1 files changed, 335 insertions, 0 deletions

diff --git a/application/helper/ApplicationUtils.php b/application/helper/ApplicationUtils.php
new file mode 100644
index 00000000..a6c03aae
--- /dev/null
+++ b/application/helper/ApplicationUtils.php
@@ -0,0 +1,335 @@
+<?php
+
+namespace Shaarli\Helper;
+
+use Exception;
+use malkusch\lock\exception\LockAcquireException;
+use malkusch\lock\mutex\FlockMutex;
+use Shaarli\Config\ConfigManager;
+
+/**
+ * Shaarli (application) utilities
+ */
+class ApplicationUtils
+{
+    /**
+     * @var string File containing the current version
+     */
+    public static $VERSION_FILE = 'shaarli_version.php';
+
+    public static $GITHUB_URL = 'https://github.com/shaarli/Shaarli';
+    public static $GIT_RAW_URL = 'https://raw.githubusercontent.com/shaarli/Shaarli';
+    public static $GIT_BRANCHES = ['latest', 'stable'];
+    private static $VERSION_START_TAG = '<?php /* ';
+    private static $VERSION_END_TAG = ' */ ?>';
+
+    /**
+     * Gets the latest version code from the Git repository
+     *
+     * The code is read from the raw content of the version file on the Git server.
+     *
+     * @param string $url     URL to reach to get the latest version.
+     * @param int    $timeout Timeout to check the URL (in seconds).
+     *
+     * @return mixed the version code from the repository if available, else 'false'
+     */
+    public static function getLatestGitVersionCode($url, $timeout = 2)
+    {
+        list($headers, $data) = get_http_response($url, $timeout);
+
+        if (strpos($headers[0], '200 OK') === false) {
+            error_log('Failed to retrieve ' . $url);
+            return false;
+        }
+
+        return $data;
+    }
+
+    /**
+     * Retrieve the version from a remote URL or a file.
+     *
+     * @param string $remote  URL or file to fetch.
+     * @param int    $timeout For URLs fetching.
+     *
+     * @return bool|string The version or false if it couldn't be retrieved.
+     */
+    public static function getVersion($remote, $timeout = 2)
+    {
+        if (startsWith($remote, 'http')) {
+            if (($data = static::getLatestGitVersionCode($remote, $timeout)) === false) {
+                return false;
+            }
+        } else {
+            if (!is_file($remote)) {
+                return false;
+            }
+            $data = file_get_contents($remote);
+        }
+
+        return str_replace(
+            [self::$VERSION_START_TAG, self::$VERSION_END_TAG, PHP_EOL],
+            ['', '', ''],
+            $data
+        );
+    }
+
+    /**
+     * Checks if a new Shaarli version has been published on the Git repository
+     *
+     * Updates checks are run periodically, according to the following criteria:
+     * - the update checks are enabled (install, global config);
+     * - the user is logged in (or this is an open instance);
+     * - the last check is older than a given interval;
+     * - the check is non-blocking if the HTTPS connection to Git fails;
+     * - in case of failure, the update file's modification date is updated,
+     *   to avoid intempestive connection attempts.
