无法使用 phpseclib 连接到远程服务器

Question

I have an odd issue on our inhouse backup app when I try to access one of the severs. I have taken out the code that our connectivity test uses and placed it in a test file so as to see what is breaking. The issue is the same weather I run this from the apps server or my own devbox.

I have enabled password logging on the remote box too but it doesn't matter if I use my version or our production version as we are unable to login using either the password or the pem we use to connect to other servers using the same provider (Digital Ocean)

So here is the code in a test-ssh.php file (I've changed the url, user and password for obvious reasons) the port is 22 so not used in code.

<?php

<?php
// Autoloader
include('./autoloader.php');
use phpseclib\Net\SSH2;

const NET_SSH2_LOGGING = 'NET_SSH2_LOG_COMPLEX';

ini_set('display_errors', true);
ini_set('error_log', 'php-error.log');

$ssh = new SSH2('123.123.123.123');
if (!$ssh->login('the-user', 'my-password')) {
    exit('Login Failed');
}

echo $ssh->exec('pwd');
echo $ssh->getLog();

The code runs until it reaches the $ssh->login line where it just exits with no error. I have tried to step through this but it is very unclear what is going on.

My logs have nothing new added when this is run and nothing is shown on the screen.

Both servers are running php8.1 and ubuntu 22.04 and as mentioned already we have other projects on other DO droplets (also on ubuntu 22.04 and php8.1 in some cases) but these work as intended and it is only this 'new' one that is breaking

Changing credentials to another box we know works does work on both my box and our backup server. At a complete loss and have been trying to resolve this for over a week!

thanks

*** EDIT *** after adding eror reporting back i now got the following errors

Warning: unpack(): Type C: not enough input, need 1, have 0 in /hdd/projects/local.backup.ecl/htdocs/phpseclib/Net/SSH2.php on line 1446

Fatal error: Uncaught TypeError: extract(): Argument #1 ($array) must be of type array, bool given in /hdd/projects/local.backup.ecl/htdocs/phpseclib/Net/SSH2.php:1446 Stack trace: #0 /hdd/projects/local.backup.ecl/htdocs/phpseclib/Net/SSH2.php(1446): extract() #1 /hdd/projects/local.backup.ecl/htdocs/phpseclib/Net/SSH2.php(1128): phpseclib\Net\SSH2->_key_exchange() #2 /hdd/projects/local.backup.ecl/htdocs/phpseclib/Net/SSH2.php(1904): phpseclib\Net\SSH2->_connect() #3 [internal function]: phpseclib\Net\SSH2->_login() #4 /hdd/projects/local.backup.ecl/htdocs/phpseclib/Net/SSH2.php(1888): call_user_func_array() #5 /hdd/projects/local.backup.ecl/htdocs/test-ssh.php(12): phpseclib\Net\SSH2->login() #6 {main} thrown in /hdd/projects/local.backup.ecl/htdocs/phpseclib/Net/SSH2.php on line 1446

Answer 1

Thanks to pointers and advice above from Chris Haas and neubert, I upgraded my phpseclib (it was 2 so upgraded to 3 as think the new server is using ecdsa which is what I now think to be the most likely cause for this error) and generally upgraded all I could with some refactoring and this is now giving the expected path to working directory and otherwise in a good point (still some amends left out of scope here)

thanks