mirror of https://github.com/acidanthera/audk.git
883 lines
30 KiB
C
883 lines
30 KiB
C
/** @file
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Implement authentication services for the authenticated variable
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service in UEFI2.2.
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Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#include "Variable.h"
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#include "AuthService.h"
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///
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/// Global database array for scratch
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///
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UINT32 mPubKeyNumber;
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UINT32 mPlatformMode;
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EFI_GUID mSignatureSupport[SIGSUPPORT_NUM] = {EFI_CERT_RSA2048_SHA256_GUID, EFI_CERT_RSA2048_SHA1_GUID};
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//
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// Public Exponent of RSA Key.
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//
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CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 };
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/**
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Initializes for authenticated varibale service.
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@retval EFI_SUCCESS The function successfully executed.
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@retval EFI_OUT_OF_RESOURCES Failed to allocate enough memory resources.
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**/
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EFI_STATUS
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AutenticatedVariableServiceInitialize (
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VOID
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)
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{
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EFI_STATUS Status;
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VARIABLE_POINTER_TRACK Variable;
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UINT8 VarValue;
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UINT32 VarAttr;
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UINTN DataSize;
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UINTN CtxSize;
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VARIABLE_HEADER VariableHeader;
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BOOLEAN Valid;
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mVariableModuleGlobal->AuthenticatedVariableGuid[Physical] = &gEfiAuthenticatedVariableGuid;
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mVariableModuleGlobal->CertRsa2048Sha256Guid[Physical] = &gEfiCertRsa2048Sha256Guid;
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mVariableModuleGlobal->ImageSecurityDatabaseGuid[Physical] = &gEfiImageSecurityDatabaseGuid;
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//
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// Initialize hash context.
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//
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CtxSize = Sha256GetContextSize ();
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mVariableModuleGlobal->HashContext[Physical] = AllocateRuntimePool (CtxSize);
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ASSERT (mVariableModuleGlobal->HashContext[Physical] != NULL);
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//
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// Check "AuthVarKeyDatabase" variable's existence.
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// If it doesn't exist, create a new one with initial value of 0 and EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set.
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//
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Status = FindVariable (
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mVariableModuleGlobal->VariableName[Physical][VAR_AUTH_KEY_DB],
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&gEfiAuthenticatedVariableGuid,
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&Variable,
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&mVariableModuleGlobal->VariableGlobal[Physical],
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mVariableModuleGlobal->FvbInstance
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);
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if (Variable.CurrPtr == 0x0) {
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VarAttr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS;
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VarValue = 0;
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mPubKeyNumber = 0;
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Status = UpdateVariable (
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mVariableModuleGlobal->VariableName[Physical][VAR_AUTH_KEY_DB],
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&gEfiAuthenticatedVariableGuid,
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&VarValue,
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sizeof(UINT8),
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VarAttr,
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0,
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0,
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FALSE,
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mVariableModuleGlobal,
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&Variable
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);
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if (EFI_ERROR (Status)) {
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return Status;
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}
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} else {
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//
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// Load database in global variable for cache.
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//
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Valid = IsValidVariableHeader (
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Variable.CurrPtr,
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Variable.Volatile,
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&mVariableModuleGlobal->VariableGlobal[Physical],
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mVariableModuleGlobal->FvbInstance,
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&VariableHeader
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);
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ASSERT (Valid);
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DataSize = DataSizeOfVariable (&VariableHeader);
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ASSERT (DataSize <= MAX_KEYDB_SIZE);
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GetVariableDataPtr (
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Variable.CurrPtr,
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Variable.Volatile,
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&mVariableModuleGlobal->VariableGlobal[Physical],
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mVariableModuleGlobal->FvbInstance,
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(CHAR16 *) mVariableModuleGlobal->PubKeyStore
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);
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mPubKeyNumber = (UINT32) (DataSize / EFI_CERT_TYPE_RSA2048_SIZE);
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}
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//
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// Check "SetupMode" variable's existence.
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// If it doesn't exist, check PK database's existence to determine the value.
