"Segmentation fault" when using phpseclib

Question

I downloaded phpseclib-0.3.10 from http://phpseclib.sourceforge.net/

My php Version : PHP 5.2.4

OS : CentOS release 6.6

When I run following I am getting "Segmentation fault" at this line $ssh->login('username', 'password')

<?php
set_include_path(get_include_path() . PATH_SEPARATOR . 'phpseclib');
include('Net/SSH2.php');
$ssh=new Net_SSH2('servername');
if (!$ssh->login('username', 'password')) {
     exit('Login Failed');
}
echo $ssh->exec('pwd');
?>

I am unable find the reason for this issue. Could you please help me to find the reason for this.

Airwaves

You might not want to hear this, but PHP 5.2 is outdated and not supported anymore. Many, many fixes have been done since then; one might have fixed the segmentation fault. – Tintoretto

Answer 1

My guess: either the fsockopen() call or the stream_select() call. You can figure it out by putting die()'s in your code at successive points within login() and the functions called therein.

Looking it up... login() calls _login():

https://github.com/phpseclib/phpseclib/blob/0.3.10/phpseclib/Net/SSH2.php#L1801

_login() calls _connect():

https://github.com/phpseclib/phpseclib/blob/0.3.10/phpseclib/Net/SSH2.php#L1817

eg. before line 964 in Net/SSH2.php add die('this far'). If it says "this far" then try adding it after. If you get a seg fault when it's after but not before that probably means it's the fsockopen that's to blame.

And just keep on doing that until you get the seg fault. Do a die('this far'); before and after the stream_select and just where-ever. And then post the line you're getting it on.

Gant

Thanks neubert for the reply. I did stack trace and I see that following lines throwing Segmentation fault Math_BigInteger->modPow() SSH2.php:1405 openssl_public_encrypt() BigInteger.php:1697 – Airwaves

Can you post a link to your phpinfo()? Maybe put it on a pastebin and post the link. Thanks! – Gant