Ticket #28625: db.php

<?php
defined( 'ABSPATH' ) OR exit;
/**
 * Plugin Name: MySQL(i) Database Connection
 * Description: Database connection that uses MySQL(i).
 * Compatibility: >= 4.3
 * Version: 1.3
 */

class wpdbi extends wpdb {

        private $ssl_key = null;
        private $ssl_cert = null;
        private $ssl_ca = null;
        private $ssl_capath = null;
        private $ssl_cipher = null;
        
        public function __construct( $dbuser, $dbpassword, $dbname, $dbhost, $ssl_key = null, $ssl_cert = null, $ssl_ca = null, $ssl_capath = null, $ssl_cipher = null ) {
                $this->ssl_key = $ssl_key;
                $this->ssl_cert = $ssl_cert;
                $this->ssl_ca = $ssl_ca;
                $this->ssl_capath = $ssl_capath;
                $this->ssl_cipher = $ssl_cipher;
                
                parent::__construct($dbuser, $dbpassword, $dbname, $dbhost);
        }

        public function db_connect( $allow_bail = true ) {
                $this->is_mysql = true;

                /*
                 * Deprecated in 3.9+ when using MySQLi. No equivalent
                 * $new_link parameter exists for mysqli_* functions.
                 */
                $new_link     = defined( 'MYSQL_NEW_LINK' ) ? MYSQL_NEW_LINK : true;
                $client_flags = defined( 'MYSQL_CLIENT_FLAGS' ) ? MYSQL_CLIENT_FLAGS : 0;

                if ( $this->use_mysqli ) {
                        $this->dbh = mysqli_init();

                        $host    = $this->dbhost;
                        $port    = null;
                        $socket  = null;
                        $is_ipv6 = false;

                        $host_data = $this->parse_db_host( $this->dbhost );
                        if ( $host_data ) {
                                list( $host, $port, $socket, $is_ipv6 ) = $host_data;
                        }

                        /*
                         * If using the `mysqlnd` library, the IPv6 address needs to be enclosed
                         * in square brackets, whereas it doesn't while using the `libmysqlclient` library.
                         * @see https://bugs.php.net/bug.php?id=67563
                         */
                        if ( $is_ipv6 && extension_loaded( 'mysqlnd' ) ) {
                                $host = "[$host]";
                        }

                        if ( WP_DEBUG ) {
                                mysqli_ssl_set($this->dbh, $this->ssl_key, $this->ssl_cert, $this->ssl_ca, $this->ssl_capath, $this->ssl_cipher); // ADDED
                                mysqli_real_connect( $this->dbh, $host, $this->dbuser, $this->dbpassword, null, $port, $socket, $client_flags );
                        } else {
                                // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
                                @mysqli_ssl_set($this->dbh, $this->ssl_key, $this->ssl_cert, $this->ssl_ca, $this->ssl_capath, $this->ssl_cipher); // ADDED
                                @mysqli_real_connect( $this->dbh, $host, $this->dbuser, $this->dbpassword, null, $port, $socket, $client_flags );
                        }

                        if ( $this->dbh->connect_errno ) {
                                $this->dbh = null;

                                /*
                                 * It's possible ext/mysqli is misconfigured. Fall back to ext/mysql if:
                                 *  - We haven't previously connected, and
                                 *  - WP_USE_EXT_MYSQL isn't set to false, and
                                 *  - ext/mysql is loaded.
                                 */
                                $attempt_fallback = true;

                                if ( $this->has_connected ) {
                                        $attempt_fallback = false;
                                } elseif ( defined( 'WP_USE_EXT_MYSQL' ) && ! WP_USE_EXT_MYSQL ) {
                                        $attempt_fallback = false;
                                } elseif ( ! function_exists( 'mysql_connect' ) ) {
                                        $attempt_fallback = false;
                                }

                                if ( $attempt_fallback ) {
                                        $this->use_mysqli = false;
                                        return $this->db_connect( $allow_bail );
                                }
                        }
                } else {
                        if ( WP_DEBUG ) {
                                $this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
                        } else {
                                // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
                                $this->dbh = @mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
                        }
                }

                if ( ! $this->dbh && $allow_bail ) {
                        wp_load_translations_early();

                        // Load custom DB error template, if present.
                        if ( file_exists( WP_CONTENT_DIR . '/db-error.php' ) ) {
                                require_once WP_CONTENT_DIR . '/db-error.php';
                                die();
                        }

                        $message = '<h1>' . __( 'Error establishing a database connection' ) . "</h1>\n";

                        $message .= '<p>' . sprintf(
                                /* translators: 1: wp-config.php, 2: Database host. */
                                __( 'This either means that the username and password information in your %1$s file is incorrect or we can&#8217;t contact the database server at %2$s. This could mean your host&#8217;s database server is down.' ),
                                '<code>wp-config.php</code>',
                                '<code>' . htmlspecialchars( $this->dbhost, ENT_QUOTES ) . '</code>'
                        ) . "</p>\n";

                        $message .= "<ul>\n";
                        $message .= '<li>' . __( 'Are you sure you have the correct username and password?' ) . "</li>\n";
                        $message .= '<li>' . __( 'Are you sure you have typed the correct hostname?' ) . "</li>\n";
                        $message .= '<li>' . __( 'Are you sure the database server is running?' ) . "</li>\n";
                        $message .= "</ul>\n";

                        $message .= '<p>' . sprintf(
                                /* translators: %s: Support forums URL. */
                                __( 'If you&#8217;re unsure what these terms mean you should probably contact your host. If you still need help you can always visit the <a href="%s">WordPress Support Forums</a>.' ),
                                __( 'https://wordpress.org/support/forums/' )
                        ) . "</p>\n";

                        $this->bail( $message, 'db_connect_fail' );

                        return false;
                } elseif ( $this->dbh ) {
                        if ( ! $this->has_connected ) {
                                $this->init_charset();
                        }

                        $this->has_connected = true;

                        $this->set_charset( $this->dbh );

                        $this->ready = true;
                        $this->set_sql_mode();
                        $this->select( $this->dbname, $this->dbh );

                        return true;
                }

                return false;
        }
}

if(!function_exists('wpdb'))
{
        function wpdb(): object
        {
                global $wpdb;
                
                return $wpdb;
        }
}

global $wpdb;

$wpdb = new wpdbi(
        DB_USER,
        DB_PASSWORD,
        DB_NAME,
        DB_HOST,
        ( defined( 'DB_SSL_KEY' ) ? DB_SSL_KEY : null ),
        ( defined( 'DB_SSL_CERT' ) ? DB_SSL_CERT : null ),
        ( defined( 'DB_SSL_CA' ) ? DB_SSL_CA : null ),
        ( defined( 'DB_SSL_CAPATH' ) ? DB_SSL_CAPATH : null ),
        ( defined( 'DB_SSL_CIPHER' ) ? DB_SSL_CIPHER : null )
);