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audk/SecurityPkg/Library/DxeTrEEPhysicalPresenceLib/DxeTrEEPhysicalPresenceLib.c

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/** @file
Execute pending TPM2 requests from OS or BIOS.
Caution: This module requires additional review when modified.
This driver will have external input - variable.
This external input must be validated carefully to avoid security issue.
TrEEExecutePendingTpmRequest() will receive untrusted input and do validation.
Copyright (c) 2013 - 2014, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <PiDxe.h>
#include <Protocol/TrEEProtocol.h>
#include <Protocol/VariableLock.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/PrintLib.h>
#include <Library/HiiLib.h>
#include <Guid/EventGroup.h>
#include <Guid/TrEEPhysicalPresenceData.h>
#include <Library/Tpm2CommandLib.h>
#define TPM_PP_SUCCESS 0
#define TPM_PP_USER_ABORT ((TPM_RESULT)(-0x10))
#define TPM_PP_BIOS_FAILURE ((TPM_RESULT)(-0x0f))
#define CONFIRM_BUFFER_SIZE 4096
EFI_HII_HANDLE mTrEEPpStringPackHandle;
/**
Get string by string id from HII Interface.
@param[in] Id String ID.
@retval CHAR16 * String from ID.
@retval NULL If error occurs.
**/
CHAR16 *
TrEEPhysicalPresenceGetStringById (
IN EFI_STRING_ID Id
)
{
return HiiGetString (mTrEEPpStringPackHandle, Id, NULL);
}
/**
Send ClearControl and Clear command to TPM.
@param[in] PlatformAuth platform auth value. NULL means no platform auth change.
@retval EFI_SUCCESS Operation completed successfully.
@retval EFI_TIMEOUT The register can't run into the expected status in time.
@retval EFI_BUFFER_TOO_SMALL Response data buffer is too small.
@retval EFI_DEVICE_ERROR Unexpected device behavior.
**/
EFI_STATUS
EFIAPI
TpmCommandClear (
IN TPM2B_AUTH *PlatformAuth OPTIONAL
)
{
EFI_STATUS Status;
TPMS_AUTH_COMMAND *AuthSession;
TPMS_AUTH_COMMAND LocalAuthSession;
if (PlatformAuth == NULL) {
AuthSession = NULL;
} else {
AuthSession = &LocalAuthSession;
ZeroMem (&LocalAuthSession, sizeof(LocalAuthSession));
LocalAuthSession.sessionHandle = TPM_RS_PW;
LocalAuthSession.hmac.size = PlatformAuth->size;
CopyMem (LocalAuthSession.hmac.buffer, PlatformAuth->buffer, PlatformAuth->size);
}
DEBUG ((EFI_D_ERROR, "Tpm2ClearControl ... \n"));
Status = Tpm2ClearControl (TPM_RH_PLATFORM, AuthSession, NO);
DEBUG ((EFI_D_ERROR, "Tpm2ClearControl - %r\n", Status));
if (EFI_ERROR (Status)) {
goto Done;
}
DEBUG ((EFI_D_ERROR, "Tpm2Clear ... \n"));
Status = Tpm2Clear (TPM_RH_PLATFORM, AuthSession);
DEBUG ((EFI_D_ERROR, "Tpm2Clear - %r\n", Status));
Done:
ZeroMem (&LocalAuthSession.hmac, sizeof(LocalAuthSession.hmac));
return Status;
}
/**
Execute physical presence operation requested by the OS.
@param[in] PlatformAuth platform auth value. NULL means no platform auth change.
@param[in] CommandCode Physical presence operation value.
@param[in, out] PpiFlags The physical presence interface flags.
@retval TPM_PP_BIOS_FAILURE Unknown physical presence operation.
@retval TPM_PP_BIOS_FAILURE Error occurred during sending command to TPM or
receiving response from TPM.
@retval Others Return code from the TPM device after command execution.
