<?php

class ssh2 {
    const SSH_COMMAND_FINISHED_FLAG = '___SSH_COMMAND_FINISHED___';

    private $host = 'localhost';
    private $port = 22;
    private $username = 'root';
    private $password = '';
    private $connectionMethods = array(
        'kex' => 'diffie-hellman-group1-sha1',
        'client_to_server' => array(
            'crypt' => '3des-cbc',
            'comp' => 'none'),
        'server_to_client' => array(
            'crypt' => 'aes256-cbc,aes192-cbc,aes128-cbc',
            'comp' => 'none'));
    private $publicKeyFile;
    private $privateKeyFile;
    private $keyPassphrase;
    private $connection = null;

    /**
     * @param string $host
     * @param int $port
     */
    public function __construct($host = 'localhost', $port = 22) {
        if (!function_exists("ssh2_connect")) {
            throw new Exception('function ssh2_connect doesn\'t exist');
        }

        $this->setHost($host);
        $this->setPort($port);
    }

    /**
     * @param array $connectionMethods
     * @return bool
     */
    public function connect($connectionMethods = false) {
        $this->setConnectionMethods(is_array($connectionMethods) ? $connectionMethods : $this->getConnectionMethods());
        $this->connection = ssh2_connect($this->getHost(), $this->getPort(), $this->getConnectionMethods());
        return (bool) $this->connection;
    }

    public function disconnect() {
        return $this->exec('exit;', 10, false);
    }

    /**
     * @return string
     */
    public function getFingerprint() {
        if ($this->connection) {
            return ssh2_fingerprint($this->connection, SSH2_FINGERPRINT_MD5 | SSH2_FINGERPRINT_HEX);
        }
        return false;
    }

    /**
     * @param string $username
     * @return array
     */
    public function getAuthMethods($username) {
        return (array) ssh2_auth_none($this->connection, $username);
    }

    /**
     * @param string $username
     * @param string $password
     * @return bool
     */
    public function authPassword($username, $password) {
        if ($this->connection) {
            $this->setUsername($username);
            $this->setPassword($password);
            return (bool) ssh2_auth_password($this->connection, $this->getUsername(), $this->getPassword());
        }
        return false;
    }

    /**
     * @param string $username
     * @param string $publicKeyFile
     * @param string $privateKeyFile
     * @param string $keyPassphrase
     * @return bool
     */
    public function authKey($username, $publicKeyFile, $privateKeyFile, $keyPassphrase = null) {
        if ($this->connection && is_file($publicKeyFile) && is_readable($publicKeyFile) && is_file($privateKeyFile) && is_readable($privateKeyFile)) {
            $this->setPublicKeyFile($publicKeyFile);
            $this->setPrivateKeyFile($privateKeyFile);
            $this->setKeyPassphrase($keyPassphrase);
            return (bool) ssh2_auth_pubkey_file($this->connection, $this->ssh_auth_user, $this->ssh_auth_pub, $this->ssh_auth_priv, $this->ssh_auth_pass);
        }
    }

    /**
     * @param string $cmd
     * @param int $timeout
     * @return string
     */
    public function exec($cmd, $timeout = 10, $saveMode = true) {
        if ($saveMode) {
            $cmd .= ' ; echo "' . self::SSH_COMMAND_FINISHED_FLAG . '"';
        }

        if (!($stream = ssh2_exec($this->connection, $cmd))) {
            throw new Exception('SSH command failed');
        }
        stream_set_blocking($stream, true);
        $data = "";

        $time_start = time();
        $data = "";
        if ($saveMode) {
            while (true) {
                $data .= fread($stream, 4096);
                $flagPosition = strpos($data, self::SSH_COMMAND_FINISHED_FLAG);
                if ($flagPosition !== false) {
                    if (substr_compare($data, self::SSH_COMMAND_FINISHED_FLAG, $flagPosition, strlen(self::SSH_COMMAND_FINISHED_FLAG)) == 0) {
                        $data = substr($data, 0, (strlen(self::SSH_COMMAND_FINISHED_FLAG) + 1) * -1);
                    }
                    break;
                }
                if ((time() - $time_start) > (int) $timeout) {
                    fclose($stream);
                    throw new Exception('ssh execution timeout');
                }
            }
        } else {
            while ($buf = fread($stream, 4096)) {
                $data .= $buf;
            }
        }

        fclose($stream);
        return $data;
    }

    /**
     * @param string $userPassword
     * @param string $cmd
     * @param int $timeout
     * @param boolean $saveMode
     * @return string
     */
    public function sudoExec($userPassword, $cmd, $timeout = 10, $saveMode = true) {
        $ssh2->exec('sudo -k', $timeout, $saveMode);
        return $ssh2->exec('echo "' . $userPassword . '" | sudo ' . $cmd, $timeout, $saveMode);
    }

    public function getHost() {
        return $this->host;
    }

    public function setHost($host) {
        $this->host = $host;
    }

    public function getPort() {
        return $this->port;
    }

    public function setPort($port) {
        $this->port = (int) $port;
    }

    public function getUsername() {
        return $this->username;
    }

    public function setUsername($username) {
        $this->username = $username;
    }

    public function getPassword() {
        return $this->password;
    }

    public function setPassword($password) {
        $this->password = $password;
    }

    public function getPublicKeyFile() {
        return $this->publicKeyFile;
    }

    public function setPublicKeyFile($publicKey) {
        $this->publicKeyFile = $publicKey;
    }

    public function getPrivateKeyFile() {
        return $this->privateKeyFile;
    }

    public function setPrivateKeyFile($privateKey) {
        $this->privateKeyFile = $privateKey;
    }

    public function getKeyPassphrase() {
        return $this->keyPassphrase;
    }

    public function setKeyPassphrase($keyPassphrase) {
        $this->keyPassphrase = $keyPassphrase;
    }

    public function getConnectionMethods() {
        return $this->connectionMethods;
    }

    public function setConnectionMethods($connectionMethods) {
        $this->connectionMethods = $connectionMethods;
    }

}

?>