1. FAQ o Win API

Q> Как определить,принадлежит ли юзер группе администраторов?
A> Два метода в одном флаконе:

#include <windows.h>
#include <stdio.h>
#include <lm.h>
#pragma hdrstop

#pragma comment( lib, "netapi32.lib" )

// My thanks to Jerry Coffin (  )
// for this much simpler method.
bool jerry_coffin_method()
{
 bool result;
 DWORD rc;
 wchar_t user_name[256];
 USER_INFO_1 *info;
 DWORD size = sizeof( user_name );

 GetUserNameW( user_name, &size);

 rc = NetUserGetInfo( NULL, user_name, 1, (byte **) &info );
 if ( rc != NERR_Success )
  return false;

 result = info->usri1_priv == USER_PRIV_ADMIN;

 NetApiBufferFree( info );
 return result;
}


bool look_at_token_method()
{
 int found;
 DWORD i, l;
 HANDLE hTok;
 PSID pAdminSid;
 SID_IDENTIFIER_AUTHORITY ntAuth = SECURITY_NT_AUTHORITY;

 byte rawGroupList[4096];
 TOKEN_GROUPS& groupList = *( (TOKEN_GROUPS *) rawGroupList );

 if ( ! OpenThreadToken( GetCurrentThread(), TOKEN_QUERY, FALSE, &hTok ) )
 {
  printf( "Cannot open thread token, trying process token [%lu].\n",
   GetLastError() );
  if ( ! OpenProcessToken( GetCurrentProcess(), TOKEN_QUERY, &hTok ) )
  {
   printf( "Cannot open process token, quitting [%lu].\n",
    GetLastError() );
   return 1;
  }
 }

 // normally, I should get the size of the group list first, but ...
 l = sizeof rawGroupList;
 if ( ! GetTokenInformation( hTok, TokenGroups, &groupList, l, &l ) )
 {
  printf( "Cannot get group list from token [%lu].\n",
   GetLastError() );
  return 1;
 }

 // here, we cobble up a SID for the Administrators group, to compare to.
 if ( ! AllocateAndInitializeSid( &ntAuth, 2, SECURITY_BUILTIN_DOMAIN_RID,
  DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0, 0, &pAdminSid ) )
 {
  printf( "Cannot create SID for Administrators [%lu].\n",
   GetLastError() );
  return 1;
 }

 // now, loop through groups in token and compare
 found = 0;
 for ( i = 0; i < groupList.GroupCount; ++ i )
 {
  if ( EqualSid( pAdminSid, groupList.Groups[i].Sid ) )
  {
   found = 1;
   break;
  }
 }

 FreeSid( pAdminSid );
 CloseHandle( hTok );
 return !!found;
}

int main()
{
 bool j, l;

 j = jerry_coffin_method();
 l = look_at_token_method();

 printf( "NetUserGetInfo(): The current user is %san Administrator.\n",
  j? "": "not " );
 printf( "Process token: The current user is %sa member of the Administrators
group.\n",
  l? "": "not " );

 return 0;
}