AskApache » PHP

Advanced WordPress wp-config.php Tweaks

AskApache — Sat, 03 Oct 2009 07:23:37 +0000

The bottom line for this article is that I want to make WordPress as fast, secure, and easy to install, run, and manage because I am using it more and more for client production sites, I will work for days in order to solve an issue so that I never have to spend time on that issue again. Time is money in this industry and that is ultimately (time) what there is to gain by tweaking WordPress.

Note: I spent no time on readability, this is primarily a read the code and figure it out article.. This is for advanced users looking for a reference or discussion and for those of you looking to advance. Feedback would be great if you make it that far..

For a better handle on the way I like to structure web site directories, see Optimize a Website for Speed, Security, and Easy Management but note it is a bit outdated compared to what I’m doing now. I don’t have the luxury of using only one type of server, or hosting provider anymore, so I have been working towards making things even more portable in order to move from host to host from server to server without issues i.e. my portable .bash_profile.

So I’ve been basically experimenting various ways to accomplish that and thought I would share what I am currently doing for my benefit and hopefully get some input. All of my WP installs run the development version, and one main idea with my setups is that upgrading is automated. So I really keep the WordPress install clean and use plugins and wp-config.php to do all the customization.

Portability – Hands-free upgrades and easy to move
Security – Additional security and protection
Speed – Less CPU and Disk I/O
Customization – All my favorite customizations

wp-config.php

These are the main settings I use.. Seriously this is more like an interactive article, because to understand it you will need to do some code grepping. You may want to grab a jolt.

ASKAPACHE_ROOT

The ASKAPACHE_ROOT variable is just a better way for me to be able to include and access all the different files in my site tree. For instance, in my non-wp php files, I can do this:

!defined('ASKAPACHE_ROOT') && require $_SERVER['DOCUMENT_ROOT'] . '/wp-config.php';
include(ASKAPACHE_ROOT . '/includes/custom-download.inc.php');

ASKAPACHE_LOCK

This is one of my all-time favorite hacks, that I think is one of the most useful methods I employ as a web developer. This allows me to use far-future-expire headers for optimum caching, while still forcing browsers to re-validate every day or so automatically, or forcing them to re-validate whenever I change the suffix. This takes advantage of the mod_rewrite trick that I use on EVERY site I run, definately worth learning. Because I practice best-practice web-standards, for every web site I create a single css file and javascript file, which I then add to the template like:

 Settings > General panel.
 */
!defined('WP_SITEURL') && define('WP_SITEURL', 'http://'.$_SERVER['SERVER_NAME']);
 
/**
 * WP_HOME is another wp-config.php option added in WordPress Version 2.2. Similar to WP_SITEURL,
 * WP_HOME overrides the wp_options table value for home but does not change it permanently.
 * home is the address you want people to type in their browser to reach your WordPress blog. It should include the http:// part. Also, do not put a slash "/" at the end.
 */
!defined('WP_HOME') && define('WP_HOME', WP_SITEURL);
 
/** no trailing slash, full paths only */
!defined('WP_CONTENT_DIR') && define( 'WP_CONTENT_DIR', ABSPATH . 'wp-content' );
 
// full url - WP_CONTENT_DIR is defined further up
!defined('WP_CONTENT_URL') && define( 'WP_CONTENT_URL', WP_SITEURL . '/wp-content');
 
/** Allows for the plugins directory to be moved from the default location. @since 2.6.0 */
// full path, no trailing slash
!defined('WP_PLUGIN_DIR') && define( 'WP_PLUGIN_DIR', WP_CONTENT_DIR . '/plugins' );
 
/** Allows for the plugins directory to be moved from the default location. @since 2.6.0 */
// full url, no trailing slash
!defined('WP_PLUGIN_URL') && define( 'WP_PLUGIN_URL', WP_CONTENT_URL . '/plugins' );
 
/** Allows for the plugins directory to be moved from the default location. @since 2.1.0 */
// Relative to ABSPATH.  For back compat.
//!defined('PLUGINDIR') && define( 'PLUGINDIR', 'wp-content/plugins' );
 
/** Number of autosaves to save. TRUE is default and enables post revisions, FALSE disables revisions completely. */
!defined('WP_POST_REVISIONS') && define('WP_POST_REVISIONS', 150);
 
/* ini_set('memory_limit', WP_MEMORY_LIMIT); */
!defined('WP_MEMORY_LIMIT') && define('WP_MEMORY_LIMIT', '64M');
 
/** Only check at this interval for new messages. Default is 5min */
/** @since 2.9  */
!defined('WP_MAIL_INTERVAL') && define('WP_MAIL_INTERVAL', 3600); // 1 hour
 
/** Saves updated post values to post from edit window every x seconds. (default 60)
 * When editing a post, WordPress uses Ajax to auto-save revisions to the post as you edit. You may want to increase this setting for longer delays in between auto-saves, or decrease the setting to make sure you never lose changes.
 * @since 2.5.0 */
!defined( 'AUTOSAVE_INTERVAL' ) && define( 'AUTOSAVE_INTERVAL', 60 );
 
/** @since 2.9.0  */
/** Permanently deletes posts, pages, attachments, and comments which have been in the trash for EMPTY_TRASH_DAYS. */
!defined( 'EMPTY_TRASH_DAYS' ) && define( 'EMPTY_TRASH_DAYS', 300 );

Debugging WordPress

One of my secrets for getting really good at this stuff is to master debugging. There is really not ever a time when I am working on a site that I don’t have color-highlighted logs scrolling automatically in an ssh window. It’s really almost impossible to fix problems with wordpress or do any kind of advanced anything without being able to view debugging info. At first I relied heavily on a custom php.ini being available on the server, but after having to deal with many hosts who don’t allow php.ini files I now rely completely on setting values using ini_set for ultimate portability. Detailed towards the end of this article and is also included in this wp-config.php

/**#@+
 * DEBUGGING STUFF
 */
/** display of notices during development. if false, error_reporting is E_ERROR | E_WARNING | E_PARSE | E_USER_ERROR | E_USER_WARNING | E_RECOVERABLE_ERROR otherwise E_ALL */
!defined('WP_DEBUG') && define('WP_DEBUG', false);
 
/** The SAVEQUERIES definition saves the database queries to a array and that array can be displayed to help analyze those queries.
 *  The information saves each query, what function called it, and how long that query took to execute.  */
!defined('SAVE_QUERIES') && define('SAVE_QUERIES', WP_DEBUG);
 
!defined('ACTION_DEBUG') && define('ACTION_DEBUG', WP_DEBUG);
 
/** This will allow you to edit the scriptname.dev.js files in the wp-includes/js and wp-admin/js directories.  */
!defined('SCRIPT_DEBUG') && define('SCRIPT_DEBUG', WP_DEBUG);

 
/** Add define('WP_DEBUG_LOG', true); to enable php debug logging to WP_CONTENT_DIR/debug.log */
//!defined('WP_DEBUG_LOG') && define('WP_DEBUG_LOG', true);
 
/** This determines whether errors should be printed to the screen as part of the output or if they should be hidden from the user.
 *  Add define('WP_DEBUG_DISPLAY', false); to wp-config.php to use the globally configured setting for display_errors and not force it to On */
!defined('WP_DEBUG_DISPLAY') && define('WP_DEBUG_DISPLAY', false);

Ultimate Security Tweaks

Well, ultimate for WP’s built-in keys and password functions, this is all for wp-config.php keep in mind. This is a very neccessary and recommended step, and is one of the only things I modify for each new installation.

Security KEYS

If like me you are familiar with password-cracking software like John the ripper, rainbow hash tables, l0pht-crack, etc.. then you will like to know that you can specify your own keys and salts for the encryption used by WP. They are AUTH_KEY, AUTH_SALT, SECURE_AUTH_KEY, SECURE_AUTH_SALT, LOGGED_IN_KEY, LOGGED_IN_SALT, NONCE_KEY, NONCE_SALT, SECRET_KEY and SECRET_SALT.

A random and long key gives you better encryption, and exponentially increasing that is using a random and long salt for the encryption. Encryptions with known salts are incredibly easy to decrypt compared to encryptions with secure salts, because the salt + key individually need to be guessed in order to find a matching hash, vs. just the key if the salt is known. See: Locating weak passwords.

A secret key is a hashing salt which makes your site harder to hack and access harder to crack by adding random elements to the password.

In simple terms, a secret key is a password with elements that make it harder to generate enough options to break through your security barriers. A password like “password” or “test” is simple and easily broken. A random, unpredictable password such as “88a7da62429ba6ad3cb3c76a09641fc” takes years to come up with the right combination.

For more information on the technical background and breakdown of secret keys and secure passwords, see:

I like to use the WordPress.org secret-key service 4 times. That’s because for each key and salt I like to do: (1 key from api +random keyboard input+1 key from api).

/**#@+
 * Authentication Unique Keys.
 *
 * Change these to different unique phrases!
 * You can generate these using the {@link https://api.wordpress.org/secret-key/1.1/ WordPress.org secret-key service}
 * You can change these at any point in time to invalidate all existing cookies.
 * This will force all users to have to log in again.
 *
 * @since 2.6.0
 *
 * Get salt to add to hashes to help prevent attacks.
 *
 * The secret key is located in two places: the database in case the secret key
 * isn't defined in the second place, which is in the wp-config.php file. If you
 * are going to set the secret key, then you must do so in the wp-config.php
 * file.
 *
 * The secret key in the database is randomly generated and will be appended to
 * the secret key that is in wp-config.php file in some instances. It is
 * important to have the secret key defined or changed in wp-config.php.
 *
 * If you have installed WordPress 2.5 or later, then you will have the
 * SECRET_KEY defined in the wp-config.php already. You will want to change the
 * value in it because hackers will know what it is. If you have upgraded to
 * WordPress 2.5 or later version from a version before WordPress 2.5, then you
 * should add the constant to your wp-config.php file.
 *
 * Below is an example of how the SECRET_KEY constant is defined with a value.
 * You must not copy the below example and paste into your wp-config.php. If you
 * need an example, then you can have a
 * {@link https://api.wordpress.org/secret-key/1.1/ secret key created} for you.
 *
 * Salting passwords helps against tools which has stored hashed values of
 * common dictionary strings. The added values makes it harder to crack if given
 * salt string is not weak.
 *
 * @since 2.5
 * @link https://api.wordpress.org/secret-key/1.1/ Create a Secret Key for wp-config.php
 *
 * @return string Salt value from either 'SECRET_KEY' or 'secret' option
 */
define('AUTH_KEY',        'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?p[B+GR{@>{Yq`c|LnG;dvq#| %OA_cbBSU6,rICC1o/c)-|');
define('SECURE_AUTH_KEY', 'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?Vp[Bb15baar8&R-r<[T|?(xhJJABGq+Ux+U$)-Hltp/');
define('LOGGED_IN_KEY',   'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?Vp[B<5n6DG|YWnJ9tY2!M1L)`{-$LW~~Ia%.uCbn!P. 41o2$Z$4');
define('NONCE_KEY',       'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?Vp[Bgu+wm 2)bS0Pd_+1rx0brX]ND8|');
define('SECRET_SALT',      '123423190847olqkfhladhfsldshafasdfasdf09a7f-90a87df98adfyapoiyaf9asd8f70a9s8d7f908a7sdf97W4qCdm2<>))U|sty)+4vpWooKls/^[vN');
/**#@-*/

Using SSL for Admin and Login

SSL is kinda required from my point of view, it is just way to easy to sniff data off the wire otherwise. At least with SSL you force them to use tools like burpsuite, paros proxy, webscarab, etc..

/** @since 2.6.0  */
!defined('FORCE_SSL_ADMIN') && define('FORCE_SSL_ADMIN', true);
 
/** @since 2.6.0  */
!defined('FORCE_SSL_LOGIN') && define('FORCE_SSL_LOGIN', true);

Mod_Rewrite to Force SSL

This is pretty cool, it forces non-https for all urls except for /wp-admin and wp-login.php, which both require https. It also checks for the logged_in_cookie, and if that is present in the request then it doesn't force non-https. Kinda confusing if you don't have a mod_rewrite cheatsheet.

RewriteCond %{THE_REQUEST} ^$ [OR]
RewriteCond %{REQUEST_URI} ^/(wp-admin|wp-login\.php).*$ [NC,OR]
RewriteCond %{HTTP_COOKIE} ^.*wp_li_sadfsdfasdf11b361cdsdfasdfasd=.*$ [NC]
RewriteRule .* - [S=1]
 
RewriteCond %{HTTPS} =on [OR]
RewriteCond %{HTTP_HOST} !^www\.askapache\.com$ [NC]
RewriteRule .* http://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]
 
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(wp-admin/.*|wp-login\.php.*)\ HTTP/ [NC]
RewriteCond %{HTTPS} !=on
RewriteRule .* https://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]

File System Permissions

You can get a basic and solid intro on file permissions by reading: Changing File Permissions, or you can check out some of my file permission research.

/** The permissions as octal number, usually 0644 for files, 0755 for dirs.
 *  http://codex.wordpress.org/Changing_File_Permissions
 *  if ( !$wp_filesystem->mkdir($remote_destination, FS_CHMOD_DIR) )
 */
!defined('FS_CHMOD_DIR') && define('FS_CHMOD_DIR', (0755 & ~ umask()));
!defined('FS_CHMOD_FILE') && define('FS_CHMOD_FILE', (0644 & ~ umask()));
/**#@-*/
 
/** Define the timeouts for the connections. Only available after the construct is called to allow for per-transport overriding of the default. */
//stream_set_timeout( $stream, FS_TIMEOUT );
//!defined('FS_TIMEOUT') && define('FS_TIMEOUT', 30);
 
//$this->link = @ftp_connect($this->options['hostname'], $this->options['port'], FS_CONNECT_TIMEOUT);
//!defined('FS_CONNECT_TIMEOUT') && define('FS_CONNECT_TIMEOUT', 30);
 
// function get_filesystem_method($args = array(), $context = false) {
//  $method = defined('FS_METHOD') ? FS_METHOD : false; //Please ensure that this is either 'direct', 'ssh', 'ftpext' or 'ftpsockets'
//!defined('FS_METHOD') && define('FS_METHOD', 'direct');
 
/** These methods for the WordPress core, plugin, and theme upgrades try to determine the WordPress path, as reported by PHP, but symlink trickery can sometimes
 * 'muck this up' so if you know the paths to the various folders on the server, as seen via your FTP user, you can manually define them in the wp-config.php file.
 * FS_METHOD forces the filesystem method. It should only be "direct", "ssh", "ftpext", or "ftpsockets".
 * FTP_BASE is the full path to the "base" folder of the WordPress installation.
 * FTP_CONTENT_DIR is the full path to the wp-content folder of the WordPress installation.
 * FTP_PLUGIN_DIR is the full path to the plugins folder of the WordPress installation.
 * FTP_PUBKEY is the full path to your SSH public key.
 * FTP_PRIKEY is the full path to your SSH private key.
 * FTP_USER is either user FTP or SSH username. Most likely these are the same, but use the appropriate one for the type of update you wish to do.
 * FTP_PASS is the password for the username entered for FTP_USER. If you are using SSH public key authentication this can be omitted.
 * FTP_HOST is the hostname:port combination for your SSH/FTP server. The standard FTP port is 21 and the standard SSH port is 22.
 */
//define('FS_METHOD', 'ftpext');
//define('FTP_BASE', '/path/to/wordpress/');
//define('FTP_CONTENT_DIR', '/path/to/wordpress/wp-content/');
//define('FTP_PLUGIN_DIR ', '/path/to/wordpress/wp-content/plugins/');
//define('FTP_PUBKEY', '/home/username/.ssh/id_rsa.pub');
//define('FTP_PRIKEY', '/home/username/.ssh/id_rsa');
//define('FTP_USER', 'username');
//define('FTP_PASS', 'password');
//define('FTP_HOST', 'ftp.example.org:21');
 
/**
 * Block requests through the proxy.
 *
 * Those who are behind a proxy and want to prevent access to certain hosts may do so. This will
 * prevent plugins from working and core functionality, if you don't include api.wordpress.org.
 *
 * You block external URL requests by defining WP_HTTP_BLOCK_EXTERNAL in your wp-config.php file
 * and this will only allow localhost and your blog to make requests.
 * The constant WP_ACCESSIBLE_HOSTS will allow additional hosts to go through for requests. The format of the
 * WP_ACCESSIBLE_HOSTS constant is a comma separated list of hostnames to allow.
 *
 * @since 2.8.0
 * @link http://core.trac.wordpress.org/ticket/8927 Allow preventing external requests.
/** @since 2.9  */
//!defined('WP_HTTP_BLOCK_EXTERNAL') && define( 'WP_HTTP_BLOCK_EXTERNAL', false );
 
/*
 * The constant WP_ACCESSIBLE_HOSTS will allow additional hosts to go through for requests. The format of the
 * WP_ACCESSIBLE_HOSTS constant is a comma separated list of hostnames to allow.
 *
 * @since 2.8.0
 * @link http://core.trac.wordpress.org/ticket/8927 Allow preventing external requests.
 * $accessible_hosts = preg_split('|,\s*|', WP_ACCESSIBLE_HOSTS);
 * return !in_array( $check['host'], $accessible_hosts ); //Inverse logic, If its in the array, then we can't access it.
 */
//!defined('WP_ACCESSIBLE_HOSTS') && define( 'WP_ACCESSIBLE_HOSTS', 'askapache.com,askapache.org' );

Cookies!

There’s always a little comfort in having non-default cookies for security (against auto-bots), and using shorter names also means smaller HTTP Packets.

The $cookie_hash is my hack to get around the fact that COOKIEHASH isn’t definable in wp-config.

/**#@+
 * COOKIES
 * Used to guarantee unique hash cookies @since 1.5 */
$cookie_hash=md5(WP_SITEURL);
 
/** Set a cookie now to see if they are supported by the browser.
 * setcookie(TEST_COOKIE, 'WP Cookie check', 0, COOKIEPATH, COOKIE_DOMAIN);
 * @since 2.3.0 */
!defined('TEST_COOKIE') && define('TEST_COOKIE', 'wp_tc');
 
/* @since 2.6.0 */
!defined('LOGGED_IN_COOKIE') && define('LOGGED_IN_COOKIE', 'wp_li_' . $cookie_hash);
 
/* @since 2.6.0 */
!defined('SECURE_AUTH_COOKIE') && define('SECURE_AUTH_COOKIE', 'wp_sa_' . $cookie_hash);
 
/* @since 2.5.0 */
!defined('AUTH_COOKIE') && define('AUTH_COOKIE', 'wp_a_' . $cookie_hash);
 
/* @since 2.0.0 */
!defined('PASS_COOKIE') && define('PASS_COOKIE', 'wp_p_' . $cookie_hash);
 
/* @since 2.0.0 */
!defined('USER_COOKIE') && define('USER_COOKIE', 'wp_u_' . $cookie_hash);
 
/* ok unset this var, its not needed as COOKIEHASH will have this value, but is not definable in wp-config.php */
unset($cookie_hash);
 
/** @since 1.2.0 */
!defined('COOKIEPATH') && define('COOKIEPATH', preg_replace('|https?://[^/]+|i', '', WP_HOME . '/' ) );
 
/** @since 1.5.0 */
!defined('SITECOOKIEPATH') && define('SITECOOKIEPATH', preg_replace('|https?://[^/]+|i', '', WP_SITEURL . '/' ) );
 
/** @since 2.6.0 */
!defined('ADMIN_COOKIE_PATH') && define( 'ADMIN_COOKIE_PATH', SITECOOKIEPATH . 'wp-admin' );
 
/** @since 2.6.0 */
!defined('PLUGINS_COOKIE_PATH') && define( 'PLUGINS_COOKIE_PATH', preg_replace('|https?://[^/]+|i', '', WP_PLUGIN_URL)  );
 
/** @since 2.0.0 */
!defined('COOKIE_DOMAIN') && define('COOKIE_DOMAIN', $_SERVER['SERVER_NAME']);

/**
  * The WP_CACHE setting, if true, includes the wp-content/advanced-cache.php script, when executing wp-settings.php.
  * For an advanced caching plugin to use, static because you would only want one
  * if ( defined('WP_CACHE') )@include WP_CONTENT_DIR . '/advanced-cache.php';
  */
!defined('WP_CACHE') && define('WP_CACHE', true);
 
/** WordPress Localized Language, defaults to en_US.
 *
 * Change this to localize WordPress.  A corresponding MO file for the chosen
 * language must be installed to wp-content/languages. For example, install
 * de.mo to wp-content/languages and set WPLANG to 'de' to enable German
 * language support. */
!defined('WPLANG') && define ('WPLANG', 'en_US');
 
/** Stores the location of the language directory. First looks for language folder in WP_CONTENT_DIR
 *   and uses that folder if it exists. Or it uses the "languages" folder in WPINC. @since 2.1.0 */
//!defined('WP_LANG_DIR') && define('WP_LANG_DIR', ABSPATH . WPINC . '/languages');
 
/** LANGDIR defines what directory the WPLANG .mo file resides. If LANGDIR is not defined WordPress looks first to wp-content/languages and then wp-includes/languages for the .mo defined by WPLANG file.  Old static relative path maintained for limited backwards compatibility - won't work in some cases*/
//!defined('LANGDIR') && define('LANGDIR', 'wp-content/languages');
 
/** Stores the location of the WordPress directory of functions, classes, and core content. @since 1.0.0 */
//!defined('WPINC') && define('WPINC', 'wp-includes');

WPMU Stuff

I personally don’t use.

