Custom Post Password Cookie Expiry Time

gistfile1.php

<?php /*

**************************************************************************

Plugin Name:  Custom Post Password Cookie Expiry Time
Description:  WordPress doesn't allow you to customize how long a post password cookie lasts. This plugin allows you to customize that value;
Version:      1.0.0
Author:       Alex Mills (Viper007Bond)
Author URI:   http://www.viper007bond.com/

**************************************************************************/

/**
 * Hook in right before the normal stuff fires in wp-login.php and set the cookie ourself
 */
add_action( 'login_form_postpass', 'login_form_postpass_custom_expiry' );

function login_form_postpass_custom_expiry() {
	global $wp_hasher;

	if ( empty( $wp_hasher ) ) {
		require_once( ABSPATH . 'wp-includes/class-phpass.php' );
		// By default, use the portable hash from phpass
		$wp_hasher = new PasswordHash(8, true);
	}

	setcookie( 'wp-postpass_' . COOKIEHASH, $wp_hasher->HashPassword( stripslashes( $_POST['post_password'] ) ), time() + 14400, COOKIEPATH );

	wp_safe_redirect( wp_get_referer() );
	exit();
}

Viper, just to confirm - I paste this in the top of wp-login.php? I completely forgot since Sat when we met.

er...functions.php of my theme...

Yes, your theme's functions.php or a plugin. Either will work.

Side note: here's the core ticket I opened about this issue: http://core.trac.wordpress.org/ticket/21466

A plugin would probably be better though -- that's what I wrote this code as (the stuff at the top of the code). You can just paste it into a new .php file, upload it to your /wp-content/plugins/ folder, and then activate it. Probably better than using your theme for this.

As of http://core.trac.wordpress.org/changeset/25450 this plugin is no longer needed.

Just hook into the new filter and return your own value.

This code is not working in the latest version of wp 4.3.1