<?php
/**
* Class for creating a backup codes provider.
*
* @package Two_Factor
*/
/**
* Class for creating a backup codes provider.
*
* @since 0.1-dev
*
* @package Two_Factor
*/
class Two_Factor_Backup_Codes extends Two_Factor_Provider {
/**
* The user meta backup codes key.
*
* @type string
*/
const BACKUP_CODES_META_KEY = '_two_factor_backup_codes';
/**
* The number backup codes.
*
* @type int
*/
const NUMBER_OF_CODES = 10;
/**
* Ensures only one instance of this class exists in memory at any one time.
*
* @since 0.1-dev
*/
public static function get_instance() {
static $instance;
$class = __CLASS__;
if ( ! is_a( $instance, $class ) ) {
$instance = new $class();
}
return $instance;
}
/**
* Class constructor.
*
* @since 0.1-dev
*/
protected function __construct() {
add_action( 'two_factor_user_options_' . __CLASS__, array( $this, 'user_options' ) );
add_action( 'admin_notices', array( $this, 'admin_notices' ) );
add_action( 'wp_ajax_two_factor_backup_codes_generate', array( $this, 'ajax_generate_json' ) );
return parent::__construct();
}
/**
* Displays an admin notice when backup codes have run out.
*
* @since 0.1-dev
*/
public function admin_notices() {
$user = wp_get_current_user();
// Return if the provider is not enabled.
if ( ! in_array( __CLASS__, Two_Factor_Core::get_enabled_providers_for_user( $user->ID ), true ) ) {
return;
}
// Return if we are not out of codes.
if ( $this->is_available_for_user( $user ) ) {
return;
}
?>
<div class="error">
<p>
<span>
<?php
echo wp_kses(
sprintf(
/* translators: %s: URL for code regeneration */
__( 'Two-Factor: You are out of backup codes and need to <a href="%s">regenerate!</a>', 'two-factor' ),
esc_url( get_edit_user_link( $user->ID ) . '#two-factor-backup-codes' )
),
array( 'a' => array( 'href' => true ) )
);
?>
<span>
</p>
</div>
<?php
}
/**
* Returns the name of the provider.
*
* @since 0.1-dev
*/
public function get_label() {
return _x( 'Backup Verification Codes (Single Use)', 'Provider Label', 'two-factor' );
}
/**
* Whether this Two Factor provider is configured and codes are available for the user specified.
*
* @since 0.1-dev
*
* @param WP_User $user WP_User object of the logged-in user.
* @return boolean
*/
public function is_available_for_user( $user ) {
// Does this user have available codes?
if ( 0 < self::codes_remaining_for_user( $user ) ) {
return true;
}
return false;
}
/**
* Inserts markup at the end of the user profile field for this provider.
*
* @since 0.1-dev
*
* @param WP_User $user WP_User object of the logged-in user.
*/
public function user_options( $user ) {
$ajax_nonce = wp_create_nonce( 'two-factor-backup-codes-generate-json-' . $user->ID );
$count = self::codes_remaining_for_user( $user );
?>
<p id="two-factor-backup-codes">
<button type="button" class="button button-two-factor-backup-codes-generate button-secondary hide-if-no-js">
<?php esc_html_e( 'Generate Verification Codes', 'two-factor' ); ?>
</button>
<span class="two-factor-backup-codes-count">
<?php
echo esc_html(
sprintf(
/* translators: %s: count */
_n( '%s unused code remaining.', '%s unused codes remaining.', $count, 'two-factor' ),
$count
)
);
?>
</span>
</p>
<div class="two-factor-backup-codes-wrapper" style="display:none;">
<ol class="two-factor-backup-codes-unused-codes"></ol>
<p class="description"><?php esc_html_e( 'Write these down! Once you navigate away from this page, you will not be able to view these codes again.', 'two-factor' ); ?></p>
<p>
<a class="button button-two-factor-backup-codes-download button-secondary hide-if-no-js" href="javascript:void(0);" id="two-factor-backup-codes-download-link" download="two-factor-backup-codes.txt"><?php esc_html_e( 'Download Codes', 'two-factor' ); ?></a>
<p>
</div>
<script type="text/javascript">
( function( $ ) {
$( '.button-two-factor-backup-codes-generate' ).click( function() {
$.ajax( {
method: 'POST',
url: ajaxurl,
data: {
action: 'two_factor_backup_codes_generate',
user_id: '<?php echo esc_js( $user->ID ); ?>',
nonce: '<?php echo esc_js( $ajax_nonce ); ?>'
},
dataType: 'JSON',
success: function( response ) {
var $codesList = $( '.two-factor-backup-codes-unused-codes' );
$( '.two-factor-backup-codes-wrapper' ).show();
$codesList.html( '' );
// Append the codes.
for ( i = 0; i < response.data.codes.length; i++ ) {
$codesList.append( '<li>' + response.data.codes[ i ] + '</li>' );
}
// Update counter.
$( '.two-factor-backup-codes-count' ).html( response.data.i18n.count );
// Build the download link.
var txt_data = 'data:application/text;charset=utf-8,' + '\n';
txt_data += response.data.i18n.title.replace( /%s/g, document.domain ) + '\n\n';
for ( i = 0; i < response.data.codes.length; i++ ) {
txt_data += i + 1 + '. ' + response.data.codes[ i ] + '\n';
}
$( '#two-factor-backup-codes-download-link' ).attr( 'href', encodeURI( txt_data ) );
}
} );
} );
} )( jQuery );
</script>
<?php
}
/**
* Generates backup codes & updates the user meta.