/** Allows for the mu-plugins directory to be moved from the default location. @since 2.8.0 */
//!defined('WPMU_PLUGIN_DIR') && define( 'WPMU_PLUGIN_DIR', WP_CONTENT_DIR . '/mu-plugins' ); // full path, no trailing slash
 
/** Allows for the mu-plugins directory to be moved from the default location. @since 2.8.0 */
//!defined('WPMU_PLUGIN_URL') && define( 'WPMU_PLUGIN_URL', WP_CONTENT_URL . '/mu-plugins' ); // full url, no trailing slash
 
/** Allows for the mu-plugins directory to be moved from the default location. @since 2.8.0 */
//!defined( 'MUPLUGINDIR' ) && define( 'MUPLUGINDIR', 'wp-content/mu-plugins' ); // Relative to ABSPATH.  For back compat.

WordPress Database

This is usually the only thing I have to manually edit when creating a new site, unless I just use the same DB and modify the $table_prefix, (farther down). I run everything I possibly can in UTF-8, but if you don’t already know alot about character sets, wow it is one of the most confusing things so you may want to save learning about that topic for another day. Otherwise the following are helpful (and show how confusing character sets are!)

If you ever setup WP to use the builtin membership features, make sure you learn about the CUSTOM_USER_TABLE and CUSTOM_USER_META_TABLE constants, I’ve found them very helpful.

/**#@+
 * MySQL settings
 */
/** The name of the database for WordPress */
define('DB_NAME', 'askapachewpblog75');
 
/** The username to access the database */
define('DB_USER', 'askapache245d');
 
/** The password for the username to access the database */
define('DB_PASSWORD', 'asdfklj2340');
 
/** The hostname to connect to the database at */
define('DB_HOST', 'mysql.askapache.com');
 
/** The charset of the database */
define('DB_CHARSET', 'utf8');
 
/** The collation of the database */
define('DB_COLLATE', 'utf8_general_ci');

$table_prefix

The $table_prefix is the value placed in the front of your database tables. Change the value if you want to use something other than wp_ for your database prefix. Typically this is changed if you are installing multiple WordPress blogs in the same database, and also for enhanced security.

Its a safe and good idea to change this value pre-installation to add more security to your WordPress blog. Exploits attempted against your WordPress blog by malicious crackers often are built with the premise that your blog uses the prefix wp_, by changing the value you mitigate some attack vectors.

/**
 * WordPress Database Table prefix.
 *
 * You can have multiple installations in one database if you give each a unique
 * prefix. Only numbers, letters, and underscores please!
 */
$table_prefix  = 'ar15_';
 
/** CUSTOM_USER_TABLE and CUSTOM_USER_META_TABLE are used to designated that the user and usermeta tables normally utilized by WordPress are not used, instead these values/tables are used to store your user information. */
//!defined('CUSTOM_USER_TABLE') && define('CUSTOM_USER_TABLE', $table_prefix . 'my_users');
//!defined('CUSTOM_USER_META_TABLE') && define('CUSTOM_USER_META_TABLE', $table_prefix . 'my_usermeta');

Setup PHP Ini Settings

 
/** Turns the output of errors on or off, you really never want this on, you should only view errors by reading the log file. */
ini_set('display_errors', WP_DEBUG_DISPLAY);
 
/** Tells whether script error messages should be logged to the server's error log or error_log. */
ini_set('log_errors', 'On');
 
/** http://us.php.net/manual/en/timezones.php */
ini_set('date.timezone', 'America/Indianapolis');
 
/** Where to log php errors */
ini_set('error_log', ASKAPACHE_ROOT . '/logs/php_error.log');
 
/** Set the memory limit, otherwise defaults to '32M' */
ini_set('memory_limit', WP_MEMORY_LIMIT);

Sessions are slow

So I only use sessions when I have a specific use… In this case I need sessions only when one of the tools in the /online-tools/ directory is being used. And that is for the captcha image. In the future I won’t ever use sessions.

if(preg_match( '#^/online-tools/#',$_SERVER['REQUEST_URI'])) session_start();

Include Custom Files

Sure you could use the my-hacks.php that WP allows, or you can just stick your functions in your TEMPLATEPATH/functions.php file, but they are executed only after the wp-settings.php file, which may be too late for your file.

In the past I’ve also used the auto_prepend_file settings to run my script before anything (index.php) but I ran into some issues on different hosts, and it wasn’t as portable.

This is useful because you can have a file with globally available functions that you can use in non-WP areas as well as WP areas. I am moving away from this more and more as I learn more about classes and build plugins instead for portability.

include_once ASKAPACHE_ROOT . '/includes/myfunctions.inc';
 
/** Sets up WordPress vars and included files. */
require_once(ABSPATH . 'wp-settings.php');
?>

Some Useful PHP

I am constantly trying to make my sites and code more portable, so I am using plugins alot more to accomplish things that I use to do with separate php. Here are some examples of minimal php.

add_filter("the_generator", create_function('$a','return "";'));
add_filter('the_content', create_function('$a', 'return ((is_feed())? $a."".get_the_title()." originally appeared on ".get_bloginfo("name")."." : $a);'), 99999);
add_filter('excerpt_length', create_function('$a', 'return 300;'),99);
add_filter('excerpt_more', create_function('$a', 'return "…";'),99);
add_action( 'wp_head', create_function('$a','echo "\n";'), 95 );
add_action( 'wp_head', create_function('$a','echo "\n";'), 96 );
add_action( 'wp_head', create_function('$a','echo "\n";'), 97 );
add_action( 'wp_head', create_function('$a','echo "\n";'), 98 );
add_action( 'wp_head', create_function('$a','echo "\n";'), 99 );

Debugging Note

If you read this far than you probably know how important debugging is, but I sometimes like to stick the best tips deep in my articles to make sure only YOU find it. GRTFM isn’t used on this site, it’s mostly a requirement because my writing can get pretty bad.. The point, debugging is more than a crucial requirement if you want to do anything cool. Don’t worry I got you.. check my AskApache Debug Viewer Plugin from the official WP site. It’s pretty close to providing as verbose amount of information that I could possibly figure out how to get out of php, probably more than you have ever seen at least, I focused on quantity. I use it all the time on new installs as there is no setup required and it tells me advanced information about the setup of the server, hacker code for sure.

Here’s a quick function to see set global vars, I just think this is interesting code.

function askapache_global_debug(){
  global $_GET,$_POST,$_COOKIE,$_SESSION,$_ENV,$_FILES,$_SERVER,$_REQUEST,$HTTP_POST_FILES,$HTTP_POST_VARS,$HTTP_SERVER_VARS,$HTTP_RAW_POST_DATA,$HTTP_GET_VARS,$HTTP_COOKIE_VARS,$HTTP_ENV_VARS;
  $gv=create_function('$n','global $$n; ob_start(); if ( is_array($$n) && sizeof($$n)>0 && print("[{$n}]\n") ) print_r($$n);return ob_get_clean();');
  foreach (array('_GET','_POST','_COOKIE','_SESSION','_ENV','_FILES','_SERVER','_REQUEST','HTTP_POST_FILES','HTTP_POST_VARS','HTTP_SERVER_VARS','HTTP_RAW_POST_DATA','HTTP_GET_VARS','HTTP_COOKIE_VARS','HTTP_ENV_VARS') as $k)echo $gv($k);
  print_r(get_defined_constants());
}

Also check the WordPress Codex page: Editing wp-config.php

Advanced WordPress wp-config.php Tweaks originally appeared on AskApache.

An AskApache Plugin Upgrade to Rule them All

AskApache — Wed, 29 Jul 2009 17:59:07 +0000

So my blog as been rather quiet for almost a year now, and very few updates if any have been released for my Password Protection PLugin, my Google 404 Plugin, and definately not for my AskApache CrazyCache plugin, which I will be releasing last… So for all of you who’ve helped me out by sending me suggestions and notifying me of errors and sticking with it… Just wanted to say sorry about that, and thanks for all the great ideas.. Well, I’ve been sticking with it as well believe it our not. I manage to get free days once in a while, and then its time to jam.

I’ve used just about every CMS/Blog/Forum/Trac/Gallery/etc) and really didn’t like a lot of the way they coded… I could use php but I didn’t KNOW php.. so I’ve had to learn php also, and it was tough to learn the advanced class usage and all the other language specific (but similar) constructs for php. It was especially difficult (but fun and challenging) to program so as to be compatible with php4 and php5 (Such is WordPress). But I kept at it, and soon you can decide for yourself what to make of it.

I can code in plenty of languages (bash, lua, windows .bat and vbs, ocaml, big fan of all things shell) and can work my way through C and even sorta somewhat with assembly. Assembly is the hardest, by far, I’m into easy and powerful languages like Python, Javascript, perl, php, ruby, and CGI. I’ve used PHP for a long time to do various things, but never to build software projects like this. Once I noticed WordPress’s core .php files and the excellent programming I wanted to try and learn hot to do it. The WordPress code is some of the best I’ve seen. It appears the way they built it was planned, and not just dreamt up while typing that I can’t help but do. Every time I read through the core code I learn a new trick or very nice way to do something. Those guys are really good, and I think WordPress is going to dominate for a long long time.

The Strategy

The Password Protection (passpro) plugin has a lot of complex stuff going on, especially for a newbie to PHP and WordPress like me, so after refactoring the whole thing at least 5 times I decided to modify my approach, and wrote the AskApache Google 404 Plugin as a way to practice on a simpler piece of code, while at the same time providing a plugin of value. Eventually I stopped thinking I could just code the whole thing in one sit-down with a stream-of-consciousness, and had to instead modularize the code and focus in on each part before moving to the next (I go without a plan because its fun, just not the most productive, but again, I’m not a programmer in the scientific sense.).

So I decided I had to really learn how WordPress Plugins work, filters, hooks, actions, and basically comfortability at reverse-engineering code, (Im a beginner for the last time), and so with the upcoming release of the AskApache Google 404 Plugin I have succeeded in making an incredibly stable plugin. That way I only have to worry about what the aapasspro plugin is doing, instead of trying to fit it into a framework.

AskApache Google 404 Upgrade

I think its rather unusual to develop a nice plugin like this 404 handler merely for the purpose of improving upon another plugin, but hey it worked. As of 08/03/2009 14:06PM EST I have about 1 hour left of finishing touches to release this upgrade. But as you cantell by my badly edited posts, I don’t have a lot of time to myself. An hour here and there is about it. So it could be up to 2 weeks before I actually have the time to commit the release to the repo. On a sidenote, have you checked out Windows 7 News? I’ve been contracted to do some technical work for them and thought they had an excellent site.

But keep in mind, the 404 PLugin is just where I practice for the passpro plugin, which truly does have features that no other software like it has ever had. I understand the technology behind this plugin, and know it would really have a great impact on improving the Web (esp. WordPress) for all of us, I’ve just had to learn how to make it.

AskApache Password Protection

Probably still a couple weeks away, this plugin is the ultimate culmination of apache hackers dreams, at least those on shared servers (who may be interested in learning how to bypass security of said servers).. So this is something I have much too fun with doing what I like to do.. network/protocol-level security. I’ve examined the source code for many software packages that I use or have used to audit a server’s security, and this simple php plugin in most instances can enumerate with accuraccy most of the server’s setup in about a minute. The catch (and the file permission problems I had to find a workaround too) is that this software is launched on the server, not remotely against the server.

Some of the software I examined was whiskers, nessus, nmap, hping, mozilla source, wireshark, ncftp, netcat, etc.. The closest comparison to the socket-level class I’ve hacked together to those is wireshark. Except that wireshark only interprets (captures) the data passing over the wire, while this class does that and in fact sends and receives the data like netcat or nmap. Its really more similar to metasploit, and can easily be used to send hex, binary, ascii, or any type of payload to the remote or local host.

The Upgrades Begin

Well I started working on them a long time ago. Both the Password Protection plugin and the Google 404 plugin needed serious work. And I finally have it all figured out. Essentially I would work on one and finish an upgrade, but I just wasn’t happy with it and I wold start all over again, refactoring the code. So as I put the finishing touches on those 2 plugins keep an eye out. They are major upgrades. I was able to meet all the goals I had for them, and came up with a lot of more improvements during the process.One of the main things I needed was a socket-level class to perform all kinds of checks and tests on. I need this also for my crazy cache plugin, which my blog is currently using , and I have a 2 more really nice pplugins I use that also needed access to a network class. I wrote about what I was doing with fsockopen, and I’ve been improving on that example ever since. I use this class to do some really powerful and exciting stuff, but you’ll see it soon enough. As an indication of ‘getting it right’ for the Password Protection plugin, the plugin will now work on Windows, Apache, IIS, Lighthttpd, and will even work running on a blackberry web server. So now everyone using wordpress can at least get some security()

Many of the the other improvements focus on using the fsockopen class and .htaccess tricks to basically enumerate and discover all the different capabilities of your particular server; That way you can learn about all the features and security that are possible for your specific server, and the securty modules wi8ll be geared for that as well. FINALLY this plugin is going to be stable, and I just cant wait to see how people react when they learn all great capability their Apache-based Server has that they didn’t have a clue about. Its amazing in that sense, and hackers will love theh way it works.. but your server admins will love it even more because its entirely 100% focused on helping you to set your site up (if you have Apache) to keep spammers out, to keep virii-serving robots and their log-hogging exploit requests and CPU/Mem robiing 404 errors off of your servers for real. This will have a noticeable affect to whoever is running the server. As you can tell.. I am pumped!

Apache is easy to configure and use, but only when you have root access. Most people on shared and private hosting aren’t even able to view the main config file, let alone execute the Apache binaries to see what features are available and what configuration is being used.

Apache can only be influenced by the main server configs and by .htaccess files. Not by php, not by perl, and the main configs are almost never accessible to the masses. But .htaccess files are. And many hosting providers allow and enable .htaccess files, a configuration file for your web server. The advanced features and capabilities of Apache were out of reach for most of us, it just wasn’t possible to enumerate or access, and most hosting providers are infamous for their lack of .htaccess (customer) support. This plugin goes around those problems to give the power back to the people.

y creating custom .htaccess files containing unpublished .htaccess tricks and techniques and combining that with the use of socket-level networking from WordPress (PHP) using fsockopen, we can effectively enumerate and discover an incredible amount of features and settings you will be able to control and use with this plugin.

Here are a few examples of the capabilities of this plugin, some of which I believe no other software can do.. (Open source free to copy!).

Current Version of Apache (Down to the API Version)
List of ALL Modules currently enabled by Apache (Such as Mod_Rewrite)
List of ALL Directives enabled by EACH enabled Module.
Enumerate .htaccess Overrides, Context Permissions
Test for any builtin Handlers (like the status handler screenshot)
Configure SSI (http://www.askapache.com/htaccess/advanced-htaccess-ssi.html#htaccess-ssi-security)

March 1, 2009
I would focus on the method that WordPress uses. The code they have now (2.8 bleeding-edge) still isn’t where it needs to be, but this is some difficult stuff and they have a brilliant start, it’ll work.. just a question of when.

The main issue with the password protection plugin working for some people and not others is due to file permission configurations. The plugin attempts to write/modify files in your blog’s root directory.

November 05, 2008
To make a long story short, I downloaded each major release of the apache httpd source code starting at version 1.3.0 and finishing with version 2.2.11, I then compiled each version and built a HTTPD from source for all these apache versions.

1.3.0

1.3.1

1.3.11

1.3.12

1.3.14

1.3.17

1.3.19

1.3.2

1.3.20

1.3.22

1.3.23

1.3.24

1.3.27

1.3.28

1.3.29

1.3.3

1.3.31

1.3.32

1.3.33

1.3.34

1.3.35

1.3.36

1.3.37

1.3.39

1.3.4

1.3.41

1.3.6

1.3.9

2.0.35

2.0.36

2.0.39

2.0.40

2.0.42

2.0.43

2.0.44

2.0.45

2.0.46

2.0.47

2.0.48

2.0.49

2.0.50

2.0.51

2.0.52

2.0.53

2.0.54

2.0.55

2.0.58

2.0.59

2.0.61

2.0.63

2.1.3-beta

2.1.6-alpha

2.1.7-beta

2.1.8-beta

2.1.9-beta

2.2.0

2.2.10

2.2.2

2.2.3

2.2.4

2.2.6

2.2.8

2.2.9

2.2.10

2.2.11

Then I went through each version and determined the compatible modules for that version, and I’m pretty confident that I was also able to find each and every directive allowed by the compatible modules for that version (including core directives). See .htaccess directive list. Basically I can now test a server using a variety of methods and determine almost 100% accurately what version of Apache (down to the API) is running, what modules (and versions) are enabled, and each and every directive that is allowed or disallowed for that version. So this is so awesome because now we can enable all sorts of additional security features.

Htaccess enabled Modules
Here are most of the modules that come with Apache. Each one can have new commands that can be used in .htaccess file scopes.

mod_actions, mod_alias, mod_asis, mod_auth_basic, mod_auth_digest, mod_authn_anon, mod_authn_dbd, mod_authn_dbm, mod_authn_default, mod_authn_file, mod_authz_dbm, mod_authz_default, mod_authz_groupfile, mod_authz_host, mod_authz_owner, mod_authz_user, mod_autoindex, mod_cache, mod_cern_meta, mod_cgi, mod_dav, mod_dav_fs, mod_dbd, mod_deflate, mod_dir, mod_disk_cache, mod_dumpio, mod_env, mod_expires, mod_ext_filter, mod_file_cache, mod_filter, mod_headers, mod_ident, mod_imagemap, mod_include, mod_info, mod_log_config, mod_log_forensic, mod_logio, mod_mem_cache, mod_mime, mod_mime_magic, mod_negotiation, mod_proxy, mod_proxy_ajp, mod_proxy_balancer, mod_proxy_connect, mod_proxy_ftp, mod_proxy_http, mod_rewrite, mod_setenvif, mod_speling, mod_ssl, mod_status, mod_substitute, mod_unique_id, mod_userdir, mod_usertrack, mod_version, mod_vhost_alias

Debugging HTTP protocol

Check this out! I’m particularly happy about this feature, which outputs an exact trace of any requests made by the plugin (such as during the testing phase) by saving the actual raw data sent out on the wire using fsockopen, RX and TX. This is useful for a number of reasons, viewing your headers, finding Redirect Loops, testing RewriteRules, and following the request hop-by-hop for debugging. The below example shows 2 requests for 2 URIs. The first URI is protected using Digest Authentication, the 2nd shows Basic.