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// Then create a new one with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set.
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//
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Status = FindVariable (
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mVariableModuleGlobal->VariableName[Physical][VAR_SETUP_MODE],
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&gEfiGlobalVariableGuid,
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&Variable,
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&mVariableModuleGlobal->VariableGlobal[Physical],
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mVariableModuleGlobal->FvbInstance
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);
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if (Variable.CurrPtr == 0x0) {
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Status = FindVariable (
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mVariableModuleGlobal->VariableName[Physical][VAR_PLATFORM_KEY],
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&gEfiGlobalVariableGuid,
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&Variable,
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&mVariableModuleGlobal->VariableGlobal[Physical],
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mVariableModuleGlobal->FvbInstance
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);
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if (Variable.CurrPtr == 0x0) {
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mPlatformMode = SETUP_MODE;
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} else {
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mPlatformMode = USER_MODE;
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}
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VarAttr = EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS;
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Status = UpdateVariable (
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mVariableModuleGlobal->VariableName[Physical][VAR_SETUP_MODE],
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&gEfiGlobalVariableGuid,
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&mPlatformMode,
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sizeof(UINT8),
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VarAttr,
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0,
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0,
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FALSE,
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mVariableModuleGlobal,
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&Variable
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);
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if (EFI_ERROR (Status)) {
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return Status;
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}
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} else {
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GetVariableDataPtr (
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Variable.CurrPtr,
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Variable.Volatile,
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&mVariableModuleGlobal->VariableGlobal[Physical],
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mVariableModuleGlobal->FvbInstance,
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(CHAR16 *) &mPlatformMode
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);
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}
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//
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// Check "SignatureSupport" variable's existence.
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// If it doesn't exist, then create a new one with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set.
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//
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Status = FindVariable (
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EFI_SIGNATURE_SUPPORT_NAME,
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&gEfiGlobalVariableGuid,
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&Variable,
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&mVariableModuleGlobal->VariableGlobal[Physical],
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mVariableModuleGlobal->FvbInstance
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);
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if (Variable.CurrPtr == 0x0) {
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VarAttr = EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS;
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Status = UpdateVariable (
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EFI_SIGNATURE_SUPPORT_NAME,
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&gEfiGlobalVariableGuid,
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mSignatureSupport,
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SIGSUPPORT_NUM * sizeof(EFI_GUID),
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VarAttr,
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0,
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0,
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FALSE,
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mVariableModuleGlobal,
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&Variable
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);
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}
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return Status;
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}
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/**
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Add public key in store and return its index.
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@param[in] VirtualMode The current calling mode for this function.
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@param[in] Global The context of this Extended SAL Variable Services Class call.
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@param[in] PubKey The input pointer to Public Key data.
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@return The index of new added item.
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**/
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UINT32
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AddPubKeyInStore (
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IN BOOLEAN VirtualMode,
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IN ESAL_VARIABLE_GLOBAL *Global,
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IN UINT8 *PubKey
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)
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{
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EFI_STATUS Status;
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BOOLEAN IsFound;
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UINT32 Index;
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VARIABLE_POINTER_TRACK Variable;
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UINT8 *Ptr;
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if (PubKey == NULL) {
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return 0;
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}
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Status = FindVariable (
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Global->VariableName[VirtualMode][VAR_AUTH_KEY_DB],
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Global->AuthenticatedVariableGuid[VirtualMode],
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&Variable,
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&Global->VariableGlobal[VirtualMode],
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Global->FvbInstance
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);
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ASSERT_EFI_ERROR (Status);
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//
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// Check whether the public key entry does exist.
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//
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IsFound = FALSE;
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for (Ptr = Global->PubKeyStore, Index = 1; Index <= mPubKeyNumber; Index++) {
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if (CompareMem (Ptr, PubKey, EFI_CERT_TYPE_RSA2048_SIZE) == 0) {
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IsFound = TRUE;
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break;
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}
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Ptr += EFI_CERT_TYPE_RSA2048_SIZE;
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}
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if (!IsFound) {
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//
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// Add public key in database.