**/
TPM_RESULT
TrEEExecutePhysicalPresence (
IN TPM2B_AUTH *PlatformAuth, OPTIONAL
IN UINT8 CommandCode,
IN OUT UINT8 *PpiFlags
)
{
EFI_STATUS Status;
switch (CommandCode) {
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_2:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_3:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_4:
Status = TpmCommandClear (PlatformAuth);
if (EFI_ERROR (Status)) {
return TPM_PP_BIOS_FAILURE;
} else {
return TPM_PP_SUCCESS;
}
case TREE_PHYSICAL_PRESENCE_SET_NO_PPI_CLEAR_FALSE:
*PpiFlags &= ~TREE_FLAG_NO_PPI_CLEAR;
return TPM_PP_SUCCESS;
case TREE_PHYSICAL_PRESENCE_SET_NO_PPI_CLEAR_TRUE:
*PpiFlags |= TREE_FLAG_NO_PPI_CLEAR;
return TPM_PP_SUCCESS;
default:
if (CommandCode <= TREE_PHYSICAL_PRESENCE_NO_ACTION_MAX) {
return TPM_PP_SUCCESS;
} else {
return TPM_PP_BIOS_FAILURE;
}
}
}
/**
Read the specified key for user confirmation.
@param[in] CautionKey If true, F12 is used as confirm key;
If false, F10 is used as confirm key.
@retval TRUE User confirmed the changes by input.
@retval FALSE User discarded the changes.
**/
BOOLEAN
TrEEReadUserKey (
IN BOOLEAN CautionKey
)
{
EFI_STATUS Status;
EFI_INPUT_KEY Key;
UINT16 InputKey;
InputKey = 0;
do {
Status = gBS->CheckEvent (gST->ConIn->WaitForKey);
if (!EFI_ERROR (Status)) {
Status = gST->ConIn->ReadKeyStroke (gST->ConIn, &Key);
if (Key.ScanCode == SCAN_ESC) {
InputKey = Key.ScanCode;
}
if ((Key.ScanCode == SCAN_F10) && !CautionKey) {
InputKey = Key.ScanCode;
}
if ((Key.ScanCode == SCAN_F12) && CautionKey) {
InputKey = Key.ScanCode;
}
}
} while (InputKey == 0);
if (InputKey != SCAN_ESC) {
return TRUE;
}
return FALSE;
}
/**
The constructor function register UNI strings into imageHandle.
It will ASSERT() if that operation fails and it will always return EFI_SUCCESS.
@param ImageHandle The firmware allocated handle for the EFI image.
@param SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The constructor successfully added string package.
@retval Other value The constructor can't add string package.
**/
EFI_STATUS
EFIAPI
TrEEPhysicalPresenceLibConstructor (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
mTrEEPpStringPackHandle = HiiAddPackages (&gEfiTrEEPhysicalPresenceGuid, ImageHandle, DxeTrEEPhysicalPresenceLibStrings, NULL);
ASSERT (mTrEEPpStringPackHandle != NULL);
return EFI_SUCCESS;
}
/**
Display the confirm text and get user confirmation.
@param[in] TpmPpCommand The requested TPM physical presence command.
@retval TRUE The user has confirmed the changes.
@retval FALSE The user doesn't confirm the changes.
**/
BOOLEAN
TrEEUserConfirm (
IN UINT8 TpmPpCommand
)
{
CHAR16 *ConfirmText;
CHAR16 *TmpStr1;
CHAR16 *TmpStr2;
UINTN BufSize;
BOOLEAN CautionKey;
UINT16 Index;
CHAR16 DstStr[81];
TmpStr2 = NULL;
CautionKey = FALSE;
BufSize = CONFIRM_BUFFER_SIZE;
ConfirmText = AllocateZeroPool (BufSize);
ASSERT (ConfirmText != NULL);
switch (TpmPpCommand) {
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_2:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_3:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_4:
CautionKey = TRUE;
TmpStr2 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_CLEAR));
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_HEAD_STR));
UnicodeSPrint (ConfirmText, BufSize, TmpStr1, TmpStr2);
FreePool (TmpStr1);
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_WARNING_CLEAR));
StrnCat (ConfirmText, TmpStr1, (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
StrnCat (ConfirmText, L" \n\n", (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
FreePool (TmpStr1);
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_CAUTION_KEY));
StrnCat (ConfirmText, TmpStr1, (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
FreePool (TmpStr1);
break;
case TREE_PHYSICAL_PRESENCE_SET_NO_PPI_CLEAR_TRUE:
CautionKey = TRUE;
TmpStr2 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_CLEAR));
