE  HashHandle;
  EFI_STATUS   Status;
 
  if (mHashInterfaceCount == 0) {
    ASSERT (FALSE);
    return EFI_UNSUPPORTED;
  }
 
  ASSERT (TdIsEnabled ());
 
  HashStart (&HashHandle);
  HashUpdate (HashHandle, DataToHash, DataToHashLen);
  Status = HashCompleteAndExtend (HashHandle, PcrIndex, NULL, 0, DigestList);
 
  return Status;
}
 
EFI_STATUS
EFIAPI
RegisterHashInterfaceLib (
  IN HASH_INTERFACE  *HashInterface
  )
{
  //
  // HashLibTdx is designed for Tdx guest. So if it is not Tdx guest,
  // return EFI_UNSUPPORTED.
  //
  if (!TdIsEnabled ()) {
    return EFI_UNSUPPORTED;
  }
 
  //
  // Only SHA384 is allowed.
  //
  if (!CompareGuid (&mSha384Guid, &HashInterface->HashGuid)) {
    return EFI_UNSUPPORTED;
  }
 
  if (mHashInterfaceCount != 0) {
    ASSERT (FALSE);
    return EFI_OUT_OF_RESOURCES;
  }
 
  CopyMem (&mHashInterface, HashInterface, sizeof (*HashInterface));
  mHashInterfaceCount++;
 
  return EFI_SUCCESS;
}