Enhance TPM driver to protect TPM physical presence flags.

[mirror_edk2.git] / SecurityPkg / Library / DxeTcgPhysicalPresenceLib / DxeTcgPhysicalPresenceLib.c

diff --git a/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c b/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c
index 44845b0f854dbb4c9dbdbb7afb7d0f2acc7e5820..427cc8d66bcda4a5f0e67550f52c778c1bbf6e16 100644 (file)
--- a/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c
+++ b/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c
@@ -8,7 +8,7 @@
 \r
   ExecutePendingTpmRequest() will receive untrusted input and do validation.\r
 \r
-Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2006 - 2013, 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
@@ -22,6 +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
@@ -909,12 +910,11 @@ UserConfirm (
 BOOLEAN\r
 HaveValidTpmRequest  (\r
   IN      EFI_PHYSICAL_PRESENCE     *TcgPpData,\r
+  IN      UINT8                     Flags,\r
   OUT     BOOLEAN                   *RequestConfirmed\r
   )\r
 {\r
-  UINT8                             Flags;\r
-  \r
-  Flags = TcgPpData->Flags;\r
+\r
   *RequestConfirmed = FALSE;\r
 \r
   switch (TcgPpData->PPRequest) {\r
@@ -1003,21 +1003,16 @@ HaveValidTpmRequest  (
 VOID\r
 ExecutePendingTpmRequest (\r
   IN      EFI_TCG_PROTOCOL          *TcgProtocol,\r
-  IN      EFI_PHYSICAL_PRESENCE     *TcgPpData\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 (TcgPpData->PPRequest == PHYSICAL_PRESENCE_NO_ACTION) {\r
-    //\r
-    // No operation request\r
-    //\r
-    return;\r
-  }\r
-\r
-  if (!HaveValidTpmRequest(TcgPpData, &RequestConfirmed)) {\r
+  if (!HaveValidTpmRequest(TcgPpData, Flags, &RequestConfirmed)) {\r
     //\r
     // Invalid operation request.\r
     //\r
@@ -1046,14 +1041,29 @@ 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
+  }\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 = PHYSICAL_PRESENCE_NO_ACTION;    \r
   }\r
@@ -1130,11 +1140,56 @@ 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
+    if (Status == EFI_NOT_FOUND) {\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
+    }\r
+    ASSERT_EFI_ERROR (Status);\r
+  }\r
+      DEBUG ((EFI_D_ERROR, "[TPM] PpiFlags = %x, Status = %r\n", PpiFlags, Status));\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
@@ -1150,7 +1205,6 @@ TcgPhysicalPresenceLibProcessRequest (
   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
@@ -1163,7 +1217,14 @@ TcgPhysicalPresenceLibProcessRequest (
     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
@@ -1191,7 +1252,7 @@ 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
@@ -1223,7 +1284,8 @@ TcgPhysicalPresenceLibNeedUserConfirm(
   BOOLEAN                 LifetimeLock;\r
   BOOLEAN                 CmdEnable;\r
   EFI_TCG_PROTOCOL        *TcgProtocol;\r
-\r
+  UINT8                   PpiFlags;\r
+  \r
   Status = gBS->LocateProtocol (&gEfiTcgProtocolGuid, NULL, (VOID **)&TcgProtocol);\r
   if (EFI_ERROR (Status)) {\r
     return FALSE;\r
@@ -1244,6 +1306,18 @@ TcgPhysicalPresenceLibNeedUserConfirm(
     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
@@ -1251,7 +1325,7 @@ TcgPhysicalPresenceLibNeedUserConfirm(
     return FALSE;\r
   }\r
 \r
-  if (!HaveValidTpmRequest(&TcgPpData, &RequestConfirmed)) {\r
+  if (!HaveValidTpmRequest(&TcgPpData, PpiFlags, &RequestConfirmed)) {\r
     //\r
     // Invalid operation request.\r
     //\r