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_PPI_HEAD_STR));
UnicodeSPrint (ConfirmText, BufSize, TmpStr1, TmpStr2);
FreePool (TmpStr1);
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_NOTE_CLEAR));
StrnCat (ConfirmText, TmpStr1, (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
FreePool (TmpStr1);
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_WARNING_CLEAR));
StrnCat (ConfirmText, TmpStr1, (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
StrnCat (ConfirmText, L" \n\n", (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
FreePool (TmpStr1);
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_CAUTION_KEY));
StrnCat (ConfirmText, TmpStr1, (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
FreePool (TmpStr1);
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_NO_PPI_INFO));
StrnCat (ConfirmText, TmpStr1, (BufSize / sizeof (CHAR16 *)) - StrLen (ConfirmText) - 1);
FreePool (TmpStr1);
break;
default:
;
}
if (TmpStr2 == NULL) {
FreePool (ConfirmText);
return FALSE;
}
TmpStr1 = TrEEPhysicalPresenceGetStringById (STRING_TOKEN (TPM_REJECT_KEY));
BufSize -= StrSize (ConfirmText);
UnicodeSPrint (ConfirmText + StrLen (ConfirmText), BufSize, TmpStr1, TmpStr2);
DstStr[80] = L'\0';
for (Index = 0; Index < StrLen (ConfirmText); Index += 80) {
StrnCpy(DstStr, ConfirmText + Index, 80);
Print (DstStr);
}
FreePool (TmpStr1);
FreePool (TmpStr2);
FreePool (ConfirmText);
if (TrEEReadUserKey (CautionKey)) {
return TRUE;
}
return FALSE;
}
/**
Check if there is a valid physical presence command request. Also updates parameter value
to whether the requested physical presence command already confirmed by user
@param[in] TcgPpData EFI TrEE Physical Presence request data.
@param[in] Flags The physical presence interface flags.
@param[out] RequestConfirmed If the physical presence operation command required user confirm from UI.
True, it indicates the command doesn't require user confirm, or already confirmed
in last boot cycle by user.
False, it indicates the command need user confirm from UI.
@retval TRUE Physical Presence operation command is valid.
@retval FALSE Physical Presence operation command is invalid.
**/
BOOLEAN
TrEEHaveValidTpmRequest (
IN EFI_TREE_PHYSICAL_PRESENCE *TcgPpData,
IN UINT8 Flags,
OUT BOOLEAN *RequestConfirmed
)
{
*RequestConfirmed = FALSE;
switch (TcgPpData->PPRequest) {
case TREE_PHYSICAL_PRESENCE_NO_ACTION:
*RequestConfirmed = TRUE;
return TRUE;
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_2:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_3:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_4:
if ((Flags & TREE_FLAG_NO_PPI_CLEAR) != 0) {
*RequestConfirmed = TRUE;
}
break;
case TREE_PHYSICAL_PRESENCE_SET_NO_PPI_CLEAR_FALSE:
*RequestConfirmed = TRUE;
break;
case TREE_PHYSICAL_PRESENCE_SET_NO_PPI_CLEAR_TRUE:
break;
default:
//
// Wrong Physical Presence command
//
return FALSE;
}
if ((Flags & TREE_FLAG_RESET_TRACK) != 0) {
//
// It had been confirmed in last boot, it doesn't need confirm again.
//
*RequestConfirmed = TRUE;
}
//
// Physical Presence command is correct
//
return TRUE;
}
/**
Check and execute the requested physical presence command.
Caution: This function may receive untrusted input.
TcgPpData variable is external input, so this function will validate
its data structure to be valid value.
@param[in] PlatformAuth platform auth value. NULL means no platform auth change.
@param[in] TcgPpData Point to the physical presence NV variable.
@param[in] Flags The physical presence interface flags.
**/
VOID
TrEEExecutePendingTpmRequest (
IN TPM2B_AUTH *PlatformAuth, OPTIONAL
IN EFI_TREE_PHYSICAL_PRESENCE *TcgPpData,
IN UINT8 Flags
)
{
EFI_STATUS Status;
UINTN DataSize;
BOOLEAN RequestConfirmed;
UINT8 NewFlags;
if (TcgPpData->PPRequest == TREE_PHYSICAL_PRESENCE_NO_ACTION) {
//
// No operation request
//
return;
}
if (!TrEEHaveValidTpmRequest(TcgPpData, Flags, &RequestConfirmed)) {
//
// Invalid operation request.
