(******************************************************************************)
(* SPGetSid - Retrieve the current user's SID in text format *)
(* *)
(* Copyright (c) 2004 Shorter Path Software *)
(* http://www.shorterpath.com *)
(******************************************************************************)
{
SID is a data structure of variable length that identifies user, group,
and computer accounts.
Every account on a network is issued a unique SID when the account is first created.
Internal processes in Windows refer to an account's SID
rather than the account's user or group name.
}
unit SPGetSid;
interface
uses
Windows, SysUtils;
function GetCurrentUserSid: string;
implementation
const
HEAP_ZERO_MEMORY = $00000008;
SID_REVISION = 1; // Current revision level
type
PTokenUser = ^TTokenUser;
TTokenUser = packed record
User: TSidAndAttributes;
end;
function ConvertSid(Sid: PSID; pszSidText: PChar; var dwBufferLen: DWORD): BOOL;
var
psia: PSIDIdentifierAuthority;
dwSubAuthorities: DWORD;
dwSidRev: DWORD;
dwCounter: DWORD;
dwSidSize: DWORD;
begin
Result := False;
dwSidRev := SID_REVISION;
if not IsValidSid(Sid) then Exit;
psia := GetSidIdentifierAuthority(Sid);
dwSubAuthorities := GetSidSubAuthorityCount(Sid)^;
dwSidSize := (15 + 12 + (12 * dwSubAuthorities) + 1) * SizeOf(Char);
if (dwBufferLen < dwSidSize) then
begin
dwBufferLen := dwSidSize;
SetLastError(ERROR_INSUFFICIENT_BUFFER);
Exit;
end;
StrFmt(pszSidText, 'S-%u-', [dwSidRev]);
if (psia.Value[0] <> 0) or (psia.Value[1] <> 0) then
StrFmt(pszSidText + StrLen(pszSidText),
'0x%.2x%.2x%.2x%.2x%.2x%.2x',
[psia.Value[0], psia.Value[1], psia.Value[2],
psia.Value[3], psia.Value[4], psia.Value[5]])
else
StrFmt(pszSidText + StrLen(pszSidText),
'%u',
[DWORD(psia.Value[5]) +
DWORD(psia.Value[4] shl 8) +
DWORD(psia.Value[3] shl 16) +
DWORD(psia.Value[2] shl 24)]);
dwSidSize := StrLen(pszSidText);
for dwCounter := 0 to dwSubAuthorities - 1 do
begin
StrFmt(pszSidText + dwSidSize, '-%u',
[GetSidSubAuthority(Sid, dwCounter)^]);
dwSidSize := StrLen(pszSidText);
end;
Result := True;
end;
function ObtainTextSid(hToken: THandle; pszSid: PChar;
var dwBufferLen: DWORD): BOOL;
var
dwReturnLength: DWORD;
dwTokenUserLength: DWORD;
tic: TTokenInformationClass;
ptu: Pointer;
begin
Result := False;
dwReturnLength := 0;
dwTokenUserLength := 0;
tic := TokenUser;
ptu := nil;
if not GetTokenInformation(hToken, tic, ptu, dwTokenUserLength,
dwReturnLength) then
begin
if GetLastError = ERROR_INSUFFICIENT_BUFFER then
begin
ptu := HeapAlloc(GetProcessHeap, HEAP_ZERO_MEMORY, dwReturnLength);
if ptu = nil then Exit;
dwTokenUserLength := dwReturnLength;
dwReturnLength := 0;
if not GetTokenInformation(hToken, tic, ptu, dwTokenUserLength,
dwReturnLength) then Exit;
end
else
Exit;
end;
if not ConvertSid((PTokenUser(ptu).User).Sid, pszSid, dwBufferLen) then Exit;
if not HeapFree(GetProcessHeap, 0, ptu) then Exit;
Result := True;
end;
function GetCurrentUserSid: string;
var
hAccessToken: THandle;
bSuccess: BOOL;
dwBufferLen: DWORD;
szSid: array[0..260] of Char;
begin
Result := '';
bSuccess := OpenThreadToken(GetCurrentThread, TOKEN_QUERY, True,
hAccessToken);
if not bSuccess then
begin
if GetLastError = ERROR_NO_TOKEN then
bSuccess := OpenProcessToken(GetCurrentProcess, TOKEN_QUERY,
hAccessToken);
end;
if bSuccess then
begin
ZeroMemory(@szSid, SizeOf(szSid));
dwBufferLen := SizeOf(szSid);
if ObtainTextSid(hAccessToken, szSid, dwBufferLen) then
Result := szSid;
CloseHandle(hAccessToken);
end;
end;
end.
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