def validate(self):
        '''Check if ofiles and ifiles match signatures recorded in md5file'''
        if 'TARGET' in env.config['SOS_DEBUG'] or 'ALL' in env.config['SOS_DEBUG']:
            env.log_to_file('TARGET', f'Validating {self.sig_id}')
        #
        # file not exist?
        sig_files = self.input_files._targets + self.output_files._targets + \
            self.dependent_files._targets
        for x in sig_files:
            if not x.target_exists('any'):
                return f'Missing target {x}'
        #
        sig = request_answer_from_controller(['step_sig', 'get', self.sig_id])
        if not sig:
            return f"No signature found for {self.sig_id}"
        return super(RuntimeInfo, self).validate(sig)
Check if ofiles and ifiles match signatures recorded in md5file