GetSidSubAuthority function (securitybaseapi.h)

Article
02/22/2024

The GetSidSubAuthority function returns a pointer to a specified subauthority in a security identifier (SID). The subauthority value is a relative identifier (RID).

Syntax

PDWORD GetSidSubAuthority(
  [in] PSID  pSid,
  [in] DWORD nSubAuthority
);

Parameters

[in] pSid

A pointer to the SID structure from which a pointer to a subauthority is to be returned.

This function does not handle SID structures that are not valid. Call the IsValidSid function to verify that the SID structure is valid before you call this function.

[in] nSubAuthority

Specifies an index value identifying the subauthority array element whose address the function will return. The function performs no validation tests on this value. An application can call the GetSidSubAuthorityCount function to discover the range of acceptable values.

Return value

If the function succeeds, the return value is a pointer to the specified SID subauthority. To get extended error information, call GetLastError.

If the function fails, the return value is undefined. The function fails if the specified SID structure is not valid or if the index value specified by the nSubAuthority parameter is out of bounds.

Remarks

The SID structure specified in pSid uses a 32-bit RID value. For applications that require longer RID values, use CreateWellKnownSid and related functions.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2003 [desktop apps \| UWP apps]
Target Platform	Windows
Header	securitybaseapi.h (include Windows.h)
Library	Advapi32.lib
DLL	Advapi32.dll