Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 878
  • Last Modified:

GetUserName WinDDK

There is an example in WinDDK called WatermakrUni. this example add watermark for pcl printer. watermark text is taken from user via user interface of printer proporties.

 i want to get username from windows so ican put it on page as watermark. When I try to compile source code with  GetUserName function,  compiler gives no error or warning.

But when I install plug in  it crash instantaly. program say acces vialotion.  when it comes to executeion of GetUserName functions. i am sending source code which I edit it

example in the this directory \WinDDK\7600.16385.1\src\print\oemdll\watermarkuni

error message =  0xC0000005: Access violation reading location 0x00000208.

GetUserName((LPWSTR)pOEMUIParam->pOEMOptItems[1].pSel,(LPDWORD)(MAX_PATH * sizeof(WCHAR))); // this is the part I added
0
Tungaalper
Asked:
Tungaalper
1 Solution
 
sarabandeCommented:
access violation is cause the second argument of GetUserName is pointer to a long word that should take the length of the name. you made a cast of a constant to LPDWORD what crashes when the function assigns a value to the address the pointer is pointing to.

the statement also crashes if one of pOEMUIParam or pOEMUIParam->pOEMOptItems or pOEMUIParam->pOEMOptItems[1] or pOEMUIParam->pOEMOptItems[1].pSel  is invalid pointer or NULL.

i don't know why you use a so complicated variable for first argument of GetUserName which is simply a char or wchar_t buffer

so use

   TCHAR buffer[1024];
   DWORD len = sizeof(buffer) / sizeof(buffer[0]);
   BOOL ret = GetUserName(buffer, &len);

and it will work.

Sara
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now