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Windows: Fix rare cases being stuck in Secure Desktop after it is used for password entry

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Cause seems to be IME as documented in KeePass project (https://keepass.info/help/kb/sec_desk.html#ime). We use the same approach as KeePass to disable IME in Secure Desktop.
This commit also add few changes:
  - we switch to secure desktop only if SetThreadDesktop succeeds
  - we call SwitchDesktop to switch to original desktop only if we actually succeeded in displaying secure desktop
This commit is contained in:
Mounir IDRASSI
2024-08-04 10:25:12 +02:00
parent 71215f1a25
commit c8b9a73916
1 changed files with 40 additions and 20 deletions
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36
src/Common/Dlgcode.c
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@@ -13921,6 +13921,23 @@ static unsigned int __stdcall SecureDesktopThread( LPVOID lpThreadParameter )
StringCbCopy(SecureDesktopName, sizeof (SecureDesktopName), pParam->szDesktopName); StringCbCopy(SecureDesktopName, sizeof (SecureDesktopName), pParam->szDesktopName);
pParam->hDesk = hSecureDesk; pParam->hDesk = hSecureDesk;
bNewDesktopSet = SetThreadDesktop (hSecureDesk);
if (bNewDesktopSet)
{
// call ImmDisableIME　from imm32.dll to disable IME since it can create issue with secure desktop
// cf: https://keepass.info/help/kb/sec_desk.html#ime
HMODULE hImmDll = LoadLibraryEx (L"imm32.dll", NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
if (hImmDll)
{
typedef BOOL (WINAPI *ImmDisableIME_t)(DWORD);
ImmDisableIME_t ImmDisableIME = (ImmDisableIME_t) GetProcAddress (hImmDll, "ImmDisableIME");
if (ImmDisableIME)
{
ImmDisableIME (0);
}
}
// wait for SwitchDesktop to succeed before using it for current thread // wait for SwitchDesktop to succeed before using it for current thread
while (true) while (true)
{ {
@@ -13931,10 +13948,6 @@ static unsigned int __stdcall SecureDesktopThread( LPVOID lpThreadParameter )
Sleep (SECUREDESKTOP_MONOTIR_PERIOD); Sleep (SECUREDESKTOP_MONOTIR_PERIOD);
} }
bNewDesktopSet = SetThreadDesktop (hSecureDesk);
if (bNewDesktopSet)
{
// create the thread that will ensure that VeraCrypt secure desktop has always user input // create the thread that will ensure that VeraCrypt secure desktop has always user input
// this is done only if the stop event is created successfully // this is done only if the stop event is created successfully
HANDLE hStopEvent = CreateEvent(NULL, TRUE, FALSE, NULL); HANDLE hStopEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
@@ -13964,6 +13977,12 @@ static unsigned int __stdcall SecureDesktopThread( LPVOID lpThreadParameter )
} }
pParam->bDlgDisplayed = TRUE; pParam->bDlgDisplayed = TRUE;
// free imm32.dll handle
if (hImmDll)
{
FreeLibrary (hImmDll);
}
} }
else else
{ {
@@ -14084,20 +14103,21 @@ INT_PTR SecureDesktopDialogBoxParam(
// dialog box was indeed displayed in Secure Desktop // dialog box was indeed displayed in Secure Desktop
retValue = param.retValue; retValue = param.retValue;
bSuccess = TRUE; bSuccess = TRUE;
}
}
if (param.hDesk) // switch back to the original desktop
{
while (!SwitchDesktop (hOriginalDesk)) while (!SwitchDesktop (hOriginalDesk))
{ {
Sleep (SECUREDESKTOP_MONOTIR_PERIOD); Sleep (SECUREDESKTOP_MONOTIR_PERIOD);
} }
SetThreadDesktop (hOriginalDesk); SetThreadDesktop (hOriginalDesk);
}
if (param.hDesk)
{
CloseDesktop (param.hDesk); CloseDesktop (param.hDesk);
} }
}
// get the new list of ctfmon.exe processes in order to find the ID of the // get the new list of ctfmon.exe processes in order to find the ID of the
// ctfmon.exe instance that corresponds to the desktop we create so that // ctfmon.exe instance that corresponds to the desktop we create so that