Populate "source" field of uploaded torrents

Value added to source field contains the site name and a random string.
This change prevents uploaders from using self-generated torrent files
unless they also add the source value themselves. This value is provided
to them on the upload page, but is still more inconvenient than before.

classes/bencodetorrent.class.php

     return true;
   }
 
+  /**
+   * Add the "source" field to the torrent
+   *
+   * @return true if a change was required
+   */
+  public function make_sourced() {
+    $Sources = Users::get_upload_sources();
+    if (empty($this->Dec)) { return false; }
+    if (isset($this->Dec['info']['source']) && ($this->Dec['info']['source'] == $Sources[0] || $this->Dec['info']['source'] == $Sources[1])) {
+      return false;
+    }
+    $this->Dec['info']['source'] = $Sources[0];
+    ksort($this->Dec['info']);
+    return true;
+  }
+
   /**
    * Calculate the torrent's info hash
    *

classes/torrent_form.class.php

 <div class="thin">
 <?    if ($this->NewTorrent) { ?>
   <p style="text-align: center;">
-    Your personal announce URL is:<br />
-    <input type="text" value="<?= ANNOUNCE_URLS[0][0] . '/' . G::$LoggedUser['torrent_pass'] . '/announce'?>" size="71" onclick="this.select();" readonly="readonly" />
+    If you would like to use your own torrent file, add the following to it:<br />
+<?      $Announces = call_user_func_array('array_merge', ANNOUNCE_URLS);
+        foreach ($Announces as $Announce) {
+?>
+    Announce: <input type="text" value="<?=$Announce . '/' . G::$LoggedUser['torrent_pass'] . '/announce'?>" size="74" onclick="this.select();" readonly="readonly" /> <br />
+<?      } ?>
+Source: <input type="text" value="<?=Users::get_upload_sources()[0]?>" size="20" onclick="this.select();" readonly="readonly" />
     <p style="text-align: center;">
+        Otherwise, add none of it and simply redownload the torrent after uploading it. All of the above data will be added by the site.<br /><br />
     <strong<?=((!$Uploads)?' class="important_text"':'')?>>
         If you never have before, be sure to read this list of <a href="wiki.php?action=article&name=uploadingpitfalls">uploading pitfalls</a>
       </strong>

classes/users.class.php

 
     Misc::send_email($Email, 'Login from new location for '.SITE_NAME, $TPL->get(), 'noreply');
   }
+  /*
+   * @return array of strings that can be added to next source flag ( [current, old] )
+   */
+  public static function get_upload_sources() {
+    if (!($SourceKey = G::$Cache->get_value('source_key_new'))) {
+      G::$Cache->cache_value('source_key_new', $SourceKey = [Users::make_secret(), time()]);
+    }
+    $SourceKeyOld = G::$Cache->get_value('source_key_old');
+    if ($SourceKey[1]-time() > 3600) {
+      G::$Cache->cache_value('source_key_old', $SourceKeyOld = $SourceKey);
+      G::$Cache->cache_value('source_key_new', $SourceKey = [Users::make_secret(), time()]);
+    }
+    G::$DB->query("
+      SELECT
+        COUNT(ID)
+      FROM torrents
+      WHERE UserID = ".G::$LoggedUser['ID']);
+    list($Uploads) = G::$DB->next_record();
+    $Source[0] = SITE_NAME.'-'.substr(hash('sha256', $SourceKey[0].G::$LoggedUser['ID'].$Uploads),0,10);
+    $Source[1] = $SourceKeyOld ? SITE_NAME.'-'.substr(hash('sha256', $SourceKeyOld[0].G::$LoggedUser['ID'].$Uploads),0,10) : $Source[0];
+    return $Source;
+  }
 }

sections/upload/upload_handle.php

 
 define('QUERY_EXCEPTION', true); // Shut up debugging
 
-//******************************************************************************//
-//--------------- Set $Properties array ----------------------------------------//
-// This is used if the form doesn't validate, and when the time comes to enter  //
-// it into the database.                            //
-// Haha wow god i'm trying to restrict the database to only have fields for //
-// movies and not add anything for other categories but this is fucking dumb //
+//*****************************************************************************//
+//--------------- Set $Properties array ---------------------------------------//
+// This is used if the form doesn't validate, and when the time comes to enter //
+// it into the database.                                                       //
+// Haha wow god i'm trying to restrict the database to only have fields for    //
+// movies and not add anything for other categories but this is fucking dumb   //
 
 $Properties = array();
 $Type = $Categories[(int)$_POST['type']];
 
 $Tor = new BencodeTorrent($TorrentName, true);
 $PublicTorrent = $Tor->make_private(); // The torrent is now private.
+$UnsourcedTorrent = $Tor->make_sourced(); // The torrent now has the source field set.
 $TorEnc = $Tor->encode();
 $InfoHash = pack('H*', $Tor->info_hash());