]> git.proxmox.com Git - mirror_edk2.git/blobdiff - SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c
Fix the return status when physical presence variable and MemoryOverwriteRequestContr...
[mirror_edk2.git] / SecurityPkg / Library / DxeTcgPhysicalPresenceLib / DxeTcgPhysicalPresenceLib.c
index 18d87ebe745ef7891a6a6a0bf0239656e7e3c709..8a5e7d17c6fca9850ba1ae0be1bd982ef769652c 100644 (file)
@@ -2,7 +2,13 @@
 \r
   Execute pending TPM requests from OS or BIOS and Lock TPM.\r
 \r
-Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>\r
+  Caution: This module requires additional review when modified.\r
+  This driver will have external input - variable.\r
+  This external input must be validated carefully to avoid security issue.\r
+\r
+  ExecutePendingTpmRequest() will receive untrusted input and do validation.\r
+\r
+Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>\r
 This program and the accompanying materials \r
 are licensed and made available under the terms and conditions of the BSD License \r
 which accompanies this distribution.  The full text of the license may be found at \r
@@ -16,6 +22,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <PiDxe.h>\r
 \r
 #include <Protocol/TcgService.h>\r
+#include <Protocol/VariableLock.h>\r
 #include <Library/DebugLib.h>\r
 #include <Library/BaseMemoryLib.h>\r
 #include <Library/UefiRuntimeServicesTableLib.h>\r
@@ -393,16 +400,23 @@ ExecutePhysicalPresence (
       return 0;\r
   \r
     case PHYSICAL_PRESENCE_ENABLE_ACTIVATE_CLEAR:\r
-      TpmResponse = ExecutePhysicalPresence (TcgProtocol, PHYSICAL_PRESENCE_ENABLE_ACTIVATE, PpiFlags);\r
-      if (TpmResponse == 0) {\r
+      //\r
+      // PHYSICAL_PRESENCE_ENABLE_ACTIVATE + PHYSICAL_PRESENCE_CLEAR\r
+      // PHYSICAL_PRESENCE_CLEAR will be executed after reboot.\r
+      //\r
+      if ((*PpiFlags & FLAG_RESET_TRACK) == 0) {\r
+        TpmResponse = ExecutePhysicalPresence (TcgProtocol, PHYSICAL_PRESENCE_ENABLE_ACTIVATE, PpiFlags);\r
+        *PpiFlags |= FLAG_RESET_TRACK;\r
+      } else {\r
         TpmResponse = ExecutePhysicalPresence (TcgProtocol, PHYSICAL_PRESENCE_CLEAR, PpiFlags);\r
+        *PpiFlags &= ~FLAG_RESET_TRACK;\r
       }\r
       return TpmResponse;\r
 \r
     case PHYSICAL_PRESENCE_ENABLE_ACTIVATE_CLEAR_ENABLE_ACTIVATE:\r
       //\r
       // PHYSICAL_PRESENCE_ENABLE_ACTIVATE + PHYSICAL_PRESENCE_CLEAR_ENABLE_ACTIVATE\r
-      // PHYSICAL_PRESENCE_CLEAR_ENABLE_ACTIVATE will be executed atfer reboot.\r
+      // PHYSICAL_PRESENCE_CLEAR_ENABLE_ACTIVATE will be executed after reboot.\r
       //\r
       if ((*PpiFlags & FLAG_RESET_TRACK) == 0) {\r
         TpmResponse = ExecutePhysicalPresence (TcgProtocol, PHYSICAL_PRESENCE_ENABLE_ACTIVATE, PpiFlags);\r
@@ -427,7 +441,7 @@ ExecutePhysicalPresence (
                           If false, F10 is used as confirm key.\r
 \r
   @retval     TRUE        User confirmed the changes by input.\r
-  @retval     FALSE       User discarded the changes.\r
+  @retval     FALSE       User discarded the changes or device error.\r
 \r
 **/\r
 BOOLEAN\r
@@ -438,22 +452,29 @@ ReadUserKey (
