SecurityPkg/Library/Tpm2CommandLib/Tpm2Context.c

   1 /** @file
   2   Implement TPM2 Context related command.
   3
   4 Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved. <BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <IndustryStandard/UefiTcgPlatform.h>
  10 #include <Library/Tpm2CommandLib.h>
  11 #include <Library/Tpm2DeviceLib.h>
  12 #include <Library/BaseMemoryLib.h>
  13 #include <Library/BaseLib.h>
  14 #include <Library/DebugLib.h>
  15
  16 #pragma pack(1)
  17
  18 typedef struct {
  19   TPM2_COMMAND_HEADER       Header;
  20   TPMI_DH_CONTEXT           FlushHandle;
  21 } TPM2_FLUSH_CONTEXT_COMMAND;
  22
  23 typedef struct {
  24   TPM2_RESPONSE_HEADER      Header;
  25 } TPM2_FLUSH_CONTEXT_RESPONSE;
  26
  27 #pragma pack()
  28
  29 /**
  30   This command causes all context associated with a loaded object or session to be removed from TPM memory.
  31
  32   @param[in]  FlushHandle        The handle of the item to flush.
  33
  34   @retval EFI_SUCCESS            Operation completed successfully.
  35   @retval EFI_DEVICE_ERROR       The command was unsuccessful.
  36 **/
  37 EFI_STATUS
  38 EFIAPI
  39 Tpm2FlushContext (
  40   IN      TPMI_DH_CONTEXT           FlushHandle
  41   )
  42 {
  43   EFI_STATUS                        Status;
  44   TPM2_FLUSH_CONTEXT_COMMAND        SendBuffer;
  45   TPM2_FLUSH_CONTEXT_RESPONSE       RecvBuffer;
  46   UINT32                            SendBufferSize;
  47   UINT32                            RecvBufferSize;
  48
  49   //
  50   // Construct command
  51   //
  52   SendBuffer.Header.tag = SwapBytes16(TPM_ST_NO_SESSIONS);
  53   SendBuffer.Header.commandCode = SwapBytes32(TPM_CC_FlushContext);
  54
  55   SendBuffer.FlushHandle = SwapBytes32 (FlushHandle);
  56
  57   SendBufferSize = (UINT32) sizeof (SendBuffer);
  58   SendBuffer.Header.paramSize = SwapBytes32 (SendBufferSize);
  59
  60   //
  61   // send Tpm command
  62   //
  63   RecvBufferSize = sizeof (RecvBuffer);
  64   Status = Tpm2SubmitCommand (SendBufferSize, (UINT8 *)&SendBuffer, &RecvBufferSize, (UINT8 *)&RecvBuffer);
  65   if (EFI_ERROR (Status)) {
  66     return Status;
  67   }
  68
  69   if (RecvBufferSize < sizeof (TPM2_RESPONSE_HEADER)) {
  70     DEBUG ((EFI_D_ERROR, "Tpm2FlushContext - RecvBufferSize Error - %x\n", RecvBufferSize));
  71     return EFI_DEVICE_ERROR;
  72   }
  73   if (SwapBytes32(RecvBuffer.Header.responseCode) != TPM_RC_SUCCESS) {
  74     DEBUG ((EFI_D_ERROR, "Tpm2FlushContext - responseCode - %x\n", SwapBytes32(RecvBuffer.Header.responseCode)));
  75     return EFI_DEVICE_ERROR;
  76   }
  77
  78   return EFI_SUCCESS;
  79 }
  80