 ______________
|  RAW TRACE   |
==================================================================================================================================
GET /htaccess/index.txt?testing=query HTTP/1.1
Host: www.askapache.com
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1) AA_PassPro/1.9 (http://www.askapache.com/)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us
Accept-Encoding: gzip, deflate
Connection: close
Referer: http://www.askapache.com/
 
HTTP/1.1 401 Authorization Required
Date: Wed, 22 Jul 2009 06:29:58 GMT
Server: Apache
WWW-Authenticate: Digest realm="do or die", nonce="03328f3ec7c7b", algorithm=MD5, domain="/", qop="auth"
Accept-Ranges: bytes
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 882
Connection: close
Content-Type: text/html; charset=UTF-8
 
GET /htaccess/index.txt?testing=query HTTP/1.1
Host: www.askapache.com
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1) AA_PassPro/1.9 (http://www.askapache.com/)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us
Accept-Encoding: gzip, deflate
Connection: close
Referer: http://www.askapache.com/
Authorization: Digest username="test",realm="do or die",nonce="03328f3ec7c7b",uri="/htaccess/index.txt?testing=query",
cnonce="82d057852a9dc497",nc=00000001,algorithm=MD5,response="9d476e9ea3",qop="auth"
 
HTTP/1.1 200 OK
Date: Wed, 22 Jul 2009 06:29:58 GMT
Server: Apache
Authentication-Info: rspauth="9051b01ee26dd62b3e2b40dada694f45", cnonce="82d057852a9dc497", nc=00000001, qop=auth
Last-Modified: Tue, 21 Jul 2009 23:56:00 GMT
Accept-Ranges: bytes
Cache-Control: max-age=3600
Expires: Wed, 22 Jul 2009 07:29:58 GMT
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 27
Connection: close
Content-Type: text/plain; charset=UTF-8
```````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````
 
 ______________
|  RAW TRACE   |
==================================================================================================================================
GET /htaccess/po.txt?testing=query HTTP/1.1
Host: www.askapache.com
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1) AA_PassPro/1.9 (http://www.askapache.com/)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us
Accept-Encoding: gzip, deflate
Connection: close
Referer: http://www.askapache.com/
 
HTTP/1.1 401 Authorization Required
Date: Wed, 22 Jul 2009 06:29:58 GMT
Server: Apache
WWW-Authenticate: Basic realm="Po Pimping"
Accept-Ranges: bytes
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 878
Connection: close
Content-Type: text/html; charset=UTF-8
 
GET /htaccess/po.txt?testing=query HTTP/1.1
Host: www.askapache.com
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1) AA_PassPro/1.9 (http://www.askapache.com/)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us
Accept-Encoding: gzip, deflate
Connection: close
Referer: http://www.askapache.com/
Authorization: Basic adfAGAltcA==
 
HTTP/1.1 200 OK
Date: Wed, 22 Jul 2009 06:29:58 GMT
Server: Apache
Last-Modified: Wed, 22 Jul 2009 05:54:39 GMT
Accept-Ranges: bytes
Cache-Control: max-age=3600
Expires: Wed, 22 Jul 2009 07:29:58 GMT
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 27
Connection: close
Content-Type: text/plain; charset=UTF-8
```````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````

.htaccess Directives

AcceptFilter, AcceptMutex, AcceptPathInfo, AccessFileName, Action, AddAlt, AddAltByEncoding, AddAltByType, AddCharset, AddDefaultCharset, AddDescription, AddEncoding, AddHandler, AddIcon, AddIconByEncoding, AddIconByType, AddInputFilter, AddLanguage, AddModuleInfo, AddOutputFilter, AddOutputFilterByType, AddType, Alias, AliasMatch, AllowCONNECT, AllowEncodedSlashes, AllowOverride, Anonymous, Anonymous_Authoritative, Anonymous_LogEmail, Anonymous_MustGiveEmail, Anonymous_NoUserID, Anonymous_NoUserId, Anonymous_VerifyEmail, AssignUserId, AuthAuthoritative, AuthBasicAuthoritative, AuthBasicProvider, AuthDBDUserPWQuery, AuthDBDUserRealmQuery, AuthDBM, AuthDBMAuthoritative, AuthDBMGroupFile, AuthDBMType, AuthDBMUserFile, AuthDefaultAuthoritative, AuthDigestAlgorithm, AuthDigestDomain, AuthDigestFile, AuthDigestGroupFile, AuthDigestNcCheck, AuthDigestNonceFormat, AuthDigestNonceLifetime, AuthDigestProvider, AuthDigestQop, AuthDigestShmemSize, AuthGroupFile, AuthLDAPAuthzEnabled, AuthLDAPBindDN, AuthLDAPBindON, AuthLDAPBindPassword, AuthLDAPCharsetConfig, AuthLDAPCompareDNOnServer, AuthLDAPDereferenceAliases, AuthLDAPEnabled, AuthLDAPFrontPageHack, AuthLDAPGroupAttribute, AuthLDAPGroupAttributeIsDN, AuthLDAPRemoteUserAttribute, AuthLDAPRemoteUserIsDN, AuthLDAPStartTLS, AuthLDAPURL, AuthLDAPUrl, AuthName, AuthType, AuthUserFile, AuthzDBMAuthoritative, AuthzDBMType, AuthzDefaultAuthoritative, AuthzGroupFileAuthoritative, AuthzLDAPAuthoritative, AuthzOwnerAuthoritative, AuthzUserAuthoritative, BS2000Account, BalancerMember, BrowserMatch, BrowserMatchNoCase, BufferedLogs, CGIMapExtension, CacheDefaultExpire, CacheDirLength, CacheDirLevels, CacheDisable, CacheEnable, CacheExpiryCheck, CacheFile, CacheForceCompletion, CacheGcClean, CacheGcDaily, CacheGcInterval, CacheGcMemUsage, CacheGcUnused, CacheIgnoreCacheControl, CacheIgnoreHeaders, CacheIgnoreNoLastMod, CacheLastModifiedFactor, CacheMaxExpire, CacheMaxFileSize, CacheMaxStreamingBuffer, CacheMinFileSize, CacheNegotiatedDocs, CacheRoot, CacheSize, CacheStoreNoStore, CacheStorePrivate, CacheTimeMargin, CharsetDefault, CharsetOptions, CharsetSourceEnc, CheckCaseOnly, CheckSpelling, ChildPerUserId, ContentDigest, CookieDomain, CookieExpires, CookieLog, CookieName, CookieStyle, CookieTracking, CoreDumpDirectory, CustomLog, DAV, DAVDepthInfinity, DAVGenericLockDB, DAVMinTimeout, DBDExptime, DBDKeep, DBDMax, DBDMin, DBDParams, DBDPersist, DBDPrepareSQL, DBDriver, Dav, DavDepthInfinity, DavGenericLockDB, DavLockDB, DavMinTimeout, DefaultIcon, DefaultLanguage, DefaultType, DeflateBufferSize, DeflateCompressionLevel, DeflateFilterNote, DeflateMemLevel, DeflateWindowSize, Directory, DirectoryIndex, DirectoryMatch, DirectorySlash, DocumentRoot, DumpIOInput, DumpIOOutput, EnableExceptionHook, EnableMMAP, EnableSendfile, ErrorDocument, ErrorLog, Example, ExpiresActive, ExpiresByType, ExpiresDefault, ExtFilterDefine, ExtFilterOptions, ExtendedStatus, FancyIndexing, FileETag, Files, FilesMatch, FilterChain, FilterDeclare, FilterProtocol, FilterProvider, FilterTrace, ForceLanguagePriority, ForceType, ForensicLog, GprofDir, GracefulShutdownTimeout, Group, Header, HeaderName, HostNameLookups, HostnameLookups, ISAIPFakeAsync, ISAPIAppendLogToErrors, ISAPIAppendLogToQuery, ISAPICacheFile, ISAPIFakeAsync, ISAPILogNotSupported, ISAPIReadAheadBuffer, IdentityCheck, IdentityCheckTimeout, IfDefine, IfModule, IfVersion, ImapBase, ImapDefault, ImapMenu, Include, IndexIgnore, IndexOptions, IndexOrderDefault, IndexStyleSheet, KeepAlive, KeepAliveTimeout, LDAPCacheEntries, LDAPCacheTTL, LDAPCertDBPath, LDAPConnectionTimeout, LDAPOpCacheEntries, LDAPOpCacheTTL, LDAPSharedCacheFile, LDAPSharedCacheSize, LDAPTrustedClientCert, LDAPTrustedGlobalCert, LDAPTrustedMode, LDAPVerifyServerCert, LanguagePriority, Limit, LimitExcept, LimitInternalRecursion, LimitRequestBody, LimitRequestFields, LimitRequestFieldsize, LimitRequestLine, LimitXMLRequestBody, Listen, ListenBacklog, LoadFile, LoadModule, Location, LocationMatch, LockFile, LogFormat, LogLevel, MCacheMaxObjectCount, MCacheMaxObjectSize, MCacheMaxStreamingBuffer, MCacheMinObjectSize, MCacheRemovalAlgorithm, MCacheSize, MMapFile, MaxClients, MaxKeepAliveRequests, MaxMemFree, MaxRequestsPerChild, MaxSpareServers, MaxSpareThreads, MaxSpareThreadsPerChild, MaxThreads, MetaDir, MetaFiles, MetaSuffix, MimeMagicFile, MinSpareServers, MinSpareThreads, ModMimeUsePathInfo, MultiviewsMatch, NWSSLTrustedCerts, NWSSLUpgradeable, NameVirtualHost, NoProxy, NumServers, Options, PassEnv, PerlAccessHandler, PerlAuthenHandler, PerlAuthzHandler, PerlChildExitHandler, PerlChildInitHandler, PerlCleanupHandler, PerlDispatchHandler, PerlFixupHandler, PerlFreshRestart, PerlHandler, PerlHeaderParserHandler, PerlInitHandler, PerlLogHandler, PerlModule, PerlPassEnv, PerlPostReadRequestHandler, PerlRequire, PerlRestartHandler, PerlSendHeader, PerlSetEnv, PerlSetVar, PerlSetupEnv, PerlTaintCheck, PerlTransHandler, PerlTypeHandler, PerlWarn, PidFile, Port, Protocol, ProtocolEcho, Proxy, ProxyBadHeader, ProxyBlock, ProxyDomain, ProxyErrorOverride, ProxyFtpDirCharset, ProxyIOBufferSize, ProxyMatch, ProxyMaxForwards, ProxyPass, ProxyPassInterpolateEnv, ProxyPassMatch, ProxyPassReverse, ProxyPassReverseCookieDomain, ProxyPassReverseCookiePath, ProxyPreserveHost, ProxyReceiveBufferSize, ProxyRemote, ProxyRemoteMatch, ProxyRequests, ProxySet, ProxyStatus, ProxyTimeout, ProxyVia, RLimitCPU, RLimitMEM, RLimitNPROC, ReadmeName, Redirect, RedirectMatch, RedirectPermanent, RedirectTemp, RemoveCharset, RemoveEncoding, RemoveHandler, RemoveInputFilter, RemoveLanguage, RemoveOutputFilter, RemoveType, RequestHeader, Require, RewriteBase, RewriteCond, RewriteEngine, RewriteLock, RewriteLog, RewriteLogLevel, RewriteMap, RewriteOptions, RewriteRule, SSIAccessEnable, SSIEndTag, SSIErrorMsg, SSIStartTag, SSITimeFormat, SSIUndefinedEcho, SSLCACertificateFile, SSLCACertificatePath, SSLCADNRequestFile, SSLCADNRequestPath, SSLCARevocationFile, SSLCARevocationPath, SSLCertificateChainFile, SSLCertificateFile, SSLCertificateKeyFile, SSLCipherSuite, SSLCryptoDevice, SSLEngine, SSLHonorCipherOrder, SSLLog, SSLLogLevel, SSLMutex, SSLOptions, SSLPassPhraseDialog, SSLProtocol, SSLProxyCACertificateFile, SSLProxyCACertificatePath, SSLProxyCARevocationFile, SSLProxyCARevocationPath, SSLProxyCipherSuite, SSLProxyEngine, SSLProxyMachineCertificateFile, SSLProxyMachineCertificatePath, SSLProxyProtocol, SSLProxyVerify, SSLProxyVerifyDepth, SSLRandomSeed, SSLRequire, SSLRequireSSL, SSLSessionCache, SSLSessionCacheTimeout, SSLUserName, SSLVerifyClient, SSLVerifyDepth, Satisfy, ScoreBoardFile, Script, ScriptAlias, ScriptAliasMatch, ScriptInterpreterSource, ScriptLog, ScriptLogBuffer, ScriptLogLength, ScriptStock, SecureListen, SendBufferSize, ServerAdmin, ServerAlias, ServerLimit, ServerName, ServerPath, ServerRoot, ServerSignature, ServerTokens, SetEnv, SetEnvIf, SetEnvIfNoCase, SetHandler, SetInputFilter, SetOutputFilter, StartServers, StartThreads, Substitute, SuexecUserGroup, ThreadLimit, ThreadStackSize, ThreadsPerChild, TimeOut, Timeout, TraceEnable, TransferLog, TypeAuthDBMUserFile, TypesConfig, UnsetEnv, UseCanonicalName, UseCanonicalPhysicalPort, User, UserDir, VirtualDocumentRoot, VirtualDocumentRootIP, VirtualHost, VirtualScriptAlias, VirtualScriptAliasIP, Win32DisableAcceptEx, XBitHack, allow, deny, order, php_admin_flag, php_admin_value, php_flag, php_value

You can view the plugins home page, old, or view it on the wordpress.org site.

An AskApache Plugin Upgrade to Rule them All originally appeared on AskApache.

PHP and AJAX shell console

AskApache — Sun, 14 Jun 2009 01:01:15 +0000

Ever wanted to execute commands on your server through php to mimick a shell login? Now you can. I’m calling this file (see below) shell.php and it allows you to run commands on your web server with the same permissions that your php executable has.

Loading Video

PHP for `shell.php`

Substitue 1.1.1.1 for your IP address.. or see below for password authentication methods.






PHP AJAX Shell


:->

Read this

Note: The history feature works by remembering the last commands that you typed.. Access them by pressing the up or down arrows on your keyboard.

This is not an interactive session, so you cannot cd to a directory and then do stuff in that directory.. You may however be able to do stuff like /bin/bash -c "cd ../../;mv this there;ls -la;" or you could try exporting your current dir or something..

Writing shell scripts and serving them on your web server works by renaming the file.sh to file.cgi and chmodding it to 750 or +x. Also make sure you try dos2unix -dv file.cgi If you can’t get it to work..

Example shell script as cgi

#!/bin/sh
export MYBNAME=`date +%mx%dx%y-%Hx%M.tgz`
tar -czf ${HOME}/backups/${MYBNAME} ${HOME}/site1/
exit 0;

Locking Down Access to your shell.php

Thanks to the comment by Andrew Ramsden, Here are a couple ways to secure your shell.php file so that only you can run this script.

Secure your remote shell by adding this to your shell.php

Add this line to the very top of your shell.php file to make sure that only you can access this script. Everyone else sees a blank screen.

if ($_SERVER['REMOTE_ADDR'] !== '1.1.1.1') die();

Secure your remote shell with htaccess

This only allows access from IP 1.1.1.1 and redirects everyone else. See Using the Allow Directive in Apache htaccess for more info.

Order deny,allow
Deny from all
Allow from 1.1.1.1
ErrorDocument 403 http://www.askapache.com

Secure your remote shell with mod_rewrite and htaccess

Based on the code from htaccess article This only allows access from user with IP of 1.1.1.1 and redirects everyone else.

RewriteEngine On
RewriteBase /
RewriteCond %{REMOTE_HOST} !^1\.1\.1\.1
RewriteRule .* http://www.askapache.com [R=302,L]

PHP and AJAX shell console originally appeared on AskApache.

Advanced Htaccess Demo/Example using Cookies, Headers, Rewrites

AskApache — Wed, 01 Apr 2009 03:07:53 +0000

Welcome to the first generation of the new .htaccess tutorials/articles. Basically these are articles detailing my BEST (almost) successful .htaccess experiments, meaning this is the only place on the net you’ll find this technique. It’s home-grown .htaccess, and its some kush, good kush. Instead of just publishing my cryptic results and code in days past, whoah.. a working demo and the NSA building ;)

Using the Mod_Rewrite Variables Cheatsheet makes this example, and all advanced .htaccess code easier to understand. Well, advanced for me at least. I know alot of AskApache visitors are some of the top gurus in many IT fields, but mostly web developers or website owners like me.. This demo is pretty self-explanatory.. Try it out to see how simple of a task this .htaccess trick performs. And make sure you read the whole article as this htaccess technique can be used to do a heck of a lot more than this simple demo.

Set PDF Viewing Mode

Inline

Download

Save As

Please make a selection, defaults to "Save As" mode.

View PDF using selected mode »

Whoa pretty sweet huh? Bet you’ve never seen that before! As I explain the htaccess code that achieves this, keep in mind this is merely one simple application for this code. It’s much more advanced than your basic htaccess trick, notice how this htaccess acts like a php script, very unusual.. I really wanted to share this trick after I created it for one of my clients because this is the tip of the iceberg. Another use would be to display an alternate style sheet depending on a users theme preference. The coolest thing about this example IMHO is that it uses multiple advanced .htaccess ideas in order for it to work, most htaccess code on the net is very singular. This code uses mod_headers to set the Content-Disposition header for forcing a download and uses mod_rewrite to:

Send different Content-Type headers
Check the value of a cookie
Set environment variables for use later by mod_headers header directive

What’s Going On

There are 3 different ways for a server to send a pdf file in response to a request for one. This causes 3 different ways to open/view the pdf file in the clients browser.

The browser display’s a “Save File As” dialog, allowing you to save the file or open.
The browser opens the pdf file “Inline”, opening the pdf file in the browser like a web page.
The browser “Downloads” the pdf file automatically as an “Attachment” and then causes an external pdf reader program like adobe reader to open the file.

Some people prefer to have the option of saving the file to view later, some prefer opening it with an external program, and some just like the pdf file to load right in the browser… The point is that by using .htaccess, we can let them choose any of the 3 methods and save their preference for all further pdf files requested from our site by that user.

How It Works

When you click on one of the 3 demo buttons above, “Inline”, “Save As”, or “Download”, a cookie named askapache_pdf is saved in your browser using the javascript below, with the value being set to which button you clicked. Then when you request the pdf file the .htaccess code below uses mod_rewrite to read the value of the askapache_pdf cookie, and depending on which was your preference it will send alternate HTTP Headers that control how your browser handles the file.

Htaccess Demo File

For the demo I created the folder /storage/pdf/ and this is the .htaccess file at /storage/pdf/.htaccess

#
# The default Content-Type for .pdf files
# This will make .pdf files default Content-Type header have
# the value 'application/pdf' - but the default can be overridden by
# using RewriteRule with the [T='different/type']
#
AddType application/pdf .pdf
 
#
# Turn on the rewrite engine
# if its already on you dont need this
#
RewriteEngine On
 
#
# Skip RewriteRules if not .pdf request, like autoindexing
# The next [2] RewriteRule directives are specific for .pdf files
# so if the filename requested does not end in .pdf
# then the [S=2] instructs the next 2 RewriteRule
# directives to be completely skipped
#
RewriteRule !.*\.pdf$ - [S=2]
 
#
# The first RewriteCond checks to see if the askapache_pdf cookie
# is NOT set.  The second RewriteCond checks to see if the askapche_pdf
# cookie has the value of s, which is the value corresponding to
# someone clicking the "Save As" button.
#
# The [NC,OR] flag means that if the cookie askapache_pdf does not
# exist, OR (next cond) if the askapache_pdf cookie does exist and is set to 's'
# then process the RewriteRule.  If neither cond is true the rewriterule is skipped.
#
# If one of the RewriteCond is true, then the RewriteRule is processed.
# The RewriteRule applies to any/all requests (.*) but doesn't rewrite anything (-)
# This RewriteRule sets an Apache environment variable ASKAPACHE_PDFS to have the
# value of 1 if either rewritecond is true.  The variable can be checked by any directives
# following the rewriterule in the whole htaccess file.  The ASKAPACHE_PDFS ends in S
# because if this variable exists then it means the users preference is 'Save As'
#
# Notice that if the user requested the pdf file without selecting a preference
# i.e. no cookie exists, then the ASKAPACHE_PDFS variable is still set.
# This just lets us pick the default preference for them, in this example the
# default is 'Save As'
#
RewriteCond %{HTTP_COOKIE} !^.*askapache_pdf.*$ [NC,OR]
RewriteCond %{HTTP_COOKIE} ^.*askapache_pdf=s.*$ [NC]
RewriteRule .* - [E=ASKAPACHE_PDFS:1]
 
#
# The RewriteCond checks the askapache_pdf cookie for the value 'a'
# which 'a' represents 'Download'
#
# If the cookies value is 'a' then the RewriteRule overrides the default
# Content-Type from 'application/pdf' set with AddType earlier, to
# 'application/octet-stream', which is a special content-type that tells the browser
# that the file cannot be loaded by the browser 'Inline', but must be saved
# which will be opened by an external viewer depending on browser
#
RewriteCond %{HTTP_COOKIE} ^.*askapache_pdf=a.*$
RewriteRule .* - [T=application/octet-stream]
 
#
# This is superfly.  If the cookie/users-preference was 'Save As' (s)
# then the RewriteRule above the last one set the environment
# variable ASKAPACHE_PDFS to have the value 1.  The Header directive here
# is ONLY processed in that variable ASKAPACHE_PDFS exists.  That is what
# the end 'env=ASKAPACHE_PDFS' does, it is the condition that must be met or
# the Header directive is skipped.
#
# If the ASKAPACHE_PDFS environment variable set by RewriteRule does exist
# then the header directive adds the header 'Content-Disposition: attachment' to
# the normal Response Headers.  The 'Content-Disposition: attachment' header
# instructs your browser to present you with the 'Save As' dialog box
# allowing you to choose whether you want to save or open
#
Header set Content-Disposition "attachment" env=ASKAPACHE_PDFS

Unique HTTP Headers Returned

When it comes down to it, the following information is the 3 modes. Notice each one is different, because these headers are the only thing controlling how your browser handles the file.