   EFI_STATUS                        Status;\r
   EFI_INPUT_KEY                     Key;\r
   UINT16                            InputKey;\r
-      \r
+  UINTN                             Index;\r
+\r
   InputKey = 0; \r
   do {\r
-    Status = gBS->CheckEvent (gST->ConIn->WaitForKey);\r
-    if (!EFI_ERROR (Status)) {\r
-      Status = gST->ConIn->ReadKeyStroke (gST->ConIn, &Key);\r
-      if (Key.ScanCode == SCAN_ESC) {\r
-        InputKey = Key.ScanCode;\r
-      }\r
-      if ((Key.ScanCode == SCAN_F10) && !CautionKey) {\r
-        InputKey = Key.ScanCode;\r
-      }\r
-      if ((Key.ScanCode == SCAN_F12) && CautionKey) {\r
-        InputKey = Key.ScanCode;\r
-      }\r
-    }      \r
+    Status = gST->ConIn->ReadKeyStroke (gST->ConIn, &Key);\r
+    if (Status == EFI_NOT_READY) {\r
+      gBS->WaitForEvent (1, &gST->ConIn->WaitForKey, &Index);\r
+      continue;\r
+    }\r
+\r
+    if (Status == EFI_DEVICE_ERROR) {\r
+      return FALSE;\r
+    }\r
+\r
+    if (Key.ScanCode == SCAN_ESC) {\r
+      InputKey = Key.ScanCode;\r
+    }\r
+    if ((Key.ScanCode == SCAN_F10) && !CautionKey) {\r
+      InputKey = Key.ScanCode;\r
+    }\r
+    if ((Key.ScanCode == SCAN_F12) && CautionKey) {\r
+      InputKey = Key.ScanCode;\r
+    }\r
   } while (InputKey == 0);\r
 \r
   if (InputKey != SCAN_ESC) {\r
@@ -873,28 +894,34 @@ UserConfirm (
 }\r
 \r
 /**\r
-  Check and execute the requested physical presence command.\r
-\r
-  @param[in] TcgProtocol          EFI TCG Protocol instance. \r
-  @param[in] TcgPpData            Point to the physical presence NV variable.\r
+  Check if there is a valid physical presence command request. Also updates parameter value \r
+  to whether the requested physical presence command already confirmed by user\r
\r
+   @param[in]  TcgPpData           EFI TCG Physical Presence request data.\r
+   @param[in]  Flags               The physical presence interface flags. \r
+   @param[out] RequestConfirmed    If the physical presence operation command required user confirm from UI.\r
+                                   True, it indicates the command doesn't require user confirm, or already confirmed \r
+                                   in last boot cycle by user.\r
+                                   False, it indicates the command need user confirm from UI.\r
+\r
+   @retval  TRUE        Physical Presence operation command is valid.\r
+   @retval  FALSE       Physical Presence operation command is invalid.\r
 \r
 **/\r
-VOID\r
-ExecutePendingTpmRequest (\r
-  IN      EFI_TCG_PROTOCOL          *TcgProtocol,\r
-  IN      EFI_PHYSICAL_PRESENCE     *TcgPpData\r
+BOOLEAN\r
+HaveValidTpmRequest  (\r
+  IN      EFI_PHYSICAL_PRESENCE     *TcgPpData,\r
+  IN      UINT8                     Flags,\r
+  OUT     BOOLEAN                   *RequestConfirmed\r
   )\r
 {\r
-  EFI_STATUS                        Status;\r
-  UINTN                             DataSize;\r
-  UINT8                             Flags;\r
-  BOOLEAN                           RequestConfirmed;\r
 \r
-  Flags            = TcgPpData->Flags;\r
-  RequestConfirmed = FALSE;  \r
+  *RequestConfirmed = FALSE;\r
+\r
