SecurityPkg/Library/Tpm2CommandLib/Tpm2Context.c

/** @file
  Implement TPM2 Context related command.

Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved. <BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <IndustryStandard/UefiTcgPlatform.h>
#include <Library/Tpm2CommandLib.h>
#include <Library/Tpm2DeviceLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>

#pragma pack(1)

typedef struct {
  TPM2_COMMAND_HEADER       Header;
  TPMI_DH_CONTEXT           FlushHandle;
} TPM2_FLUSH_CONTEXT_COMMAND;

typedef struct {
  TPM2_RESPONSE_HEADER      Header;
} TPM2_FLUSH_CONTEXT_RESPONSE;

#pragma pack()

/**
  This command causes all context associated with a loaded object or session to be removed from TPM memory.

  @param[in]  FlushHandle        The handle of the item to flush.

  @retval EFI_SUCCESS            Operation completed successfully.
  @retval EFI_DEVICE_ERROR       The command was unsuccessful.
**/
EFI_STATUS
EFIAPI
Tpm2FlushContext (
  IN      TPMI_DH_CONTEXT           FlushHandle
  )
{
  EFI_STATUS                        Status;
  TPM2_FLUSH_CONTEXT_COMMAND        SendBuffer;
  TPM2_FLUSH_CONTEXT_RESPONSE       RecvBuffer;
  UINT32                            SendBufferSize;
  UINT32                            RecvBufferSize;

  //
  // Construct command
  //
  SendBuffer.Header.tag = SwapBytes16(TPM_ST_NO_SESSIONS);
  SendBuffer.Header.commandCode = SwapBytes32(TPM_CC_FlushContext);

  SendBuffer.FlushHandle = SwapBytes32 (FlushHandle);

  SendBufferSize = (UINT32) sizeof (SendBuffer);
  SendBuffer.Header.paramSize = SwapBytes32 (SendBufferSize);

  //
  // send Tpm command
  //
  RecvBufferSize = sizeof (RecvBuffer);
  Status = Tpm2SubmitCommand (SendBufferSize, (UINT8 *)&SendBuffer, &RecvBufferSize, (UINT8 *)&RecvBuffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  if (RecvBufferSize < sizeof (TPM2_RESPONSE_HEADER)) {
    DEBUG ((EFI_D_ERROR, "Tpm2FlushContext - RecvBufferSize Error - %x\n", RecvBufferSize));
    return EFI_DEVICE_ERROR;
  }
  if (SwapBytes32(RecvBuffer.Header.responseCode) != TPM_RC_SUCCESS) {
    DEBUG ((EFI_D_ERROR, "Tpm2FlushContext - responseCode - %x\n", SwapBytes32(RecvBuffer.Header.responseCode)));
    return EFI_DEVICE_ERROR;
  }

  return EFI_SUCCESS;
}