How can I encrypt a Joomla Configuration Parameter that is stored in the database? - joomla

Question

I found this question, which is identical to what I need to do:
How do you Encrypt and Decrypt a PHP String?
I've got everything working to the point of encrypting the data before it is saved. In the event function onExtensionBeforeSave, I have access to the table. I can get the values that need to be encrypted from jinput and encrypt them. What I can't figure out is how to put the encrypted data into the table object in a way that it will replace the un-encrypted data before it is stored/saved.

Answer 1

I was able to figure this out. In the extension event onExtensionBeforeSave, I get the post data, load the config.xml file to check the form fields for my custom fields (type='encryptedtext'), encryt those and use the table object to bind and check it, so it will be stored correctly.
function onExtensionBeforeSave($context, $table, $isNew)
{
$jinput = JFactory::getApplication()->input;
$component = $jinput->get('component');
if($component !== 'com_store') // Only encrypting fields in the store component for now
{
return true;
}
$form_path = JPATH_ADMINISTRATOR . '\\components\\' . $component . '\\config.xml';
$xml = simplexml_load_file($form_path);
$has_encrypted = false;
foreach($xml->fieldset as $fieldset)
{
foreach($fieldset as $field)
{
if($field['type'] == 'encryptedtext') // is our custom form field type to be encrypted
{
$has_encrypted = true;
if(!$fields) // get fields if it hasn't already been done
{
$fields = $jinput->get('jform', '', 'array');
}
$field = (string)$field['name'];
$value = (string)$fields[$field];
$cipher = "aes-256-ctr";
$ivlen = openssl_cipher_iv_length($cipher);
$iv = openssl_random_pseudo_bytes($ivlen, $isStrongCrypto);
if (!$isStrongCrypto)
{
throw new \Exception("Not a strong key");
}
$keyhash = openssl_digest($component, 'sha256', true);
$opts = OPENSSL_RAW_DATA;
$encrypted = openssl_encrypt($value, $cipher, $keyhash, $opts, $iv);
if ($encrypted === false)
{
throw new \Exception('Encryption failed: ' . openssl_error_string());
}
$result = $iv . $encrypted;
$result = base64_encode($result);
$fields[$field] = $result;
}
}
}
if(!has_encrypted)
{
return false;
}
$data = array(
'params'=>$fields,
'option'=>$component
);
if (!$table->bind($data))
{
throw new RuntimeException($table->getError());
}
if (!$table->check())
{
throw new RuntimeException($table->getError());
}
return true;
}
All that is left is to decrypt it in the getInput function of the custom field. I answer this in case someone needs it, and I would love some critique if people see improvements, or if it's complete junk ...