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//
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if (mPubKeyNumber == MAX_KEY_NUM) {
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//
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// Notes: Database is full, need enhancement here, currently just return 0.
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//
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return 0;
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}
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CopyMem (Global->PubKeyStore + mPubKeyNumber * EFI_CERT_TYPE_RSA2048_SIZE, PubKey, EFI_CERT_TYPE_RSA2048_SIZE);
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Index = ++mPubKeyNumber;
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//
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// Update public key database variable.
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//
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Status = UpdateVariable (
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Global->VariableName[VirtualMode][VAR_AUTH_KEY_DB],
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Global->AuthenticatedVariableGuid[VirtualMode],
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Global->PubKeyStore,
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mPubKeyNumber * EFI_CERT_TYPE_RSA2048_SIZE,
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EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS,
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0,
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0,
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VirtualMode,
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Global,
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&Variable
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);
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ASSERT_EFI_ERROR (Status);
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}
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return Index;
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}
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/**
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Verify data payload with AuthInfo in EFI_CERT_TYPE_RSA2048_SHA256 type.
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Follow the steps in UEFI2.2.
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@param[in] VirtualMode The current calling mode for this function.
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@param[in] Global The context of this Extended SAL Variable Services Class call.
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@param[in] Data The pointer to data with AuthInfo.
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@param[in] DataSize The size of Data.
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@param[in] PubKey The public key used for verification.
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@retval EFI_INVALID_PARAMETER Invalid parameter.
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@retval EFI_SECURITY_VIOLATION Authentication failed.
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@retval EFI_SUCCESS Authentication successful.
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**/
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EFI_STATUS
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VerifyDataPayload (
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IN BOOLEAN VirtualMode,
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IN ESAL_VARIABLE_GLOBAL *Global,
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IN UINT8 *Data,
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IN UINTN DataSize,
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IN UINT8 *PubKey
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)
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{
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BOOLEAN Status;
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EFI_VARIABLE_AUTHENTICATION *CertData;
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EFI_CERT_BLOCK_RSA_2048_SHA256 *CertBlock;
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UINT8 Digest[SHA256_DIGEST_SIZE];
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VOID *Rsa;
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VOID *HashContext;
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Rsa = NULL;
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CertData = NULL;
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CertBlock = NULL;
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if (Data == NULL || PubKey == NULL) {
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return EFI_INVALID_PARAMETER;
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}
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CertData = (EFI_VARIABLE_AUTHENTICATION *) Data;
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CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) (CertData->AuthInfo.CertData);
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//
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// wCertificateType should be WIN_CERT_TYPE_EFI_GUID.
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// Cert type should be EFI_CERT_TYPE_RSA2048_SHA256.
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//
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if ((CertData->AuthInfo.Hdr.wCertificateType != WIN_CERT_TYPE_EFI_GUID) ||
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!CompareGuid (&CertData->AuthInfo.CertType, Global->CertRsa2048Sha256Guid[VirtualMode])
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) {
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//
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// Invalid AuthInfo type, return EFI_SECURITY_VIOLATION.
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//
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return EFI_SECURITY_VIOLATION;
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}
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//
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// Hash data payload with SHA256.
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//
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ZeroMem (Digest, SHA256_DIGEST_SIZE);
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HashContext = Global->HashContext[VirtualMode];
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Status = Sha256Init (HashContext);
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if (!Status) {
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goto Done;
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}
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Status = Sha256Update (HashContext, Data + AUTHINFO_SIZE, (UINTN) (DataSize - AUTHINFO_SIZE));
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if (!Status) {
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goto Done;
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}
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//
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// Hash Monotonic Count.
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//
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Status = Sha256Update (HashContext, &CertData->MonotonicCount, sizeof (UINT64));
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if (!Status) {
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goto Done;
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}
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Status = Sha256Final (HashContext, Digest);
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if (!Status) {
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goto Done;
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}
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//
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// Generate & Initialize RSA Context.
