'Obtains client_key and client_secret credentials from current course.'

def get_client_key_secret(self):

    course = self.get_course()
    for lti_passport in course.lti_passports:
        try:
            (lti_id, key, secret) = [i.strip() for i in lti_passport.split(':')]
        except ValueError:
            _ = self.runtime.service(self, 'i18n').ugettext
            msg = _('Could    not    parse    LTI    passport:    {lti_passport}.    Should    be    "id:key:secret"    string.').format(lti_passport='{0!r}'.format(lti_passport))
            raise LTIError(msg)
        if (lti_id == self.lti_id.strip()):
            return (key, secret)
    return ('', '')
