Identifying Self-Registering Servers

Applications need to check to see if a given server module is self-registering without actually loading the .DLL or .EXE for performance reasons and to avoid possible negative side-affects of code within the module being executed without the module first being registered. To accomplish this, the .DLL or .EXE must be tagged with a version resource that can be read without actually causing any code in the module to be executed. On Windows platforms, this involves using the version resource to hold a self-registration keyword. Since the VERSIONINFO section is fixed and cannot be easily extended, the following string is added to the StringFileInfo, with an empty key value:

VALUE "OLESelfRegister", ""

For example:

VS_VERSION_INFO     VERSIONINFO
  FILEVERSION       1,0,0,1
  PRODUCTVERSION    1,0,0,1
  FILEFLAGSMASK     VS_FFI_FILEFLAGSMASK
#ifdef _DEBUG
  FILEFLAGS         VS_FF_DEBUG|VS_FF_PRIVATEBUILD|VS_FF_PRERELEASE
#else
  FILEFLAGS         0 // final version
#endif
  FILEOS            VOS_DOS_WINDOWS16
  FILETYPE          VFT_APP
  FILESUBTYPE       0   // not used
BEGIN
  BLOCK "StringFileInfo"
  BEGIN
    BLOCK "040904E4" // Lang=US English, CharSet=Windows Multilingual
    BEGIN
    VALUE "CompanyName",     "\0"
    VALUE "FileDescription", "BUTTON OLE Control DLL\0"
    VALUE "FileVersion",     "1.0.001\0"
    VALUE "InternalName",    "BUTTON\0"
    VALUE "LegalCopyright",  "\0"
    VALUE "LegalTrademarks", "\0"
    VALUE "OriginalFilename","BUTTON.DLL\0"
    VALUE "ProductName",     "BUTTON\0"
    VALUE "ProductVersion",  "1.0.001\0"
    VALUE "OLESelfRegister", "" // New keyword
    END
  END
  BLOCK "VarFileInfo"
  BEGIN
    VALUE "Translation", 0x409, 1252
  END
END

To support self-registering servers, an application can add a browse button to its object selection user interface, which pops up a standard File.Open dialog. After the user chooses a .DLL or .EXE the application can check to see if it is marked for self-registration and, if so, call its DllRegisterServer entry point (or execute the .EXE with the /REGSERVER command line switch). The .DLL or .EXE should register itself at this point.