problems sharing folder for a specific user   

I'm having trouble sharing a specific folder with set of rights for
specific user account. Can anyone shed some light on this, unclear to
me, issue?

Here is the code I use:

#include <windows.h>
#include <tchar.h>
#include <comdef.h>
#include <lm.h>
#include <aclapi.h>
#include <string>

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

typedef std::basic_string<_TCHAR> tstring;

bool getUserSid(LPCTSTR user, PSID &sid) {
      DWORD sidsize = 0UL;
      TCHAR domain[256] = {};
      DWORD domainsize = 0UL;
      SID_NAME_USE use;
      BOOL ret = ::LookupAccountName(  NULL
                                       ,user
                                       ,NULL
                                       ,&sidsize
                                       ,NULL
                                       ,&domainsize
                                       ,&use
                                    );
      DWORD er = ::GetLastError();
      _com_error errt(HRESULT_FROM_WIN32(er));
      OutputDebugString(errt.ErrorMessage());
      sid = static_cast<PSID>(::LocalAlloc(LMEM_ZEROINIT,sidsize));
      ret = ::LookupAccountName(  NULL
                                  ,user
                                  ,sid
                                  ,&sidsize
                                  ,&domain[0]
                                  ,&domainsize
                                  ,&use
                               );
      er = ::GetLastError();
      _com_error err2(HRESULT_FROM_WIN32(er));
      OutputDebugString(err2.ErrorMessage());
      return (ret == TRUE);
}


bool ShareFolderForUser(const std::wstring& path,
const tstring& user, const std::wstring& shareName
, const DWORD perms) {
      bool result = true;

      PSID userSID = NULL;
      if (!getUserSid(user.c_str(),userSID) && !IsValidSid(userSID)) {
          ::LocalFree(userSID); userSID = NULL; (userSID);
          return result;
      }

      EXPLICIT_ACCESS ea[1] = {};
      ea[0].grfAccessPermissions = perms;
      ea[0].grfAccessMode = SET_ACCESS;
      ea[0].grfInheritance = NO_INHERITANCE;
      ea[0].Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
      ea[0].Trustee.TrusteeType = TRUSTEE_IS_USER;
      ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
      ea[0].Trustee.ptstrName = static_cast<LPTSTR>(userSID);

      PACL pACL = NULL;
      DWORD dwRes = SetEntriesInAcl(1, ea, NULL, &pACL);
      if (ERROR_SUCCESS != dwRes) {
          ::LocalFree(userSID); userSID = NULL; (userSID);
          return result;
      }

      PSECURITY_DESCRIPTOR pdesc =
static_cast<PSECURITY_DESCRIPTOR>(LocalAlloc(LPTR,SECURITY_DESCRIPTOR_MIN_LENGTH));
      if (NULL == pdesc) {
          ::LocalFree(userSID); userSID = NULL; (userSID);
          return result;
      }
      if ( !( InitializeSecurityDescriptor(pdesc,
SECURITY_DESCRIPTOR_REVISION)
             && SetSecurityDescriptorDacl(pdesc,TRUE,pACL,FALSE) ) )  {
          ::LocalFree(pACL); pACL = NULL; (pACL);
          ::LocalFree(userSID); userSID = NULL; (userSID);
          return result;
      }

      SECURITY_ATTRIBUTES sa = {sizeof(SECURITY_ATTRIBUTES), pdesc, FALSE};

      SHARE_INFO_502 p = {};
      p.shi502_netname = const_cast<LPWSTR>(shareName.c_str());
      p.shi502_type = STYPE_DISKTREE;
      p.shi502_path = const_cast<LPWSTR>(path.c_str());
      p.shi502_remark = L"";
      p.shi502_max_uses = static_cast<DWORD>(-1);
      p.shi502_permissions = perms;
      p.shi502_security_descriptor = &sa;
      DWORD er = 0UL;
      NET_API_STATUS nst = ::NetShareAdd(  NULL
                                          ,502UL
                                          ,reinterpret_cast<LPBYTE>(&p)
                                          ,&er
                                          );
      result = (nst == NERR_Success);
      if (!result) {
          _com_error e(HRESULT_FROM_WIN32(nst));
          OutputDebugString(e.ErrorMessage());
          if ( er == SHARE_FILE_SD_PARMNUM) {
              OutputDebugString(_T("\nInvalid Security Descriptor"));
          }
      }

      ::LocalFree(pACL); pACL = NULL; (pACL);
      ::LocalFree(pdesc); pdesc = NULL; (pdesc);
      ::LocalFree(userSID); userSID = NULL; (userSID);
      return result;
}


int main() {
    	ShareFolderForUser( L"C:\\data\\trt"
                              ,"<somevalidaccount>"
                              ,L"trt"
                              ,ACCESS_ALL);

     return 0;
}

date: Sun, 24 Aug 2008 14:39:51 -0300   author:   Darko Miletic