Save As Mode (askapache_pdf=s)

Content-Disposition: attachment
Content-Type: application/pdf

Inline Mode (askapache_pdf=i)

Content-Type: application/pdf

Download Mode (askapache_pdf=a)

Content-Type: application/octet-stream

Javascript used by Demo

The best place for javascript is quirksmode, here is a definitive article on setting, reading, parsing, etc.. COOKIES.

  if(!gi('pdfr'))return;
  var pdfr=gi('pdfr');
  var cval=getCookie('askapache_pdf');

  if(cval=='i'){pdfr.innerHTML='Currently set to "Inline".';}
  else if(cval=='a'){pdfr.innerHTML='Currently set to "Download" mode.';}
  else if(cval=='s'){pdfr.innerHTML='Currently set to "Save As" mode.';}
 
  addMyEvent(gi('pdfi'),"mousedown",function(){setCookie("askapache_pdf", "i", "", "/", "www.askapache.com"); gi('pdfr').innerHTML = 'Changed mode to "Inline".'; return false; });
  addMyEvent(gi('pdfa'),"mousedown",function(){setCookie("askapache_pdf", "a", "", "/", "www.askapache.com"); gi('pdfr').innerHTML = 'Changed mode to "Download".'; return false; });
  addMyEvent(gi('pdfs'),"mousedown",function(){setCookie("askapache_pdf", "s", "", "/", "www.askapache.com"); gi('pdfr').innerHTML = 'Changed mode to "Save As".'; return false; });

Alternative Method – No Cookies + PHP

This is what I came up with first for my client, and then while programming the php I noticed.. Hey! I think I can do the same thing using .htaccess, which would save me on cpu/memory/potential security/etc.. but this works great too. Though you will need to hack the code to get it working probably..

Note that the .htaccess rewrite code I used here used FILENAME-i.pdf or FILENAME-s.pdf to pass the preference to the pdf-dl.php script, it also worked for FILENAME.pdf?i=i

pdf-dl.php

if (
!isset($_GET['file'])
|| ($f=$_GET['file'])===false
|| ($fp=@fopen($f,"rb"))===false
|| ($fi=pathinfo($f))===false
|| ($fi['fsize']=filesize($f))===false
|| strtolower($fi["extension"])!='pdf'
) die('Failed');

ob_start();
header('Accept-Ranges: bytes');
header("Content-Length: {$fi['fsize']}");
header('Content-Type: application/pdf');
if(!isset($_GET['i'])) header("Content-Disposition: attachment; filename=\"{$fi['basename']}\"");

$sent = 0;
while ( !feof($fp) && $sent < $fi['fsize'] && ($buf = fread($fp, 8192)) != '' ){
echo $buf;
$sent += strlen($buf);
flush();
ob_flush();
}
fclose($fp);
exit;
?>

Alternate Method .htaccess

#
# Deny direct request to pdf-dl.php file
#
RewriteCond %{THE_REQUEST} ^.*pdf-dl\.php.*$ [NC]
RewriteRule .* - [F]
 
#
# Handle PDF files named anything-i.pdf as inline
#
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ([^/]*)-i\.pdf$  /cgi-bin/pdf-dl.php?i=i&file=%{DOCUMENT_ROOT}/storage/pdf/$1.pdf [L,NC,QSA,S=1]
 
#
# Handle PDF files without -i.pdf as attachments
#
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ([^/]*)\.pdf$  /cgi-bin/pdf-dl.php?file=%{DOCUMENT_ROOT}/storage/pdf/$1.pdf [L,NC,QSA]

More Info

The following is more information about the Content-Dispositon header and related headers, and will make you an expert at this if you read it all.. (no thanks)

Interesting Reading

Here is the thread of the original draft proposal for the Content-Disposition header.

Content-Disposition Header, Rens Troost - 22 Jun 1993
- Re: Content-Disposition Header, Nathaniel Borenstein
  - Re: Content-Disposition Header, Gabe Beged-Dov
    - Re: Content-Disposition Header, Rens Troost
    - Re: Content-Disposition Header, Gabe Beged-Dov
    - Content-Disposition Header and multipart/alternative, Rens Troost
    - Re: Content-Disposition Header and multipart/alternative, Nathaniel Borenstein
  - Re: Content-Disposition Header, Keith Moore
    - Re: Content-Disposition Header, Nathaniel Borenstein
    - Re: Content-Disposition Header, Ed Levinson (Contractor)
    - Re: Content-Disposition Header, Keith Moore
    - Re: Content-Disposition Header, Rens Troost
    - Re: Content-Disposition Header, Harald Tveit Alvestrand
  - Re: Content-Disposition Header, Steve Dorner
    - Re: Content-Disposition Header, Rens Troost
      - Re: Content-Disposition Header, Keith Moore
  - Re: Content-Disposition Header, Carlyn M. Lowery

Intense Reading

Advanced Htaccess Demo/Example using Cookies, Headers, Rewrites originally appeared on AskApache.

Htaccess SEO Trends by Google

AskApache — Sun, 29 Mar 2009 06:10:03 +0000

How Relevant Is .htaccess?

Scale is based on the average worldwide traffic of htaccess in all years.

.htaccess vs. htaccess

htaccess vs. httpd.conf

mod_rewrite vs. mod_security

Web Server Comparisons

Of course IIS is well-known to someone like me… but who cares about the big servers when small, light, super-fast servers are on the rise? See this Comparison of Web Servers.

Apache HTTP vs. Windows IIS

Fnord, Nginx, LightHttpd

Fnord what is going on?

Web Programming Comparisons

An interesting look at the search engine trends of programming languages out there today…

Did Ruby Pass Perl!

Keep in mind that Google may be interpreting “ruby” to be a precious stone… and what is a “perl” exactly? ;)

Perl vs. PHP, Old Debate

SEO

Wow. Big surpise there ;)

Treo vs. Blackberry vs. Palm

I love my Blackberry Curve! I used to love my Sony Clie, and I won’t forget my many Palms!

AskApache WebSite

Google Trends also lets you compare websites, I can’t believe its been over a year for askapache.com, thanks for stopping by!

Google Trends – Rocks!

Fun, free, and helpful tool from who else?

Htaccess SEO Trends by Google originally appeared on AskApache.

Password Protection Plugin Status

AskApache — Sun, 01 Mar 2009 17:39:57 +0000

I wanted to address why the update to the AskApache Password Protection plugin didn’t happen pre-2009 as I had hoped.. Mostly due to my job but I thought I could at least fill you in. Oh and this is going to get very boring very fast, unless you’re ready to rumble in the zone.

File Permissions!

The main issue with the password protection plugin working for some people and not others is due to file permission configurations. WordPress is simply a group of .php files saved on your server. The actual program that is in fact running WordPress is the PHP interpreter, which is in turn controlled by the Apache Server. Almost all computers are running at least 2 servers, the Web Server which serves and displays your files, and a FTP server.

Here’s a detailed look at the Apache Security Model, from ApacheSecurity.net, a blog maintained by Ivan Ristic, the author of ModSecurity.

The problem is happening because when you login to your FTP server with your username and password, the files that you upload are then owned by that username and password, which is almost always an actual user account on the server system. But the Apache Server is an executable file itself, and it is not owned by your FTP username, for security reasons. Apache controls the PHP Interpreter, which parses and executes the WordPress and plugin files as a separate user. ( SuEXEC, Apache Security Tips )

So what happens is the askapache-password-protect.php file saved on your server and is owned by the user that created it (if you downloaded it to your computer then used ftp to transfer, your ftp user owns it.. if you used a php downloader script, then the php process owner owns it) So when you click on the Run Tests button from the WordPress administration website what you are doing is sending a request via HTTP to your Apache Server process, which sees the requested file is .php so it then runs the php interpreter to execute the askapache-password-protect.php file, then that file uses programming to attempt and write/modify a file in your blog’s root directory.

Process Owner vs. File Owner

So who owns your blog’s root directory? Your ftp user account/ you do.. but who owns the process that is trying to write/modify a file that is owned by your ftp user? The PHP Process that is actually executing the file access/write requests. This is the core way that 99% of all web sites get cracked into.. All these malicious robots and exploit bots do is attempt to write a file onto your server so that it can then be used to take over your site. If they can save a file on your blog’s directory (uploads, insecure plugin code, not filtering user input, etc..) it inherits the permissions of the process that actually wrote the data bits onto the hard-drive.

So some server-admins/web hosts configure the php interpreter to not have write access anywhere except for a couple neccessary locations like /tmp. They have auto-installation’s available through their online web panels, meaning instead of executing .php scripts in your user directory as the php process they force you to use, they can bypass all that because the installation scripts they use are all on their systems, not on your “locked-down” cluster.

This is the fundamental security battle that network server security is all based on.. Apache is owned by a powerful user because it owns the server process, so apache is often run as the user dhapache or nobody.. If a cracker is able to find a way to get a file saved on your server with the dhapache user as the owner then they’ve basically just gotten control of the whole thing. When you upload a file to your server using the add attachment form in wordpress, the file first goes through the dhapache user which passes the file to the php process owner which has much less permissions. Apache has been in open-source development for many many years now, its the safest most secure server in the world, windows servers are hackable, apache servers are hacked usually only when the sysadmin configures it wrong or accidentally.

Believe it or not, as confusing as my feeble explanation was, this is only like .1% of whats going on.. I’ve basically spent the last several months developing the new version specifically to be able to work no matter what configuration you have. What I ended up doing was finding ways to bypass this security on a couple hosting providers that are setup in this way, but even though I got it to work in most instances it basically was hacking their systems, and if I published that code to automatically bypass web-hosts security setups I think I’d be in big trouble and they would just close those specific holes and the plugin would not work again. So I decided instead of exploiting host-specifics hacks to get the plugin to work that I would focus on the method that WordPress sorta uses. The code they have now (2.8 bleeding-edge) still isn’t where it needs to be, but this is some difficult stuff and they have a brilliant start, it’ll work.. just a question of when.

`wp-admin/includes/file.php`

Ok so this function get_filesystem_method is a brilliant bit of code that would’ve been beyond my current PHP skills to come up with. It determines which if any of the following methods can be used to modify files on your server from within WordPress, which is exactly what the new version of the passpro plugin needs to use. The first test simply creates a file from within php using wp_tempnam, a function that attempts to locate and write to a temporary location on your server that has the best chance of having write access. If it is successfully created (this code assumes that it will be, something they need to fix) then the fileowner (uses stat internally) of the temp file just created is compared to the owner of the php script… Normally this works and then the plugin woks too, but on some hosts the script is running as a separate user than that of the file which means you can’t directly access the local file system. That is what is occurring for most of you who experience permission problems while testing the plugin. There are thousands of caveats for each little part depending on your php version, php setup, server setup, server version, which Server API you are using, the type of SAPI being used, and on and on..

function get_filesystem_method($args = array()) {
  $method = false;
  if( function_exists('getmyuid') && function_exists('fileowner') ){
    $temp_file = wp_tempnam();
    if ( getmyuid() == fileowner($temp_file) ) $method = 'direct';
    unlink($temp_file);
  }
  if ( ! $method && isset($args['connection_type']) && 'ssh' == $args['connection_type'] && extension_loaded('ssh2') )
          $method = 'ssh2';
  if ( ! $method && extension_loaded('ftp') )
          $method = 'ftpext';
  if ( ! $method && ( extension_loaded('sockets') || function_exists('fsockopen') ) )
          $method = 'ftpsockets'; //Sockets: Socket extension; PHP Mode: FSockopen / fwrite / fread
  return apply_filters('filesystem_method', $method);
}

Enumerating Permissions can be Annoying

This was part of some tests I did to see what kind of access I had with the very helpful posix functions which are very accurate as well since they were designed for a system with file permissions, ie. not Win. Don’t ask me how because I won’t tell you, but on one of the hosts I was testing on that did not allow direct access I was able to get the Apache server running as dhapache to erroneously write a file into my users blog directory. This is a big security no-no and I now have my .htaccess file written into the blog directory where it should go, but instead of my php script’s user having write access to the file so I can modify it, its owned by dhapache! Because the file is owned by dhapache I shouldn’t even be allowed to know it exists, but there it is. So the next step was to try and take ownership of the .htaccess file so that I could modify it. I tried and tried but was unsuccessful, I couldn’t modify it so that was another dead end. Actually it took me awhile to figure out how to remove the file from my directory. Being that it was owned by dhapache I couldn’t delete or modify it using my php process or even through ftp/ssh! Sysadmins regularly run find commands that search the servers for any files owned by dhapache that should not be there as this is a big red flag that someone has found a way to manipulate dhapache which could potentially lead to modifying dhapche-owned server config files.. Luckily I was able to delete it by basically running the hack again to overwrite the file.

  if ((posix_setgid(getmygid())) !== false) $this->to_log('', 1,
      "Success Changing SETGID of {$file}  to " . getmygid(), 3);
  elseif ((posix_setgid(filegroup(__file__))) !== false) $this->to_log('', 1,
      "Success Changing SETUID of {$file} to " . filegroup(__file__), 3);
  if ((posix_setegid(getmygid())) !== false) $this->to_log('', 1,
      "Success Changing SETEGID of {$file} to " . getmygid(), 3);
  elseif ((posix_setegid(filegroup(__file__))) !== false) $this->to_log('', 1,
      "Success Changing SETEGID of {$file} to " . filegroup(__file__), 3);
  if ((posix_setuid(getmyuid())) !== false) $this->to_log('', 1,
      "Success Changing SETUID of {$file}  to " . getmyuid(), 3);
  elseif ((posix_setuid(get_current_user())) !== false) $this->to_log('', 1,
      "Success Changing SETUID of {$file} to " . get_current_user(), 3);
  if ((posix_seteuid(getmyuid())) !== false) $this->to_log('', 1,
      "Success Changing SETEUID of {$file} to " . getmyuid(), 3);
  elseif ((posix_seteuid(get_current_user())) !== false) $this->to_log('', 1,
      "Success Changing SETEUID of {$file} to " . get_current_user(), 3);
  if ((chmod($file, FS_CHMOD_DIR) || chmod($file, 0776) || chmod($file, 0766) || chmod($file,
    FS_CHMOD_FILE)) !== false) $this->to_log('', 1, "Success Changing Mode of {$file}", 3);
  if ((chown($file, getmyuid())) !== false) $this->to_log('', 1,
      "Success Changing Ownership of {$file} to " . getmyuid(), 3);
  elseif ((chown($file, get_current_user())) !== false) $this->to_log('', 1,
      "Success Changing Ownership of {$file} to " . get_current_user(), 3);
  if ((chgrp($file, getmygid())) !== false) $this->to_log('', 1,
      "Success Changing Group of {$file} to " . getmygid(), 3);
  elseif ((chgrp($file, filegroup(__file__))) !== false) $this->to_log('', 1,
      "Success Changing Group of {$file} to " . filegroup(__file__), 3);
  if ((chmod($file, FS_CHMOD_DIR) || chmod($file, 0776) || chmod($file, 0766) || chmod($file,
    FS_CHMOD_FILE)) !== false) $this->to_log('', 1, "Success Changing Mode of {$file}", 3);
  if ((chown($file, getmyuid())) !== false) $this->to_log('', 1,
      "Success Changing Ownership of {$file} to " . getmyuid(), 3);
  elseif ((chown($file, get_current_user())) !== false) $this->to_log('', 1,
      "Success Changing Ownership of {$file} to " . get_current_user(), 3);
  if ((chgrp($file, getmygid())) !== false) $this->to_log('', 1,
      "Success Changing Group of {$file} to " . getmygid(), 3);
  elseif ((chgrp($file, filegroup(__file__))) !== false) $this->to_log('', 1,
      "Success Changing Group of {$file} to " . filegroup(__file__), 3);
  return (!$this->_fclose($fh)) ? $this->to_log(__function__ . ':' . __line__ .
    " Error closing {$mode} handle for {$file}", 0) : $total;

If php process isn’t allowed to write to your web directory but you have an ftp account that is, then we request your ftp username/password in wordpress and if the php process running the askapache-password-protect.php plugin script is allowed access to raw networking sockets using fsockopen then we can basically access and write to your blog’s .htaccess file by using php to mimick an ftp client session. There are also other protocols and options available using php if ftp/fsockopen isn’t allowed, but you run out of alternatives quick. Using the curl extension is one option.

So I wrote my own ftp library for a fsockopen class I had already developed for specific test requirements in unreleased versions, so the release of the new askapache password protect plugin will work for 75% or so of the people who have trouble now.. not to mention the insane logging and debugging I’ve added while looking for the reasons some web-hosts still don’t work. Some use custom php security modules, wrappers, and custom virtual servers that are akin to a vmware server. So for maybe 10% of those running apache who have had problems they would still have them. I’m still playing with some ssh capability from within the plugin similar to the ftp technique.. I really hope WordPress just adds this functionality by updating their current filesystem classes..

