The ADT_SECURITY_DESCRIPTOR structure contains a security descriptor in self-relative format and a value that includes the length of the buffer that contains the descriptor. For more information, see [MS-DTYP] section 2.4.6.

 typedef struct _ADT_SECURITY_DESCRIPTOR {
   DWORD Length;
   [size_is(Length)] unsigned char* Buffer;
 } ADT_SECURITY_DESCRIPTOR,
  *PADT_SECURITY_DESCRIPTOR;

Length: The length of the Buffer member.

Buffer: A buffer for the security descriptor in self-relative form. For more information, see [MS-DTYP] section 2.4.6.