GPG_Utility::c_random PHP Method

    static function c_random()
    {
        return random_int(0, 0xff);
    }

 private function gpg_session($key_id, $key_type, $session_key, $public_key)
 {
     $mod = array();
     $exp = array();
     $enc = "";
     $s = base64_decode($public_key);
     $l = floor((ord($s[0]) * 256 + ord($s[1]) + 7) / 8);
     $mod = mpi2b(substr($s, 0, $l + 2));
     if ($key_type) {
         $grp = array();
         $y = array();
         $B = array();
         $C = array();
         $l2 = floor((ord($s[$l + 2]) * 256 + ord($s[$l + 3]) + 7) / 8) + 2;
         $grp = mpi2b(substr($s, $l + 2, $l2));
         $y = mpi2b(substr($s, $l + 2 + $l2));
         $exp[0] = $this->el[GPG_Utility::c_random() & 7];
         $B = bmodexp($grp, $exp, $mod);
         $C = bmodexp($y, $exp, $mod);
     } else {
         $exp = mpi2b(substr($s, $l + 2));
     }
     $c = 0;
     $lsk = strlen($session_key);
     for ($i = 0; $i < $lsk; $i++) {
         $c += ord($session_key[$i]);
     }
     $c &= 0xffff;
     $lm = ($l - 2) * 8 + 2;
     $m = chr($lm / 256) . chr($lm % 256) . chr(2) . GPG_Utility::s_random($l - $lsk - 6, 1) . "" . chr(7) . $session_key . chr($c / 256) . chr($c & 0xff);
     if ($key_type) {
         $enc = b2mpi($B) . b2mpi(bmod(bmul(mpi2b($m), $C), $mod));
         return $this->gpg_header(0x84, strlen($enc) + 10) . chr(3) . $key_id . chr(16) . $enc;
     } else {
         $enc = b2mpi(bmodexp(mpi2b($m), $exp, $mod));
         return $this->gpg_header(0x84, strlen($enc) + 10) . chr(3) . $key_id . chr(1) . $enc;
     }
 }