From ed094569d6a1248b1b6ca6d0439e5bdf0db36aa2 Mon Sep 17 00:00:00 2001 From: Dong Guo Date: Tue, 3 Sep 2013 07:39:26 +0000 Subject: [PATCH] Enhance TPM driver to protect TPM physical presence flags. Signed-off-by: Dong Guo Reviewed-by: Yao Jiewen Reviewed-by: Ouyang, Qian git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14619 6f19259b-4bc3-4df7-8a09-765794883524 --- .../Include/Guid/PhysicalPresenceData.h | 25 +++-- .../DxeTcgPhysicalPresenceLib.c | 98 ++++++++++++++++--- .../DxeTcgPhysicalPresenceLib.inf | 3 +- SecurityPkg/Tcg/TcgSmm/TcgSmm.c | 19 +++- 4 files changed, 120 insertions(+), 25 deletions(-) diff --git a/SecurityPkg/Include/Guid/PhysicalPresenceData.h b/SecurityPkg/Include/Guid/PhysicalPresenceData.h index 4db20a7b16..942865784c 100644 --- a/SecurityPkg/Include/Guid/PhysicalPresenceData.h +++ b/SecurityPkg/Include/Guid/PhysicalPresenceData.h @@ -4,7 +4,7 @@ cleared after it is processed in the next boot cycle. The TPM response is saved to variable. -Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.
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 @@ -29,17 +29,8 @@ typedef struct { UINT8 PPRequest; ///< Physical Presence request command. UINT8 LastPPRequest; UINT32 PPResponse; - UINT8 Flags; } EFI_PHYSICAL_PRESENCE; -// -// The definition bit of the flags -// -#define FLAG_NO_PPI_PROVISION BIT0 -#define FLAG_NO_PPI_CLEAR BIT1 -#define FLAG_NO_PPI_MAINTENANCE BIT2 -#define FLAG_RESET_TRACK BIT3 - // // The definition of physical presence operation actions // @@ -67,6 +58,20 @@ typedef struct { #define PHYSICAL_PRESENCE_ENABLE_ACTIVATE_CLEAR 21 #define PHYSICAL_PRESENCE_ENABLE_ACTIVATE_CLEAR_ENABLE_ACTIVATE 22 +// +// This variable is used to save TPM Management Flags and corresponding operations. +// It should be protected from malicious software (e.g. Set it as read-only variable). +// +#define PHYSICAL_PRESENCE_FLAGS_VARIABLE L"PhysicalPresenceFlags" + +// +// The definition bit of the TPM Management Flags +// +#define FLAG_NO_PPI_PROVISION BIT0 +#define FLAG_NO_PPI_CLEAR BIT1 +#define FLAG_NO_PPI_MAINTENANCE BIT2 +#define FLAG_RESET_TRACK BIT3 + extern EFI_GUID gEfiPhysicalPresenceGuid; #endif diff --git a/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c b/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c index 3414cd2ea4..427cc8d66b 100644 --- a/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c +++ b/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.c @@ -22,6 +22,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. #include #include +#include #include #include #include @@ -909,12 +910,11 @@ UserConfirm ( BOOLEAN HaveValidTpmRequest ( IN EFI_PHYSICAL_PRESENCE *TcgPpData, + IN UINT8 Flags, OUT BOOLEAN *RequestConfirmed ) { - UINT8 Flags; - - Flags = TcgPpData->Flags; + *RequestConfirmed = FALSE; switch (TcgPpData->PPRequest) { @@ -1003,14 +1003,16 @@ HaveValidTpmRequest ( VOID ExecutePendingTpmRequest ( IN EFI_TCG_PROTOCOL *TcgProtocol, - IN EFI_PHYSICAL_PRESENCE *TcgPpData + IN EFI_PHYSICAL_PRESENCE *TcgPpData, + IN UINT8 Flags ) { EFI_STATUS Status; UINTN DataSize; BOOLEAN