From 70c7664cd3d2689f2ba9ed6bf0de0fc44501f613 Mon Sep 17 00:00:00 2001 From: "Yao, Jiewen" Date: Tue, 28 Jul 2015 07:20:58 +0000 Subject: Add Secure MOR implementation. Add a new module MemoryOverwriteRequestControlLock to register VarCheck handler to enforce MorLock Policy. Only SMM version is added because MOR is only supported in SMM variable case. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: "Yao, Jiewen" Reviewed-by: "Chao Zhang" git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18092 6f19259b-4bc3-4df7-8a09-765794883524 --- .../MemoryOverwriteRequestControlLock/TcgMorLock.c | 196 +++++++++++++++++++++ 1 file changed, 196 insertions(+) create mode 100644 SecurityPkg/Tcg/MemoryOverwriteRequestControlLock/TcgMorLock.c (limited to 'SecurityPkg/Tcg/MemoryOverwriteRequestControlLock/TcgMorLock.c') diff --git a/SecurityPkg/Tcg/MemoryOverwriteRequestControlLock/TcgMorLock.c b/SecurityPkg/Tcg/MemoryOverwriteRequestControlLock/TcgMorLock.c new file mode 100644 index 0000000000..7ca707915e --- /dev/null +++ b/SecurityPkg/Tcg/MemoryOverwriteRequestControlLock/TcgMorLock.c @@ -0,0 +1,196 @@ +/** @file + TCG MOR (Memory Overwrite Request) Lock Control Driver. + + This driver initilize MemoryOverwriteRequestControlLock variable. + This module will add Variable Hook and allow MemoryOverwriteRequestControlLock variable set only once. + +Copyright (c) 2015, 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 +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 +#include +#include +#include +#include +#include +#include "TcgMorLock.h" + +typedef struct { + CHAR16 *VariableName; + EFI_GUID *VendorGuid; +} VARIABLE_TYPE; + +VARIABLE_TYPE mMorVariableType[] = { + {MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME, &gEfiMemoryOverwriteControlDataGuid}, + {MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME, &gEfiMemoryOverwriteRequestControlLockGuid}, +}; + +/** + Returns if this is MOR related variable. + + @param VariableName the name of the vendor's variable, it's a Null-Terminated Unicode String + @param VendorGuid Unify identifier for vendor. + + @retval TRUE The variable is MOR related. + @retval FALSE The variable is NOT MOR related. +**/ +BOOLEAN +IsAnyMorVariable ( + IN CHAR16 *VariableName, + IN EFI_GUID *VendorGuid + ) +{ + UINTN Index; + + for (Index = 0; Index < sizeof(mMorVariableType)/sizeof(mMorVariableType[0]); Index++) { + if ((StrCmp (VariableName, mMorVariableType[Index].VariableName) == 0) && + (CompareGuid (VendorGuid, mMorVariableType[Index].VendorGuid))) { + return TRUE; + } + } + return FALSE; +} + +/** + Returns if this is MOR lock variable. + + @param VariableName the name of the vendor's variable, it's a Null-Terminated Unicode String + @param VendorGuid Unify identifier for vendor. + + @retval TRUE The variable is MOR lock variable. + @retval FALSE The variable is NOT MOR lock variable. +**/ +BOOLEAN +IsMorLockVariable ( + IN CHAR16 *VariableName, + IN EFI_GUID *VendorGuid + ) +{ + if ((StrCmp (VariableName, MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME) == 0) && + (CompareGuid (VendorGuid, &gEfiMemoryOverwriteRequestControlLockGuid))) { + return TRUE; + } + return FALSE; +} + +/** + This service is a checker handler for the UEFI Runtime Service SetVariable() + + @param VariableName the name of the vendor's variable, as a + Null-Terminated Unicode String + @param VendorGuid Unify identifier for vendor. + @param Attributes Point to memory location to return the attributes of variable. If the point + is NULL, the parameter would be ignored. + @param DataSize The size in bytes of Data-Buffer. + @param Data Point to the content of the variable. + + @retval EFI_SUCCESS The firmware has successfully stored the variable and its data as + defined by the Attributes. + @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits was supplied, or the + DataSize exceeds the maximum allowed. + @retval EFI_INVALID_PARAMETER VariableName is an empty Unicode string. + @retval EFI_OUT_OF_RESOURCES Not enough storage is available to hold the variable and its data. + @retval EFI_DEVICE_ERROR The variable could not be saved due to a hardware failure. + @retval EFI_WRITE_PROTECTED The variable in question is read-only. + @retval EFI_WRITE_PROTECTED The variable in question cannot be deleted. + @retval EFI_SECURITY_VIOLATION The variable could not be written due to EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS + set but the AuthInfo does NOT pass the validation check carried + out by the firmware. + @retval EFI_NOT_FOUND The variable trying to be updated or deleted was not found. + +**/ +EFI_STATUS +EFIAPI +SetVariableCheckHandlerMor ( + IN CHAR16 *VariableName, + IN EFI_GUID *VendorGuid, + IN UINT32 Attributes, + IN UINTN DataSize, + IN VOID *Data + ) +{ + UINTN MorLockDataSize; + BOOLEAN MorLock; + EFI_STATUS Status; + + // + // do not handle non-MOR variable + // + if (!IsAnyMorVariable (VariableName, VendorGuid)) { + return EFI_SUCCESS; + } + + MorLockDataSize = sizeof(MorLock); + Status = InternalGetVariable ( + MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME, + &gEfiMemoryOverwriteRequestControlLockGuid, + NULL, + &MorLockDataSize, + &MorLock + ); + if (!EFI_ERROR (Status) && MorLock) { + // + // If lock, deny access + // + return EFI_INVALID_PARAMETER; + } + + // + // check format + // + if (IsMorLockVariable(VariableName, VendorGuid)) { + // + // Delete not OK + // + if ((DataSize == 0) || (Data == NULL) || (Attributes == 0)) { + return EFI_INVALID_PARAMETER; + } + // + // set to any other value not OK + // + if ((DataSize != sizeof(UINT8)) || ((*(UINT8 *)Data != 1) && (*(UINT8 *)Data != 0))) { + return EFI_INVALID_PARAMETER; + } + } + // + // Or grant access + // + return EFI_SUCCESS; +} + +/** + Entry Point for MOR Lock Control driver. + + @param[in] ImageHandle Image handle of this driver. + @param[in] SystemTable A Pointer to the EFI System Table. + + @retval EFI_SUCEESS + @return Others Some error occurs. +**/ +EFI_STATUS +EFIAPI +MorLockDriverInit ( + VOID + ) +{ + EFI_STATUS Status; + UINT8 Data; + + Data = 0; + Status = InternalSetVariable ( + MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME, + &gEfiMemoryOverwriteRequestControlLockGuid, + EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, + 1, + &Data + ); + return Status; +} -- cgit v1.2.3