[php] How To Execute SSH Commands Via PHP

I am looking to SSH out via PHP. What is the best/most secure way to go about this? I know I can do:

shell_exec("SSH [email protected] mkdir /testing");

Anything better? That feels so 'naughty' :).

//Update 2018, works//

Method1:

Download phpseclib v1 and use this code:

<?php
set_include_path(__DIR__ . '/phpseclib1.0.11');
include("Net/SSH2.php");

$key ="MyPassword";
  /* ### if using PrivateKey ### 
  include("Crypt/RSA.php");
  $key = new Crypt_RSA();
  $key->loadKey(file_get_contents('private-key.ppk'));
  */

$ssh = new Net_SSH2('www.example.com', 22);   // Domain or IP
if (!$ssh->login('your_username', $key))  exit('Login Failed');

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

or Method2:

Download newest phpseclib v2 (requires composer install at first):

<?php

set_include_path($path=__DIR__ . '/phpseclib-master/phpseclib');
include ($path.'/../vendor/autoload.php');

$loader = new \Composer\Autoload\ClassLoader();

use phpseclib\Net\SSH2;

$key ="MyPassword";
  /* ### if using PrivateKey ### 
  use phpseclib\Crypt\RSA;
  $key = new RSA();
  $key->load(file_get_contents('private-key.ppk'));
  */

$ssh = new SSH2('www.example.com', 22);   // Domain or IP
if (!$ssh->login('your_username', $key))   exit('Login Failed'); 

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

p.s. if you get "Connection timed out" then it's probably the issue of HOST/FIREWALL (local or remote) or like that, not a fault of script.

Use the ssh2 functions. Anything you'd do via an exec() call can be done directly using these functions, saving you a lot of connections and shell invocations.

For those using the Symfony framework, the phpseclib can also be used to connect via SSH. It can be installed using composer:

composer require phpseclib/phpseclib

Next, simply use it as follows:

use phpseclib\Net\SSH2;

// Within a controller for example:
$ssh = new SSH2('hostname or ip');
if (!$ssh->login('username', 'password')) {
    // Login failed, do something
}

$return_value = $ssh->exec('command');

I've had a hard time with ssh2 in php mostly because the output stream sometimes works and sometimes it doesn't. I'm just gonna paste my lib here which works for me very well. If there are small inconsistencies in code it's because I have it plugged in a framework but you should be fine porting it:

<?php

class Components_Ssh {

    private $host;

    private $user;

    private $pass;

    private $port;

    private $conn = false;

    private $error;

    private $stream;

    private $stream_timeout = 100;

    private $log;

    private $lastLog;

    public function __construct ( $host, $user, $pass, $port, $serverLog ) {
        $this->host = $host;
        $this->user = $user;
        $this->pass = $pass;
        $this->port = $port;
        $this->sLog = $serverLog;

        if ( $this->connect ()->authenticate () ) {
            return true;
        }
    }

    public function isConnected () {
        return ( boolean ) $this->conn;
    }

    public function __get ( $name ) {
        return $this->$name;
    }

    public function connect () {
        $this->logAction ( "Connecting to {$this->host}" );
        if ( $this->conn = ssh2_connect ( $this->host, $this->port ) ) {
            return $this;
        }
        $this->logAction ( "Connection to {$this->host} failed" );
        throw new Exception ( "Unable to connect to {$this->host}" );
    }

    public function authenticate () {
        $this->logAction ( "Authenticating to {$this->host}" );
        if ( ssh2_auth_password ( $this->conn, $this->user, $this->pass ) ) {
            return $this;
        }
        $this->logAction ( "Authentication to {$this->host} failed" );
        throw new Exception ( "Unable to authenticate to {$this->host}" );
    }

    public function sendFile ( $localFile, $remoteFile, $permision = 0644 ) {
        if ( ! is_file ( $localFile ) ) throw new Exception ( "Local file {$localFile} does not exist" );
        $this->logAction ( "Sending file $localFile as $remoteFile" );

