Initial commit

#pma/libraries/session.inc.php

@@ -0,0 +1,169 @@
+<?php
+/* vim: set expandtab sw=4 ts=4 sts=4: */
+/**
+ * session handling
+ *
+ * @todo    add an option to use mm-module for session handler
+ *
+ * @package PhpMyAdmin
+ * @see     https://www.php.net/session
+ */
+if (! defined('PHPMYADMIN')) {
+    exit;
+}
+
+// verify if PHP supports session, die if it does not
+
+if (!@function_exists('session_name')) {
+    PMA_warnMissingExtension('session', true);
+} elseif (ini_get('session.auto_start') !== '' && session_name() != 'phpMyAdmin') {
+    // Do not delete the existing session, it might be used by other
+    // applications; instead just close it.
+    session_write_close();
+}
+
+// disable starting of sessions before all settings are done
+// does not work, besides how it is written in php manual
+//ini_set('session.auto_start', '0');
+
+// session cookie settings
+session_set_cookie_params(
+    0, $GLOBALS['PMA_Config']->getRootPath(),
+    '', $GLOBALS['PMA_Config']->isHttps(), true
+);
+
+// cookies are safer (use @ini_set() in case this function is disabled)
+@ini_set('session.use_cookies', 'true');
+
+// optionally set session_save_path
+$path = $GLOBALS['PMA_Config']->get('SessionSavePath');
+if (!empty($path)) {
+    session_save_path($path);
+}
+
+// use cookies only
+@ini_set('session.use_only_cookies', '1');
+// strict session mode (do not accept random string as session ID)
+@ini_set('session.use_strict_mode', '1');
+// make the session cookie HttpOnly
+@ini_set('session.cookie_httponly', '1');
+// do not force transparent session ids
+@ini_set('session.use_trans_sid', '0');
+
+// delete session/cookies when browser is closed
+@ini_set('session.cookie_lifetime', '0');
+
+// warn but don't work with bug
+@ini_set('session.bug_compat_42', 'false');
+@ini_set('session.bug_compat_warn', 'true');
+
+// use more secure session ids
+@ini_set('session.hash_function', '1');
+
+// some pages (e.g. stylesheet) may be cached on clients, but not in shared
+// proxy servers
+session_cache_limiter('private');
+
+// start the session
+// on some servers (for example, sourceforge.net), we get a permission error
+// on the session data directory, so I add some "@"
+
+
+function PMA_sessionFailed($errors)
+{
+    $messages = array();
+    foreach ($errors as $error) {
+        /*
+         * Remove path from open() in error message to avoid path disclossure
+         *
+         * This can happen with PHP 5 when nonexisting session ID is provided,
+         * since PHP 7, session existence is checked first.
+         *
+         * This error can also happen in case of session backed error (eg.
+         * read only filesystem) on any PHP version.
+         *
+         * The message string is currently hardcoded in PHP, so hopefully it
+         * will not change in future.
+         */
+        $messages[] = preg_replace(
+            '/open\(.*, O_RDWR\)/',
+            'open(SESSION_FILE, O_RDWR)',
+            htmlspecialchars($error->getMessage())
+        );
+    }
+
+    /*
+     * Session initialization is done before selecting language, so we
+     * can not use translations here.
+     */
+    PMA_fatalError(
+        'Error during session start; please check your PHP and/or '
+        . 'webserver log file and configure your PHP '
+        . 'installation properly. Also ensure that cookies are enabled '
+        . 'in your browser.'
+        . '<br /><br />'
+        . implode('<br /><br />', $messages)
+    );
+}
+
+// See bug #1538132. This would block normal behavior on a cluster
+//ini_set('session.save_handler', 'files');
+
+$session_name = 'phpMyAdmin';
+@session_name($session_name);
+
+// on first start of session we check for errors
+// f.e. session dir cannot be accessed - session file not created
+$orig_error_count = $GLOBALS['error_handler']->countErrors(false);
+
+$session_result = session_start();
+
+if ($session_result !== true
+    || $orig_error_count != $GLOBALS['error_handler']->countErrors(false)
+) {
+    setcookie($session_name, '', 1);
+    $errors = $GLOBALS['error_handler']->sliceErrors($orig_error_count);
+    PMA_sessionFailed($errors);
+}
+unset($orig_error_count, $session_result);
+
+/**
+ * Disable setting of session cookies for further session_start() calls.
+ */
+@ini_set('session.use_cookies', 'true');
+
+/**
+ * Token which is used for authenticating access queries.
+ * (we use "space PMA_token space" to prevent overwriting)
+ */
+if (! isset($_SESSION[' PMA_token '])) {
+    if (! function_exists('openssl_random_pseudo_bytes')) {
+        $_SESSION[' PMA_token '] = bin2hex(phpseclib\Crypt\Random::string(16));
+    } else {
+        $_SESSION[' PMA_token '] = bin2hex(openssl_random_pseudo_bytes(16));
+    }
+
+    /**
+     * Check for disk space on session storage by trying to write it.
+     *
+     * This seems to be most reliable approach to test if sessions are working,
+     * otherwise the check would fail with custom session backends.
+     */
+    $orig_error_count = $GLOBALS['error_handler']->countErrors();
+    session_write_close();
+    if ($GLOBALS['error_handler']->countErrors() > $orig_error_count) {
+        $errors = $GLOBALS['error_handler']->sliceErrors($orig_error_count);
+        PMA_sessionFailed($errors);
+    }
+    session_start();
+}
+/**
+ * Check if token is properly generated (both above functions can return false).
+ */
+if (empty($_SESSION[' PMA_token '])) {
+    PMA_fatalError(
+        'Failed to generate random CSRF token!'
+    );
+}
+
+require_once 'libraries/session.lib.php';