   switch (TcgPpData->PPRequest) {\r
     case PHYSICAL_PRESENCE_NO_ACTION:\r
-      return;\r
+      *RequestConfirmed = TRUE;\r
+      return TRUE;\r
     case PHYSICAL_PRESENCE_ENABLE:\r
     case PHYSICAL_PRESENCE_DISABLE:\r
     case PHYSICAL_PRESENCE_ACTIVATE:\r
@@ -907,42 +934,102 @@ ExecutePendingTpmRequest (
     case PHYSICAL_PRESENCE_DEACTIVATE_DISABLE_OWNER_FALSE:\r
     case PHYSICAL_PRESENCE_SET_OPERATOR_AUTH:\r
       if ((Flags & FLAG_NO_PPI_PROVISION) != 0) {\r
-        RequestConfirmed = TRUE;\r
+        *RequestConfirmed = TRUE;\r
       }\r
       break;\r
 \r
     case PHYSICAL_PRESENCE_CLEAR:\r
     case PHYSICAL_PRESENCE_ENABLE_ACTIVATE_CLEAR:\r
       if ((Flags & FLAG_NO_PPI_CLEAR) != 0) {\r
-        RequestConfirmed = TRUE;\r
+        *RequestConfirmed = TRUE;\r
       }\r
       break;\r
 \r
     case PHYSICAL_PRESENCE_DEFERRED_PP_UNOWNERED_FIELD_UPGRADE:\r
       if ((Flags & FLAG_NO_PPI_MAINTENANCE) != 0) {\r
-        RequestConfirmed = TRUE;\r
+        *RequestConfirmed = TRUE;\r
       }\r
       break;\r
 \r
     case PHYSICAL_PRESENCE_CLEAR_ENABLE_ACTIVATE:\r
     case PHYSICAL_PRESENCE_ENABLE_ACTIVATE_CLEAR_ENABLE_ACTIVATE:\r
       if ((Flags & FLAG_NO_PPI_CLEAR) != 0 && (Flags & FLAG_NO_PPI_PROVISION) != 0) {\r
-        RequestConfirmed = TRUE;\r
+        *RequestConfirmed = TRUE;\r
       }\r
-      break;  \r
+      break;\r
 \r
     case PHYSICAL_PRESENCE_SET_NO_PPI_PROVISION_FALSE:\r
     case PHYSICAL_PRESENCE_SET_NO_PPI_CLEAR_FALSE:\r
     case PHYSICAL_PRESENCE_SET_NO_PPI_MAINTENANCE_FALSE:\r
-      RequestConfirmed = TRUE;\r
+      *RequestConfirmed = TRUE;\r
       break;\r
+\r
+    case PHYSICAL_PRESENCE_SET_NO_PPI_PROVISION_TRUE:\r
+    case PHYSICAL_PRESENCE_SET_NO_PPI_CLEAR_TRUE:\r
+    case PHYSICAL_PRESENCE_SET_NO_PPI_MAINTENANCE_TRUE:\r
+      break;\r
+\r
+    default:\r
+      //\r
+      // Wrong Physical Presence command\r
+      //\r
+      return FALSE;\r
   }\r
 \r
   if ((Flags & FLAG_RESET_TRACK) != 0) {\r
     //\r
     // It had been confirmed in last boot, it doesn't need confirm again.\r
     //\r
-    RequestConfirmed = TRUE;\r
+    *RequestConfirmed = TRUE;\r
+  }\r
+\r
+  //\r
+  // Physical Presence command is correct\r
+  //\r
+  return TRUE;\r
+}\r
+\r
+\r
+/**\r
+  Check and execute the requested physical presence command.\r
+\r
+  Caution: This function may receive untrusted input.\r
+  TcgPpData variable is external input, so this function will validate\r
+  its data structure to be valid value.\r
+\r
+  @param[in] TcgProtocol          EFI TCG Protocol instance. \r
+  @param[in] TcgPpData            Point to the physical presence NV variable.\r
+  @param[in] Flags                The physical presence interface flags.\r
+\r
+**/\r
+VOID\r
+ExecutePendingTpmRequest (\r
+  IN      EFI_TCG_PROTOCOL          *TcgProtocol,\r
+  IN      EFI_PHYSICAL_PRESENCE     *TcgPpData,\r
+  IN      UINT8                     Flags\r
+  )\r
+{\r
+  EFI_STATUS                        Status;\r
+  UINTN                             DataSize;\r
+  BOOLEAN                           RequestConfirmed;\r
+  UINT8                             NewFlags;\r
