PHPIndex

<?php

namespace RobThree\Auth\Providers\Time;

use DateTime;

/**
 * Takes the time from any webserver by doing a HEAD request on the specified URL and extracting the 'Date:' header
 */
class HttpTimeProvider implements ITimeProvider
{
    /** @var string */
    public $url;

    /** @var string */
    public $expectedtimeformat;

    /** @var array */
    public $options;

    /**
     * @param string $url
     * @param string $expectedtimeformat
     * @param array $options
     */
    public function __construct($url = 'https://google.com', $expectedtimeformat = 'D, d M Y H:i:s O+', $options = null)
    {
        $this->url = $url;
        $this->expectedtimeformat = $expectedtimeformat;
        if ($options === null) {
            $options = array(
                'http' => array(
                    'method' => 'HEAD',
                    'follow_location' => false,
                    'ignore_errors' => true,
                    'max_redirects' => 0,
                    'request_fulluri' => true,
                    'header' => array(
                        'Connection: close',
                        'User-agent: TwoFactorAuth HttpTimeProvider (https://github.com/RobThree/TwoFactorAuth)',
                        'Cache-Control: no-cache'
                    )
                )
            );
        } elseif (!is_array($options)) {
            throw new TimeException('Options must be an array or null');
        }
        $this->options = $options;
    }

    /**
     * {@inheritdoc}
     */
    public function getTime()
    {
        try {
            $context  = stream_context_create($this->options);
            $fd = fopen($this->url, 'rb', false, $context);
            $headers = stream_get_meta_data($fd);
            fclose($fd);

            foreach ($headers['wrapper_data'] as $h) {
                if (strcasecmp(substr($h, 0, 5), 'Date:') === 0) {
                    return DateTime::createFromFormat($this->expectedtimeformat, trim(substr($h, 5)))->getTimestamp();
                }
            }
            throw new \Exception('Invalid or no "Date:" header found');
        } catch (\Exception $ex) {
            throw new TimeException(sprintf('Unable to retrieve time from %s (%s)', $this->url, $ex->getMessage()));
        }

    }
}

<?php

namespace RobThree\Auth\Providers\Time;

interface ITimeProvider
{
    /**
     * @return int the current timestamp according to this provider
     */
    public function getTime();
}

<?php

namespace RobThree\Auth\Providers\Time;

class LocalMachineTimeProvider implements ITimeProvider
{
    public function getTime()
    {
        return time();
    }
}

<?php

namespace RobThree\Auth\Providers\Time;

/**
 * Takes the time from any NTP server
 */
class NTPTimeProvider implements ITimeProvider
{
    /** @var string */
    public $host;

    /** @var int */
    public $port;

    /** @var int */
    public $timeout;

    /**
     * @param string $host
     * @param int $port
     * @param int $timeout
     */
    public function __construct($host = 'time.google.com', $port = 123, $timeout = 1)
    {
        $this->host = $host;

        if (!is_int($port) || $port <= 0 || $port > 65535) {
            throw new TimeException('Port must be 0 < port < 65535');
        }
        $this->port = $port;

        if (!is_int($timeout) || $timeout < 0) {
            throw new TimeException('Timeout must be >= 0');
        }
        $this->timeout = $timeout;
    }

    /**
     * {@inheritdoc}
     */
    public function getTime()
    {
        try {
            /* Create a socket and connect to NTP server */
            $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
            socket_set_option($sock, SOL_SOCKET, SO_RCVTIMEO, ['sec' => $this->timeout, 'usec' => 0]);
            socket_connect($sock, $this->host, $this->port);

            /* Send request */
            $msg = "\010" . str_repeat("\0", 47);
            socket_send($sock, $msg, strlen($msg), 0);

            /* Receive response and close socket */
            if (socket_recv($sock, $recv, 48, MSG_WAITALL) === false) {
                throw new \Exception(socket_strerror(socket_last_error($sock)));
            }
            socket_close($sock);

            /* Interpret response */
            $data = unpack('N12', $recv);
            $timestamp = (int) sprintf('%u', $data[9]);

            /* NTP is number of seconds since 0000 UT on 1 January 1900 Unix time is seconds since 0000 UT on 1 January 1970 */
            return $timestamp - 2208988800;
        } catch (\Exception $ex) {
            throw new TimeException(sprintf('Unable to retrieve time from %s (%s)', $this->host, $ex->getMessage()));
        }
    }
}

<?php

namespace RobThree\Auth\Providers\Time;

use RobThree\Auth\TwoFactorAuthException;

class TimeException extends TwoFactorAuthException {}