SecurityPkg/Tcg/TcgDxe/TpmComm.c

   1 /** @file
   2   Utility functions used by TPM Dxe driver.
   3
   4 Copyright (c) 2005 - 2013, 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/Tpm12.h>
  16 #include <IndustryStandard/UefiTcgPlatform.h>
  17 #include <Library/TpmCommLib.h>
  18 #include <Library/BaseMemoryLib.h>
  19
  20 #include "TpmComm.h"
  21
  22 /**
  23   Extend a TPM PCR.
  24
  25   @param[in]  TpmHandle       TPM handle.
  26   @param[in]  DigestToExtend  The 160 bit value representing the event to be recorded.
  27   @param[in]  PcrIndex        The PCR to be updated.
  28   @param[out] NewPcrValue     New PCR value after extend.
  29
  30   @retval EFI_SUCCESS         Operation completed successfully.
  31   @retval EFI_DEVICE_ERROR    The command was unsuccessful.
  32
  33 **/
  34 EFI_STATUS
  35 TpmCommExtend (
  36   IN      TIS_TPM_HANDLE            TpmHandle,
  37   IN      TPM_DIGEST                *DigestToExtend,
  38   IN      TPM_PCRINDEX              PcrIndex,
  39      OUT  TPM_DIGEST                *NewPcrValue
  40   )
  41 {
  42   EFI_STATUS                        Status;
  43   TPM_DIGEST                        NewValue;
  44   TPM_RQU_COMMAND_HDR               CmdHdr;
  45   TPM_RSP_COMMAND_HDR               RspHdr;
  46
  47   if (NewPcrValue == NULL) {
  48     NewPcrValue = &NewValue;
  49   }
  50
  51   CmdHdr.tag = TPM_TAG_RQU_COMMAND;
  52   CmdHdr.paramSize =
  53     sizeof (CmdHdr) + sizeof (PcrIndex) + sizeof (*DigestToExtend);
  54   CmdHdr.ordinal = TPM_ORD_Extend;
  55   Status = TisPcExecute (
  56              TpmHandle,
  57              "%h%d%r%/%h%r",
  58              &CmdHdr,
  59              PcrIndex,
  60              DigestToExtend,
  61              (UINTN)sizeof (*DigestToExtend),
  62              &RspHdr,
  63              NewPcrValue,
  64              (UINTN)sizeof (*NewPcrValue)
  65              );
  66   if (EFI_ERROR (Status)) {
  67     return Status;
  68   }
  69   if (RspHdr.returnCode != 0) {
  70     return EFI_DEVICE_ERROR;
  71   }
  72   return EFI_SUCCESS;
  73 }
  74
  75 /**
  76   Get TPM capability flags.
  77
  78   @param[in]  TpmHandle    TPM handle.
  79   @param[in]  FlagSubcap   Flag subcap.
  80   @param[out] FlagBuffer   Pointer to the buffer for returned flag structure.
  81   @param[in]  FlagSize     Size of the buffer.
  82
  83   @retval EFI_SUCCESS      Operation completed successfully.
  84   @retval EFI_DEVICE_ERROR The command was unsuccessful.
  85
  86 **/
  87 EFI_STATUS
  88 TpmCommGetFlags (
  89   IN      TIS_TPM_HANDLE            TpmHandle,
  90   IN      UINT32                    FlagSubcap,
  91      OUT  VOID                      *FlagBuffer,
  92   IN      UINTN                     FlagSize
  93   )
  94 {
  95   EFI_STATUS                        Status;
  96   TPM_RQU_COMMAND_HDR               CmdHdr;
  97   TPM_RSP_COMMAND_HDR               RspHdr;
  98   UINT32                            Size;
  99
 100   CmdHdr.tag = TPM_TAG_RQU_COMMAND;
 101   CmdHdr.paramSize = sizeof (CmdHdr) + sizeof (UINT32) * 3;
 102   CmdHdr.ordinal = TPM_ORD_GetCapability;
 103
 104   Status = TisPcExecute (
 105              TpmHandle,
 106              "%h%d%d%d%/%h%d%r",
 107              &CmdHdr,
 108              TPM_CAP_FLAG,
 109              sizeof (FlagSubcap),
 110              FlagSubcap,
 111              &RspHdr,
 112              &Size,
 113              FlagBuffer,
 114              FlagSize
 115              );
 116   if (EFI_ERROR (Status)) {
 117     return Status;
 118   }
 119   if (RspHdr.returnCode != 0) {
 120     return EFI_DEVICE_ERROR;
 121   }
 122   return EFI_SUCCESS;
 123 }
 124
 125 /**
 126   Add a new entry to the Event Log.
 127
 128   @param[in, out] EventLogPtr   Pointer to the Event Log data.
 129   @param[in, out] LogSize       Size of the Event Log.
 130   @param[in]      MaxSize       Maximum size of the Event Log.
 131   @param[in]      NewEventHdr   Pointer to a TCG_PCR_EVENT_HDR data structure.
 132   @param[in]      NewEventData  Pointer to the new event data.
 133
 134   @retval EFI_SUCCESS           The new event log entry was added.
 135   @retval EFI_OUT_OF_RESOURCES  No enough memory to log the new event.
 136
 137 **/
 138 EFI_STATUS
 139 TpmCommLogEvent (
 140   IN OUT  UINT8                     **EventLogPtr,
 141   IN OUT  UINTN                     *LogSize,
 142   IN      UINTN                     MaxSize,
 143   IN      TCG_PCR_EVENT_HDR         *NewEventHdr,
 144   IN      UINT8                     *NewEventData
 145   )
 146 {
 147   UINTN                            NewLogSize;
 148
 149   //
 150   // Prevent Event Overflow
 151   //
 152   if (NewEventHdr->EventSize > (UINTN)(~0) - sizeof (*NewEventHdr)) {
 153     return EFI_OUT_OF_RESOURCES;
 154   }
 155
 156   NewLogSize = sizeof (*NewEventHdr) + NewEventHdr->EventSize;
 157   if (NewLogSize > MaxSize - *LogSize) {
 158     return EFI_OUT_OF_RESOURCES;
 159   }
 160
 161   *EventLogPtr += *LogSize;
 162   *LogSize += NewLogSize;
 163   CopyMem (*EventLogPtr, NewEventHdr, sizeof (*NewEventHdr));
 164   CopyMem (
 165     *EventLogPtr + sizeof (*NewEventHdr),
 166     NewEventData,
 167     NewEventHdr->EventSize
 168     );
 169   return EFI_SUCCESS;
 170 }