Add sslCAFile option to DatabaseMysqli

[mediawiki.git] / includes / PHPVersionCheck.php

<?php
// @codingStandardsIgnoreFile Generic.Arrays.DisallowLongArraySyntax
// @codingStandardsIgnoreFile Generic.Files.LineLength
// @codingStandardsIgnoreFile MediaWiki.Usage.DirUsage.FunctionFound
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * Check PHP Version, as well as for composer dependencies in entry points,
 * and display something vaguely comprehensible in the event of a totally
 * unrecoverable error.
 * @class
 */
class PHPVersionCheck {
        /* @var string The number of the MediaWiki version used */
        var $mwVersion = '1.30';
        var $functionsExtensionsMapping = array(
                'mb_substr'   => 'mbstring',
                'utf8_encode' => 'xml',
                'ctype_digit' => 'ctype',
                'json_decode' => 'json',
                'iconv'       => 'iconv',
                'mime_content_type' => 'fileinfo',
        );

        /**
         * @var string Which entry point we are protecting. One of:
         *   - index.php
         *   - load.php
         *   - api.php
         *   - mw-config/index.php
         *   - cli
         */
        var $entryPoint = null;

        /**
         * @param string $entryPoint Which entry point we are protecting. One of:
         *   - index.php
         *   - load.php
         *   - api.php
         *   - mw-config/index.php
         *   - cli
         * @return $this
         */
        function setEntryPoint( $entryPoint ) {
                $this->entryPoint = $entryPoint;
        }

        /**
         * Returns the version of the installed php implementation.
         *
         * @param string $impl By default, the function returns the info of the currently installed PHP
         *  implementation. Using this parameter the caller can decide, what version info will be
         *  returned. Valid values: HHVM, PHP
         * @return array An array of information about the php implementation, containing:
         *  - 'version': The version of the php implementation (specific to the implementation, not
         *  the version of the implemented php version)
         *  - 'implementation': The name of the implementation used
         *  - 'vendor': The development group, vendor or developer of the implementation.
         *  - 'upstreamSupported': The minimum version of the implementation supported by the named vendor.
         *  - 'minSupported': The minimum version supported by MediWiki
         *  - 'upgradeURL': The URL to the website of the implementation that contains
         *  upgrade/installation instructions.
         */
        function getPHPInfo( $impl = false ) {
                if (
                        ( defined( 'HHVM_VERSION' ) && $impl !== 'PHP' ) ||
                        $impl === 'HHVM'
                ) {
                        return array(
                                'implementation' => 'HHVM',
                                'version' => defined( 'HHVM_VERSION' ) ? HHVM_VERSION : 'undefined',
                                'vendor' => 'Facebook',
                                'upstreamSupported' => '3.6.5',
                                'minSupported' => '3.6.5',
                                'upgradeURL' => 'https://docs.hhvm.com/hhvm/installation/introduction',
                        );
                }
                return array(
                        'implementation' => 'PHP',
                        'version' => PHP_VERSION,
                        'vendor' => 'the PHP Group',
                        'upstreamSupported' => '5.5.0',
                        'minSupported' => '5.5.9',
                        'upgradeURL' => 'https://secure.php.net/downloads.php',
                );
        }

        /**
         * Displays an error, if the installed php version does not meet the minimum requirement.
         *
         * @return $this
         */
        function checkRequiredPHPVersion() {
                $phpInfo = $this->getPHPInfo();
                $minimumVersion = $phpInfo['minSupported'];
                $otherInfo = $this->getPHPInfo( $phpInfo['implementation'] === 'HHVM' ? 'PHP' : 'HHVM' );
                if (
                        !function_exists( 'version_compare' )
                        || version_compare( $phpInfo['version'], $minimumVersion ) < 0
                ) {
                        $shortText = "MediaWiki $this->mwVersion requires at least {$phpInfo['implementation']}"
                                . " version $minimumVersion or {$otherInfo['implementation']} version "
                                . "{$otherInfo['minSupported']}, you are using {$phpInfo['implementation']} "
                                . "{$phpInfo['version']}.";

