check_admin_referer( int|string $action = -1, string $query_arg = '_wpnonce' )
Ensures intent by verifying that a user was referred from another admin page with the correct security nonce.
Description Description
This function ensures the user intends to perform a given action, which helps protect against clickjacking style attacks. It verifies intent, not authorisation, therefore it does not verify the user’s capabilities. This should be performed with current_user_can() or similar.
If the nonce value is invalid, the function will exit with an "Are You Sure?" style message.
Parameters Parameters
- $action
-
(int|string) (Optional) The nonce action.
Default value: -1
- $query_arg
-
(string) (Optional) Key to check for nonce in
$_REQUEST.Default value: '_wpnonce'
Return Return
(false|int) False if the nonce is invalid, 1 if the nonce is valid and generated between 0-12 hours ago, 2 if the nonce is valid and generated between 12-24 hours ago.
Source Source
File: wp-includes/pluggable.php
function check_admin_referer( $action = -1, $query_arg = '_wpnonce' ) {
if ( -1 === $action ) {
_doing_it_wrong( __FUNCTION__, __( 'You should specify a nonce action to be verified by using the first parameter.' ), '3.2.0' );
}
$adminurl = strtolower( admin_url() );
$referer = strtolower( wp_get_referer() );
$result = isset( $_REQUEST[ $query_arg ] ) ? wp_verify_nonce( $_REQUEST[ $query_arg ], $action ) : false;
/**
* Fires once the admin request has been validated or not.
*
* @since 1.5.1
*
* @param string $action The nonce action.
* @param false|int $result False if the nonce is invalid, 1 if the nonce is valid and generated between
* 0-12 hours ago, 2 if the nonce is valid and generated between 12-24 hours ago.
*/
do_action( 'check_admin_referer', $action, $result );
if ( ! $result && ! ( -1 === $action && strpos( $referer, $adminurl ) === 0 ) ) {
wp_nonce_ays( $action );
die();
}
return $result;
}
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Changelog Changelog
| Version | Description |
|---|---|
| 2.5.0 | The $query_arg parameter was added. |
| 1.2.0 | Introduced. |
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Usage in a plugin’s option page
Here is an example of how you might use this in a plugin’s option page. You add a nonce to a form using the wp_nonce_field() function:
Then in the page where the form submits to, you can verify whether or not the form was submitted and update values if it was successfully submitted:
<?php // if this fails, check_admin_referer() will automatically print a "failed" page and die. if ( ! empty( $_POST ) && check_admin_referer( 'name_of_my_action', 'name_of_nonce_field' ) ) { // process form data, e.g. update fields } // Display the formNote – Obsolete usage
script dies if the admin referer is not validated.