//
if (TcgPpData->PPRequest <= TREE_PHYSICAL_PRESENCE_NO_ACTION_MAX) {
TcgPpData->PPResponse = TPM_PP_SUCCESS;
} else {
TcgPpData->PPResponse = TPM_PP_BIOS_FAILURE;
}
TcgPpData->LastPPRequest = TcgPpData->PPRequest;
TcgPpData->PPRequest = TREE_PHYSICAL_PRESENCE_NO_ACTION;
DataSize = sizeof (EFI_TREE_PHYSICAL_PRESENCE);
Status = gRT->SetVariable (
TREE_PHYSICAL_PRESENCE_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
DataSize,
TcgPpData
);
return;
}
if (!RequestConfirmed) {
//
// Print confirm text and wait for approval.
//
RequestConfirmed = TrEEUserConfirm (TcgPpData->PPRequest
);
}
//
// Execute requested physical presence command
//
TcgPpData->PPResponse = TPM_PP_USER_ABORT;
NewFlags = Flags;
if (RequestConfirmed) {
TcgPpData->PPResponse = TrEEExecutePhysicalPresence (PlatformAuth, TcgPpData->PPRequest,
&NewFlags);
}
//
// Save the flags if it is updated.
//
if (Flags != NewFlags) {
Status = gRT->SetVariable (
TREE_PHYSICAL_PRESENCE_FLAGS_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
sizeof (UINT8),
&NewFlags
);
}
//
// Clear request
//
if ((NewFlags & TREE_FLAG_RESET_TRACK) == 0) {
TcgPpData->LastPPRequest = TcgPpData->PPRequest;
TcgPpData->PPRequest = TREE_PHYSICAL_PRESENCE_NO_ACTION;
}
//
// Save changes
//
DataSize = sizeof (EFI_TREE_PHYSICAL_PRESENCE);
Status = gRT->SetVariable (
TREE_PHYSICAL_PRESENCE_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
DataSize,
TcgPpData
);
if (EFI_ERROR (Status)) {
return;
}
if (TcgPpData->PPResponse == TPM_PP_USER_ABORT) {
return;
}
//
// Reset system to make new TPM settings in effect
//
switch (TcgPpData->LastPPRequest) {
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_2:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_3:
case TREE_PHYSICAL_PRESENCE_CLEAR_CONTROL_CLEAR_4:
break;
default:
if (TcgPpData->PPRequest != TREE_PHYSICAL_PRESENCE_NO_ACTION) {
break;
}
return;
}
Print (L"Rebooting system to make TPM2 settings in effect\n");
gRT->ResetSystem (EfiResetCold, EFI_SUCCESS, 0, NULL);
ASSERT (FALSE);
}
/**
Check and execute the pending TPM request.
The TPM request may come from OS or BIOS. This API will display request information and wait
for user confirmation if TPM request exists. The TPM request will be sent to TPM device after
the TPM request is confirmed, and one or more reset may be required to make TPM request to
take effect.
This API should be invoked after console in and console out are all ready as they are required
to display request information and get user input to confirm the request.
@param[in] PlatformAuth platform auth value. NULL means no platform auth change.
**/
VOID
EFIAPI
TrEEPhysicalPresenceLibProcessRequest (
IN TPM2B_AUTH *PlatformAuth OPTIONAL
)
{
EFI_STATUS Status;
UINTN DataSize;
EFI_TREE_PHYSICAL_PRESENCE TcgPpData;
EFI_TREE_PROTOCOL *TreeProtocol;
EDKII_VARIABLE_LOCK_PROTOCOL *VariableLockProtocol;
UINT8 PpiFlags;
Status = gBS->LocateProtocol (&gEfiTrEEProtocolGuid, NULL, (VOID **) &TreeProtocol);
if (EFI_ERROR (Status)) {
return ;
}
//
// Initialize physical presence flags.
