Creating a Null DACL

The following pseudocode creates a mutex with a null DACL.

If you are creating one of these objects in an application and the object will be shared with a service, you could also use a null DACL to grant everyone access. As an alternative, you could add an access-control entry (ACE) to the DACL that grants access to the user account that the service is running under. This would restrict access to the object to the service.

PSECURITY_DESCRIPTOR pSD; 
SECURITY_ATTRIBUTES sa; 

pSD = (PSECURITY_DESCRIPTOR) LocalAlloc(LPTR,
      SECURITY_DESCRIPTOR_MIN_LENGTH); 

if (pSD == NULL)
   Error(...); 

if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION))
   Error(...); 

// Add a null DACL to the security descriptor. 
if (!SetSecurityDescriptorDacl(pSD, TRUE, (PACL) NULL, FALSE))
    Error(...);

sa.nLength = sizeof(sa); 
sa.lpSecurityDescriptor = pSD;
sa.bInheritHandle = TRUE; 
mutex = CreateMutex(&sa, FALSE, "SOMENAME");