Fsockopen Payload Class

Here’s what I had several versions ago.. Just sticking it up here in case anyone is curious, one cool thing this version starts to incorporate is being able to send direct data payloads across the socket so it can be used like the metasploit framework to send payloads of exploits, but of course we’re using it to mimick other protocols like ftp, which can be setup by feeding hex into the socket direct from a real ftp client, and piping the output. Keep in mind that this is my first time using php classes, so the learning curve has been incredible…

 '1.0', 'method' => 'GET', 'referer' =>
   'http://www.askapache.com/', 'port' => '80', 'ua' =>
   'Mozilla/5.0 (compatible; AskApache_Net/1.6; http://www.askapache.com/)', 'scheme' =>
   'http', 'transport' => '', 'host' => '', 'user' => '', 'pass' => '', 'path' => '/',
   'query' => '', 'fragment' => '');
  var $authtype = 'Basic';
  var $timeout = 15;
  var $_dh = '';
  var $_digest = array('realm' => '', 'nonce' => '', 'uri' => '', 'algorithm' => 'MD5',
   'qop' => 'auth', 'opaque' => '', 'domain' => '', 'nc' => '00000001', 'cnonce' =>
   '82d057852a9dc497', 'A1' => '', 'A2' => '', 'response' => '');
  var $_ACLF = "\r\n";
  var $_request_body = '';
  var $_request_headers = array();
  var $_response_headers = array();
  var $my_headers;
  var $_response_header = '';
  var $_response_protocol = '';
  var $_response_version = '';
  var $_response_code = '';
  var $_response_message = '';
  var $_response_body = '';
  var $_errs = array(3 => 'Socket creation failed', 4 => 'DNS lookup failure', 5 =>
   'Connection refused or timed out', 111 => 'Connection refused', 113 =>
   'No route to host', 110 => 'Connection timed out', 104 => 'Connection reset by client');

  /**
   * AskApache_Net::AskApache_Net()
   */
  function AskApache_Net()
  {
   return $this->__construct();
  }

  /**
   * AskApache_Net::__destruct()
   */
  function __destruct()
  {
   $this->_timer('class');
   return true;
  }

  /**
   * AskApache_Net::__construct()
   */
  function __construct()
  {
   $this->_timer('class');
   $this->_ACLF = chr(13) . chr(10);
   @set_time_limit(60);
   return true;
  }

  /**
   * AskApache_Net::hsockit()
   */
  function hsockit($URI)
  {
   $this->msg(__function__ . ':' . __line__, 3);
   $this->_socket['method'] = 'HEAD';
   return $this->sockit($URI);
  }

  /**
   * AskApache_Net::sockit()
   */
  function sockit($URI = '')
  {
   $this->msg(__function__ . ':' . __line__, 3);
   if (!$this->_build_sock($URI)) return $this->msg(__function__ . ':' . __line__,
     "Failed!", 0);
   if (!$this->_connect()) return $this->msg(__function__ . ':' . __line__, "Failed!", 0);
   $this->_build_request();
   if (!$this->_build_request()) return $this->msg(__function__ . ':' . __line__,
     "Failed!", 0);
   if (!$this->_tx()) return $this->msg(__function__ . ':' . __line__, "tx Failed!", 0);
   if (!$this->_rx()) return $this->msg(__function__ . ':' . __line__, "rx Failed!", 0);
   if (!$this->_disconnect()) return $this->msg(__function__ . ':' . __line__,
     "disconnect Failed!", 0);
   if ((bool)$this->net_debug === true) {
    foreach (array('out_payload', '_request_body', '_response_header', '_response_body') as
     $nam) {
     if (is_array($this->$nam)) {
      if (sizeof($this->$nam) > 1) {
       echo "\n\n{$nam}\n";
       print_r($this->$nam);
      }
     } else {
 
      if (!empty($this->$nam)) {
       echo "\n\n{$nam}\n";
       echo $this->$nam;
      }
     }
    }
    $this->tcp_trace(1);
   }
   return (int)$this->_response_code;
  }

  /**
   * AskApache_Net::_build_sock()
   */
  function _build_sock($url)
  {
   $this->msg(__function__ . ':' . __line__, 3);
   $socket_info = &$this->_socket;
   if (!$u_bits = parse_url($url)) return false;
   if (empty($u_bits['method'])) $u_bits['method'] = 'GET';
   if (empty($u_bits['protocol'])) $u_bits['protocol'] = '1.0';
   if (empty($u_bits['host'])) $u_bits['host'] = $_SERVER['HTTP_HOST'];
   if (empty($u_bits['scheme'])) $u_bits['scheme'] = 'http';
   if (empty($u_bits['port'])) $u_bits['port'] = $_SERVER['SERVER_PORT'];
   $u_bits['path'] = (empty($u_bits['path']) ? '/' : $u_bits['path']) . (!empty($u_bits['query']) ?
    '?' . $u_bits['query'] : '');
   if (empty($u_bits['ua'])) $u_bits['ua'] =
     'Mozilla/5.0 (compatible; AskApache_Net/1.0; http://www.askapache.com)';
   if (empty($u_bits['referer'])) $u_bits['referer'] = 'http://www.askapache.com';
   if (empty($u_bits['fragment'])) unset($u_bits['fragment']);
   if (empty($u_bits['user'])) unset($u_bits['user']);
   if (empty($u_bits['pass'])) unset($u_bits['pass']);
   if ($u_bits['scheme'] == 'https' || $this->_socket['scheme'] == 'https') $u_bits['transport'] =
     'ssl://';
   if ($u_bits['scheme'] == 'https' || $this->_socket['scheme'] == 'https') $u_bits['port'] =
     '443';
   $socket_info = $this->_parse_args($u_bits, $socket_info);
   extract($socket_info, EXTR_SKIP);
   return true;
  }

  /**
   * AskApache_Net::_build_auth_header()
   */
  function _build_auth_header()
  {
   $this->msg(__function__ . ':' . __line__, 3);
   if ($this->authtype == 'Basic') $this->_request_headers[] = 'Authorization: Basic ' .
     base64_encode($this->_socket['user'] . ":" . $this->_socket['pass']);
   elseif ($this->authtype == 'Digest') {
    $this->msg(__function__ . ':' . __line__, 3);
    $this->_socket['protocol'] = '1.1';
    $hdr = $mtx = array();
    preg_match_all('/(\w+)=(?:"([^"]+)"|([^\s,]+))/', $this->_dh, $mtx, PREG_SET_ORDER);
    foreach ($mtx as $m) $hdr[$m[1]] = $m[2] ? $m[2] : $m[3];
    foreach ($hdr as $key => $val)
     if (array_key_exists($key, $this->_digest) && !empty($val)) $this->_digest[$key] = $val;
    $this->_digest['uri'] = $this->_socket['path'];
    $this->_digest['A1'] = md5($this->_socket['user'] . ':' . $this->_digest['realm'] .
     ':' . $this->_socket['pass']);
    $this->_digest['A2'] = md5($this->_socket['method'] . ':' . $this->_socket['path']);
    $this->_digest['response'] = md5($this->_digest['A1'] . ':' . $this->_digest['nonce'] .
     ':' . $this->_digest['nc'] . ':' . $this->_digest['cnonce'] . ':' . $this->_digest['qop'] .
     ':' . $this->_digest['A2']);
    $this->_request_headers[] = sprintf('Authorization: Digest username="%1$s", realm="%2$s", nonce="%3$s",'.
     'uri="%4$s", algorithm=%5$s, response="%6$s", qop="%7$s", nc="%8$s"%9$s%10$s',
     $this->_socket['user'], $this->_digest['realm'], $this->_digest['nonce'], $this->
     _digest['uri'], $this->_digest['algorithm'], $this->_digest['response'], $this->
     _digest['qop'], $this->_digest['nc'], !empty($this->_digest['cnonce']) ? ', cnonce="' .
     $this->_digest['cnonce'] . '"' : '', !empty($this->_digest['opaque']) ? ', opaque="' .
     $this->_digest['opaque'] . '"' : '');
   }
   return true;
  }

  /**
   * AskApache_Net::_build_request()
   */
  function _build_request()
  {
   $this->msg(__function__ . ':' . __line__, 3);
   $this->_request_headers[] = $this->_socket['method'] . " " . $this->_socket['path'] .
    " HTTP/" . $this->_socket['protocol'];
   if (is_array($this->my_headers) && sizeof($this->my_headers) > 0) $this->
     _request_headers = array_merge($this->_request_headers, $this->my_headers);
   else {
    $this->_request_headers[] = "Host: " . $this->_socket['host'];
    $this->_request_headers[] = "User-Agent: " . $this->_socket['ua'];
    $this->_request_headers[] = 'Accept: application/xhtml+xml,text/html;q=0.9,*/*;q=0.5';
    $this->_request_headers[] = 'Accept-Language: en-us,en;q=0.5';
    $this->_request_headers[] = 'Accept-Encoding: none';
    $this->_request_headers[] = 'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7';
    $this->_request_headers[] = 'Referer: ' . $this->_socket['referer'];
   }
   if (!empty($this->_socket['user']) && !empty($this->_socket['pass'])) $this->
     _build_auth_header();
   if ($this->out_payload !== false) $this->_request_body = $this->out_payload;
   else  $this->_request_body = join($this->_ACLF, $this->_request_headers) . $this->
     _ACLF . $this->_ACLF;
   return true;
  }

  /**
   * AskApache_Net::_tx()
   */
  function _tx()
  {
   $this->msg(__function__ . ':' . __line__, 3);
   return (bool)(is_resource($this->_fp) && $this->_netwrite($this->_fp, $this->
    _request_body));
  }

  /**
   * AskApache_Net::_rx()
   */
  function _rx()
  {
   $this->msg(__function__ . ':' . __line__, 3);
   if (!is_resource($this->_fp)) return false;
   $this->_response = $this->_netread($this->_fp, 500000);
   $parts = explode($this->_ACLF . $this->_ACLF, ltrim($this->_response), 2);
   $this->_response_header = trim($parts[0]);
   $this->_response_body = trim($parts[1]);
   if (preg_match('#([^/]*)/([\d\.]+) ([\d]*?) (.*)#', $this->_response_header, $htx)) {
    $this->_response_protocol = trim($htx[1]);
    $this->_response_version = trim($htx[2]);
    $this->_response_code = trim($htx[3]);
    $this->_response_message = trim($htx[4]);
   }
   if (preg_match_all('#([^:]+)\:?(.*)#', str_replace($htx, '', $this->_response_header),
    $mtx, PREG_SET_ORDER)) {
    foreach ($mtx as $m) {
     $this->_headers[strtolower(trim($m[1]))] = trim($m[2]);
     if (preg_match('/(WWW|Proxy)-Authenticate:.*Digest/i', trim($m[1]))) $this->_dh =
       trim($m[1]);
    }
   }
   return true;
  }

  /**
   * AskApache_Net::tcp_trace()
   */
  function tcp_trace($p = false)
  {
   $this->_timer(__function__ );
   $ret = join("\n", array_merge((array )$this->_request_headers, array(''), (array )$this->
    _response_headers));
   if ($p !== false) {
    echo $ret;
    $ret = true;
   }
   $this->_timer(__function__ );
   return $ret;
  }

  /**
   * AskApache_Net::_get_ip()
   */
  function _get_ip($host)
  {
   $this->msg(__function__ . ':' . __line__, 3);
 
   if (!preg_match('/^[\t ]*[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+[\t ]*$/', $host)) $hostip =
     gethostbyname($host);
   $ip = ($hostip == $host) ? $host : long2ip(ip2long($hostip));
   return $ip;
  }

  /**
   * AskApache_Net::_connect()
   */
  function _connect()
  {
   $this->msg(__function__ . ':' . __line__, 3);
   if (false === ($this->_fp = fsockopen($this->_get_ip($this->_socket['host']), $this->
    _socket['port'], $errno, $errstr, $this->timeout)) || !is_resource($this->_fp)) {
    $err = (array_key_exists($errno, $this->_errs)) ? $this->_errs[$errno] :
     'Connection failed';
    return $this->msg(__function__ . ':' . __line__ . " Fsockopen failed! [{$errno}] {$err} ({$errstr})",
     0);
   }
   if (function_exists("socket_set_timeout")) socket_set_timeout($this->_fp, $this->
     timeout);
   elseif (function_exists("stream_set_timeout")) stream_set_timeout($this->_fp, $this->
     timeout);
   usleep(10000);
   return true;
  }

  /**
   * AskApache_Net::_disconnect()
   */
  function _disconnect()
  {
   $this->msg(__function__ . ':' . __line__, 3);
   if (is_resource($this->_fp)) return $this->_fclose($this->_fp);
   else  $this->_fp = null;
   return true;
  }

  /**
   * AskApache_Net::get_response_headers()
   */
  function get_response_headers($header = false)
  {
   $this->msg(__function__ . ':' . __line__, 3);
   if ($header !== false && array_key_exists($header, $this->_response_headers)) return $this->
     _response_headers[$header];
   return $this->_response_headers;
  }

  /**
   * AskApache_Net::get_response_body()
   */
  function get_response_body()
  {
   $this->msg(__function__ . ':' . __line__, 3);
   return $this->_response_body;
  }

  /**
   * AskApache_Net::_netread()
   */
  function _netread(&$fh, $ts = 50000000, $bs = 124)
  {
   $this->_timer(__function__ );
   for ($d = $b = '', $rt = $at = $r = 0; ($fh !== false && !feof($fh) && $b !== false &&
    $at < 50000000 && $rt < $ts); $r = $ts - $rt, $bs = (($bs > $r) ? $r : $bs), $this->
    _timer("R: {$rt}"), $b = fread($fh, $bs), $br = strlen($b), $d .= $b, $this->_timer("R: {$rt}"),
    $rt += $br, $at++, $this->msg("[RT: {$rt}]\t[BR: {$br}" . (($ts != 50000000) ? "]\t\t [{$r} / {$ts}]" :
    " : {$bs}]\t[{$at}]"))) ;
   $this->_timer(__function__ );
   return ((strlen($d) != 0)) ? $d : false;
  }

  /**
   * AskApache_Net::_netwrite()
   */
  function _netwrite(&$fh, $d = '', $bs = 512)
  {
   $this->_timer(__function__ );
 
   for ($bw = $wt = $at = 0, $dat = '', $ts = strlen($d); ($fh !== false && $bw !== false &&
    $at < 50000000 && $wt < $ts); $r = $ts - $wt, $bs = (($bs > $r) ? $r : $bs), $dat =
    substr($d, $wt, $bs), $bw = fwrite($fh, $dat), $wt += $bw, $this->msg("[WT: {$wt}]\t[BW: {$bw}]\t\t[I: {$r} / {$ts}:{$bs}] - {$at}"),
    $at++) ;
   $this->msg("[WT: {$wt}]\t[BW: {$bw}]\t\t[I: {$r} / {$ts}:{$bs}] - {$at}");
   $this->_timer(__function__ );
   return ($wt == $ts) ? true : false;
  }
 }
endif;
?>

So I decided to finally give in to what I’ve been avoiding all along and added a php-software-based method that will work on everycomputer, windows, blackberrys, etc.. That took me about 15minutes as its just a few lines of code.. The problem I have with it is that php is what is actually controlling the sending, receiving, and verifying of the authentication headers instead of using the builtin super-secure apache method.

Here’s how you would block someone using the apache/askapache way:

[Exploit Request] => ([BLOCKED]-AskApache)

This prevents the exploit from even reaching PHP, saving your computer a lot of CPU/memory and bandwdith, and obviously can’t exploit wordpress if php isn’t even loading.

Here’s how the php-software-based method blocks the same request:

[Exploit Request] => (AskApache) => (PHP) => (WordPress) => ([BLOCKED]-askapache-password-protect.php)

So the last bit of programming and research I’m doing at the moment is how to cause the askapache-password-protect plugin to execute as soon as possible, ideally it would execute before WordPress starts.. And I am still crazy swamped at work, this was the longest non-posting period of the blog to date!

Password Protection Plugin Status originally appeared on AskApache.

.htaccess Plugin Blocks Spam, Hackers, and Password Protects Blog

AskApache — Sat, 22 Nov 2008 14:18:12 +0000

Well what can I say, other than this is sooo DOPE! Here is a list of the modules this plugin (version 4.7 unreleased) will automatically detect. I compiled the list myself using every module included with any default Apache installation for ALL the versions listed below, 1.3 to 2.2+

Want to know something else I’m including in this plugin? For each and every module that is detected, this plugin can then detect ALL of the modules .htaccess Directives! For instance, RewriteRule, AccessFileName, AddHandler, etc.. are each a directive belonging to a module that is allowed to be used from within .htaccess files.

Talk about sick.. these tricks have the diamond disease!

Screenshot Unreleased 4.7

I’ve been making a lot of progress as these screenshots illustrate, including the ability to detect 100% accurately the modules that are enabled on your server. Big deal! you might say… “How does knowing the modules help?”

Well it just so happens that in addition to detecting which modules are loaded on your server, this plugin will also detect which Directives are enabled for each module that are allowed to be used from within your .htaccess file! Future release will provide the ability to explore the different .htaccess directives allowed by your server, so you can do all sorts of cool Apache .htaccess tricks to secure your blog and make it run better.

Apache Module Detection

Future releases of this plugin will also let you search for non-default modules, wild, beta, and others.

mod_access
mod_actions
mod_alias
mod_asis
mod_auth
mod_auth_anon
mod_auth_basic
mod_auth_dbm
mod_auth_digest
mod_auth_ldap
mod_authn_alias
mod_authn_anon
mod_authn_dbd
mod_authn_dbm
mod_authn_default
mod_authn_file
mod_authnz_ldap
mod_authz_dbm
mod_authz_default
mod_authz_groupfile
mod_authz_host
mod_authz_owner
mod_authz_user
mod_autoindex
mod_bucketeer
mod_cache
mod_case_filter
mod_case_filter_in
mod_cern_meta
mod_cgi
mod_cgid
mod_charset_lite
mod_dav
mod_dav_fs
mod_dav_lock
mod_dbd
mod_deflate
mod_dir
mod_disk_cache
mod_dumpio
mod_echo
mod_env
mod_example
mod_expires
mod_ext_filter
mod_file_cache
mod_filter
mod_headers
mod_ident
mod_imagemap
mod_imap
mod_include
mod_info
mod_isapi
mod_log_config
mod_log_forensic
mod_logio
mod_mem_cache
mod_mime
mod_mime_magic
mod_mycore
mod_negotiation
mod_netware
mod_nw_ssl
mod_optional_fn_export
mod_optional_fn_import
mod_optional_hook_export
mod_optional_hook_import
mod_proxy
mod_proxy_ajp
mod_proxy_balancer
mod_proxy_connect
mod_proxy_ftp
mod_proxy_http
mod_rewrite
mod_security
mod_setenvif
mod_so
mod_speling
mod_ssl
mod_status
mod_substitute
mod_suexec
mod_test
mod_unique_id
mod_userdir
mod_usertrack
mod_version
mod_vhost_alias
mod_win32

The original plugin page and description can be found here.

UPDATE: 11/22/08

To make a long story short, I downloaded each major release of the apache httpd source code from version 1.3.0 to version 2.2.10, then I configured and compiled each for a custom HTTPD installation built from source. This allowed me to find every directive allowed in .htaccess files for each particular version. YES!

http://wordpress.org/support/rss/topic/214390
I’ve been working on a completely improved version on/off for about a month with the specific goal of finally ending all the little errors that can crop up when dealing with .htaccess.

To that effect I am succeeding marvelously, first I’ve converted the plugin to a class (4+5 compat), I’ve replaced my error_handling with WordPress’s WP_Error class, and the coolest change is the new tests I’ve added.

To make a long story short, I downloaded each major release of the apache httpd source code starting at version 1.3.0 and finishing with version 2.2.10, I then compiled each version and built a HTTPD from source for all the apache versions.

1.3.0, 1.3.1, 1.3.11, 1.3.12, 1.3.14, 1.3.17, 1.3.19, 1.3.2, 1.3.20, 1.3.22, 1.3.23, 1.3.24, 1.3.27, 1.3.28, 1.3.29, 1.3.3, 1.3.31, 1.3.32, 1.3.33, 1.3.34, 1.3.35, 1.3.36, 1.3.37, 1.3.39, 1.3.4, 1.3.41, 1.3.6, 1.3.9, 2.0.35, 2.0.36, 2.0.39, 2.0.40, 2.0.42, 2.0.43, 2.0.44, 2.0.45, 2.0.46, 2.0.47, 2.0.48, 2.0.49, 2.0.50, 2.0.51, 2.0.52, 2.0.53, 2.0.54, 2.0.55, 2.0.58, 2.0.59, 2.0.61, 2.0.63, 2.1.3-beta, 2.1.6-alpha, 2.1.7-beta, 2.1.8-beta, 2.1.9-beta, 2.2.0, 2.2.10, 2.2.2, 2.2.3, 2.2.4, 2.2.6, 2.2.8, 2.2.9

Then I went through each version and determined the compatible modules for that version, and I’m pretty confident that I was also able to find each and every directive allowed by the compatible modules for that version (including core directives). See .htaccess directive list.

Basically I can now test a server using a variety of methods and determine almost 100% accurately what version of Apache (down to the API) is running, what modules (and versions) are enabled, and each and every directive that is allowed or disallowed for that version.

So this is so awesome because now we can enable all sorts of additional security features.

Other big changes are:

Completely hands-off updates, so that updating the plugin keeps all your settings.

making each SID module have its own configuration and options (like protecting individual files, individual request, and custom exploit strings).

Advanced ErrorDocument usage and handling (like tracking repeat offenders and suggesting they be blocked, emailing admin with custom info, etc..)

Multi User/Group password Control

And this time I am developing the plugin using a plethora of wordpress installations and configurations, to make sure that it will work regardless of a custom siteurl, blogid, etc..

Release will come before 2009.. I have some vacations to take and business to finish first.

