Windows: Update EFI NVRAM variable only if changed or doesn't exist and add configuration to force setting EFI BootNext to veraCrypt bootloader before each shutdown

This commit is contained in:
Mounir IDRASSI 2019-10-26 22:49:37 +02:00
parent f22abf93dd
commit ca46cf928a
No known key found for this signature in database
GPG Key ID: 02C30AE90FAE4A6F
3 changed files with 27 additions and 12 deletions

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@ -1030,7 +1030,7 @@ namespace VeraCrypt
static EfiBoot EfiBootInst;
BootEncryption::BootEncryption (HWND parent, bool postOOBE)
BootEncryption::BootEncryption (HWND parent, bool postOOBE, bool setBootNext)
: DriveConfigValid (false),
ParentWindow (parent),
RealSystemDriveSizeValid (false),
@ -1041,7 +1041,8 @@ namespace VeraCrypt
SelectedEncryptionAlgorithmId (0),
SelectedPrfAlgorithmId (0),
VolumeHeaderValid (false),
PostOOBEMode (postOOBE)
PostOOBEMode (postOOBE),
SetBootNext (setBootNext)
{
HiddenOSCandidatePartition.IsGPT = FALSE;
HiddenOSCandidatePartition.Number = (size_t) -1;
@ -2693,7 +2694,7 @@ namespace VeraCrypt
}
}
void EfiBoot::SetStartExec(wstring description, wstring execPath, uint16 statrtOrderNum , wchar_t* type, uint32 attr) {
void EfiBoot::SetStartExec(wstring description, wstring execPath, bool setBootNext, uint16 statrtOrderNum , wchar_t* type, uint32 attr) {
SetPrivilege(SE_SYSTEM_ENVIRONMENT_NAME, TRUE);
// Check EFI
if (!IsEfiBoot()) {
@ -2783,8 +2784,14 @@ namespace VeraCrypt
// Set variable
wchar_t varName[256];
StringCchPrintfW(varName, ARRAYSIZE (varName), L"%s%04X", type == NULL ? L"Boot" : type, statrtOrderNum);
// only set value if it doesn't already exist
byte* existingVar = new byte[varSize];
DWORD existingVarLen = GetFirmwareEnvironmentVariableW (varName, EfiVarGuid, existingVar, varSize);
if ((existingVarLen != varSize) || (0 != memcmp (existingVar, startVar, varSize)))
SetFirmwareEnvironmentVariable(varName, EfiVarGuid, startVar, varSize);
delete [] startVar;
delete [] existingVar;
// Update order
wstring order = L"Order";
@ -2821,6 +2828,8 @@ namespace VeraCrypt
SetFirmwareEnvironmentVariable(order.c_str(), EfiVarGuid, startOrder, startOrderLen);
}
if (setBootNext)
{
// set BootNext value
wstring next = L"Next";
next.insert(0, type == NULL ? L"Boot" : type);
@ -2828,6 +2837,7 @@ namespace VeraCrypt
SetFirmwareEnvironmentVariable(next.c_str(), EfiVarGuid, &statrtOrderNum, 2);
}
}
bool EfiBoot::CompareFiles (const wchar_t* fileName1, const wchar_t* fileName2)
{
@ -3329,7 +3339,7 @@ namespace VeraCrypt
// restore boot menu entry in case of PostOOBE
if (PostOOBEMode)
EfiBootInst.SetStartExec(L"VeraCrypt BootLoader (DcsBoot)", L"\\EFI\\VeraCrypt\\DcsBoot.efi");
EfiBootInst.SetStartExec(L"VeraCrypt BootLoader (DcsBoot)", L"\\EFI\\VeraCrypt\\DcsBoot.efi", SetBootNext);
if (EfiBootInst.FileExists (L"\\EFI\\Microsoft\\Boot\\bootmgfw_ms.vc"))
{

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@ -205,7 +205,7 @@ namespace VeraCrypt
bool IsEfiBoot();
void DeleteStartExec(uint16 statrtOrderNum = 0xDC5B, wchar_t* type = NULL);
void SetStartExec(wstring description, wstring execPath, uint16 statrtOrderNum = 0xDC5B, wchar_t* type = NULL, uint32 attr = 1);
void SetStartExec(wstring description, wstring execPath, bool setBootNext = true, uint16 statrtOrderNum = 0xDC5B, wchar_t* type = NULL, uint32 attr = 1);
void SaveFile(const wchar_t* name, byte* data, DWORD size);
void GetFileSize(const wchar_t* name, unsigned __int64& size);
void ReadFile(const wchar_t* name, byte* data, DWORD size);
@ -237,7 +237,7 @@ namespace VeraCrypt
class BootEncryption
{
public:
BootEncryption (HWND parent, bool postOOBE = false);
BootEncryption (HWND parent, bool postOOBE = false, bool setBootNext = false);
~BootEncryption ();
enum FilterType
@ -349,6 +349,7 @@ namespace VeraCrypt
bool RescueVolumeHeaderValid;
bool VolumeHeaderValid;
bool PostOOBEMode;
bool SetBootNext;
};
}
@ -366,6 +367,7 @@ namespace VeraCrypt
#define VC_SYSTEM_FAVORITES_SERVICE_ARG_SKIP_MOUNT L"/SkipMount"
#define VC_SYSTEM_FAVORITES_SERVICE_CONFIG_DONT_UPDATE_LOADER 0x1
#define VC_SYSTEM_FAVORITES_SERVICE_CONFIG_FORCE_SET_BOOTNEXT 0x2
#define VC_WINDOWS_UPGRADE_POSTOOBE_CMDLINE_OPTION L"/PostOOBE"

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@ -9430,7 +9430,10 @@ static DWORD WINAPI SystemFavoritesServiceCtrlHandler ( DWORD dwControl,
if (!BootEncStatus.HiddenSystem)
{
// re-install our bootloader again in case the update process has removed it.
BootEncryption bootEnc (NULL, true);
bool bForceSetNextBoot = false;
if (BootEncObj->ReadServiceConfigurationFlags () & VC_SYSTEM_FAVORITES_SERVICE_CONFIG_FORCE_SET_BOOTNEXT)
bForceSetNextBoot = true;
BootEncryption bootEnc (NULL, true, bForceSetNextBoot);
bootEnc.InstallBootLoader (true);
}
}