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//
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Rsa = RsaNew ();
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ASSERT (Rsa != NULL);
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//
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// Set RSA Key Components.
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// NOTE: Only N and E are needed to be set as RSA public key for signature verification.
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//
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Status = RsaSetKey (Rsa, RsaKeyN, PubKey, EFI_CERT_TYPE_RSA2048_SIZE);
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if (!Status) {
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goto Done;
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}
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Status = RsaSetKey (Rsa, RsaKeyE, mRsaE, sizeof (mRsaE));
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if (!Status) {
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goto Done;
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}
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//
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// Verify the signature.
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//
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Status = RsaPkcs1Verify (
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Rsa,
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Digest,
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SHA256_DIGEST_SIZE,
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CertBlock->Signature,
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EFI_CERT_TYPE_RSA2048_SHA256_SIZE
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);
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Done:
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if (Rsa != NULL) {
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RsaFree (Rsa);
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}
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if (Status) {
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return EFI_SUCCESS;
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} else {
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return EFI_SECURITY_VIOLATION;
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}
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}
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/**
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Update platform mode.
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@param[in] VirtualMode The current calling mode for this function.
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@param[in] Global The context of this Extended SAL Variable Services Class call.
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@param[in] Mode SETUP_MODE or USER_MODE.
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**/
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VOID
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UpdatePlatformMode (
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IN BOOLEAN VirtualMode,
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IN ESAL_VARIABLE_GLOBAL *Global,
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IN UINT32 Mode
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)
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{
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EFI_STATUS Status;
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VARIABLE_POINTER_TRACK Variable;
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UINT32 VarAttr;
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Status = FindVariable (
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Global->VariableName[VirtualMode][VAR_SETUP_MODE],
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Global->GlobalVariableGuid[VirtualMode],
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&Variable,
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&Global->VariableGlobal[VirtualMode],
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Global->FvbInstance
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);
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ASSERT_EFI_ERROR (Status);
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mPlatformMode = Mode;
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VarAttr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS;
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Status = UpdateVariable (
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Global->VariableName[VirtualMode][VAR_SETUP_MODE],
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Global->GlobalVariableGuid[VirtualMode],
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&mPlatformMode,
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sizeof(UINT8),
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VarAttr,
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0,
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0,
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VirtualMode,
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Global,
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&Variable
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);
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ASSERT_EFI_ERROR (Status);
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}
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/**
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Process variable with platform key for verification.
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@param[in] VariableName The name of Variable to be found.
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@param[in] VendorGuid The variable vendor GUID.
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@param[in] Data The data pointer.
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@param[in] DataSize The size of Data found. If size is less than the
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data, this value contains the required size.
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@param[in] VirtualMode The current calling mode for this function.
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@param[in] Global The context of this Extended SAL Variable Services Class call.
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@param[in] Variable The variable information which is used to keep track of variable usage.
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@param[in] Attributes The attribute value of the variable.
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@param[in] IsPk Indicates whether to process pk.
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@retval EFI_INVALID_PARAMETER Invalid parameter.
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@retval EFI_SECURITY_VIOLATION The variable does NOT pass the validation
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check carried out by the firmware.
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@retval EFI_SUCCESS The variable passed validation successfully.
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**/
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EFI_STATUS
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ProcessVarWithPk (
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IN CHAR16 *VariableName,
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IN EFI_GUID *VendorGuid,
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IN VOID *Data,
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IN UINTN DataSize,
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IN BOOLEAN VirtualMode,
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IN ESAL_VARIABLE_GLOBAL *Global,
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IN VARIABLE_POINTER_TRACK *Variable,
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IN UINT32 Attributes OPTIONAL,
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IN BOOLEAN IsPk
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)
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{
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EFI_STATUS Status;
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VARIABLE_POINTER_TRACK PkVariable;
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EFI_SIGNATURE_LIST *OldPkList;
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EFI_SIGNATURE_DATA *OldPkData;
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EFI_VARIABLE_AUTHENTICATION *CertData;
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VARIABLE_HEADER VariableHeader;
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BOOLEAN Valid;
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OldPkList = NULL;
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if ((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) {
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//
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// PK and KEK should set EFI_VARIABLE_NON_VOLATILE attribute.
