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Drupal example source code file (filters.encryption.inc)

This example Drupal source code file (filters.encryption.inc) is included in the DevDaily.com "Drupal Source Code Warehouse" project. The intent of this project is to help you "Learn Drupal by Example".

PHP - Drupal tags/keywords

array, backup, data, directory, encryption, file, from, function, if, options, php, return, success, the

The filters.encryption.inc Drupal example source code

<?php
// $Id: filters.encryption.inc,v 1.1.2.6 2010/03/24 04:02:58 ronan Exp $


/**
 * @file
 * A filter for encrypting bckups with AES.
 */

/**
 * A filter for encrypting backup files.
 *
 * @ingroup backup_migrate_filters
 */
class backup_migrate_filter_encryption extends backup_migrate_filter {
  var $op_weights = array('backup' => 170, 'restore' => -170);

  /**
   * This function is called on a backup file after the backup has been completed.
   */
  function backup($file, $settings) {
    return $this->file_encrypt($file, $settings);
  }

  /**
   * This function is called on a backup file before importing it.
   */
  function restore($file, &$settings) {
    return $this->file_decrypt($file);
  }

  /**
   * Get the form for the settings for this filter.
   */
  function backup_settings_default() {
    return array('compression' => 'none');
  }

  /**
   * Get the form for the settings for this filter.
   */
  function backup_settings_form($settings) {
    $form = array();
    $options = $this->_backup_migrate_get_encryption_form_item_options();
    if (count($options) > 1) {
      $form['file']['encryption'] = array(
        "#type" => "select",
        "#title" => t("File Encryption (EXPERIMENTAL)"),
        "#options" => $options,
        "#default_value" => @$settings['encryption'],
        '#description' => t('Encrypted files can only be restored by Backup and Migrate and only on sites with the same encryption key. <strong>This functionality is experimental, and should only be used for testing.</strong>'),
      );
    }
    else {
      $form['file']['encryption'] = array(
        "#type" => 'item',
        "#title" => t("File Encryption"),
        "#value" => t('Install the !link to enable backup file encryption.', array('!link' => l(t('AES Encryption Module'), 'http://drupal.org/project/aes'))),
      );
    }

    return $form;
  }

  /**
   * Return a list of backup filetypes.
   */
  function file_types() {
    return array(
      "aes" => array(
        "extension" => "aes",
        "filemime" => "application/octet-stream",
        "backup" => TRUE,
        "restore" => TRUE,
      ),
    );
  }

  /**
   * Get the compression options as an options array for a form item.
   */
  function _backup_migrate_get_encryption_form_item_options() {
    $options = array();
    $options = array('' => t('No Encryption'));
    if (@function_exists("aes_encrypt")) {
      $options['aes'] = t("AES Encryption");
    }
    return $options;
  }

  /**
   * AES encrypt a file.
   */
  function aes_encrypt($source, $dest) {
    $success = FALSE;
    if (function_exists('aes_encrypt')) {
      if ($data = $source->get_contents()) {
        // Add a marker to the end of the data so we can trim the padding on decrpypt.
        $data = pack("a*H2", $data, "80");
        if ($data = aes_encrypt($data, FALSE)) {
          $dest->put_contents($data);
          $success = TRUE;
        }
      }
    }
    return $success;
  }

  /**
   * Gzip decode a file.
   */
  function aes_decrypt($source, $dest) {
    $success = FALSE;
    if (function_exists('aes_decrypt')) {
      if ($data = $source->get_contents()) {
        if ($data = aes_decrypt($data, FALSE)) {
          // Trim all the padding zeros plus our non-zero marker.
          $data = substr(rtrim($data, "\0"), 0, -1);
          $dest->put_contents($data);
          $success = TRUE;
        }
      }
    }
    return $success;
  }

  /**
   * Compress a file with the given settings.
   *  Also updates settings to reflect new file mime and file extension.
   */
  function file_encrypt($file, $settings) {
    if (!empty($settings->filters['encryption'])) {
      switch ($settings->filters['encryption']) {
        case "aes":
          $from = $file->push_type('aes');
          $from = new backup_file(array('filepath' => $from));
          if (!$success = $this->aes_encrypt($from, $file)) {
            $file = NULL;
          }
          break;
      }
      if (!$file) {
        _backup_migrate_message("Could not encrypt backup file. Try backing up without encryption.", array(), 'error');
      }
    }
    return $file;
  }

  /**
   * Decompress a file with the given settings.
   *  Also updates settings to reflect new file mime and file extension.
   */
  function file_decrypt($file) {
    $success = FALSE;
    if ($file) {
      switch ($file->type_id()) {
        case "aes":
          $from = $file->pop_type();
          $success = $this->aes_decrypt($from, $file);
          break;
        default:
          return $file;
        break;
    }
  
      if (!$success) {
        if (function_exists('aes_decrypt')) {
          _backup_migrate_message("Could not decrpyt backup file. Please check that the file is valid and that the encryption key of the server matches the server that created the backup.", array(), 'error');
        }
        else {
          _backup_migrate_message('You must install the !link to restore encrypted backkups.', array('!link' => l(t('AES Encryption Module'), 'http://drupal.org/project/aes')), 'error');
        }
      }
    }
    return $success ? $file : NULL;
  }
}

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