SecurityPkg/Library/Tpm2CommandLib/Tpm2Context.c

   1 /** @file
   2   Implement TPM2 Context related command.
   3
   4 Copyright (c) 2014, Intel Corporation. All rights reserved. <BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include <IndustryStandard/UefiTcgPlatform.h>
  16 #include <Library/Tpm2CommandLib.h>
  17 #include <Library/Tpm2DeviceLib.h>
  18 #include <Library/BaseMemoryLib.h>
  19 #include <Library/BaseLib.h>
  20 #include <Library/DebugLib.h>
  21
  22 #pragma pack(1)
  23
  24 typedef struct {
  25   TPM2_COMMAND_HEADER       Header;
  26   TPMI_DH_CONTEXT           FlushHandle;
  27 } TPM2_FLUSH_CONTEXT_COMMAND;
  28
  29 typedef struct {
  30   TPM2_RESPONSE_HEADER      Header;
  31 } TPM2_FLUSH_CONTEXT_RESPONSE;
  32
  33 #pragma pack()
  34
  35 /**
  36   This command causes all context associated with a loaded object or session to be removed from TPM memory.
  37
  38   @param[in]  FlushHandle        The handle of the item to flush.
  39
  40   @retval EFI_SUCCESS            Operation completed successfully.
  41   @retval EFI_DEVICE_ERROR       The command was unsuccessful.
  42 **/
  43 EFI_STATUS
  44 EFIAPI
  45 Tpm2FlushContext (
  46   IN      TPMI_DH_CONTEXT           FlushHandle
  47   )
  48 {
  49   EFI_STATUS                        Status;
  50   TPM2_FLUSH_CONTEXT_COMMAND        SendBuffer;
  51   TPM2_FLUSH_CONTEXT_RESPONSE       RecvBuffer;
  52   UINT32                            SendBufferSize;
  53   UINT32                            RecvBufferSize;
  54
  55   //
  56   // Construct command
  57   //
  58   SendBuffer.Header.tag = SwapBytes16(TPM_ST_NO_SESSIONS);
  59   SendBuffer.Header.commandCode = SwapBytes32(TPM_CC_FlushContext);
  60
  61   SendBuffer.FlushHandle = SwapBytes32 (FlushHandle);
  62
  63   SendBufferSize = (UINT32) sizeof (SendBuffer);
  64   SendBuffer.Header.paramSize = SwapBytes32 (SendBufferSize);
  65
  66   //
  67   // send Tpm command
  68   //
  69   RecvBufferSize = sizeof (RecvBuffer);
  70   Status = Tpm2SubmitCommand (SendBufferSize, (UINT8 *)&SendBuffer, &RecvBufferSize, (UINT8 *)&RecvBuffer);
  71   if (EFI_ERROR (Status)) {
  72     return Status;
  73   }
  74
  75   if (RecvBufferSize < sizeof (TPM2_RESPONSE_HEADER)) {
  76     DEBUG ((EFI_D_ERROR, "Tpm2FlushContext - RecvBufferSize Error - %x\n", RecvBufferSize));
  77     return EFI_DEVICE_ERROR;
  78   }
  79   if (SwapBytes32(RecvBuffer.Header.responseCode) != TPM_RC_SUCCESS) {
  80     DEBUG ((EFI_D_ERROR, "Tpm2FlushContext - responseCode - %x\n", SwapBytes32(RecvBuffer.Header.responseCode)));
  81     return EFI_DEVICE_ERROR;
  82   }
  83
  84   return EFI_SUCCESS;
  85 }
  86