<?php

class ssh2
{

	private $host = 'host';
	private $user = 'user';
	private $port = '22';
	private $password = 'password';
	private $con = null;
	private $pubKeyFile = null;
	private $privKeyFile = null;
	private $shell_type = 'xterm';
	private $shell = null;
	private $log = array();
	private $sftp = null;
	private $knownHost = null;

	function __construct($host = '', $port = '', $knownHost = NULL)
	{
		if ($host != '') {
			$this->host = $host;
		}
		if ($port != '') {
			$this->port = $port;
		}
		if (!is_null($knownHost)) {
			$this->knownHost = $knownHost;
		}

		$this->con = ssh2_connect($this->host, $this->port, array('hostkey'=>'ssh-rsa,ssh-dss'));

		if (!$this->con) {
			$this->log[] = 'Connection failed!';
			$this->con = NULL;
		}
		else {
			//If a host fingerprint has been required, check it.
			if (!is_null($this->knownHost)) {
				$fingerprint = ssh2_fingerprint($this->con, SSH2_FINGERPRINT_MD5 | SSH2_FINGERPRINT_HEX);

				if (is_string($fingerprint)) {
					if (strcasecmp($fingerprint, $this->knownHost) != 0) {
						$this->log[] = 'HOSTKEY MISMATCH! (Expected "' . $this->knownHost . '" and received "' . $fingerprint . '" [comparison is case-insensitive]; possible Man-In-The-Middle Attack?';
						$this->con = NULL;
					}
				}
				else {
					$this->log[] = 'Could not determine remote host fingerprint (returned value was "' . $fingerprint . '"); aborting connection';
					$this->con = NULL;
				}
			}
		}
	}

	function __destruct()
	{
		$this->disconnect();
	}

	function getCon()
	{
		return $this->con;
	}

	function getSftp()
	{
		return $this->sftp;
	}

	function authKeyFile($user, $pubKeyFile, $privKeyFile)
	{
		if ($user != '') {
			$this->user = $user;
		}
		if ($pubKeyFile != '') {
			$this->pubKeyFile = $pubKeyFile;
		}
		if ($privKeyFile != '') {
			$this->privKeyFile = $privKeyFile;
		}

		if (!ssh2_auth_pubkey_file($this->con, $this->user, $this->pubKeyFile, $this->privKeyFile)) {
			$this->log[] = 'Public key authorization failed (public key "' . $this->pubKeyFile . '" and private key "' . $this->privKeyFile . '")!';
			return FALSE;
		}
		else {
			return TRUE;
		}
	}

	function sftpCon()
	{
		global $startTime;

		echo 'Calling ssh2_sftp(); time elapsed: ' . (microtime(true) - $startTime) . PHP_EOL;

		$sftp = ssh2_sftp($this->con);

		$this->sftp = $sftp;
	}

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

	function disconnect()
	{
		ssh2_disconnect($this->con);
	}

}

class SshTest
{

	public static function connectToSshServer($server)
	{
		global $startTime;

		//Establish an SSH session, so we can use file_exists()
		//on the remote server (requires sftp wrapper).

		echo 'Calling "new ssh2()"; time elapsed: ' . ((microtime(true) - $startTime)) . PHP_EOL;

		$ssh = new ssh2($server['hostname'], '22', $server['fingerprint']);

		echo 'Calling "$ssh->getCon()"; time elapsed: ' . (microtime(true) - $startTime) . PHP_EOL;

		if ($ssh->getCon() !== NULL) {
			//We were able to open an SSH session and the remote
			//server has the fingerprint that we expect. It's safe
			//to supply authentication credentials (as safe as possible, anyway).

			echo 'Calling "$ssh->authKeyFile()"; time elapsed: ' . (microtime(true) - $startTime) . PHP_EOL;

			if ($ssh->authKeyFile($server['sshUser'], $server['publicKey'], $server['privateKey'])) {
				//If authenticaton was successful, establish
				//an SFTP session so that sftp wrappers are available.

				echo 'Calling "$ssh->sftpCon()"; time elapsed: ' . (microtime(true) - $startTime) . PHP_EOL;

				$ssh->sftpCon();
			}
		}

		echo 'Returning from SshTest::connectToSshServer(); time elapsed: ' . (microtime(true) - $startTime) . PHP_EOL;

		return $ssh;
	}

}

################################################################################

$testSshServers = array(
	1 => array(
		'hostname' => 'localhost',
		'fingerprint' => 'DF551756B1D7AE3592AD574AD4D9F462',
		'sshUser' => 'user',
		'publicKey' => '/var/www/example.com/.ssh/user.pub',
		'privateKey' => '/var/www/example.com/.ssh/user',
	),
);

global $startTime;

$startTime = microtime(true);

$ssh = SshTest::connectToSshServer($testSshServers[1]);

var_dump($ssh);

echo 'Attempting ssh2_disconnect(); time elapsed: ' . (microtime(true) - $startTime) . PHP_EOL;

$ssh->disconnect();

echo 'Exiting; time elapsed: ' . (microtime(true) - $startTime) . PHP_EOL;

exit;

/*
Typical output:

php -f /var/www/example.com/web/php7-ssh2-segfault-test.php
Calling "new ssh2()"; time elapsed: 6.9141387939453E-6
Calling "$ssh->getCon()"; time elapsed: 0.054915904998779
Calling "$ssh->authKeyFile()"; time elapsed: 0.055253982543945
Calling "$ssh->sftpCon()"; time elapsed: 0.066303968429565
Calling ssh2_sftp(); time elapsed: 0.066792964935303
Returning from SshTest::connectToSshServer(); time elapsed: 0.25690102577209
object(ssh2)#1 (12) {
  ["host":"ssh2":private]=>
  string(9) "localhost"
  ["user":"ssh2":private]=>
  string(3) "user"
  ["port":"ssh2":private]=>
  string(2) "22"
  ["password":"ssh2":private]=>
  string(8) "password"
  ["con":"ssh2":private]=>
  resource(4) of type (SSH2 Session)
  ["pubKeyFile":"ssh2":private]=>
  string(29) "/var/www/example.com/.ssh/user.pub"
  ["privKeyFile":"ssh2":private]=>
  string(25) "/var/www/example.com/.ssh/user"
  ["shell_type":"ssh2":private]=>
  string(5) "xterm"
  ["shell":"ssh2":private]=>
  NULL
  ["log":"ssh2":private]=>
  array(0) {
  }
  ["sftp":"ssh2":private]=>
  resource(5) of type (SSH2 SFTP)
  ["knownHost":"ssh2":private]=>
  string(32) "DF551756B1D7AE3592AD574AD4D9F462"
}
Attempting ssh2_disconnect(); time elapsed: 0.26224684715271
Exiting; time elapsed: 0.26915097236633
Segmentation fault (core dumped)
*/