Encrypting fields on an entity

I should have also mentioned:

I did try both Mcrypt and Basic encryption with both File and Drupal Private Key.
I did check the weights of my modules and made sure encrypt was coming after my custom module.

If I have it set to Basic encryption, add an entity, and then go to edit it, I get this message logged a bunch of times before the page times out:

Warning: Division by zero in encrypt_encryption_methods_basic() (line 30 of /home/quickstart/websites/pacb.dev/sites/all/modules/encrypt/plugins/encryption_methods/default.inc).

Thanks,
Mickey

I ended up having to do 3 things to get it working:

1. Hacked encrypt/modules/encryptfapi/encryptfapi.module to work for my specific case and save the patch so I can update and reapply if updates still don't support fields.
2. Create a field formatter that called the decrypt function so I could display the field unencrypted on the entity detail page.
3. Then because I needed to be able to search on the encrypted field, I had to alter the query with hook_views_query_alter.

It's not pretty but it works. Let me know if you want to see code.

Mickey

Hi Barrett,

Sorry for the delay. Here is what I used. Like I said, it is a hack.

In MYMODULE.module:

1. Using hook_form_alter, add $form['field_MYFIELD]['#encrypt'] = TRUE; on your form element.
2. Add a field formatter:

function MYMODULE_field_formatter_info() {
  return array(
    // Machine name of the formatter.
    'MYMODULE_decrypt_ssn' => array(
      // Label for the administrative UI.
      'label' => t('Decrypt'),
      // Field types it supports.
      'field types' => array('text'),
    ),
  );
}

function MYMODULE_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  //Load the file for the decrypt function
  module_load_include('module', 'encrypt');
  
  $output = array();
  // Verify the formatter type.
  if ($display['type'] == 'MYMODULE_decrypt_ssn') {
    // Handle multi-valued fields.
    foreach ($items as $delta => $item) {
      // See which option was selected.
      $output[$delta] = array(
        '#markup' => decrypt($item['value'], array('base64' => 
TRUE)),
      );
    }
  }
  return $output;
}

3. I had a view with a combined exposed filter that I needed to be able to search on so I had to alter the view query. This code lives in a MYMODULE.views.inc file:

function MYMODULE_views_query_alter(&$view, &$query) {
  // (Example assuming a view with an combined exposed filter containing ssn field.)
  // If the input for combined filter is numeric and the ssn field exists in the view,
  // encrypt the ssn before searching the database.
  if (isset($view->exposed_raw_input['combine']) && is_numeric($view->exposed_raw_input['combine'])) {
    dsm($query);  
    // Traverse through the 'where' part of the query.
    foreach ($query->where as &$condition_group) {
      foreach ($condition_group['conditions'] as &$condition) {
         //If this is the part of the query filtering on the combined fields and ssn is one of the combined fields, change the condition to filter on the encrypted ssn.
        if (strpos($condition['field'], 'CONCAT_WS') !== false && strpos($condition['field'], 'field_ssn_value') !== false) {
          $condition = array(
            'field' => $condition['field'], 
            'value' => array(':views_combine' => '%' . encrypt($view->exposed_raw_input['combine'], array('base64' => TRUE)) . '%'), 
            'operator' => 'formula',
          );
        }
      }
    }
  }
}

4. And then I added the attached patch to the encrypt module.

Hope this helps.

Mickey

Duh. The patch.