axtu-auth-client will save ak and tk into two files so that axtu can use them

ak /var/axtu/asianux-auth
tk /var/axtu/tmp/axTK19799

bool classAuthen::SetTk(void)

then axtu will read ak&tk by

if(m_clsAuth->GetAK(m_strUserId) && (m_clsAuth->GetDontGetTk()?true:m_clsAuth->GetTK(m_strUserPass))))
ak is pass to   m_strUserId
tk to           m_strUserPass

        m_clsDown->setUser(m_strUserId);
        m_clsDown->setPass(m_strUserPass);

then we see

const int user_max_length * 32;

const int pass_max_length * 16;//why 16 here, since tk is also 32 bit??

...
void classDownloader::setUser(string strUser)
{
        strncpy(opt.user,strUser.c_str(),user_max_length+1);
}

/-!
@brief A user Password is set.

To download the files from server protected by mod_auth_mysql.
@param strPass - user Password
-/
void classDownloader::setPass(string strPass)
{
        strncpy(opt.passwd,strPass.c_str(),pass_max_length+1);
}