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//
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return EFI_INVALID_PARAMETER;
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}
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if (mPlatformMode == USER_MODE) {
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if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) == 0) {
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//
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// In user mode, PK and KEK should set EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS attribute.
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//
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return EFI_INVALID_PARAMETER;
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}
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CertData = (EFI_VARIABLE_AUTHENTICATION *) Data;
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|
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if (Variable->CurrPtr != 0x0) {
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Valid = IsValidVariableHeader (
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Variable->CurrPtr,
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Variable->Volatile,
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&Global->VariableGlobal[VirtualMode],
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Global->FvbInstance,
|
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&VariableHeader
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);
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ASSERT (Valid);
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|
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if (CertData->MonotonicCount <= VariableHeader.MonotonicCount) {
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//
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// Monotonic count check fail, suspicious replay attack, return EFI_SECURITY_VIOLATION.
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//
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return EFI_SECURITY_VIOLATION;
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}
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}
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//
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// Get platform key from variable.
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//
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Status = FindVariable (
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Global->VariableName[VirtualMode][VAR_PLATFORM_KEY],
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Global->GlobalVariableGuid[VirtualMode],
|
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&PkVariable,
|
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&Global->VariableGlobal[VirtualMode],
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Global->FvbInstance
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);
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ASSERT_EFI_ERROR (Status);
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ZeroMem (Global->KeyList, MAX_KEYDB_SIZE);
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GetVariableDataPtr (
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PkVariable.CurrPtr,
|
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PkVariable.Volatile,
|
|
&Global->VariableGlobal[VirtualMode],
|
|
Global->FvbInstance,
|
|
(CHAR16 *) Global->KeyList
|
|
);
|
|
|
|
OldPkList = (EFI_SIGNATURE_LIST *) Global->KeyList;
|
|
OldPkData = (EFI_SIGNATURE_DATA *) ((UINT8 *) OldPkList + sizeof (EFI_SIGNATURE_LIST) + OldPkList->SignatureHeaderSize);
|
|
Status = VerifyDataPayload (VirtualMode, Global, Data, DataSize, OldPkData->SignatureData);
|
|
if (!EFI_ERROR (Status)) {
|
|
Status = UpdateVariable (
|
|
VariableName,
|
|
VendorGuid,
|
|
(UINT8*)Data + AUTHINFO_SIZE,
|
|
DataSize - AUTHINFO_SIZE,
|
|
Attributes,
|
|
0,
|
|
CertData->MonotonicCount,
|
|
VirtualMode,
|
|
Global,
|
|
Variable
|
|
);
|
|
|
|
if (!EFI_ERROR (Status)) {
|
|
//
|
|
// If delete PK in user mode, need change to setup mode.
|
|
//
|
|
if ((DataSize == AUTHINFO_SIZE) && IsPk) {
|
|
UpdatePlatformMode (VirtualMode, Global, SETUP_MODE);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
Status = UpdateVariable (VariableName, VendorGuid, Data, DataSize, Attributes, 0, 0, VirtualMode, Global, Variable);
|
|
//
|
|
// If enroll PK in setup mode, need change to user mode.
|
|
//
|
|
if ((DataSize != 0) && IsPk) {
|
|
UpdatePlatformMode (VirtualMode, Global, USER_MODE);
|
|
}
|
|
}
|
|
|
|
return Status;
|
|
}
|
|
|
|
/**
|
|
Process variable with key exchange key for verification.
|
|
|
|
@param[in] VariableName The name of Variable to be found.
|
|
@param[in] VendorGuid The variable vendor GUID.
|
|
@param[in] Data The data pointer.
|
|
@param[in] DataSize The size of Data found. If size is less than the
|
|
data, this value contains the required size.
|
|
@param[in] VirtualMode The current calling mode for this function.
|
|
@param[in] Global The context of this Extended SAL Variable Services Class call.