        $sftp = ssh2_sftp ( $this->conn );
        $sftpStream = @fopen ( 'ssh2.sftp://' . $sftp . $remoteFile, 'w' );
        if ( ! $sftpStream ) {
            //  if 1 method failes try the other one
            if ( ! @ssh2_scp_send ( $this->conn, $localFile, $remoteFile, $permision ) ) {
                throw new Exception ( "Could not open remote file: $remoteFile" );
            }
            else {
                return true;
            }
        }

        $data_to_send = @file_get_contents ( $localFile );

        if ( @fwrite ( $sftpStream, $data_to_send ) === false ) {
            throw new Exception ( "Could not send data from file: $localFile." );
        }

        fclose ( $sftpStream );

        $this->logAction ( "Sending file $localFile as $remoteFile succeeded" );
        return true;
    }

    public function getFile ( $remoteFile, $localFile ) {
        $this->logAction ( "Receiving file $remoteFile as $localFile" );
        if ( ssh2_scp_recv ( $this->conn, $remoteFile, $localFile ) ) {
            return true;
        }
        $this->logAction ( "Receiving file $remoteFile as $localFile failed" );
        throw new Exception ( "Unable to get file to {$remoteFile}" );
    }

    public function cmd ( $cmd, $returnOutput = false ) {
        $this->logAction ( "Executing command $cmd" );
        $this->stream = ssh2_exec ( $this->conn, $cmd );

        if ( FALSE === $this->stream ) {
            $this->logAction ( "Unable to execute command $cmd" );
            throw new Exception ( "Unable to execute command '$cmd'" );
        }
        $this->logAction ( "$cmd was executed" );

        stream_set_blocking ( $this->stream, true );
        stream_set_timeout ( $this->stream, $this->stream_timeout );
        $this->lastLog = stream_get_contents ( $this->stream );

        $this->logAction ( "$cmd output: {$this->lastLog}" );
        fclose ( $this->stream );
        $this->log .= $this->lastLog . "\n";
        return ( $returnOutput ) ? $this->lastLog : $this;
    }

    public function shellCmd ( $cmds = array () ) {
        $this->logAction ( "Openning ssh2 shell" );
        $this->shellStream = ssh2_shell ( $this->conn );

        sleep ( 1 );
        $out = '';
        while ( $line = fgets ( $this->shellStream ) ) {
            $out .= $line;
        }

        $this->logAction ( "ssh2 shell output: $out" );

        foreach ( $cmds as $cmd ) {
            $out = '';
            $this->logAction ( "Writing ssh2 shell command: $cmd" );
            fwrite ( $this->shellStream, "$cmd" . PHP_EOL );
            sleep ( 1 );
            while ( $line = fgets ( $this->shellStream ) ) {
                $out .= $line;
                sleep ( 1 );
            }
            $this->logAction ( "ssh2 shell command $cmd output: $out" );
        }

        $this->logAction ( "Closing shell stream" );
        fclose ( $this->shellStream );
    }

    public function getLastOutput () {
        return $this->lastLog;
    }

    public function getOutput () {
        return $this->log;
    }

    public function disconnect () {
        $this->logAction ( "Disconnecting from {$this->host}" );
        // if disconnect function is available call it..
        if ( function_exists ( 'ssh2_disconnect' ) ) {
            ssh2_disconnect ( $this->conn );
        }
        else { // if no disconnect func is available, close conn, unset var
            @fclose ( $this->conn );
            $this->conn = false;
        }
        // return null always
        return NULL;
    }

    public function fileExists ( $path ) {
        $output = $this->cmd ( "[ -f $path ] && echo 1 || echo 0", true );
        return ( bool ) trim ( $output );
    }
}

Do you have the SSH2 extension available?

Docs: http://www.php.net/manual/en/function.ssh2-exec.php

$connection = ssh2_connect('shell.example.com', 22);
ssh2_auth_password($connection, 'username', 'password');

$stream = ssh2_exec($connection, '/usr/local/bin/php -i');

I would use phpseclib, a pure PHP SSH implementation. An example:

<?php
include('Net/SSH2.php');

$ssh = new Net_SSH2('www.domain.tld');
if (!$ssh->login('username', 'password')) {
    exit('Login Failed');
}

echo $ssh->exec('pwd');
echo $ssh->exec('ls -la');
?>