RequestConfirmed; + UINT8 NewFlags; - if (!HaveValidTpmRequest(TcgPpData, &RequestConfirmed)) { + if (!HaveValidTpmRequest(TcgPpData, Flags, &RequestConfirmed)) { // // Invalid operation request. // @@ -1039,14 +1041,29 @@ ExecutePendingTpmRequest ( // Execute requested physical presence command // TcgPpData->PPResponse = TPM_PP_USER_ABORT; + NewFlags = Flags; if (RequestConfirmed) { - TcgPpData->PPResponse = ExecutePhysicalPresence (TcgProtocol, TcgPpData->PPRequest, &TcgPpData->Flags); + TcgPpData->PPResponse = ExecutePhysicalPresence (TcgProtocol, TcgPpData->PPRequest, &NewFlags); } + // + // Save the flags if it is updated. + // + if (Flags != NewFlags) { + Status = gRT->SetVariable ( + PHYSICAL_PRESENCE_FLAGS_VARIABLE, + &gEfiPhysicalPresenceGuid, + EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, + sizeof (UINT8), + &NewFlags + ); + } + + // // Clear request // - if ((TcgPpData->Flags & FLAG_RESET_TRACK) == 0) { + if ((NewFlags & FLAG_RESET_TRACK) == 0) { TcgPpData->LastPPRequest = TcgPpData->PPRequest; TcgPpData->PPRequest = PHYSICAL_PRESENCE_NO_ACTION; } @@ -1123,11 +1140,56 @@ TcgPhysicalPresenceLibProcessRequest ( UINTN DataSize; EFI_PHYSICAL_PRESENCE TcgPpData; EFI_TCG_PROTOCOL *TcgProtocol; + EDKII_VARIABLE_LOCK_PROTOCOL *VariableLockProtocol; + UINT8 PpiFlags; Status = gBS->LocateProtocol (&gEfiTcgProtocolGuid, NULL, (VOID **)&TcgProtocol); if (EFI_ERROR (Status)) { return ; } + + // + // Initialize physical presence flags. + // + DataSize = sizeof (UINT8); + Status = gRT->GetVariable ( + PHYSICAL_PRESENCE_FLAGS_VARIABLE, + &gEfiPhysicalPresenceGuid, + NULL, + &DataSize, + &PpiFlags + ); + if (EFI_ERROR (Status)) { + if (Status == EFI_NOT_FOUND) { + PpiFlags = FLAG_NO_PPI_PROVISION; + Status = gRT->SetVariable ( + PHYSICAL_PRESENCE_FLAGS_VARIABLE, + &gEfiPhysicalPresenceGuid, + EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, + sizeof (UINT8), + &PpiFlags + ); + } + ASSERT_EFI_ERROR (Status); + } + DEBUG ((EFI_D_ERROR, "[TPM] PpiFlags = %x, Status = %r\n", PpiFlags, Status)); + + // + // 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, + PHYSICAL_PRESENCE_FLAGS_VARIABLE, + &gEfiPhysicalPresenceGuid + ); + if (EFI_ERROR (Status)) { + DEBUG ((EFI_D_ERROR, "[TPM] Error when lock variable %s, Status = %r\n", PHYSICAL_PRESENCE_FLAGS_VARIABLE, Status)); + ASSERT_EFI_ERROR (Status); + } + } // // Initialize physical presence variable. @@ -1143,7 +1205,6 @@ TcgPhysicalPresenceLibProcessRequest ( if (EFI_ERROR (Status)) { if (Status == EFI_NOT_FOUND) { ZeroMem ((VOID*)&TcgPpData, sizeof (TcgPpData)); - TcgPpData.Flags |= FLAG_NO_PPI_PROVISION; DataSize = sizeof (EFI_PHYSICAL_PRESENCE); Status = gRT->SetVariable ( PHYSICAL_PRESENCE_VARIABLE, @@ -1156,7 +1217,7 @@ TcgPhysicalPresenceLibProcessRequest ( ASSERT_EFI_ERROR (Status); } - DEBUG ((EFI_D_INFO, "[TPM] Flags=%x, PPRequest=%x\n", TcgPpData.Flags, TcgPpData.PPRequest)); + DEBUG ((EFI_D_INFO, "[TPM] Flags=%x, PPRequest=%x\n", PpiFlags, TcgPpData.PPRequest)); if (TcgPpData.PPRequest == PHYSICAL_PRESENCE_NO_ACTION) { // @@ -1191,7 +1252,7 @@ TcgPhysicalPresenceLibProcessRequest ( // // Execute pending TPM request. // - ExecutePendingTpmRequest (TcgProtocol, &TcgPpData); + ExecutePendingTpmRequest (TcgProtocol, &TcgPpData, PpiFlags); DEBUG ((EFI_D_INFO, "[TPM] PPResponse = %x\n", TcgPpData.PPResponse)); // @@ -1223,7 +1284,8 @@ TcgPhysicalPresenceLibNeedUserConfirm( BOOLEAN LifetimeLock; BOOLEAN CmdEnable; EFI_TCG_PROTOCOL *TcgProtocol; - + UINT8 PpiFlags; + Status = gBS->LocateProtocol (&gEfiTcgProtocolGuid, NULL, (VOID **)&TcgProtocol); if (EFI_ERROR (Status)) { return FALSE; @@ -1244,6 +1306,18 @@ TcgPhysicalPresenceLibNeedUserConfirm( return FALSE; } + DataSize = sizeof (UINT8); + Status = gRT->GetVariable ( + PHYSICAL_PRESENCE_FLAGS_VARIABLE, + &gEfiPhysicalPresenceGuid, + NULL, + &DataSize, + &PpiFlags + ); + if (EFI_ERROR (Status)) { + return FALSE; + } + if (TcgPpData.PPRequest == PHYSICAL_PRESENCE_NO_ACTION) { // // No operation request @@ -1251,7 +1325,7 @@ TcgPhysicalPresenceLibNeedUserConfirm( return FALSE; } - if (!HaveValidTpmRequest(&TcgPpData, &RequestConfirmed)) { + if (!HaveValidTpmRequest(&TcgPpData, PpiFlags, &RequestConfirmed)) { // // Invalid operation request. // diff --git a/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.inf b/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.inf index 0a197fd31c..d700ed2e83 100644 --- a/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.inf +++ b/SecurityPkg/Library/DxeTcgPhysicalPresenceLib/DxeTcgPhysicalPresenceLib.inf @@ -6,7 +6,7 @@ # This driver will have external input - variable. # This external input must be validated carefully to avoid security issue. # -# Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.
+# Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.
# 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 @@ -53,6 +53,7 @@ [Protocols] gEfiTcgProtocolGuid + gEdkiiVariableLockProtocolGuid [Guids] gEfiPhysicalPresenceGuid diff --git a/SecurityPkg/Tcg/TcgSmm/TcgSmm.c b/SecurityPkg/Tcg/TcgSmm/TcgSmm.c index 7a16b9ca26..97cd916d07 100644 --- a/SecurityPkg/Tcg/TcgSmm/TcgSmm.c +++ b/SecurityPkg/Tcg/TcgSmm/TcgSmm.c @@ -8,7 +8,7 @@ PhysicalPresenceCallback() and MemoryClearCallback() will receive untrusted input and do some check. -Copyright (c) 2011 - 2012, Intel Corporation. All rights reserved.
+Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.
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 @@ -103,7 +103,22 @@ PhysicalPresenceCallback ( } mTcgNvs->PhysicalPresence.ReturnCode = PP_SUBMIT_REQUEST_SUCCESS; } else if (mTcgNvs->PhysicalPresence.Parameter == ACPI_FUNCTION_GET_USER_CONFIRMATION_STATUS_FOR_REQUEST) { - Flags = PpData.Flags; + // + // Get the Physical Presence flags + // + DataSize = sizeof (UINT8); + Status = mSmmVariable->SmmGetVariable ( + PHYSICAL_PRESENCE_FLAGS_VARIABLE, + &gEfiPhysicalPresenceGuid, + NULL, + &DataSize, + &Flags + ); + if (EFI_ERROR (Status)) { + mTcgNvs->PhysicalPresence.ReturnCode = PP_SUBMIT_REQUEST_GENERAL_FAILURE; + return EFI_SUCCESS; + } + RequestConfirmed = FALSE; switch (mTcgNvs->PhysicalPresence.Request) { -- 2.39.2