+\r
+  if (!HaveValidTpmRequest(TcgPpData, Flags, &RequestConfirmed)) {\r
+    //\r
+    // Invalid operation request.\r
+    //\r
+    TcgPpData->PPResponse = TPM_PP_BIOS_FAILURE;\r
+    TcgPpData->LastPPRequest = TcgPpData->PPRequest;\r
+    TcgPpData->PPRequest = PHYSICAL_PRESENCE_NO_ACTION;\r
+    DataSize = sizeof (EFI_PHYSICAL_PRESENCE);\r
+    Status = gRT->SetVariable (\r
+                    PHYSICAL_PRESENCE_VARIABLE,\r
+                    &gEfiPhysicalPresenceGuid,\r
+                    EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r
+                    DataSize,\r
+                    TcgPpData\r
+                    );\r
+    return;\r
   }\r
 \r
   if (!RequestConfirmed) {\r
@@ -956,16 +1043,34 @@ ExecutePendingTpmRequest (
   // Execute requested physical presence command\r
   //\r
   TcgPpData->PPResponse = TPM_PP_USER_ABORT;\r
+  NewFlags = Flags;\r
   if (RequestConfirmed) {\r
-    TcgPpData->PPResponse = ExecutePhysicalPresence (TcgProtocol, TcgPpData->PPRequest, &TcgPpData->Flags);\r
+    TcgPpData->PPResponse = ExecutePhysicalPresence (TcgProtocol, TcgPpData->PPRequest, &NewFlags);\r
+  }\r
+\r
+  //\r
+  // Save the flags if it is updated.\r
+  //\r
+  if (Flags != NewFlags) {\r
+    Status   = gRT->SetVariable (\r
+                      PHYSICAL_PRESENCE_FLAGS_VARIABLE,\r
+                      &gEfiPhysicalPresenceGuid,\r
+                      EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r
+                      sizeof (UINT8),\r
+                      &NewFlags\r
+                      ); \r
+    if (EFI_ERROR (Status)) {\r
+      return;\r
+    }\r
   }\r
 \r
+\r
   //\r
   // Clear request\r
   //\r
-  if ((TcgPpData->Flags & FLAG_RESET_TRACK) == 0) {\r
+  if ((NewFlags & FLAG_RESET_TRACK) == 0) {\r
     TcgPpData->LastPPRequest = TcgPpData->PPRequest;\r
-    TcgPpData->PPRequest = 0;    \r
+    TcgPpData->PPRequest = PHYSICAL_PRESENCE_NO_ACTION;    \r
   }\r
 \r
   //\r
@@ -1004,7 +1109,7 @@ ExecutePendingTpmRequest (
     case PHYSICAL_PRESENCE_ENABLE_ACTIVATE_CLEAR_ENABLE_ACTIVATE:      \r
       break;\r
     default:\r
-      if (TcgPpData->PPRequest != 0) {\r
+      if (TcgPpData->PPRequest != PHYSICAL_PRESENCE_NO_ACTION) {\r
         break;\r
       }\r
       return;\r
@@ -1040,11 +1145,57 @@ TcgPhysicalPresenceLibProcessRequest (
   UINTN                             DataSize;\r
   EFI_PHYSICAL_PRESENCE             TcgPpData;\r
   EFI_TCG_PROTOCOL                  *TcgProtocol;\r
+  EDKII_VARIABLE_LOCK_PROTOCOL      *VariableLockProtocol;\r
+  UINT8                             PpiFlags;\r
   \r
   Status = gBS->LocateProtocol (&gEfiTcgProtocolGuid, NULL, (VOID **)&TcgProtocol);\r
   if (EFI_ERROR (Status)) {\r
     return ;\r
   }\r
+\r
+  //\r
+  // Initialize physical presence flags.\r
+  //\r
+  DataSize = sizeof (UINT8);\r
+  Status = gRT->GetVariable (\r
+                  PHYSICAL_PRESENCE_FLAGS_VARIABLE,\r
+                  &gEfiPhysicalPresenceGuid,\r
+                  NULL,\r
+                  &DataSize,\r
+                  &PpiFlags\r
+                  );\r
+  if (EFI_ERROR (Status)) {\r