.htaccess Security Modules

Directory Protection

Enable the DirectoryIndex Protection, preventing directory index listings and defaulting. [Disable]

Options -Indexes
DirectoryIndex index.html index.php /index.php

Password Protect wp-login.php

Requires a valid user/pass to access the login page - *** Safe, Use [401]


Order Deny,Allow
Deny from All
Satisfy Any
 
AuthName "Protected By AskApache"
AuthUserFile /home/askapache.com/.htpasswda1
AuthType Basic
Require valid-user

Password Protect wp-admin

Requires a valid user/pass to access any non-static (css, js, images) file in this directory. - *** Safe, Use [401]

Options -ExecCGI -Indexes +FollowSymLinks -Includes
DirectoryIndex index.php /index.php
 
Order Deny,Allow
 
Deny from All
Satisfy Any
 
AuthName "Protected By AskApache"
AuthUserFile /home/askapache.com/.htpasswda1
AuthType Basic
Require valid-user
 

Allow from All

 


SecFilterEngine Off

Allow from All

Protect wp-content

Denies any Direct request for files ending in .php with a 403 Forbidden.. May break plugins/themes [401]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /wp-content/.*$ [NC]
RewriteCond %{REQUEST_FILENAME} !^.+flexible-upload-wp25js.php$
RewriteCond %{REQUEST_FILENAME} ^.+\.(php|html|htm|txt)$
RewriteRule .* - [F,NS,L]

Protect wp-includes

Denies any Direct request for files ending in .php with a 403 Forbidden.. May break plugins/themes [403]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /wp-includes/.*$ [NC]
RewriteCond %{THE_REQUEST} !^[A-Z]{3,9}\ /wp-includes/js/.+/.+\ HTTP/ [NC]
RewriteCond %{REQUEST_FILENAME} ^.+\.php$
RewriteRule .* - [F,NS,L]

Common Exploits

Block common exploit requests with 403 Forbidden. These can help alot, may break some plugins. [403]

RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ ///.*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\?\=?(http|ftp|ssl|https):/.*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\?\?.*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\.(asp|ini|dll).*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\.(htpasswd|htaccess|aahtpasswd).*\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

Stop Hotlinking

Denies any request for static files (images, css, etc) if referrer is not local site or empty. [403]

RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{HTTP_REFERER} !^http://www.askapache.com.*$ [NC]
RewriteRule \.(ico|pdf|flv|jpg|jpeg|mp3|mpg|mp4|mov|wav|wmv|png|gif|swf|css|js)$ - [F,NS,L]

Safe Request Methods

Denies any request not using GET,PROPFIND,POST,OPTIONS,PUT,HEAD - *** Safe, Use [403]

RewriteCond %{REQUEST_METHOD} !^(GET|HEAD|POST|PROPFIND|OPTIONS|PUT)$ [NC]
RewriteRule .* - [F,NS,L]

Forbid Proxies

Denies any POST Request using a Proxy Server. Can still access site, but not comment. See Perishable Press [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP:VIA}%{HTTP:FORWARDED}%{HTTP:USERAGENT_VIA}%{HTTP:X_FORWARDED_FOR}%{HTTP:PROXY_CONNECTION} !^$ [OR]
RewriteCond %{HTTP:XPROXY_CONNECTION}%{HTTP:HTTP_PC_REMOTE_ADDR}%{HTTP:HTTP_CLIENT_IP} !^$
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

Real wp-comments-post.php

Denies any POST attempt made to a non-existing wp-comments-post.php - *** Safe, Use [403]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*/wp-comments-post\.php.*\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

HTTP PROTOCOL

Denies any badly formed HTTP PROTOCOL in the request, 0.9, 1.0, and 1.1 only - *** Safe, Use [403]

RewriteCond %{THE_REQUEST} !^[A-Z]{3,9}\ .+\ HTTP/(0\.9|1\.0|1\.1) [NC]
RewriteRule .* - [F,NS,L]

SPECIFY CHARACTERS

Denies any request for a url containing characters other than “a-zA-Z0-9.+/-?=&” – REALLY helps but may break your site depending on your links. [403]

RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{THE_REQUEST} !^[A-Z]{3,9}\ [a-zA-Z0-9\.\+_/\-\?\=\&]+\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

BAD Content Length

Denies any POST request that doesnt have a Content-Length Header - *** Safe, Use [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP:Content-Length} ^$
RewriteCond %{REQUEST_URI} !^/(wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

BAD Content Type

Denies any POST request with a content type other than application/x-www-form-urlencoded|multipart/form-data - *** Safe, Use [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP:Content-Type} !^(application/x-www-form-urlencoded|multipart/form-data.*(boundary.*)?)$ [NC]
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

Directory Traversal

Denies Requests containing ../ or ./. which is a directory traversal exploit attempt - *** Safe, Use [403]

PHPSESSID Cookie

Only blocks when a PHPSESSID cookie is sent by the user and it contains characters other than 0-9a-z - *** Safe, Use [403]

NO HOST:

Denies requests that dont contain a HTTP HOST Header. - *** Safe, Use [403]

RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{HTTP_HOST} ^$
RewriteRule .* - [F,NS,L]

Bogus Graphics Exploit

Denies obvious exploit using bogus graphics - *** Safe, Use [403]

RewriteCond %{HTTP:Content-Disposition} \.php [NC]
RewriteCond %{HTTP:Content-Type} image/.+ [NC]
RewriteRule .* - [F,NS,L]

No UserAgent, No Post

Denies POST requests by blank user-agents. May prevent a small number of visitors from POSTING. [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP_USER_AGENT} ^-?$
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

No Referer, No Comment

Denies any comment attempt with a blank HTTP_REFERER field, highly indicative of spam. May prevent some visitors from POSTING. [403]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*/wp-comments-post\.php.*\ HTTP/ [NC]
RewriteCond %{HTTP_REFERER} ^-?$
RewriteRule .* - [F,NS,L]

Trackback Spam

Denies obvious trackback spam. See Holy Shmoly! [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP_USER_AGENT} ^.*(opera|mozilla|firefox|msie|safari).*$ [NC]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.+/trackback/?\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

SSL-Only Site

Redirects all non-SSL (https) requests to your https-enabled url [301]

Anti-Spam, Anti-Exploits

Denies Obvious Spam and uses advanced mod_security protection [Read More]

.htaccess Security Module Screenshot

.htaccess Plugin Blocks Spam, Hackers, and Password Protects Blog originally appeared on AskApache.

Chmod, Umask, Stat, Fileperms, and File Permissions

AskApache — Wed, 19 Nov 2008 10:16:56 +0000

Unix file permissions are one of the more difficult subjects to grasp.. Well, ok maybe “grasp” isn’t the word.. Master is the right word.. Unix file permissions is a hard topic to fully master, mainly I think because there aren’t many instances when a computer user encounters them. Windows has been trying to figure it out for decades with little progress, so don’t feel bad if you don’t know much about it. Unless you’re with the program and running Mac or any other BSD/Unix based OS you’ve never had the ability to secure your system in this most basic and fundamental way. Usually the first time someone encounters file permissions it’s because their website was cracked..

.htaccess

$ chmod 604 .htaccess

604 -rw----r--  /home/askapache/cgi-bin/.htaccess

php.cgi

$ chmod 711 php.cgi

$ 711 -rwx--x--x  /home/askapache/cgi-bin/php.cgi

.php.ini

$ chmod 600 php.ini

$ 600 -rw-------  /home/askapache/cgi-bin/php.ini

I’m in the process of developing an updated version of the .htaccess security plugin, and one thing I have been working on is file permissions. Some people had problems trying to create files on their server and I realized it was bad programming on my part.. so I began researching permissions in detail. I went deep into the source code of Apache (which is why this site is called AskApache, BTW), PHP, Python, Ocaml, Perl, Ruby, and POSIX operating systems and got a pretty good handle on it now..

Tips before we dig in

Here’s a few things I’ve learned that I didn’t know before (using php).

Deleting Files and Directories

Deleting a file may require chmodding the file to 666 or even 777 before you are able to delete it. You also might have to chmod the parent directory of the file as well. Also, you may have to chdir to the directory the file is in. And lastly you may have to change the owner or group of the file. Further than that you can try renaming the file first then deleting it..

Deleting a directory means you need to remove every file in it first. It needs to be empty. And if your file system uses NFS or some other networked FS you might have even more problems deleting files. If the file you are trying to delete is being used by say, Apache or php then you might have to kill that process first.

Creating Files in Restrictive Environments

My research has been geared to try and make my code as robust as possible, I’m throwing everything but the kitchen sink into some of these functions because so many people are on such different types of servers. To create a file in a restrictive environment is a fun excercise to take.. You can write a file using many different functions, but there are some tricks if they all fail. One trick is instead of trying to “write” the data to the file, you can UPLOAD the data to the server and let PHP handle the file as if you used an upload form. I like to use fsockopen to do it, as some installations have been setup to prevent this type of fake upload.

Then there are the various other hacks like using an ftp connection (if you know the user/pass) to send the file from php, using ssh from php, whatever is available on the hosts php installation. In addition to those more involved workarounds you can often get around this problem by doing little hacks discussed at php.net in the comments for various functions. Such as changing the umask, changing directories with chdir first, creating a temporary file using a function like tempfile and then renaming or copying the tempfile to your desired file which sometimes gives you the permissions needed to write to the location.

If the php installation is newer than you can also look into creating your own stream context to pass write the data direct.

Stat Function

I’ve created a stat function in php that goes farther than the normal stat function… Just give the function a file to stat, and it returns an array of information.

function askapache_stat($filename) {
clearstatcache();
$ss=@stat($filename);
if(!$ss) die(“Couldnt stat {$filename}”);
$file_convert=array(0140000=>’ssocket’,0120000=>’llink’,0100000=>’-file’,0060000=>’bblock’,0040000=>’ddir’,0020000=>’cchar’,0010000=>’pfifo’);
$p=$ss['mode'];
$t=decoct($ss['mode'] & 0170000);
$str = (array_key_exists(octdec($t),$file_convert)) ? $file_convert[octdec($t)]{0} : ‘u’;
$str.=(($p&0×0100)?’r':’-').(($p&0×0080)?’w':’-').(($p&0×0040)?(($p&0×0800)?’s’:'x’):(($p&0×0800)?’S':’-'));
$str.=(($p&0×0020)?’r':’-').(($p&0×0010)?’w':’-').(($p&0×0008)?(($p&0×0400)?’s’:'x’):(($p&0×0400)?’S':’-'));
$str.=(($p&0×0004)?’r':’-').(($p&0×0002)?’w':’-').(($p&0×0001)?(($p&0×0200)?’t':’x'):(($p&0×0200)?’T':’-'));

$s=array(
‘perms’=>array(
‘umask’=>sprintf(“%04o”,umask()),
‘human’=>$str,
‘octal1′=>sprintf(“%o”, ($ss['mode'] & 000777)),
‘octal2′=>sprintf(“0%o”, 0777 & $p),
‘decimal’=>sprintf(“%04o”, $p),
‘fileperms’=>@fileperms($filename),
‘mode1′=>$p,
‘mode2′=>$ss['mode']),

‘filetype’=>array(
‘type’=>substr($file_convert[octdec($t)],1),
‘type_octal’=>sprintf(“%07o”, octdec($t)),
‘is_file’=>@is_file($filename),
‘is_dir’=>@is_dir($filename),
‘is_link’=>@is_link($filename),
‘is_readable’=> @is_readable($filename),
‘is_writable’=> @is_writable($filename)),

‘owner’=>array(
‘fileowner’=>$ss['uid'],
‘filegroup’=>$ss['gid'],
‘owner_name’=>(function_exists(‘posix_getpwuid’)) ? @reset(@posix_getpwuid($ss['uid'])) : ”,
‘group_name’=>(function_exists(‘posix_getgrgid’)) ? @reset(@posix_getgrgid($ss['gid'])) : ”),

‘file’=>array(
‘filename’=>$filename,
‘realpath’=>(@realpath($filename) != $filename) ? @realpath($filename) : ”,
‘dirname’=>@dirname($filename),
‘basename’=>@basename($filename)),

‘device’=>array(
‘device’=>$ss['dev'], //Device
‘device_number’=>$ss['rdev'], //Device number, if device.
‘inode’=>$ss['ino'], //File serial number
‘link_count’=>$ss['nlink'], //link count
‘link_to’=>($s['type']==’link’) ? @readlink($filename) : ”),

’size’=>array(
’size’=>$ss['size'], //Size of file, in bytes.
‘blocks’=>$ss['blocks'], //Number 512-byte blocks allocated
‘block_size’=> $ss['blksize']), //Optimal block size for I/O.

‘time’=>array(
‘mtime’=>$ss['mtime'], //Time of last modification
‘atime’=>$ss['atime'], //Time of last access.
‘ctime’=>$ss['ctime'], //Time of last status change
‘accessed’=>@date(‘Y M D H:i:s’,$ss['atime']),
‘modified’=>@date(‘Y M D H:i:s’,$ss['mtime']),
‘created’=>@date(‘Y M D H:i:s’,$ss['ctime'])),
);

clearstatcache();
return $s;
}

PHP Stat Function Output

Example output, say from print_r(askapache_stat( __FILE__ ) );

Array(
[perms] => Array
(
[umask] => 0022
[human] => -rw-r--r--
[octal1] => 644
[octal2] => 0644
[decimal] => 100644
[fileperms] => 33188
[mode1] => 33188
[mode2] => 33188
)

[filetype] => Array
(
[type] => file
[type_octal] => 0100000
[is_file] => 1
[is_dir] =>
[is_link] =>
[is_readable] => 1
[is_writable] => 1
)

[owner] => Array
(
[fileowner] => 035483
[filegroup] => 23472
[owner_name] => askapache
[group_name] => grp22558
)

[file] => Array
(
[filename] => /home/askapache/askapache-stat/htdocs/ok/g.php
[realpath] =>
[dirname] => /home/askapache/askapache-stat/htdocs/ok
[basename] => g.php
)

[device] => Array
(
[device] => 25
[device_number] => 0
[inode] => 92455020
[link_count] => 1
[link_to] =>
)

[size] => Array
(
[size] => 2652
[blocks] => 8
[block_size] => 8192
)

[time] => Array
(
[mtime] => 1227685253
[atime] => 1227685138
[ctime] => 1227685253
[accessed] => 2008 Nov Tue 23:38:58
[modified] => 2008 Nov Tue 23:40:53
[created] => 2008 Nov Tue 23:40:53
)
)

Every Permission 0000 to 0777

This shows what each numeric permission does to a REGULAR file. I'll provide the code to do this below so you can do the same thing on your server.

chmod 0: ----------
chmod 1: ---------x
chmod 2: --------w-
chmod 3: --------wx
chmod 4: -------r--
chmod 5: -------r-x
chmod 6: -------rw-
chmod 7: -------rwx
chmod 10: ------x---
chmod 11: ------x--x
chmod 12: ------x-w-
chmod 13: ------x-wx
chmod 14: ------xr--
chmod 15: ------xr-x
chmod 16: ------xrw-
chmod 17: ------xrwx
chmod 20: -----w----
chmod 21: -----w---x
chmod 22: -----w--w-
chmod 23: -----w--wx
chmod 24: -----w-r--
chmod 25: -----w-r-x
chmod 26: -----w-rw-
chmod 27: -----w-rwx
chmod 30: -----wx---
chmod 31: -----wx--x
chmod 32: -----wx-w-
chmod 33: -----wx-wx
chmod 34: -----wxr--
chmod 35: -----wxr-x
chmod 36: -----wxrw-
chmod 37: -----wxrwx
chmod 40: ----r-----
chmod 41: ----r----x
chmod 42: ----r---w-
chmod 43: ----r---wx
chmod 44: ----r--r--
chmod 45: ----r--r-x
chmod 46: ----r--rw-
chmod 47: ----r--rwx
chmod 50: ----r-x---
chmod 51: ----r-x--x
chmod 52: ----r-x-w-
chmod 53: ----r-x-wx
chmod 54: ----r-xr--
chmod 55: ----r-xr-x
chmod 56: ----r-xrw-
chmod 57: ----r-xrwx
chmod 60: ----rw----
chmod 61: ----rw---x
chmod 62: ----rw--w-
chmod 63: ----rw--wx
chmod 64: ----rw-r--
chmod 65: ----rw-r-x
chmod 66: ----rw-rw-
chmod 67: ----rw-rwx
chmod 70: ----rwx---
chmod 71: ----rwx--x
chmod 72: ----rwx-w-
chmod 73: ----rwx-wx
chmod 74: ----rwxr--
chmod 75: ----rwxr-x
chmod 76: ----rwxrw-
chmod 77: ----rwxrwx
chmod 100: ---x------
chmod 101: ---x-----x
chmod 102: ---x----w-
chmod 103: ---x----wx
chmod 104: ---x---r--
chmod 105: ---x---r-x
chmod 106: ---x---rw-
chmod 107: ---x---rwx
chmod 110: ---x--x---
chmod 111: ---x--x--x
chmod 112: ---x--x-w-
chmod 113: ---x--x-wx
chmod 114: ---x--xr--
chmod 115: ---x--xr-x
chmod 116: ---x--xrw-
chmod 117: ---x--xrwx
chmod 120: ---x-w----
chmod 121: ---x-w---x
chmod 122: ---x-w--w-
chmod 123: ---x-w--wx
chmod 124: ---x-w-r--
chmod 125: ---x-w-r-x
chmod 126: ---x-w-rw-
chmod 127: ---x-w-rwx
chmod 130: ---x-wx---
chmod 131: ---x-wx--x
chmod 132: ---x-wx-w-
chmod 133: ---x-wx-wx
chmod 134: ---x-wxr--
chmod 135: ---x-wxr-x
chmod 136: ---x-wxrw-
chmod 137: ---x-wxrwx
chmod 140: ---xr-----
chmod 141: ---xr----x
chmod 142: ---xr---w-
chmod 143: ---xr---wx
chmod 144: ---xr--r--
chmod 145: ---xr--r-x
chmod 146: ---xr--rw-
chmod 147: ---xr--rwx
chmod 150: ---xr-x---
chmod 151: ---xr-x--x
chmod 152: ---xr-x-w-
chmod 153: ---xr-x-wx
chmod 154: ---xr-xr--
chmod 155: ---xr-xr-x
chmod 156: ---xr-xrw-
chmod 157: ---xr-xrwx
chmod 160: ---xrw----
chmod 161: ---xrw---x
chmod 162: ---xrw--w-
chmod 163: ---xrw--wx
chmod 164: ---xrw-r--
chmod 165: ---xrw-r-x
chmod 166: ---xrw-rw-
chmod 167: ---xrw-rwx
chmod 170: ---xrwx---
chmod 171: ---xrwx--x
chmod 172: ---xrwx-w-
chmod 173: ---xrwx-wx
chmod 174: ---xrwxr--
chmod 175: ---xrwxr-x
chmod 176: ---xrwxrw-
chmod 177: ---xrwxrwx
chmod 200: --w-------
chmod 201: --w------x
chmod 202: --w-----w-
chmod 203: --w-----wx
chmod 204: --w----r--
chmod 205: --w----r-x
chmod 206: --w----rw-
chmod 207: --w----rwx
chmod 210: --w---x---
chmod 211: --w---x--x
chmod 212: --w---x-w-
chmod 213: --w---x-wx
chmod 214: --w---xr--
chmod 215: --w---xr-x
chmod 216: --w---xrw-
chmod 217: --w---xrwx
chmod 220: --w--w----
chmod 221: --w--w---x
chmod 222: --w--w--w-
chmod 223: --w--w--wx
chmod 224: --w--w-r--
chmod 225: --w--w-r-x
chmod 226: --w--w-rw-
chmod 227: --w--w-rwx
chmod 230: --w--wx---
chmod 231: --w--wx--x
chmod 232: --w--wx-w-
chmod 233: --w--wx-wx
chmod 234: --w--wxr--
chmod 235: --w--wxr-x
chmod 236: --w--wxrw-
chmod 237: --w--wxrwx
chmod 240: --w-r-----
chmod 241: --w-r----x
chmod 242: --w-r---w-
chmod 243: --w-r---wx
chmod 244: --w-r--r--
chmod 245: --w-r--r-x
chmod 246: --w-r--rw-
chmod 247: --w-r--rwx
chmod 250: --w-r-x---
chmod 251: --w-r-x--x
chmod 252: --w-r-x-w-
chmod 253: --w-r-x-wx
chmod 254: --w-r-xr--
chmod 255: --w-r-xr-x
chmod 256: --w-r-xrw-
chmod 257: --w-r-xrwx
chmod 260: --w-rw----
chmod 261: --w-rw---x
chmod 262: --w-rw--w-
chmod 263: --w-rw--wx
chmod 264: --w-rw-r--
chmod 265: --w-rw-r-x
chmod 266: --w-rw-rw-
chmod 267: --w-rw-rwx
chmod 270: --w-rwx---
chmod 271: --w-rwx--x
chmod 272: --w-rwx-w-
chmod 273: --w-rwx-wx
chmod 274: --w-rwxr--
chmod 275: --w-rwxr-x
chmod 276: --w-rwxrw-
chmod 277: --w-rwxrwx
chmod 300: --wx------
chmod 301: --wx-----x
chmod 302: --wx----w-
chmod 303: --wx----wx
chmod 304: --wx---r--
chmod 305: --wx---r-x
chmod 306: --wx---rw-
chmod 307: --wx---rwx
chmod 310: --wx--x---
chmod 311: --wx--x--x
chmod 312: --wx--x-w-
chmod 313: --wx--x-wx
chmod 314: --wx--xr--
chmod 315: --wx--xr-x
chmod 316: --wx--xrw-
chmod 317: --wx--xrwx
chmod 320: --wx-w----
chmod 321: --wx-w---x
chmod 322: --wx-w--w-
chmod 323: --wx-w--wx
chmod 324: --wx-w-r--
chmod 325: --wx-w-r-x
chmod 326: --wx-w-rw-
chmod 327: --wx-w-rwx
chmod 330: --wx-wx---
chmod 331: --wx-wx--x
chmod 332: --wx-wx-w-
chmod 333: --wx-wx-wx
chmod 334: --wx-wxr--
chmod 335: --wx-wxr-x
chmod 336: --wx-wxrw-
chmod 337: --wx-wxrwx
chmod 340: --wxr-----
chmod 341: --wxr----x
chmod 342: --wxr---w-
chmod 343: --wxr---wx
chmod 344: --wxr--r--
chmod 345: --wxr--r-x
chmod 346: --wxr--rw-
chmod 347: --wxr--rwx
chmod 350: --wxr-x---
chmod 351: --wxr-x--x
chmod 352: --wxr-x-w-
chmod 353: --wxr-x-wx
chmod 354: --wxr-xr--
chmod 355: --wxr-xr-x
chmod 356: --wxr-xrw-
chmod 357: --wxr-xrwx
chmod 360: --wxrw----
chmod 361: --wxrw---x
chmod 362: --wxrw--w-
chmod 363: --wxrw--wx
chmod 364: --wxrw-r--
chmod 365: --wxrw-r-x
chmod 366: --wxrw-rw-
chmod 367: --wxrw-rwx
chmod 370: --wxrwx---
chmod 371: --wxrwx--x
chmod 372: --wxrwx-w-
chmod 373: --wxrwx-wx
chmod 374: --wxrwxr--
chmod 375: --wxrwxr-x
chmod 376: --wxrwxrw-
chmod 377: --wxrwxrwx