//
DataSize = sizeof (UINT8);
Status = gRT->GetVariable (
TREE_PHYSICAL_PRESENCE_FLAGS_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
NULL,
&DataSize,
&PpiFlags
);
if (EFI_ERROR (Status)) {
PpiFlags = 0;
Status = gRT->SetVariable (
TREE_PHYSICAL_PRESENCE_FLAGS_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
sizeof (UINT8),
&PpiFlags
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "[TPM2] Set physical presence flag failed, Status = %r\n", Status));
return ;
}
}
DEBUG ((EFI_D_INFO, "[TPM2] PpiFlags = %x\n", PpiFlags));
//
// This flags variable controls whether physical presence is required for TPM command.
// It should be protected from malicious software. We set it as read-only variable here.
//
Status = gBS->LocateProtocol (&gEdkiiVariableLockProtocolGuid, NULL, (VOID **)&VariableLockProtocol);
if (!EFI_ERROR (Status)) {
Status = VariableLockProtocol->RequestToLock (
VariableLockProtocol,
TREE_PHYSICAL_PRESENCE_FLAGS_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "[TPM2] Error when lock variable %s, Status = %r\n", TREE_PHYSICAL_PRESENCE_FLAGS_VARIABLE, Status));
ASSERT_EFI_ERROR (Status);
}
}
//
// Initialize physical presence variable.
//
DataSize = sizeof (EFI_TREE_PHYSICAL_PRESENCE);
Status = gRT->GetVariable (
TREE_PHYSICAL_PRESENCE_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
NULL,
&DataSize,
&TcgPpData
);
if (EFI_ERROR (Status)) {
ZeroMem ((VOID*)&TcgPpData, sizeof (TcgPpData));
DataSize = sizeof (EFI_TREE_PHYSICAL_PRESENCE);
Status = gRT->SetVariable (
TREE_PHYSICAL_PRESENCE_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
DataSize,
&TcgPpData
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "[TPM2] Set physical presence variable failed, Status = %r\n", Status));
return ;
}
}
DEBUG ((EFI_D_INFO, "[TPM2] Flags=%x, PPRequest=%x (LastPPRequest=%x)\n", PpiFlags, TcgPpData.PPRequest, TcgPpData.LastPPRequest));
//
// Execute pending TPM request.
//
TrEEExecutePendingTpmRequest (PlatformAuth, &TcgPpData, PpiFlags);
DEBUG ((EFI_D_INFO, "[TPM2] PPResponse = %x (LastPPRequest=%x, Flags=%x)\n", TcgPpData.PPResponse, TcgPpData.LastPPRequest, PpiFlags));
}
/**
Check if the pending TPM request needs user input to confirm.
The TPM request may come from OS. This API will check if TPM request exists and need user
input to confirmation.
@retval TRUE TPM needs input to confirm user physical presence.
@retval FALSE TPM doesn't need input to confirm user physical presence.
**/
BOOLEAN
EFIAPI
TrEEPhysicalPresenceLibNeedUserConfirm(
VOID
)
{
EFI_STATUS Status;
EFI_TREE_PHYSICAL_PRESENCE TcgPpData;
UINTN DataSize;
BOOLEAN RequestConfirmed;
EFI_TREE_PROTOCOL *TreeProtocol;
UINT8 PpiFlags;
Status = gBS->LocateProtocol (&gEfiTrEEProtocolGuid, NULL, (VOID **) &TreeProtocol);
if (EFI_ERROR (Status)) {
return FALSE;
}
//
// Check Tpm requests
//
DataSize = sizeof (EFI_TREE_PHYSICAL_PRESENCE);
Status = gRT->GetVariable (
TREE_PHYSICAL_PRESENCE_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
NULL,
&DataSize,
&TcgPpData
);
if (EFI_ERROR (Status)) {
return FALSE;
}
DataSize = sizeof (UINT8);
Status = gRT->GetVariable (
TREE_PHYSICAL_PRESENCE_FLAGS_VARIABLE,
&gEfiTrEEPhysicalPresenceGuid,
NULL,
&DataSize,
&PpiFlags
);
if (EFI_ERROR (Status)) {
return FALSE;
}
if (TcgPpData.PPRequest == TREE_PHYSICAL_PRESENCE_NO_ACTION) {
//
// No operation request
//
return FALSE;
}
if (!TrEEHaveValidTpmRequest(&TcgPpData, PpiFlags, &RequestConfirmed)) {
//
// Invalid operation request.
//
return FALSE;
}
if (!RequestConfirmed) {
//
// Need UI to confirm
//
return TRUE;
}
return FALSE;
}
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