Unexpected behavior when using phpseclib

Question

I've recently tried to implement the phpseclib library to log into a SFTP server to list all the files in a directory and download them. After downloading them, move them to a different directory on the server.

I'm not having much luck... So following the code straight from their site, but added logging.

set_include_path(get_include_path() . PATH_SEPARATOR . 'phpseclib');

require('Net\SSH2.php');
require('Crypt\RSA.php');   

define('NET_SSH2_LOGGING', 2);
$ssh = new Net_SSH2('host_name', 'port');
$key = new Crypt_RSA();
$key->loadKey(file_get_contents('path_to_rsa_file'));
if (!$ssh->login('username', $key)) {
  exit('Login Failed');
}

$ssh->exec("pwd");

That results in the following error:

Unable to request pseudo-terminal

Admittedly this is an older version, I'm not sure exactly which one, so I thought maybe I should update. After pulling in the latest version via composer, and running the same code as above, I get no errors, but I get this in the logs:

<- NET_SSH2_MSG_USERAUTH_SUCCESS (since last: 0.1395, network: 0.1394s)

-> NET_SSH2_MSG_CHANNEL_OPEN (since last: 0.0006, network: 0.0005s)
00000000  00:00:00:07:73:65:73:73:69:6f:6e:00:00:00:00:7f  ....session.....
00000010  ff:ff:ff:00:00:40:00                             .....@.

<- NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION (since last: 0.1232, network: 0.1231s)
00000000  00:00:00:00:00:00:00:00:ff:ff:ff:ff:00:00:80:00  ................

-> NET_SSH2_MSG_CHANNEL_REQUEST (since last: 0.0008, network: 0.0006s)
00000000  00:00:00:00:00:00:00:04:65:78:65:63:01:00:00:00  ........exec....
00000010  03:70:77:64                                      .pwd

<- NET_SSH2_MSG_CHANNEL_FAILURE (since last: 0.123, network: 0.1228s)
00000000  00:00:00:00                                      ....

Any one have any ideas? I've also tried using the SFTP class, but it failed with other problems "Notice: Connection closed prematurely".

Thanks for any help!

Answer 1

Looks like the server just doesn't support exec(). You might have better luck with read() / write():

http://phpseclib.sourceforge.net/ssh/examples.html#interactive

As for SFTP... I'd need to see logs to have any ideas.