+     *
+     * @param string $currentVersion the current version code
+     * @param string $updateFile     the file where to store the latest version code
+     * @param int    $checkInterval  the minimum interval between update checks (in seconds
+     * @param bool   $enableCheck    whether to check for new versions
+     * @param bool   $isLoggedIn     whether the user is logged in
+     * @param string $branch         check update for the given branch
+     *
+     * @throws Exception an invalid branch has been set for update checks
+     *
+     * @return mixed the new version code if available and greater, else 'false'
+     */
+    public static function checkUpdate(
+        $currentVersion,
+        $updateFile,
+        $checkInterval,
+        $enableCheck,
+        $isLoggedIn,
+        $branch = 'stable'
+    ) {
+        // Do not check versions for visitors
+        // Do not check if the user doesn't want to
+        // Do not check with dev version
+        if (!$isLoggedIn || empty($enableCheck) || $currentVersion === 'dev') {
+            return false;
+        }
+
+        if (is_file($updateFile) && (filemtime($updateFile) > time() - $checkInterval)) {
+            // Shaarli has checked for updates recently - skip HTTP query
+            $latestKnownVersion = file_get_contents($updateFile);
+
+            if (version_compare($latestKnownVersion, $currentVersion) == 1) {
+                return $latestKnownVersion;
+            }
+            return false;
+        }
+
+        if (!in_array($branch, self::$GIT_BRANCHES)) {
+            throw new Exception(
+                'Invalid branch selected for updates: "' . $branch . '"'
+            );
+        }
+
+        // Late Static Binding allows overriding within tests
+        // See http://php.net/manual/en/language.oop5.late-static-bindings.php
+        $latestVersion = static::getVersion(
+            self::$GIT_RAW_URL . '/' . $branch . '/' . self::$VERSION_FILE
+        );
+
+        if (!$latestVersion) {
+            // Only update the file's modification date
+            file_put_contents($updateFile, $currentVersion);
+            return false;
+        }
+
+        // Update the file's content and modification date
+        file_put_contents($updateFile, $latestVersion);
+
+        if (version_compare($latestVersion, $currentVersion) == 1) {
+            return $latestVersion;
+        }
+
+        return false;
+    }
+
+    /**
+     * Checks the PHP version to ensure Shaarli can run
+     *
+     * @param string $minVersion minimum PHP required version
+     * @param string $curVersion current PHP version (use PHP_VERSION)
+     *
+     * @return bool true on success
+     *
+     * @throws Exception the PHP version is not supported
+     */
+    public static function checkPHPVersion($minVersion, $curVersion)
+    {
+        if (version_compare($curVersion, $minVersion) < 0) {
+            $msg = t(
+                'Your PHP version is obsolete!'
+                . ' Shaarli requires at least PHP %s, and thus cannot run.'
+                . ' Your PHP version has known security vulnerabilities and should be'
+                . ' updated as soon as possible.'
+            );
+            throw new Exception(sprintf($msg, $minVersion));
+        }
+        return true;
+    }
+
+    /**
+     * Checks Shaarli has the proper access permissions to its resources
+     *
+     * @param ConfigManager $conf        Configuration Manager instance.
+     * @param bool          $minimalMode In minimal mode we only check permissions to be able to display a template.
+     *                                   Currently we only need to be able to read the theme and write in raintpl cache.
+     *
+     * @return array A list of the detected configuration issues
+     */
+    public static function checkResourcePermissions(ConfigManager $conf, bool $minimalMode = false): array
+    {
+        $errors = [];
+        $rainTplDir = rtrim($conf->get('resource.raintpl_tpl'), '/');
+
+        // Check script and template directories are readable
+        foreach (
+            [
+            'application',
+            'inc',
+            'plugins',
+            $rainTplDir,
+            $rainTplDir . '/' . $conf->get('resource.theme'),
+            ] as $path
+        ) {
+            if (!is_readable(realpath($path))) {
+                $errors[] = '"' . $path . '" ' . t('directory is not readable');
+            }
+        }
+
+        // Check cache and data directories are readable and writable
+        if ($minimalMode) {
+            $folders = [
+                $conf->get('resource.raintpl_tmp'),
+            ];
+        } else {