|
|
@param[in] Variable The variable information which is used to keep track of variable usage.
|
|
@param[in] Attributes The attribute value of the variable.
|
|
|
|
@retval EFI_INVALID_PARAMETER Invalid parameter.
|
|
@retval EFI_SECURITY_VIOLATION The variable did NOT pass the validation
|
|
check carried out by the firmware.
|
|
@retval EFI_SUCCESS The variable passed validation successfully.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
ProcessVarWithKek (
|
|
IN CHAR16 *VariableName,
|
|
IN EFI_GUID *VendorGuid,
|
|
IN VOID *Data,
|
|
IN UINTN DataSize,
|
|
IN BOOLEAN VirtualMode,
|
|
IN ESAL_VARIABLE_GLOBAL *Global,
|
|
IN VARIABLE_POINTER_TRACK *Variable,
|
|
IN UINT32 Attributes OPTIONAL
|
|
)
|
|
{
|
|
EFI_STATUS Status;
|
|
VARIABLE_POINTER_TRACK KekVariable;
|
|
EFI_SIGNATURE_LIST *KekList;
|
|
EFI_SIGNATURE_DATA *KekItem;
|
|
UINT32 KekCount;
|
|
EFI_VARIABLE_AUTHENTICATION *CertData;
|
|
EFI_CERT_BLOCK_RSA_2048_SHA256 *CertBlock;
|
|
BOOLEAN IsFound;
|
|
UINT32 Index;
|
|
VARIABLE_HEADER VariableHeader;
|
|
BOOLEAN Valid;
|
|
|
|
KekList = NULL;
|
|
|
|
if (mPlatformMode == USER_MODE) {
|
|
if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) == 0) {
|
|
//
|
|
// In user mode, should set EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS attribute.
|
|
//
|
|
return EFI_INVALID_PARAMETER;
|
|
}
|
|
|
|
CertData = (EFI_VARIABLE_AUTHENTICATION *) Data;
|
|
CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) (CertData->AuthInfo.CertData);
|
|
if (Variable->CurrPtr != 0x0) {
|
|
Valid = IsValidVariableHeader (
|
|
Variable->CurrPtr,
|
|
Variable->Volatile,
|
|
&Global->VariableGlobal[VirtualMode],
|
|
Global->FvbInstance,
|
|
&VariableHeader
|
|
);
|
|
ASSERT (Valid);
|
|
|
|
if (CertData->MonotonicCount <= VariableHeader.MonotonicCount) {
|
|
//
|
|
// Monotonic count check fail, suspicious replay attack, return EFI_SECURITY_VIOLATION.
|
|
//
|
|
return EFI_SECURITY_VIOLATION;
|
|
}
|
|
}
|
|
//
|
|
// Get KEK database from variable.
|
|
//
|
|
Status = FindVariable (
|
|
Global->VariableName[VirtualMode][VAR_KEY_EXCHANGE_KEY],
|
|
Global->GlobalVariableGuid[VirtualMode],
|
|
&KekVariable,
|
|
&Global->VariableGlobal[VirtualMode],
|
|
Global->FvbInstance
|
|
);
|
|
ASSERT_EFI_ERROR (Status);
|
|
|
|
ZeroMem (Global->KeyList, MAX_KEYDB_SIZE);
|
|
GetVariableDataPtr (
|
|
KekVariable.CurrPtr,
|
|
KekVariable.Volatile,
|
|
&Global->VariableGlobal[VirtualMode],
|
|
Global->FvbInstance,
|
|
(CHAR16 *) Global->KeyList
|
|
);
|
|
//
|
|
// Enumerate all Kek items in this list to verify the variable certificate data.
|
|
// If anyone is authenticated successfully, it means the variable is correct!