chmod 400: -r--------
chmod 401: -r-------x
chmod 402: -r------w-
chmod 403: -r------wx
chmod 404: -r-----r--
chmod 405: -r-----r-x
chmod 406: -r-----rw-
chmod 407: -r-----rwx
chmod 410: -r----x---
chmod 411: -r----x--x
chmod 412: -r----x-w-
chmod 413: -r----x-wx
chmod 414: -r----xr--
chmod 415: -r----xr-x
chmod 416: -r----xrw-
chmod 417: -r----xrwx
chmod 420: -r---w----
chmod 421: -r---w---x
chmod 422: -r---w--w-
chmod 423: -r---w--wx
chmod 424: -r---w-r--
chmod 425: -r---w-r-x
chmod 426: -r---w-rw-
chmod 427: -r---w-rwx
chmod 430: -r---wx---
chmod 431: -r---wx--x
chmod 432: -r---wx-w-
chmod 433: -r---wx-wx
chmod 434: -r---wxr--
chmod 435: -r---wxr-x
chmod 436: -r---wxrw-
chmod 437: -r---wxrwx
chmod 440: -r--r-----
chmod 441: -r--r----x
chmod 442: -r--r---w-
chmod 443: -r--r---wx
chmod 444: -r--r--r--
chmod 445: -r--r--r-x
chmod 446: -r--r--rw-
chmod 447: -r--r--rwx
chmod 450: -r--r-x---
chmod 451: -r--r-x--x
chmod 452: -r--r-x-w-
chmod 453: -r--r-x-wx
chmod 454: -r--r-xr--
chmod 455: -r--r-xr-x
chmod 456: -r--r-xrw-
chmod 457: -r--r-xrwx
chmod 460: -r--rw----
chmod 461: -r--rw---x
chmod 462: -r--rw--w-
chmod 463: -r--rw--wx
chmod 464: -r--rw-r--
chmod 465: -r--rw-r-x
chmod 466: -r--rw-rw-
chmod 467: -r--rw-rwx
chmod 470: -r--rwx---
chmod 471: -r--rwx--x
chmod 472: -r--rwx-w-
chmod 473: -r--rwx-wx
chmod 474: -r--rwxr--
chmod 475: -r--rwxr-x
chmod 476: -r--rwxrw-
chmod 477: -r--rwxrwx
chmod 500: -r-x------
chmod 501: -r-x-----x
chmod 502: -r-x----w-
chmod 503: -r-x----wx
chmod 504: -r-x---r--
chmod 505: -r-x---r-x
chmod 506: -r-x---rw-
chmod 507: -r-x---rwx
chmod 510: -r-x--x---
chmod 511: -r-x--x--x
chmod 512: -r-x--x-w-
chmod 513: -r-x--x-wx
chmod 514: -r-x--xr--
chmod 515: -r-x--xr-x
chmod 516: -r-x--xrw-
chmod 517: -r-x--xrwx
chmod 520: -r-x-w----
chmod 521: -r-x-w---x
chmod 522: -r-x-w--w-
chmod 523: -r-x-w--wx
chmod 524: -r-x-w-r--
chmod 525: -r-x-w-r-x
chmod 526: -r-x-w-rw-
chmod 527: -r-x-w-rwx
chmod 530: -r-x-wx---
chmod 531: -r-x-wx--x
chmod 532: -r-x-wx-w-
chmod 533: -r-x-wx-wx
chmod 534: -r-x-wxr--
chmod 535: -r-x-wxr-x
chmod 536: -r-x-wxrw-
chmod 537: -r-x-wxrwx
chmod 540: -r-xr-----
chmod 541: -r-xr----x
chmod 542: -r-xr---w-
chmod 543: -r-xr---wx
chmod 544: -r-xr--r--
chmod 545: -r-xr--r-x
chmod 546: -r-xr--rw-
chmod 547: -r-xr--rwx
chmod 550: -r-xr-x---
chmod 551: -r-xr-x--x
chmod 552: -r-xr-x-w-
chmod 553: -r-xr-x-wx
chmod 554: -r-xr-xr--
chmod 555: -r-xr-xr-x
chmod 556: -r-xr-xrw-
chmod 557: -r-xr-xrwx
chmod 560: -r-xrw----
chmod 561: -r-xrw---x
chmod 562: -r-xrw--w-
chmod 563: -r-xrw--wx
chmod 564: -r-xrw-r--
chmod 565: -r-xrw-r-x
chmod 566: -r-xrw-rw-
chmod 567: -r-xrw-rwx
chmod 570: -r-xrwx---
chmod 571: -r-xrwx--x
chmod 572: -r-xrwx-w-
chmod 573: -r-xrwx-wx
chmod 574: -r-xrwxr--
chmod 575: -r-xrwxr-x
chmod 576: -r-xrwxrw-
chmod 577: -r-xrwxrwx
chmod 600: -rw-------
chmod 601: -rw------x
chmod 602: -rw-----w-
chmod 603: -rw-----wx
chmod 604: -rw----r--
chmod 605: -rw----r-x
chmod 606: -rw----rw-
chmod 607: -rw----rwx
chmod 610: -rw---x---
chmod 611: -rw---x--x
chmod 612: -rw---x-w-
chmod 613: -rw---x-wx
chmod 614: -rw---xr--
chmod 615: -rw---xr-x
chmod 616: -rw---xrw-
chmod 617: -rw---xrwx
chmod 620: -rw--w----
chmod 621: -rw--w---x
chmod 622: -rw--w--w-
chmod 623: -rw--w--wx
chmod 624: -rw--w-r--
chmod 625: -rw--w-r-x
chmod 626: -rw--w-rw-
chmod 627: -rw--w-rwx
chmod 630: -rw--wx---
chmod 631: -rw--wx--x
chmod 632: -rw--wx-w-
chmod 633: -rw--wx-wx
chmod 634: -rw--wxr--
chmod 635: -rw--wxr-x
chmod 636: -rw--wxrw-
chmod 637: -rw--wxrwx
chmod 640: -rw-r-----
chmod 641: -rw-r----x
chmod 642: -rw-r---w-
chmod 643: -rw-r---wx
chmod 644: -rw-r--r--
chmod 645: -rw-r--r-x
chmod 646: -rw-r--rw-
chmod 647: -rw-r--rwx
chmod 650: -rw-r-x---
chmod 651: -rw-r-x--x
chmod 652: -rw-r-x-w-
chmod 653: -rw-r-x-wx
chmod 654: -rw-r-xr--
chmod 655: -rw-r-xr-x
chmod 656: -rw-r-xrw-
chmod 657: -rw-r-xrwx
chmod 660: -rw-rw----
chmod 661: -rw-rw---x
chmod 662: -rw-rw--w-
chmod 663: -rw-rw--wx
chmod 664: -rw-rw-r--
chmod 665: -rw-rw-r-x
chmod 666: -rw-rw-rw-
chmod 667: -rw-rw-rwx
chmod 670: -rw-rwx---
chmod 671: -rw-rwx--x
chmod 672: -rw-rwx-w-
chmod 673: -rw-rwx-wx
chmod 674: -rw-rwxr--
chmod 675: -rw-rwxr-x
chmod 676: -rw-rwxrw-
chmod 677: -rw-rwxrwx
chmod 700: -rwx------
chmod 701: -rwx-----x
chmod 702: -rwx----w-
chmod 703: -rwx----wx
chmod 704: -rwx---r--
chmod 705: -rwx---r-x
chmod 706: -rwx---rw-
chmod 707: -rwx---rwx
chmod 710: -rwx--x---
chmod 711: -rwx--x--x
chmod 712: -rwx--x-w-
chmod 713: -rwx--x-wx
chmod 714: -rwx--xr--
chmod 715: -rwx--xr-x
chmod 716: -rwx--xrw-
chmod 717: -rwx--xrwx
chmod 720: -rwx-w----
chmod 721: -rwx-w---x
chmod 722: -rwx-w--w-
chmod 723: -rwx-w--wx
chmod 724: -rwx-w-r--
chmod 725: -rwx-w-r-x
chmod 726: -rwx-w-rw-
chmod 727: -rwx-w-rwx
chmod 730: -rwx-wx---
chmod 731: -rwx-wx--x
chmod 732: -rwx-wx-w-
chmod 733: -rwx-wx-wx
chmod 734: -rwx-wxr--
chmod 735: -rwx-wxr-x
chmod 736: -rwx-wxrw-
chmod 737: -rwx-wxrwx
chmod 740: -rwxr-----
chmod 741: -rwxr----x
chmod 742: -rwxr---w-
chmod 743: -rwxr---wx
chmod 744: -rwxr--r--
chmod 745: -rwxr--r-x
chmod 746: -rwxr--rw-
chmod 747: -rwxr--rwx
chmod 750: -rwxr-x---
chmod 751: -rwxr-x--x
chmod 752: -rwxr-x-w-
chmod 753: -rwxr-x-wx
chmod 754: -rwxr-xr--
chmod 755: -rwxr-xr-x
chmod 756: -rwxr-xrw-
chmod 757: -rwxr-xrwx
chmod 760: -rwxrw----
chmod 761: -rwxrw---x
chmod 762: -rwxrw--w-
chmod 763: -rwxrw--wx
chmod 764: -rwxrw-r--
chmod 765: -rwxrw-r-x
chmod 766: -rwxrw-rw-
chmod 767: -rwxrw-rwx
chmod 770: -rwxrwx---
chmod 771: -rwxrwx--x
chmod 772: -rwxrwx-w-
chmod 773: -rwxrwx-wx
chmod 774: -rwxrwxr--
chmod 775: -rwxrwxr-x
chmod 776: -rwxrwxrw-
chmod 777: -rwxrwxrwx

Congratulations!

Here's my custom stat function, which I am definately not finished with, so check back in a couple days and if you find any improvements please hook me up with a comment!

function askapache_stat( $filename ) {
$p=@fileperms($filename);
$s=@stat($filename);
$str='';
$t=decoct($s['mode'] & 0170000);

switch (octdec($t)) {
case 0140000: $str = 's'; $stat['type']='socket'; break;
case 0120000: $str = 'l'; $stat['type']='link'; break;
case 0100000: $str = '-'; $stat['type']='file'; break;
case 0060000: $str = 'b'; $stat['type']='block'; break;
case 0040000: $str = 'd'; $stat['type']='dir'; break;
case 0020000: $str = 'c'; $stat['type']='char'; break;
case 0010000: $str = 'p'; $stat['type']='fifo'; break;
default: $str = 'u'; $stat['type']='unknown'; break;
}

$stat['type_octal'] = sprintf("%07o", octdec($t));

$str .= (($p&0x0100)?'r':'-').(($p&0x0080)?'w':'-').(($p&0x0040)?(($p&0x0800)?'s':'x'):(($p&0x0800)?'S':'-'));
$str .= (($p&0x0020)?'r':'-').(($p&0x0010)?'w':'-').(($p&0x0008)?(($p&0x0400)?'s':'x'):(($p&0x0400)?'S':'-'));
$str .= (($p&0x0004)?'r':'-').(($p&0x0002)?'w':'-').(($p&0x0001)?(($p&0x0200)?'t':'x'):(($p&0x0200)?'T':'-'));

$stat['default_umask']=sprintf("%04o",umask());
$stat['perm_human']=$str;
$stat['perm_octal1'] = sprintf( "%o", ( $s['mode'] & 00777 ) );
$stat['perm_octal2'] = sprintf("0%o", 0777 & $p);
$stat['perm_dec'] = sprintf("%04o", $p);
$stat['perm_mode']=$s['mode']; // File mode.

$stat['file'] = @realpath($filename);
$stat['basename'] = basename( $filename );

$stat['user_id'] = $s['uid'];
$stat['group_id'] = $s['gid'];

$stat['device']=$s['dev']; // Device
$stat['device_number']=$s['rdev']; // Device number, if device.
$stat['inode']=$s['ino']; // File serial number
$stat['link_count']=$s['nlink']; // link count
if($stat['type']=='link')$stat['link_to']=@readlink( $filename );

$stat['size']=$s['size']; // Size of file, in bytes.
$stat['block_size']=$s['blksize']; // Optimal block size for I/O.
$stat['blocks']=$s['blocks']; // Number 512-byte blocks allocated

$stat['time_access']=@date( 'Y M D H:i:s',$s['atime']); // Time of last access.
$stat['time_modified']=@date( 'Y M D H:i:s',$s['mtime']); // Time of last modification
$stat['time_created']=@date( 'Y M D H:i:s',$s['ctime']); // Time of last status change

clearstatcache();
return $stat;
}

header('Content-Type: text/plain');
$stat=askapache_stat(__FILE__);
print_r($stat);

Defining Permission Bits

!defined('S_IFMT') && define('S_IFMT', 0170000); // mask for all types
!defined('S_IFSOCK') && define('S_IFSOCK', 0140000); // type: socket
!defined('S_IFLNK') && define('S_IFLNK', 0120000); // type: symbolic link
!defined('S_IFREG') && define('S_IFREG', 0100000); // type: regular file
!defined('S_IFBLK') && define('S_IFBLK', 0060000); // type: block device
!defined('S_IFDIR') && define('S_IFDIR', 0040000); // type: directory
!defined('S_IFCHR') && define('S_IFCHR', 0020000); // type: character device
!defined('S_IFIFO') && define('S_IFIFO', 0010000); // type: fifo

!defined('S_ISUID') && define('S_ISUID', 0004000); // set-uid bit
!defined('S_ISGID') && define('S_ISGID', 0002000); // set-gid bit
!defined('S_ISVTX') && define('S_ISVTX', 0001000); // sticky bit
!defined('S_IRWXU') && define('S_IRWXU', 00700); // mask for owner permissions
!defined('S_IRUSR') && define('S_IRUSR', 00400); // owner: read permission
!defined('S_IWUSR') && define('S_IWUSR', 00200); // owner: write permission
!defined('S_IXUSR') && define('S_IXUSR', 00100); // owner: execute permission
!defined('S_IRWXG') && define('S_IRWXG', 00070); // mask for group permissions
!defined('S_IRGRP') && define('S_IRGRP', 00040); // group: read permission
!defined('S_IWGRP') && define('S_IWGRP', 00020); // group: write permission
!defined('S_IXGRP') && define('S_IXGRP', 00010); // group: execute permission
!defined('S_IRWXO') && define('S_IRWXO', 00007); // mask for others permissions
!defined('S_IROTH') && define('S_IROTH', 00004); // others: read permission
!defined('S_IWOTH') && define('S_IWOTH', 00002); // others: write permission
!defined('S_IXOTH') && define('S_IXOTH', 00001); // others: execute permission

How File Permissions Work

When PHP is installed on your server by you or whoever runs the server, it uses the file permissions that are used by the Operating System running the server.. If you are smart or just lucky than you are running some type of BSD/Unix/Solaris/Linux/Sun based Operating system and PHP won't have any problems. If you are running on a Locked, proprietary OS like Windows, PHP will still work but it has to use a lot of shortcuts and hacks to basically "Pretend" to act like the OS is BSD/Unix, and some key features just won't be available.

The OS Permission Bits

Here's the file permissions my Linux server uses, and which PHP automatically uses. The code basically just defines the default permissions for files, and defines the file atributes for each file that you can access by using the stat function, which I've improved upon to make things easier.

Download: POSIX Standard: 5.6 File Characteristicssys/stat.h

Protection bits for File Owner

#define S_IRWXU 00700
#define S_IRUSR 00400
#define S_IWUSR 00200
#define S_IXUSR 00100

Protection bits for File Group

#define S_IRWXG 00070
#define S_IRGRP 00040
#define S_IWGRP 00020
#define S_IXGRP 00010

Protection bits for All Others

#define S_IRWXO 00007
#define S_IROTH 00004
#define S_IWOTH 00002
#define S_IXOTH 00001

Some Example Permissions

0477 // owner has read only, other and group has rwx
0677 // owner has rw only, other and group has rwx

0444 // all have read only
0666 // all have rw only

0400 // owner has read only, group and others have no permission
0600 // owner has rw only, group and others have no permission

0470 // owner has read only, group has rwx, others have no permission
0407 // owner has read only, other has rwx, group has no permission

0670 // owner has rw only, group has rwx, others have no permission
0607 // owner has rw only, group has no permission and others have rwx

What's a File

A file is not merely its contents, a name, and a file type. A file also has an owner (a user ID), a group (a group ID), permissions (what the owner can do with the file, what people in the group can do, and what everyone else can do), various timestamps, and other information. Collectively, we call these a file's attributes.

Structure of File Mode Bits

The file mode bits have two parts: the file permission bits, which control ordinary access to the file, and special mode bits, which affect only some files.

There are three kinds of permissions that a user can have for a file:

permission to read the file. For directories, this means permission to list the contents of the directory.
permission to write to (change) the file. For directories, this means permission to create and remove files in the directory.
permission to execute the file (run it as a program). For directories, this means permission to access files in the directory.

There are three categories of users who may have different permissions to perform any of the above operations on a file:

the file's owner.
other users who are in the file's group
everyone else.

Files are given an owner and group when they are created. Usually the owner is the current user and the group is the group of the directory the file is in, but this varies with the operating system, the file system the file is created on, and the way the file is created. You can change the owner and group of a file by using the chown and chgrp commands.

In addition to the three sets of three permissions listed above, the file mode bits have three special components, which affect only executable files (programs) and, on most systems, directories:

Set the process's effective user ID to that of the file upon execution (called the set-user-ID bit, or sometimes the setuid bit). For directories on a few systems, give files created in the directory the same owner as the directory, no matter who creates them, and set the set-user-ID bit of newly-created subdirectories.
Set the process's effective group ID to that of the file upon execution (called the set-group-ID bit, or sometimes the setgid bit). For directories on most systems, give files created in the directory the same group as the directory, no matter what group the user who creates them is in, and set the set-group-ID bit of newly-created subdirectories.
Prevent unprivileged users from removing or renaming a file in a directory unless they own the file or the directory; this is called the restricted deletion flag for the directory, and is commonly found on world-writable directories like /tmp.