                        $longText = "Error: You might be using an older {$phpInfo['implementation']} version. \n"
                                . "MediaWiki $this->mwVersion needs {$phpInfo['implementation']}"
                                . " $minimumVersion or higher or {$otherInfo['implementation']} version "
                                . "{$otherInfo['minSupported']}.\n\nCheck if you have a"
                                . " newer php executable with a different name, such as php5.\n\n";

                        $longHtml = <<<HTML
                        Please consider <a href="{$phpInfo['upgradeURL']}">upgrading your copy of
                        {$phpInfo['implementation']}</a>.
                        {$phpInfo['implementation']} versions less than {$phpInfo['upstreamSupported']} are no 
                        longer supported by {$phpInfo['vendor']} and will not receive
                        security or bugfix updates.
                </p>
                <p>
                        If for some reason you are unable to upgrade your {$phpInfo['implementation']} version,
                        you will need to <a href="https://www.mediawiki.org/wiki/Download">download</a> an 
                        older version of MediaWiki from our website.
                        See our<a href="https://www.mediawiki.org/wiki/Compatibility#PHP">compatibility page</a>
                        for details of which versions are compatible with prior versions of {$phpInfo['implementation']}.
HTML;
                        $this->triggerError(
                                "Supported {$phpInfo['implementation']} versions",
                                $shortText,
                                $longText,
                                $longHtml
                        );
                }
        }

        /**
         * Displays an error, if the vendor/autoload.php file could not be found.
         *
         * @return $this
         */
        function checkVendorExistence() {
                if ( !file_exists( dirname( __FILE__ ) . '/../vendor/autoload.php' ) ) {
                        $shortText = "Installing some external dependencies (e.g. via composer) is required.";

                        $longText = "Error: You are missing some external dependencies. \n"
                                . "MediaWiki now also has some external dependencies that need to be installed\n"
                                . "via composer or from a separate git repo. Please see\n"
                                . "https://www.mediawiki.org/wiki/Download_from_Git#Fetch_external_libraries\n"
                                . "for help on installing the required components.";

                        $longHtml = <<<HTML
                MediaWiki now also has some external dependencies that need to be installed via
                composer or from a separate git repo. Please see
                <a href="https://www.mediawiki.org/wiki/Download_from_Git#Fetch_external_libraries">mediawiki.org</a>
                for help on installing the required components.
HTML;

                        $this->triggerError( 'External dependencies', $shortText, $longText, $longHtml );
                }
        }

        /**
         * Displays an error, if a PHP extension does not exist.
         *
         * @return $this
         */
        function checkExtensionExistence() {
                $missingExtensions = array();
                foreach ( $this->functionsExtensionsMapping as $function => $extension ) {
                        if ( !function_exists( $function ) ) {
                                $missingExtensions[] = $extension;
                        }
                }

                if ( $missingExtensions ) {
                        $shortText = "Installing some PHP extensions is required.";

                        $missingExtText = '';
                        $missingExtHtml = '';
                        $baseUrl = 'https://secure.php.net';
                        foreach ( $missingExtensions as $ext ) {
                                $missingExtText .= " * $ext <$baseUrl/$ext>\n";
                                $missingExtHtml .= "<li><b>$ext</b> "
                                        . "(<a href=\"$baseUrl/$ext\">more information</a>)</li>";
                        }

                        $cliText = "Error: Missing one or more required components of PHP.\n"
                                . "You are missing a required extension to PHP that MediaWiki needs.\n"
                                . "Please install:\n" . $missingExtText;

                        $longHtml = <<<HTML
                You are missing a required extension to PHP that MediaWiki
                requires to run. Please install:
                <ul>
                $missingExtHtml
                </ul>
HTML;

                        $this->triggerError( 'Required components', $shortText, $cliText, $longHtml );
                }
        }