+    PpiFlags = FLAG_NO_PPI_PROVISION;\r
+    Status   = gRT->SetVariable (\r
+                      PHYSICAL_PRESENCE_FLAGS_VARIABLE,\r
+                      &gEfiPhysicalPresenceGuid,\r
+                      EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r
+                      sizeof (UINT8),\r
+                      &PpiFlags\r
+                      );\r
+    if (EFI_ERROR (Status)) {\r
+      DEBUG ((EFI_D_ERROR, "[TPM] Set physical presence flag failed, Status = %r\n", Status));\r
+      return ;\r
+    }\r
+  }\r
+  DEBUG ((EFI_D_INFO, "[TPM] PpiFlags = %x\n", PpiFlags));\r
+\r
+  //\r
+  // This flags variable controls whether physical presence is required for TPM command. \r
+  // It should be protected from malicious software. We set it as read-only variable here.\r
+  //\r
+  Status = gBS->LocateProtocol (&gEdkiiVariableLockProtocolGuid, NULL, (VOID **)&VariableLockProtocol);\r
+  if (!EFI_ERROR (Status)) {\r
+    Status = VariableLockProtocol->RequestToLock (\r
+                                     VariableLockProtocol,\r
+                                     PHYSICAL_PRESENCE_FLAGS_VARIABLE,\r
+                                     &gEfiPhysicalPresenceGuid\r
+                                     );\r
+    if (EFI_ERROR (Status)) {\r
+      DEBUG ((EFI_D_ERROR, "[TPM] Error when lock variable %s, Status = %r\n", PHYSICAL_PRESENCE_FLAGS_VARIABLE, Status));\r
+      ASSERT_EFI_ERROR (Status);\r
+    }\r
+  }\r
   \r
   //\r
   // Initialize physical presence variable.\r
@@ -1058,22 +1209,29 @@ TcgPhysicalPresenceLibProcessRequest (
                   &TcgPpData\r
                   );\r
   if (EFI_ERROR (Status)) {\r
-    if (Status == EFI_NOT_FOUND) {\r
-      ZeroMem ((VOID*)&TcgPpData, sizeof (TcgPpData));\r
-      TcgPpData.Flags |= FLAG_NO_PPI_PROVISION;\r
-      DataSize = sizeof (EFI_PHYSICAL_PRESENCE);\r
-      Status   = gRT->SetVariable (\r
-                        PHYSICAL_PRESENCE_VARIABLE,\r
-                        &gEfiPhysicalPresenceGuid,\r
-                        EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r
-                        DataSize,\r
-                        &TcgPpData\r
-                        );\r
+    ZeroMem ((VOID*)&TcgPpData, sizeof (TcgPpData));\r
+    DataSize = sizeof (EFI_PHYSICAL_PRESENCE);\r
+    Status   = gRT->SetVariable (\r
+                      PHYSICAL_PRESENCE_VARIABLE,\r
+                      &gEfiPhysicalPresenceGuid,\r
+                      EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,\r
+                      DataSize,\r
+                      &TcgPpData\r
+                      );\r
+    if (EFI_ERROR (Status)) {\r
+      DEBUG ((EFI_D_ERROR, "[TPM] Set physical presence variable failed, Status = %r\n", Status));\r
+      return;\r
     }\r
-    ASSERT_EFI_ERROR (Status);\r
   }\r
 \r
-  DEBUG ((EFI_D_INFO, "[TPM] Flags=%x, PPRequest=%x\n", TcgPpData.Flags, TcgPpData.PPRequest));\r
+  DEBUG ((EFI_D_INFO, "[TPM] Flags=%x, PPRequest=%x\n", PpiFlags, TcgPpData.PPRequest));\r
+\r
+  if (TcgPpData.PPRequest == PHYSICAL_PRESENCE_NO_ACTION) {\r
+    //\r
+    // No operation request\r