+            $folders = [
+            $conf->get('resource.thumbnails_cache'),
+            $conf->get('resource.data_dir'),
+            $conf->get('resource.page_cache'),
+            $conf->get('resource.raintpl_tmp'),
+            ];
+        }
+
+        foreach ($folders as $path) {
+            if (!is_readable(realpath($path))) {
+                $errors[] = '"' . $path . '" ' . t('directory is not readable');
+            }
+            if (!is_writable(realpath($path))) {
+                $errors[] = '"' . $path . '" ' . t('directory is not writable');
+            }
+        }
+
+        if ($minimalMode) {
+            return $errors;
+        }
+
+        // Check configuration files are readable and writable
+        foreach (
+            [
+                 $conf->getConfigFileExt(),
+                 $conf->get('resource.datastore'),
+                 $conf->get('resource.ban_file'),
+                 $conf->get('resource.log'),
+                 $conf->get('resource.update_check'),
+             ] as $path
+        ) {
+            if (!is_file(realpath($path))) {
+                # the file may not exist yet
+                continue;
+            }
+
+            if (!is_readable(realpath($path))) {
+                $errors[] = '"' . $path . '" ' . t('file is not readable');
+            }
+            if (!is_writable(realpath($path))) {
+                $errors[] = '"' . $path . '" ' . t('file is not writable');
+            }
+        }
+
+        return $errors;
+    }
+
+    public static function checkDatastoreMutex(): array
+    {
+        $mutex = new FlockMutex(fopen(SHAARLI_MUTEX_FILE, 'r'), 2);
+        try {
+            $mutex->synchronized(function () {
+                return true;
+            });
+        } catch (LockAcquireException $e) {
+            $errors[] = t('Lock can not be acquired on the datastore. You might encounter concurrent access issues.');
+        }
+
+        return $errors ?? [];
+    }
+
+    /**
+     * Returns a salted hash representing the current Shaarli version.
+     *
+     * Useful for assets browser cache.
+     *
+     * @param string $currentVersion of Shaarli
+     * @param string $salt           User personal salt, also used for the authentication
+     *
+     * @return string version hash
+     */
+    public static function getVersionHash($currentVersion, $salt)
+    {
+        return hash_hmac('sha256', $currentVersion, $salt);
+    }
+
+    /**
+     * Get a list of PHP extensions used by Shaarli.
+     *
+     * @return array[] List of extension with following keys:
+     *                   - name: extension name
+     *                   - required: whether the extension is required to use Shaarli
+     *                   - desc: short description of extension usage in Shaarli
+     *                   - loaded: whether the extension is properly loaded or not
+     */
+    public static function getPhpExtensionsRequirement(): array
+    {
+        $extensions = [
+            ['name' => 'json', 'required' => true, 'desc' => t('Configuration parsing')],
+            ['name' => 'simplexml', 'required' => true, 'desc' => t('Slim Framework (routing, etc.)')],
+            ['name' => 'mbstring', 'required' => true, 'desc' => t('Multibyte (Unicode) string support')],
+            ['name' => 'gd', 'required' => false, 'desc' => t('Required to use thumbnails')],
+            ['name' => 'intl', 'required' => false, 'desc' => t('Localized text sorting (e.g. e->è->f)')],
+            ['name' => 'curl', 'required' => false, 'desc' => t('Better retrieval of bookmark metadata and thumbnail')],
+            ['name' => 'gettext', 'required' => false, 'desc' => t('Use the translation system in gettext mode')],
+            ['name' => 'ldap', 'required' => false, 'desc' => t('Login using LDAP server')],
+        ];
+
+        foreach ($extensions as &$extension) {
+            $extension['loaded'] = extension_loaded($extension['name']);
+        }
+
+        return $extensions;
+    }
+
+    /**
+     * Return the EOL date of given PHP version. If the version is unknown,
+     * we return today + 2 years.
+     *
+     * @param string $fullVersion PHP version, e.g. 7.4.7
+     *
+     * @return string Date format: YYYY-MM-DD
+     */
+    public static function getPhpEol(string $fullVersion): string
+    {
+        preg_match('/(\d+\.\d+)\.\d+/', $fullVersion, $matches);
+
+        return [
+            '7.1' => '2019-12-01',
+            '7.2' => '2020-11-30',
+            '7.3' => '2021-12-06',
+            '7.4' => '2022-11-28',
+            '8.0' => '2023-12-01',
+        ][$matches[1]] ?? (new \DateTime('+2 year'))->format('Y-m-d');
+    }
+}