        /**
         * Output headers that prevents error pages to be cached.
         */
        function outputHTMLHeader() {
                $protocol = isset( $_SERVER['SERVER_PROTOCOL'] ) ? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.0';

                header( "$protocol 500 MediaWiki configuration Error" );
                // Don't cache error pages!  They cause no end of trouble...
                header( 'Cache-control: none' );
                header( 'Pragma: no-cache' );
        }

        /**
         * Returns an error page, which is suitable for output to the end user via a web browser.
         *
         * @param string $title
         * @param string $longHtml
         * @param string $shortText
         * @return string
         */
        function getIndexErrorOutput( $title, $longHtml, $shortText ) {
                $pathinfo = pathinfo( $_SERVER['SCRIPT_NAME'] );
                if ( $this->entryPoint == 'mw-config/index.php' ) {
                        $dirname = dirname( $pathinfo['dirname'] );
                } else {
                        $dirname = $pathinfo['dirname'];
                }
                $encLogo =
                        htmlspecialchars( str_replace( '//', '/', $dirname . '/' ) .
                                'resources/assets/mediawiki.png' );
                $shortHtml = htmlspecialchars( $shortText );

                header( 'Content-type: text/html; charset=UTF-8' );

                $finalOutput = <<<HTML
<!DOCTYPE html>
<html lang="en" dir="ltr">
        <head>
                <meta charset="UTF-8" />
                <title>MediaWiki {$this->mwVersion}</title>
                <style media='screen'>
                        body {
                                color: #000;
                                background-color: #fff;
                                font-family: sans-serif;
                                padding: 2em;
                                text-align: center;
                        }
                        p, img, h1, h2, ul  {
                                text-align: left;
                                margin: 0.5em 0 1em;
                        }
                        h1 {
                                font-size: 120%;
                        }
                        h2 {
                                font-size: 110%;
                        }
                </style>
        </head>
        <body>
                <img src="{$encLogo}" alt='The MediaWiki logo' />
                <h1>MediaWiki {$this->mwVersion} internal error</h1>
                <div class='error'>
                <p>
                        {$shortHtml}
                </p>
                <h2>{$title}</h2>
                <p>
                        {$longHtml}
                </p>
                </div>
        </body>
</html>
HTML;

                return $finalOutput;
        }

        /**
         * Display something vaguely comprehensible in the event of a totally unrecoverable error.
         * Does not assume access to *anything*; no globals, no autoloader, no database, no localisation.
         * Safe for PHP4 (and putting this here means that WebStart.php and GlobalSettings.php
         * no longer need to be).
         *
         * Calling this function kills execution immediately.
         *
         * @param string $title HTML code to be put within an <h2> tag
         * @param string $shortText
         * @param string $longText
         * @param string $longHtml
         */
        function triggerError( $title, $shortText, $longText, $longHtml ) {
                switch ( $this->entryPoint ) {
                        case 'cli':
                                $finalOutput = $longText;
                                break;
                        case 'index.php':
                        case 'mw-config/index.php':
                                $this->outputHTMLHeader();
                                $finalOutput = $this->getIndexErrorOutput( $title, $longHtml, $shortText );
                                break;
                        case 'load.php':
                                $this->outputHTMLHeader();
                                $finalOutput = "/* $shortText */";
                                break;
                        default:
                                $this->outputHTMLHeader();
                                // Handle everything that's not index.php
                                $finalOutput = $shortText;
                }

                echo "$finalOutput\n";
                die( 1 );
        }
}

/**
 * Check php version and that external dependencies are installed, and
 * display an informative error if either condition is not satisfied.
 *
 * @note Since we can't rely on anything, the minimum PHP versions and MW current
 * version are hardcoded here
 */
function wfEntryPointCheck( $entryPoint ) {
        $phpVersionCheck = new PHPVersionCheck();
        $phpVersionCheck->setEntryPoint( $entryPoint );
        $phpVersionCheck->checkRequiredPHPVersion();
        $phpVersionCheck->checkVendorExistence();
        $phpVersionCheck->checkExtensionExistence();
}