dice-ware-passwords.php

<?php
/*
Plugin Name: Diceware passwords
Description: Use Diceware method for generating passwords in WordPress.
Version: 1.1
Author: George Botsev
Author URI:  https://www.george.botsev.it
License:     GPL2
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: diceware
Domain Path: /languages
*/
add_action('current_screen', 'diceware_passwords_init');

function diceware_passwords_init() {
	$screen = get_current_screen();
	if ( $screen->id == "profile" || $screen->id == "user" || $screen->id == "user-edit") {
		add_filter( 'random_password', 'dice_ware_password' );
	}
}
register_activation_hook( __FILE__, 'download_and_process_wordlist' );

function dice_ware_password( $password ) {
	$uploads_dir   = wp_upload_dir();
	$wordlist_path = $uploads_dir['basedir'] . '/diceware-wordlist.txt';
	if ( ! is_readable( $wordlist_path ) ) {
		download_and_process_wordlist();
	}
	$dice_ware_password = generate_dice_ware_password();

	return $dice_ware_password;
}

function download_and_process_wordlist() {
	$url      = 'https://theworld.com/~reinhold/diceware.wordlist.asc';
	$response = wp_remote_get( $url );

	if ( is_wp_error( $response ) ) {
		return;
	}

	$wordlist = wp_remote_retrieve_body( $response );

	$start             = strpos( $wordlist, "\n\n" ) + 2;
	$end               = strpos( $wordlist, "\n-----BEGIN PGP SIGNATURE-----" );
	$stripped_wordlist = trim( substr( $wordlist, $start, $end - $start ) );

	$uploads_dir   = wp_upload_dir();
	$wordlist_path = $uploads_dir['basedir'] . '/diceware-wordlist.txt';

	file_put_contents( $wordlist_path, $stripped_wordlist );
}

function get_dice_ware_wordlist() {
	$uploads_dir   = wp_upload_dir();
	$wordlist_path = $uploads_dir['basedir'] . '/diceware-wordlist.txt';

	$wordlist_contents = file_get_contents( $wordlist_path );
	$lines             = explode( "\n", $wordlist_contents );

	$dice_ware_wordlist = [];
	foreach ( $lines as $line ) {
		list( $key, $word ) = explode( "\t", $line );
		$dice_ware_wordlist[ $key ] = $word;
	}

	return $dice_ware_wordlist;
}

add_action( 'admin_menu', 'dice_ware_menu' );

function dice_ware_menu() {
	add_users_page(
		'Diceware Settings',
		'Diceware Passwords',
		'manage_options',
		'dice-ware-settings',
		'dice_ware_settings_page'
	);
}

function dice_ware_settings_page() {
	?>
    <div class="wrap">
        <h2>Diceware Password Settings</h2>
        <form method="post" action="options.php">
			<?php settings_fields( 'dice-ware-settings-group' ); ?>
			<?php do_settings_sections( 'dice-ware-settings-group' ); ?>
            <table class="form-table">
                <tr valign="top">
                    <th scope="row">Number of Dice Rolls</th>
                    <td><input type="number" name="dice_ware_rolls"
                               value="<?php echo esc_attr( get_option( 'dice_ware_rolls', 6 ) ); ?>"/></td>
                    <td>Specify the number of dice rolls that are to be performed in order to get a password of that
                        lenght
                    </td>
                </tr>
                <tr valign="top">
                    <th scope="row">Separator</th>
                    <td><input type="text" name="dice_ware_separator"
                               value="<?php echo esc_attr( get_option( 'dice_ware_separator', '-' ) ); ?>"/></td>
                    <td>Specify the separator between the different words of the password</td>
                </tr>
                <tr valign="top">
                    <th scope="row">Capitalize first letter</th>
                    <td><input type="checkbox" name="dice_ware_cap"
                               value="true" <?php checked( true, (bool) get_option( 'dice_ware_cap', 'true' ) ) ?> />
                    </td>
                    <td>Specify if you wish the first letter of every word to be a capital letter</td>
                </tr>
            </table>
			<?php submit_button(); ?>
        </form>
    </div>
	<?php
}

add_action( 'admin_init', 'dice_ware_settings' );

function dice_ware_settings() {
	register_setting( 'dice-ware-settings-group', 'dice_ware_rolls' );
	register_setting( 'dice-ware-settings-group', 'dice_ware_separator' );
	register_setting( 'dice-ware-settings-group', 'dice_ware_cap' );

	add_settings_section(
		'dice-ware-main-section',
		'Main Settings',
		'dice_ware_main_section_callback',
		'dice-ware-settings',
		'dice-ware-separator',
		'dice-ware-cap'

	);

	add_settings_field(
		'dice_ware_rolls',
		'Number of Dice Rolls',
		'dice_ware_rolls_callback',
		'dice-ware-settings',
		'dice-ware-main-section',
		'dice_ware_separator',
		'dice_ware_separator_callback',
		'dice_ware_cap',
		'dice_ware_cap_callback',
	);
}

function dice_ware_main_section_callback() {
	echo 'Configure Diceware settings below:';
}

function dice_ware_rolls_callback() {
	$value = esc_attr( get_option( 'dice_ware_rolls', 6 ) );
	echo "<input type='number' name='dice_ware_rolls' value='$value' />";
}

function dice_ware_separator_callback() {
	$value = esc_attr( get_option( 'dice_ware_separator', '-' ) );
	echo "<input type='text' name='dice_ware_separator' value='$value' />";
}

function dice_ware_cap_callback() {
	$value = esc_attr( get_option( 'dice_ware_cap', true ) );
	echo "<input name='dice_ware_cap' type='checkbox' value='true'" . checked( true, get_option( 'dice_ware_cap', 'true' ) ) . "/>";
}

function generate_dice_ware_password() {
	$dice_ware_wordlist = get_dice_ware_wordlist();

	$word_count = get_option( 'dice_ware_rolls', 6 );
	$separator  = get_option( 'dice_ware_separator', '-' );
	$cap        = (bool) get_option( 'dice_ware_cap', true );
	$password   = [];
	for ( $i = 0; $i < $word_count; $i ++ ) {
		$roll_result = "";
		for ( $j = 0; $j < 5; $j ++ ) {
			$roll_result .= strval( mt_rand( 1, 6 ) );
		}
		$password[] = $dice_ware_wordlist[ $roll_result ];
	}
	if ( $cap === true ) {
		foreach ( $password as $index => $word ) {
			$password[ $index ] = ucfirst( $word );
		}
	}

	return implode( $separator, $password );
}

?>