Win32 Security in Managed C++

Listing 5 Extract from AccessToken.cpp

SID *AccessToken::get_User()
{
  if(0 == m_user)
  {
    token_information<TokenUser>  user(m_hToken);

    if(!user)
    {
      throw new SecurityException(::GetLastError());
    }
    else
    {
      m_user = new SID(user->User.Sid);
    }
  }

  return m_user;
}

GroupList *AccessToken::get_Groups()
{
  if(0 == m_groups)
  {
    m_groups = _get_groups(TokenGroups);
  }

  return m_groups;
}

GroupList *AccessToken::get_RestrictedSIDs()
{
  if(0 == m_restrictedSIDs)
  {
    m_restrictedSIDs = _get_groups(TokenRestrictedSids);
  }

  return m_restrictedSIDs;
}

PrivilegeList *AccessToken::get_Privileges()
{
  if(0 == m_privileges)
  {
    winstl::token_information<TokenPrivileges>  privileges(m_hToken);

    if(!privileges)
    {
      throw new SecurityException(::GetLastError());
    }
    else
    {
      m_privileges = new PrivilegeList(privileges->PrivilegeCount, 		   privileges->Privileges);
    }

    return m_privileges;
  }

  return m_privileges;
}

TokenType AccessToken::get_Type()
{
  TOKEN_TYPE  tt;
  DWORD       chRequired;

  if(!::GetTokenInformation(m_hToken, ::TokenType, 	           &tt, sizeof(tt), &chRequired))
  {
    throw new SecurityException(::GetLastError(), 	           "Could not elicit type from token");
  }

  return TokenType(tt);
}

GroupList *AccessToken::_get_groups(TOKEN_INFORMATION_CLASS tic)
{
  GroupList *grouplist;
  DWORD     cbRequired;
  DWORD     dwErr;

  stlsoft_assert(tic == TokenGroups || tic == TokenRestrictedSids);

  ::GetTokenInformation(m_hToken, tic, NULL, 0, &cbRequired);
  dwErr = ::GetLastError();

  if(ERROR_INSUFFICIENT_BUFFER != dwErr)
  {
    throw new SecurityException(dwErr);
  }
  else
  {
    TOKEN_GROUPS  *groups = static_cast<TOKEN_GROUPS*>(Sec_Alloc(cbRequired));

    if(!::GetTokenInformation(m_hToken, tic, groups, cbRequired, &cbRequired))
    {
      throw new SecurityException(::GetLastError());
    }
    else
    {
      try
      {
        grouplist = new GroupList(groups->GroupCount, groups->Groups);
      }
      catch(Exception *x)
      {
        Sec_Free(groups);

        throw x;
      }
    }
  }

  return grouplist;
}