/home/smartonegroup/public_html/system/vendor/smarty/smarty/docs/api/security.md
# Security
Security is good for situations when you have untrusted parties editing
the templates, and you want to reduce the risk of system
security compromises through the template language.
The settings of the security policy are defined by overriding public properties of an
instance of the \Smarty\Security class. These are the possible settings:
- `$secure_dir` is an array of template directories that are
considered secure. A directory configured using `$smarty->setTemplateDir()` is
considered secure implicitly. The default is an empty array.
- `$trusted_uri` is an array of regular expressions matching URIs that
are considered trusted. This security directive is used by
[`{fetch}`](../designers/language-custom-functions/language-function-fetch.md) and
[`{html_image}`](../designers/language-custom-functions/language-function-html-image.md). URIs passed to
these functions are reduced to `{$PROTOCOL}://{$HOSTNAME}` to allow
simple regular expressions (without having to deal with edge cases
like authentication-tokens).
The expression `'#https?://.*smarty.net$#i'` would allow accessing
the following URIs:
- `http://smarty.net/foo`
- `http://smarty.net/foo`
- `http://www.smarty.net/foo`
- `http://smarty.net/foo`
- `https://foo.bar.www.smarty.net/foo/bla?blubb=1`
but deny access to these URIs:
- `http://smarty.com/foo` (not matching top-level domain \"com\")
- `ftp://www.smarty.net/foo` (not matching protocol \"ftp\")
- `http://www.smarty.net.otherdomain.com/foo` (not matching end of
domain \"smarty.net\")
- `$static_classes` is an array of classes that are considered
trusted. The default is an empty array which allows access to all
static classes. To disable access to all static classes set
$static_classes = null.
- `$streams` is an array of streams that are considered trusted and
can be used from within template. To disable access to all streams
set $streams = null. An empty array ( $streams = [] ) will
allow all streams. The default is array('file').
- `$allowed_modifiers` is an array of (registered / autoloaded)
modifiers that should be accessible to the template. If this array
is non-empty, only the herein listed modifiers may be used. This is
a whitelist.
- `$disabled_modifiers` is an array of (registered / autoloaded)
modifiers that may not be accessible to the template.
- `$allowed_tags` is a boolean flag which controls if constants can
function-, block and filter plugins that should be accessible to the
template. If this array is non-empty, only the herein listed
modifiers may be used. This is a whitelist.
- `$disabled_tags` is an array of (registered / autoloaded) function-,
block and filter plugins that may not be accessible to the template.
- `$allow_constants` is a boolean flag which controls if constants can
be accessed by the template. The default is "true".
- `$allow_super_globals` is a boolean flag which controls if the PHP
super globals can be accessed by the template. The default is
"true".
If security is enabled, no private methods, functions or properties of
static classes or assigned objects can be accessed (beginning with
'_') by the template.
To customize the security policy settings you can extend the
\Smarty\Security class or create an instance of it.
```php
<?php
use Smarty\Smarty;
class My_Security_Policy extends \Smarty\Security {
public $allow_constants = false;
}
$smarty = new Smarty();
$smarty->enableSecurity('My_Security_Policy');
```
```php
<?php
use Smarty\Smarty;
$smarty = new Smarty();
$my_security_policy = new \Smarty\Security($smarty);
$my_security_policy->allow_constants = false;
$smarty->enableSecurity($my_security_policy);
```
```php
<?php
use Smarty\Smarty;
$smarty = new Smarty();
// enable default security
$smarty->enableSecurity();
```
> **Note**
>
> Most security policy settings are only checked when the template gets
> compiled. For that reason you should delete all cached and compiled
> template files when you change your security settings.