v1.0 Initial commit of project

vendor/robthree/twofactorauth/lib/Providers/Time/NTPTimeProvider.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace RobThree\Auth\Providers\Time;
+
+use Exception;
+
+use function socket_create;
+
+/**
+ * Takes the time from any NTP server
+ */
+class NTPTimeProvider implements ITimeProvider
+{
+    public function __construct(public string $host = 'time.google.com', public int $port = 123, public int $timeout = 1)
+    {
+        if ($this->port <= 0 || $this->port > 65535) {
+            throw new TimeException('Port must be 0 < port < 65535');
+        }
+
+        if ($this->timeout < 0) {
+            throw new TimeException('Timeout must be >= 0');
+        }
+    }
+
+    /**
+     * {@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, array('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()));
+        }
+    }
+}