The LSAPR_SID_INFORMATION structure contains a PRPC_SID value.

 typedef struct _LSAPR_SID_INFORMATION {
   PRPC_SID Sid;
 } LSAPR_SID_INFORMATION,
  *PLSAPR_SID_INFORMATION;

Sid: Contains the PRPC_SID value, as specified in [MS-DTYP] section 2.4.2.3. This field MUST be non-NULL.