*
* @since 0.1-dev
*
* @param WP_User $user WP_User object of the logged-in user.
* @param array $args Optional arguments for assigning new codes.
* @return array
*/
public function generate_codes( $user, $args = '' ) {
$codes = array();
$codes_hashed = array();
// Check for arguments.
if ( isset( $args['number'] ) ) {
$num_codes = (int) $args['number'];
} else {
$num_codes = self::NUMBER_OF_CODES;
}
// Append or replace (default).
if ( isset( $args['method'] ) && 'append' === $args['method'] ) {
$codes_hashed = (array) get_user_meta( $user->ID, self::BACKUP_CODES_META_KEY, true );
}
for ( $i = 0; $i < $num_codes; $i++ ) {
$code = $this->get_code();
$codes_hashed[] = wp_hash_password( $code );
$codes[] = $code;
unset( $code );
}
update_user_meta( $user->ID, self::BACKUP_CODES_META_KEY, $codes_hashed );
// Unhashed.
return $codes;
}
/**
* Generates a JSON object of backup codes.
*
* @since 0.1-dev
*/
public function ajax_generate_json() {
$user = get_user_by( 'id', filter_input( INPUT_POST, 'user_id', FILTER_SANITIZE_NUMBER_INT ) );
check_ajax_referer( 'two-factor-backup-codes-generate-json-' . $user->ID, 'nonce' );
// Setup the return data.
$codes = $this->generate_codes( $user );
$count = self::codes_remaining_for_user( $user );
$i18n = array(
/* translators: %s: count */
'count' => esc_html( sprintf( _n( '%s unused code remaining.', '%s unused codes remaining.', $count, 'two-factor' ), $count ) ),
/* translators: %s: the site's domain */
'title' => esc_html__( 'Two-Factor Backup Codes for %s', 'two-factor' ),
);
// Send the response.
wp_send_json_success(
array(
'codes' => $codes,
'i18n' => $i18n,
)
);
}
/**
* Returns the number of unused codes for the specified user
*
* @param WP_User $user WP_User object of the logged-in user.
* @return int $int The number of unused codes remaining
*/
public static function codes_remaining_for_user( $user ) {
$backup_codes = get_user_meta( $user->ID, self::BACKUP_CODES_META_KEY, true );
if ( is_array( $backup_codes ) && ! empty( $backup_codes ) ) {
return count( $backup_codes );
}
return 0;
}
/**
* Prints the form that prompts the user to authenticate.
*
* @since 0.1-dev
*
* @param WP_User $user WP_User object of the logged-in user.
*/
public function authentication_page( $user ) {
require_once ABSPATH . '/wp-admin/includes/template.php';
?>
<p><?php esc_html_e( 'Enter a backup verification code.', 'two-factor' ); ?></p><br/>
<p>
<label for="authcode"><?php esc_html_e( 'Verification Code:', 'two-factor' ); ?></label>
<input type="tel" name="two-factor-backup-code" id="authcode" class="input" value="" size="20" pattern="[0-9]*" />
</p>
<?php
submit_button( __( 'Submit', 'two-factor' ) );
}
/**
* Validates the users input token.
*
* In this class we just return true.
*
* @since 0.1-dev
*
* @param WP_User $user WP_User object of the logged-in user.
* @return boolean
*/
public function validate_authentication( $user ) {
$backup_code = isset( $_POST['two-factor-backup-code'] ) ? sanitize_text_field( wp_unslash( $_POST['two-factor-backup-code'] ) ) : '';
return $this->validate_code( $user, $backup_code );
}
/**
* Validates a backup code.
*
* Backup Codes are single use and are deleted upon a successful validation.
*
* @since 0.1-dev
*
* @param WP_User $user WP_User object of the logged-in user.
* @param int $code The backup code.
* @return boolean
*/
public function validate_code( $user, $code ) {
$backup_codes = get_user_meta( $user->ID, self::BACKUP_CODES_META_KEY, true );
if ( is_array( $backup_codes ) && ! empty( $backup_codes ) ) {
foreach ( $backup_codes as $code_index => $code_hashed ) {
if ( wp_check_password( $code, $code_hashed, $user->ID ) ) {
$this->delete_code( $user, $code_hashed );
return true;
}
}
}
return false;
}
/**
* Deletes a backup code.
*
* @since 0.1-dev
*
* @param WP_User $user WP_User object of the logged-in user.
* @param string $code_hashed The hashed the backup code.
*/
public function delete_code( $user, $code_hashed ) {
$backup_codes = get_user_meta( $user->ID, self::BACKUP_CODES_META_KEY, true );
// Delete the current code from the list since it's been used.
$backup_codes = array_flip( $backup_codes );
unset( $backup_codes[ $code_hashed ] );
$backup_codes = array_values( array_flip( $backup_codes ) );
// Update the backup code master list.
update_user_meta( $user->ID, self::BACKUP_CODES_META_KEY, $backup_codes );
}
}