|
|
//
|
|
KekList = (EFI_SIGNATURE_LIST *) Global->KeyList;
|
|
IsFound = FALSE;
|
|
KekCount = (KekList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - KekList->SignatureHeaderSize) / KekList->SignatureSize;
|
|
KekItem = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekList + sizeof (EFI_SIGNATURE_LIST) + KekList->SignatureHeaderSize);
|
|
for (Index = 0; Index < KekCount; Index++) {
|
|
if (CompareMem (KekItem->SignatureData, CertBlock->PublicKey, EFI_CERT_TYPE_RSA2048_SIZE) == 0) {
|
|
IsFound = TRUE;
|
|
break;
|
|
}
|
|
KekItem = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekItem + KekList->SignatureSize);
|
|
}
|
|
|
|
if (!IsFound) {
|
|
return EFI_SECURITY_VIOLATION;
|
|
}
|
|
|
|
Status = VerifyDataPayload (VirtualMode, Global, Data, DataSize, CertBlock->PublicKey);
|
|
if (!EFI_ERROR (Status)) {
|
|
Status = UpdateVariable (
|
|
VariableName,
|
|
VendorGuid,
|
|
(UINT8*)Data + AUTHINFO_SIZE,
|
|
DataSize - AUTHINFO_SIZE,
|
|
Attributes,
|
|
0,
|
|
CertData->MonotonicCount,
|
|
VirtualMode,
|
|
Global,
|
|
Variable
|
|
);
|
|
}
|
|
} else {
|
|
//
|
|
// If in setup mode, no authentication needed.
|
|
//
|
|
Status = UpdateVariable (
|
|
VariableName,
|
|
VendorGuid,
|
|
Data,
|
|
DataSize,
|
|
Attributes,
|
|
0,
|
|
0,
|
|
VirtualMode,
|
|
Global,
|
|
Variable
|
|
);
|
|
}
|
|
|
|
return Status;
|
|
}
|
|
|
|
/**
|
|
Process variable with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set, and return the index of associated public key.
|
|
|
|
@param[in] Data The data pointer.
|
|
@param[in] DataSize The size of Data found. If size is less than the
|
|
data, this value contains the required size.
|
|
@param[in] VirtualMode The current calling mode for this function.
|
|
@param[in] Global The context of this Extended SAL Variable Services Class call.
|
|
@param[in] Variable The variable information which is used to keep track of variable usage.
|
|
@param[in] Attributes The attribute value of the variable.
|
|
@param[out] KeyIndex The output index of corresponding public key in database.
|
|
@param[out] MonotonicCount The output value of corresponding Monotonic Count.
|
|
|
|
@retval EFI_INVALID_PARAMETER Invalid parameter.
|
|
@retval EFI_WRITE_PROTECTED The variable is write-protected and needs authentication with
|
|
EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set.
|
|
@retval EFI_SECURITY_VIOLATION The variable is with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
|
|
set, but the AuthInfo does NOT pass the validation
|
|
check carried out by the firmware.
|
|
@retval EFI_SUCCESS The variable is not write-protected, or passed validation successfully.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
VerifyVariable (
|
|
IN VOID *Data,
|
|
IN UINTN DataSize,
|
|
IN BOOLEAN VirtualMode,
|
|
IN ESAL_VARIABLE_GLOBAL *Global,
|
|
IN VARIABLE_POINTER_TRACK *Variable,
|
|
IN UINT32 Attributes OPTIONAL,
|
|
OUT UINT32 *KeyIndex OPTIONAL,
|
|
OUT UINT64 *MonotonicCount OPTIONAL
|
|
)
|
|
{
|
|
EFI_STATUS Status;
|
|
BOOLEAN IsDeletion;
|
|
BOOLEAN IsFirstTime;
|
|
UINT8 *PubKey;
|
|
EFI_VARIABLE_AUTHENTICATION *CertData;
|
|
EFI_CERT_BLOCK_RSA_2048_SHA256 *CertBlock;
|
|
VARIABLE_HEADER VariableHeader;
|
|
BOOLEAN Valid;
|
|
|
|
CertData = NULL;
|
|
CertBlock = NULL;
|
|
PubKey = NULL;
|
|
IsDeletion = FALSE;
|
|
Valid = FALSE;
|
|
|
|
if (KeyIndex != NULL) {
|
|
*KeyIndex = 0;
|
|
}
|
|
//
|
|
// Determine if first time SetVariable with the EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS.
