RtlCreateServiceSid - NtDoc

#ifndef _NTRTL_H
#if (PHNT_VERSION >= PHNT_VISTA)

NTSYSAPI
NTSTATUS
NTAPI
RtlCreateServiceSid(
    _In_ PUNICODE_STRING ServiceName,
    _Out_writes_bytes_opt_(*ServiceSidLength) PSID ServiceSid,
    _Inout_ PULONG ServiceSidLength
    );

#endif
#endif
View code on GitHub