$tmp_file = tmpfile();
$tmp_file_path = stream_get_meta_data($tmp_file)['uri'];

$zip = new ZipArchive;
$res = $zip->open($tmp_file_path, ZipArchive::CREATE);

foreach ($ptah_p7s->Signs as $i => $sign) {
    $zip->addFromString("signature{$i}.p7s", base64_decode($sign));
}

$zip->close();

header('Content-type: application/zip');
header('Content-Disposition: attachment; filename="download.zip"');
echo(file_get_contents($tmp_file_path));