randomize-salts.php

<?php
/*
Plugin Name: Salts Randomizer
Plugin URI: http://aristeides.com
Description: Change salts daily
Author: Aristeides Stathopoulos
Version: 0.1
Author URI: http://aristeides.com
*/

/**
 * This plugin provides a simple way to automatically change the salts on a daily basis.
 * It requires you make the following changes in your wp-config.php file:
 *
 * 1. 	Delete the salts from your wp-config.php file.
 * 		Your salts should look something like this:
define('AUTH_KEY',         'H(NL )[uG;!}C*ffXUI3|]^%uPAHh+TW99Xq+?0lo;  t<(pt,HIRhE}w%f$O4@u');
define('SECURE_AUTH_KEY',  'Tq<&r3f%?wJ/NymFf/ZVFD_HSh-,ktsk;=8<yM+tW&6G#0$-+^[?|1yx|H+g)K2|');
define('LOGGED_IN_KEY',    'oC+O+.s:yhH6_vf+jw.!&mX!r>JXZ)I HX-_%w<m;o;0WJ^ct =rEpb$?5X>|+_`');
define('NONCE_KEY',        'Ue-+g1V4N`($[sN$*paCE^bK!IAGiF)!cun+b^52%5lUDl_k8~8(/g;c36=^Ay??');
define('AUTH_SALT',        '+96{JTkN,ldj_j/gA +@&m]- _u*$R:!:&djqSD<O-1y-5TB4D~>T:jTD[-K2}DW');
define('SECURE_AUTH_SALT', '&:uO[z- XPTCsd+Lw5CX|_U/-N.AHy$OzZP-)%^rS/xg[}<?!N]$4>FGcNXj?7.h');
define('LOGGED_IN_SALT',   'bh8LJ?--&c^>|?u=c=Q^=hwx&C&hcQpt|J8ao*a1K(7U|M#K;~;/<w xdvRxs]8C');
define('NONCE_SALT',       'VdO]W KoH?XjeF{@)S5XM<e.-xk[}wg1-8+<Jv<nIdtP(YjI=bU9|>=mahk<t~fW');
 *
 * 2.	After you delete the salts, add this line in their place:
require_once(ABSPATH . 'salts-random-filename.php');
 * Of course you can change that to your own, completely random filename.
 *
 * For the first time this runs, you should copy the salts you deleted from your wp-config.php file in that file like this:
<?php
define('AUTH_KEY',         'H(NL )[uG;!}C*ffXUI3|]^%uPAHh+TW99Xq+?0lo;  t<(pt,HIRhE}w%f$O4@u');
define('SECURE_AUTH_KEY',  'Tq<&r3f%?wJ/NymFf/ZVFD_HSh-,ktsk;=8<yM+tW&6G#0$-+^[?|1yx|H+g)K2|');
define('LOGGED_IN_KEY',    'oC+O+.s:yhH6_vf+jw.!&mX!r>JXZ)I HX-_%w<m;o;0WJ^ct =rEpb$?5X>|+_`');
define('NONCE_KEY',        'Ue-+g1V4N`($[sN$*paCE^bK!IAGiF)!cun+b^52%5lUDl_k8~8(/g;c36=^Ay??');
define('AUTH_SALT',        '+96{JTkN,ldj_j/gA +@&m]- _u*$R:!:&djqSD<O-1y-5TB4D~>T:jTD[-K2}DW');
define('SECURE_AUTH_SALT', '&:uO[z- XPTCsd+Lw5CX|_U/-N.AHy$OzZP-)%^rS/xg[}<?!N]$4>FGcNXj?7.h');
define('LOGGED_IN_SALT',   'bh8LJ?--&c^>|?u=c=Q^=hwx&C&hcQpt|J8ao*a1K(7U|M#K;~;/<w xdvRxs]8C');
define('NONCE_SALT',       'VdO]W KoH?XjeF{@)S5XM<e.-xk[}wg1-8+<Jv<nIdtP(YjI=bU9|>=mahk<t~fW');
 *
 * In other words, DO NOT FORGET TO ADD THE <?php in from of the define lines.
 */


/**
 * The main plugin class
 */
class Salts_Randomizer {

	/**
	 * Class constructor
	 */
	function __construct() {

		// If the current transients are valid, do not proceed.
		if ( ! $this->check_transients() ) {

			add_action( 'get_footer', array( $this, 'update' ) );

		}
	}

	/**
	 * Update the salts with new values
	 */
	function update() {

		$filename = ABSPATH . 'salts-random-filename.php';

		// Write new salts to disk
		$this->write_to_file( $filename, $this->get_new_salts() );

		// Save the transients
		$this->save_transients( $this->get_new_salts() );
	}

	/**
	 * Check if the existing salts are valid or expired
	 */
	function check_transients() {

		$salts = get_transient( 'salts_rand' );

		if ( ! $salts ) {
			return false;
		} else {
			return true;
		}

	}

	/**
	 * Save salts in the db
	 */
	function save_transients( $salts = null, $expiration = 86400  ) {

		// On mulrisites use set_site_transient() instead of set_transient()
		if ( is_multisite() ) {
			set_site_transient( 'salts_rand', $salts, $expiration );
		} else {
			set_transient( 'salts_rand', $salts, $expiration );
		}
	}

	/**
	 * Get new transients from the WordPress API.
	 */
	function get_new_salts() {

		$new_keys = wp_remote_get( 'https://api.wordpress.org/secret-key/1.1/salt/' );

		return $new_keys;

	}

	/**
	 * Write the new salts to disk
	 */
	function write_to_file( $file, $content ) {

		global $wp_filesystem;

		$wp_filesystem->put_contents( $file, '<?php ' . $content, FS_CHMOD_FILE );

	}

}

$salts_randomizer = new Salts_Randomizer();

Thanks for this plugin. I installed and am seeing errors in log file.
[28-May-2016 12:35:41 UTC] PHP Fatal error: Call to a member function put_contents() on a non-object in /home3/redpill/public_html/markmccoy.com/WP2/wp-content/plugins/mu-plugins/randomize-salts.php on line 123
Line 123 reads:
$wp_filesystem->put_contents( $file, '<?php ' . $content, FS_CHMOD_FILE );

$file is defined on line 68 with my custom file name
$filename = ABSPATH . 'salty_hash.php';

That file is located in my WP root directory where wp-config.php is located.

wp-config.php has
require_once(ABSPATH . 'salty_hash.php');

Any ideas?
Thanks!