+    //\r
+    return;\r
+  }\r
 \r
   Status = GetTpmCapability (TcgProtocol, &LifetimeLock, &CmdEnable);\r
   if (EFI_ERROR (Status)) {\r
@@ -1101,7 +1259,7 @@ TcgPhysicalPresenceLibProcessRequest (
   //\r
   // Execute pending TPM request.\r
   //  \r
-  ExecutePendingTpmRequest (TcgProtocol, &TcgPpData);\r
+  ExecutePendingTpmRequest (TcgProtocol, &TcgPpData, PpiFlags);\r
   DEBUG ((EFI_D_INFO, "[TPM] PPResponse = %x\n", TcgPpData.PPResponse));\r
 \r
   //\r
@@ -1110,3 +1268,101 @@ TcgPhysicalPresenceLibProcessRequest (
   TpmPhysicalPresence (TcgProtocol, TPM_PHYSICAL_PRESENCE_NOTPRESENT | TPM_PHYSICAL_PRESENCE_LOCK);\r
 }\r
 \r
+/**\r
+  Check if the pending TPM request needs user input to confirm.\r
+\r
+  The TPM request may come from OS. This API will check if TPM request exists and need user\r
+  input to confirmation.\r
+  \r
+  @retval    TRUE        TPM needs input to confirm user physical presence.\r
+  @retval    FALSE       TPM doesn't need input to confirm user physical presence.\r
+\r
+**/\r
+BOOLEAN\r
+EFIAPI\r
+TcgPhysicalPresenceLibNeedUserConfirm(\r
+  VOID\r
+  )\r
+{\r
+  EFI_STATUS              Status;\r
+  EFI_PHYSICAL_PRESENCE   TcgPpData;\r
+  UINTN                   DataSize;\r
+  BOOLEAN                 RequestConfirmed;\r
+  BOOLEAN                 LifetimeLock;\r
+  BOOLEAN                 CmdEnable;\r
+  EFI_TCG_PROTOCOL        *TcgProtocol;\r
+  UINT8                   PpiFlags;\r
+  \r
+  Status = gBS->LocateProtocol (&gEfiTcgProtocolGuid, NULL, (VOID **)&TcgProtocol);\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Check Tpm requests\r
+  //\r
+  DataSize = sizeof (EFI_PHYSICAL_PRESENCE);\r
+  Status = gRT->GetVariable (\r
+                  PHYSICAL_PRESENCE_VARIABLE,\r
+                  &gEfiPhysicalPresenceGuid,\r
+                  NULL,\r
+                  &DataSize,\r
+                  &TcgPpData\r
+                  );\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+\r
+  DataSize = sizeof (UINT8);\r
+  Status = gRT->GetVariable (\r
+                  PHYSICAL_PRESENCE_FLAGS_VARIABLE,\r
+                  &gEfiPhysicalPresenceGuid,\r
+                  NULL,\r
+                  &DataSize,\r
+                  &PpiFlags\r
+                  );\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+  \r
+  if (TcgPpData.PPRequest == PHYSICAL_PRESENCE_NO_ACTION) {\r
+    //\r
+    // No operation request\r
+    //\r
+    return FALSE;\r
+  }\r
+\r
+  if (!HaveValidTpmRequest(&TcgPpData, PpiFlags, &RequestConfirmed)) {\r
+    //\r
+    // Invalid operation request.\r
+    //\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Check Tpm Capability\r
+  //\r
+  Status = GetTpmCapability (TcgProtocol, &LifetimeLock, &CmdEnable);\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+\r
+  if (!CmdEnable) {\r
+    if (LifetimeLock) {\r
+      //\r
+      // physicalPresenceCMDEnable is locked, can't execute physical presence command.\r
+      //\r
+      return FALSE;\r
+    }\r
+  }\r
+\r
+  if (!RequestConfirmed) {\r
+    //\r
+    // Need UI to confirm\r
+    //\r
+    return TRUE;\r
+  }\r
+\r
+  return FALSE;\r
+}\r
+\r