|
|
//
|
|
ZeroMem (&VariableHeader, sizeof (VARIABLE_HEADER));
|
|
if (Variable->CurrPtr != 0x0) {
|
|
Valid = IsValidVariableHeader (
|
|
Variable->CurrPtr,
|
|
Variable->Volatile,
|
|
&Global->VariableGlobal[VirtualMode],
|
|
Global->FvbInstance,
|
|
&VariableHeader
|
|
);
|
|
ASSERT (Valid);
|
|
}
|
|
|
|
if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {
|
|
if (KeyIndex == NULL) {
|
|
return EFI_INVALID_PARAMETER;
|
|
}
|
|
|
|
//
|
|
// Determine current operation type.
|
|
//
|
|
if (DataSize == AUTHINFO_SIZE) {
|
|
IsDeletion = TRUE;
|
|
}
|
|
//
|
|
// Determine whether this is the first time with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set.
|
|
//
|
|
if (Variable->CurrPtr == 0x0) {
|
|
IsFirstTime = TRUE;
|
|
} else if (Valid &&(VariableHeader.Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) == 0) {
|
|
IsFirstTime = TRUE;
|
|
} else {
|
|
*KeyIndex = VariableHeader.PubKeyIndex;
|
|
IsFirstTime = FALSE;
|
|
}
|
|
} else if (Valid && (VariableHeader.Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {
|
|
//
|
|
// If the variable is already write-protected, it always needs authentication before update.
|
|
//
|
|
return EFI_WRITE_PROTECTED;
|
|
} else {
|
|
//
|
|
// If without EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, set and attributes collision.
|
|
// That means it is not authenticated variable, just return EFI_SUCCESS.
|
|
//
|
|
return EFI_SUCCESS;
|
|
}
|
|
|
|
//
|
|
// Get PubKey and check Monotonic Count value corresponding to the variable.
|
|
//
|
|
CertData = (EFI_VARIABLE_AUTHENTICATION *) Data;
|
|
CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) (CertData->AuthInfo.CertData);
|
|
PubKey = CertBlock->PublicKey;
|
|
|
|
if (MonotonicCount != NULL) {
|
|
//
|
|
// Update Monotonic Count value.
|
|
//
|
|
*MonotonicCount = CertData->MonotonicCount;
|
|
}
|
|
|
|
if (!IsFirstTime) {
|
|
//
|
|
// Check input PubKey.
|
|
//
|
|
if (CompareMem (PubKey, Global->PubKeyStore + (*KeyIndex - 1) * EFI_CERT_TYPE_RSA2048_SIZE, EFI_CERT_TYPE_RSA2048_SIZE) != 0) {
|
|
return EFI_SECURITY_VIOLATION;
|
|
}
|
|
//
|
|
// Compare the current monotonic count and ensure that it is greater than the last SetVariable
|
|
// operation with the EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS attribute set.
|
|
//
|
|
if (CertData->MonotonicCount <= VariableHeader.MonotonicCount) {
|
|
//
|
|
// Monotonic count check fail, suspicious replay attack, return EFI_SECURITY_VIOLATION.
|
|
//
|
|
return EFI_SECURITY_VIOLATION;
|
|
}
|
|
}
|
|
//
|
|
// Verify the certificate in Data payload.
|
|
//
|
|
Status = VerifyDataPayload (VirtualMode, Global, Data, DataSize, PubKey);
|
|
if (!EFI_ERROR (Status)) {
|
|
//
|
|
// Now, the signature has been verified!
|
|
//
|
|
if (IsFirstTime && !IsDeletion) {
|
|
//
|
|
// Update public key database variable if need and return the index.
|
|
//
|
|
*KeyIndex = AddPubKeyInStore (VirtualMode, Global, PubKey);
|
|
}
|
|
}
|
|
|
|
return Status;
|
|
}
|
|
|