For regular files on some older systems, save the program's text image on the swap device so it will load more quickly when run; this is called the sticky bit.

Setting Permissions

The basic symbolic operations on a file's permissions are adding, removing, and setting the permission that certain users have to read, write, and execute or search the file. These operations have the following format:

users operation permissions

The spaces between the three parts above are shown for readability only; symbolic modes cannot contain spaces. The users part tells which users' access to the file is changed. It consists of one or more of the following letters (or it can be empty). When more than one of these letters is given, the order that they are in does not matter.

u - the user who owns the file.
g - other users who are in the file's group.
o - all other users.
a - all users; the same as ugo.

The operation part tells how to change the affected users' access to the file, and is one of the following symbols:

+ - to add the permissions to whatever permissions the users already have for the file.
- - to remove the permissions from whatever permissions the users already have for the file.
= - to make the permissions the only permissions that the users have for the file.

The permissions part tells what kind of access to the file should be changed; it is normally zero or more of the following letters. As with the users part, the order does not matter when more than one letter is given. Omitting the permissions part is useful only with the = operation, where it gives the specified users no access at all to the file.

r - the permission the users have to read the file.
w - the permission the users have to write to the file.
x - the permission the users have to execute the file, or search it if it is a directory.

For example, to give everyone permission to read and write a regular file, but not to execute it, use:

a=rw

To remove write permission for all users other than the file's owner, use:

go-w

The above command does not affect the access that the owner of the file has to it, nor does it affect whether other users can read or execute the file.

To give everyone except a file's owner no permission to do anything with that file, use the mode below. Other users could still remove the file, if they have write permission on the directory it is in.

go=

Another way to specify the same thing is:

og-rwx

Copying Existing Permissions

You can base a file's permissions on its existing permissions. To do this, instead of using a series of r, w, or x letters after the operator, you use the letter u, g, or o. For example, the mode

o+g

adds the permissions for users who are in a file's group to the permissions that other users have for the file. Thus, if the file started out as mode 664 (rw-rw-r--), the above mode would change it to mode 666 (rw-rw-rw-). If the file had started out as mode 741 (rwxr----x), the above mode would change it to mode 745 (rwxr--r-x). The - and = operations work analogously.

Umask and Protection

If the users part of a symbolic mode is omitted, it defaults to a (affect all users), except that any permissions that are set in the system variable umask are not affected. The value of umask can be set using the umask command. Its default value varies from system to system.

Omitting the users part of a symbolic mode is generally not useful with operations other than +. It is useful with + because it allows you to use umask as an easily customizable protection against giving away more permission to files than you intended to. As an example, if umask has the value 2, which removes write permission for users who are not in the file's group, then the mode:

+w

adds permission to write to the file to its owner and to other users who are in the file's group, but not to other users. In contrast, the mode:

a+w

ignores umask, and does give write permission for the file to all users.

Directories, Set-User-ID and Set-Group-ID Bits

On most systems, if a directory's set-group-ID bit is set, newly created subfiles inherit the same group as the directory, and newly created subdirectories inherit the set-group-ID bit of the parent directory. On a few systems, a directory's set-user-ID bit has a similar effect on the ownership of new subfiles and the set-user-ID bits of new subdirectories. These mechanisms let users share files more easily, by lessening the need to use chmod or chown to share new files.

These convenience mechanisms rely on the set-user-ID and set-group-ID bits of directories. If commands like chmod and mkdir routinely cleared these bits on directories, the mechanisms would be less convenient and it would be harder to share files. Therefore, a command like chmod does not affect the set-user-ID or set-group-ID bits of a directory unless the user specifically mentions them in a symbolic mode, or sets them in a numeric mode. For example, on systems that support set-group-ID inheritance:

# These commands leave the set-user-ID and
# set-group-ID bits of the subdirectories alone,
# so that they retain their default values.
mkdir A B C
chmod 755 A
chmod 0755 B
chmod u=rwx,go=rx C
mkdir -m 755 D
mkdir -m 0755 E
mkdir -m u=rwx,go=rx F

If you want to try to set these bits, you must mention them explicitly in the symbolic or numeric modes, e.g.:

# These commands try to set the set-user-ID
# and set-group-ID bits of the subdirectories.
mkdir G H
chmod 6755 G
chmod u=rwx,go=rx,a+s H
mkdir -m 6755 I
mkdir -m u=rwx,go=rx,a+s J

If you want to try to clear these bits, you must mention them explicitly in a symbolic mode, e.g.:

# This command tries to clear the set-user-ID
# and set-group-ID bits of the directory D.
chmod a-s D

Numeric Modes

The permissions granted to the user, to other users in the file's group, and to other users not in the file's group each require three bits, which are represented as one octal digit. The three special mode bits also require one bit each, and they are as a group represented as another octal digit. Here is how the bits are arranged, starting with the lowest valued bit:

Other users not in the file's group:

1 Execute/search
2 Write
4 Read

Other users in the file's group:

10 Execute/search
20 Write
40 Read

The file's owner:

100 Execute/search
200 Write
400 Read

Special mode bits:

1000 Restricted deletion flag or sticky bit
2000 Set group ID on execution
4000 Set user ID on execution

For example, numeric mode 4755 corresponds to symbolic mode u=rwxs,go=rx, and numeric mode 664 corresponds to symbolic mode ug=rw,o=r. Numeric mode 0 corresponds to symbolic mode a=.

Apache's Internal Bits (hex)

#define APR_FPROT_USETID   0x8000 /* Set user id */
#define APR_FPROT_UREAD   0x0400 /* Read by user */
#define APR_FPROT_UWRITE   0x0200 /* Write by user */
#define APR_FPROT_UEXECUTE 0x0100 /* Execute by user */
 
#define APR_FPROT_GSETID   0x4000 /* Set group id */
#define APR_FPROT_GREAD   0x0040 /* Read by group */
#define APR_FPROT_GWRITE   0x0020 /* Write by group */
#define APR_FPROT_GEXECUTE 0x0010 /* Execute by group */
 
#define APR_FPROT_WSTICKY 0x2000 /* Sticky bit */
#define APR_FPROT_WREAD   0x0004 /* Read by others */
#define APR_FPROT_WWRITE 0x0002 /* Write by others */
#define APR_FPROT_WEXECUTE 0x0001 /* Execute by others */
 
#define APR_FPROT_OS_DEFAULT  0x0FFF /* use OS's default permissions */
 
/* additional permission flags for apr_file_copy  and apr_file_append */
#define APR_FPROT_FILE_SOURCE_PERMS 0x1000 /* Copy source file's permissions */

Download: httpd-2.2.10/srclib/apr/file_io/unix/fileacc.c Here's some interesting bitmasking done by Apache that uses the defined bits set earlier by stat.h

apr_unix_perms2mode(perms){
 mode=0;
 if (perms & APR_USETID) mode |= S_ISUID;
 if (perms & APR_UREAD)  mode |= S_IRUSR;
 if (perms & APR_UWRITE) mode |= S_IWUSR;
 if (perms & APR_UEXECUTE) mode |= S_IXUSR;
 
 if (perms & APR_GSETID) mode |= S_ISGID;
 if (perms & APR_GREAD)  mode |= S_IRGRP;
 if (perms & APR_GWRITE) mode |= S_IWGRP;
 if (perms & APR_GEXECUTE) mode |= S_IXGRP;
 
 if (perms & APR_WSTICKY) mode |= S_ISVTX;
 if (perms & APR_WREAD)  mode |= S_IROTH;
 if (perms & APR_WWRITE) mode |= S_IWOTH;
 if (perms & APR_WEXECUTE) mode |= S_IXOTH;
 return mode;
}
 
apr_unix_mode2perms(mode){
 perms = 0;
 if (mode & S_ISUID)perms |= APR_USETID;
 if (mode & S_IRUSR)perms |= APR_UREAD;
 if (mode & S_IWUSR)perms |= APR_UWRITE;
 if (mode & S_IXUSR)perms |= APR_UEXECUTE;
 
 if (mode & S_ISGID)perms |= APR_GSETID;
 if (mode & S_IRGRP)perms |= APR_GREAD;
 if (mode & S_IWGRP)perms |= APR_GWRITE;
 if (mode & S_IXGRP)perms |= APR_GEXECUTE;
 
 if (mode & S_ISVTX)perms |= APR_WSTICKY;
 if (mode & S_IROTH)perms |= APR_WREAD;
 if (mode & S_IWOTH)perms |= APR_WWRITE;
 if (mode & S_IXOTH)perms |= APR_WEXECUTE;
 return perms;
}

umask

umask(int mask){
 arg1;
 int oldumask;
 int arg_count = ZEND_NUM_ARGS();
 oldumask = umask(077);
 
 if (BG(umask) == -1) BG(umask) = oldumask;
 if (arg_count == 0) umask(oldumask);
 
 convert_to_long_ex(arg1);
 umask(Z_LVAL_PP(arg1));
 RETURN_LONG(oldumask);
}

File Attributes

Each file will have attributes based on the type of OS.. Using the stat command you can view them.

Viewing stat results

* %a - Access rights in octal
* %A - Access rights in human readable form
* %b - Number of blocks allocated (see %B)
* %B - The size in bytes of each block reported by %b
* %d - Device number in decimal
* %D - Device number in hex
* %f - Raw mode in hex
* %F - File type
* %g - Group ID of owner
* %G - Group name of owner
* %h - Number of hard links
* %i - Inode number
* %n - File name
* %N - Quoted file name with dereference if symbolic link
* %o - I/O block size
* %s - Total size, in bytes
* %t - Major device type in hex
* %T - Minor device type in hex
* %u - User ID of owner
* %U - User name of owner
* %x - Time of last access
* %X - Time of last access as seconds since Epoch
* %y - Time of last modification
* %Y - Time of last modification as seconds since Epoch
* %z - Time of last change
* %Z - Time of last change as seconds since Epoch

The OS Attribute Bits

These defined values are what allows your operating system to determine the type of file being accessed.

#define S_IFMT   00170000  /* These bits determine file type. */
#define S_IFSOCK 0140000  /* Socket file */
#define S_IFLNK   0120000  /* Symbolic Link */
#define S_IFREG   0100000  /* Regular file */
#define S_IFDIR   0040000  /* Directory */
#define S_IFIFO  0010000   /* FIFO first-in-first-out file */
 
/* Such devices can be read either a character at a time or a "block" (many characters) at a time,
hence we say there are block special files and character special files. */
#define S_IFBLK   0060000  /* Block device */
#define S_IFCHR  0020000  /* Character device */

Special Permission Bits

#define S_ISUID  0004000  /* Set user ID on execution.  */
#define S_ISGID  0002000  /* Set group ID on execution.  */
#define S_ISVTX  0001000 /* Save swapped text after use (sticky).  */

Bitmasking to determine Filetype

#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
#define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
#define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
#define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)

Default Permission Masks

#define S_IRWXUGO (S_IRWXU|S_IRWXG|S_IRWXO)
#define S_IALLUGO (S_ISUID|S_ISGID|S_ISVTX|S_IRWXUGO)
#define S_IRUGO  (S_IRUSR|S_IRGRP|S_IROTH)
#define S_IWUGO  (S_IWUSR|S_IWGRP|S_IWOTH)
#define S_IXUGO  (S_IXUSR|S_IXGRP|S_IXOTH)

Download: httpd-2.2.10/srclib/apr/file_io/unix/filestat.c, this file shows a simple way to determine the type of file.

filetype_from_mode(mode){
 type;
 switch (mode & S_IFMT) {
  case S_IFREG:  type = APR_REG;  break;
  case S_IFDIR:  type = APR_DIR;  break;
  case S_IFLNK:  type = APR_LNK;  break;
 
  case S_IFCHR:  type = APR_CHR;  break;
  case S_IFBLK:  type = APR_BLK;  break;
  case S_IFFIFO: type = APR_PIPE; break;
  case S_IFSOCK: type = APR_SOCK; break;
  default: type = APR_UNKFILE;
 }
 return type;
}

Apache Stat Bits

#define APR_FINFO_LINK  0x00000001 /* Stat the link not the file itself if it is a link */
#define APR_FINFO_MTIME  0x00000010 /* Modification Time */
#define APR_FINFO_CTIME  0x00000020 /* Creation or inode-changed time */
#define APR_FINFO_ATIME  0x00000040 /* Access Time */
#define APR_FINFO_SIZE  0x00000100 /* Size of the file */
#define APR_FINFO_CSIZE  0x00000200 /* Storage size consumed by the file */
#define APR_FINFO_DEV  0x00001000 /* Device */
#define APR_FINFO_INODE  0x00002000 /* Inode */
#define APR_FINFO_NLINK  0x00004000 /* Number of links */
#define APR_FINFO_TYPE  0x00008000 /* Type */
#define APR_FINFO_USER  0x00010000 /* User */
#define APR_FINFO_GROUP  0x00020000 /* Group */
#define APR_FINFO_UPROT  0x00100000 /* User protection bits */
#define APR_FINFO_GPROT  0x00200000 /* Group protection bits */
#define APR_FINFO_WPROT  0x00400000 /* World protection bits */
#define APR_FINFO_ICASE  0x01000000 /* if dev is case insensitive */
#define APR_FINFO_NAME  0x02000000 /* name in proper case */
#define APR_FINFO_MIN  0x00008170 /* type, mtime, ctime, atime, size */
#define APR_FINFO_IDENT  0x00003000 /* dev and inode */
#define APR_FINFO_OWNER  0x00030000 /* user and group */
#define APR_FINFO_PROT  0x00700000 /* all protections */
#define APR_FINFO_NORM  0x0073b170 /* an atomic unix apr_stat() */
#define APR_FINFO_DIRENT 0x02000000 /* an atomic unix apr_dir_read() */

The Apache file information structure.

apr_uid_t user;  /* The user id that owns the file */
apr_gid_t group;  /* The group id that owns the file */
apr_ino_t inode; /* The inode of the file. */
apr_dev_t device; /* The id of the device the file is on. */
apr_int32_t nlink; /* The number of hard links to the file. */
apr_off_t size;  /* The size of the file */
apr_off_t csize; /* The storage size consumed by the file */
apr_time_t atime; /* The time the file was last accessed */
apr_time_t mtime; /* The time the file was last modified */
apr_time_t ctime; /* The time the file was created, or the inode was last changed */
const char *fname; /* The pathname of the file (possibly unrooted) */
const char *name; /* The file's name (no path) in filesystem case */

File Time Attributes

touch
If changing both the access and modification times to the current time, touch can change the timestamps for files that the user running it does not own but has write permission for. Otherwise, the user must own the files.

Although touch provides options for changing two of the times the times of last access and modification of a file, there is actually a third one as well: the inode change time. This is often referred to as a file's ctime. The inode change time represents the time when the file's meta-information last changed. One common example of this is when the permissions of a file change. Changing the permissions doesn't access the file, so the atime doesn't change, nor does it modify the file, so the mtime doesn't change. Yet, something about the file itself has changed, and this must be noted somewhere. This is the job of the ctime field. This is necessary, so that, for example, a backup program can make a fresh copy of the file, including the new permissions value. Another operation that modifies a file's ctime without affecting the others is renaming. In any case, it is not possible, in normal operations, for a user to change the ctime field to a user-specified value.

WebHost allows you to create multiple users per account. Each user can have domain assigned to its home home directory accessible via FTP or SSH/SCP. The problem with multiple users on the same account is that they share the same default unix group, and default permissions allow their files to be easily modified by the members of this group. Usually this doesn't pose a problem as each user is probably trusted by account owner to not to mess with others files, but if one of the users have their web application hacked then all other users on the same account will be in danger.

By default all files in your account are created with 644 privileges and directories are with 775. That means any user can read your files and any user from the same account can move and add files in your freshly made directories. Your home directory is different, though. By default it carries 751 attribute meaning that only members of your group can see your files, but can't add any new. These group access schemes are possible, because every user in your account has its primary/default group set to "pgxxxxxx", which is assigned to every new file you create by default. The normal way to secure users from web-intrusion is to assign a separate group to the web-server user, removing it from default group. This way, exploited scripts will not be able to traverse into home directories of other users on your account. To allow account users to update centralized web-site they could be added to web-site group explicitly. But this "normal way" doesn't work with DreamHost, because you can't delete web-user from the default group and unless you set access for every new file explicitly, it will be possible for an intruder to read it.

To make managing privileges easier in interactive sessions "umask 007" command can be specified in your .bash_profile - this makes all new files carry xx0 mask. You also need to control your scripts (web based or cron/shell) so that they set mask for critical files explicitly. To secure account users from access by means of hacked user script you would also like to define another group for every user in your account and change group ownership of the user's home directory to that group with "set gid" bit set (and optional umask 007 in .bash_profile).

Therefore, to secure your users from web-intrusion you need to:

Add a separate user and group for every domain where apache will be running
Add a separate group for other user accounts
Change the default group for new files created by your users by changing the group of their home directory and setting "set gid" bit for it (it is impossible to do this with FTP accounts, therefore you will need to login in each account via SSH)
Add users who need access to web-site into the web-user group
Optionally set umask 007 in .bash_profile for every user to tweak default WebHost775/664 permissions to something like 770/660 for directories and files that are not meant to be read by Apache (660 could also be used for all web scripts including .php as they are not read by dhapache CGI, but merely executed)

Apache Security

All your web files that need to be read by Apache should be readable by everyone as Apache itself is run under dhapache user. However, executable scripts like .php are executed under your own user and do not have to be world readable as they are not actually read by Apache, but executed via suEXEC. Quite the opposite - to prevent your code or database settings from being messed by any third-parties you SHOULD set permissions to these files explicitly to something like 640 or even 600 depending on who do you trust.

Multiuser security setup example

For our example, we will create a rainforce_www user and a aapp_www group for serving web files with apache and setup a rainforce user with a 'aapp group to manage mail and keep other files on DH privately. Since these records already exist, you will need to subsitute your own names.

Login to create the users rainforce_www and rainforce with shell access.
Create two groups - aapp_www and aapp. Note that users created in previous step are still members of the same default pgxxxxxx group.
Add rainforce_www to 'the 'aapp_www group and rainforce to both the aapp_www and aapp groups
Move your domain to rainforce_www account (mine is rainforce.org)
Now login to SSH with your rainforce_www user and change the default group for your home directory with "sgid" bit set to make all current and new files/directories created in this directory have the same aapp_www group.

 $ chgrp -R aapp_www .
 $ chmod 2751 .
 $ chmod 2771 rainforce.org

By setting 2771 the directory will be writable by the owner, the group and will be only executable by others. The contents of an executable only directory cannot be listed, but the files inside it can be read (if the permissions of the file allow it). It is important that the directory can be executable in order to allow static content (e.g. .html files) inside it to be read. Remember that directories you don't want anyone to have web access to, should be 0770 (writable by the owner and group, or 0750 writable by the owner and readable by group). Such strict permissions should by applied to password files, php include files or databases files (such as SQLite, BDB, etc).

Do the same for rainforce user, but specify aapp group instead.

 $ chgrp -R aapp .
 $ chmod 2751 .

Optionally modify umask in .bash_profile in user's home to 007 to make all files created by this user have 660 permissions set by default. If you want that newly created files by accessible by the web, you need to manually setup it's permissions to 664.

Now I can login as the user "rainforce" and update the web-site in the ../rainforce_www/rainforce.org directory. There is one more setup needed. Because files copied from other accounts can have 644 permissions set instead of 664, you need a script which will update permissions to 664 or 660 to allow other group members modify such files.

SSH key fingerprints

Just gen your own I guess

External Links

Original Article from DreamHost Wiki

Content is available under GNU Free Documentation License 1.2.

Example File Permission Bits

`/usr/lib/w3m/cgi-bin/dirlist.cgi`

sub utype {
  local($_) = @_;
  local(%T) = (
    0010000, 'PIPE',
    0020000, 'CHR',
    0040000, 'DIR',
    0060000, 'BLK',
    0100000, 'FILE',
    0120000, 'LINK',
    0140000, 'SOCK',
  );
  return $T{($_ & 0170000)} || 'FILE';
}
 
sub umode {
  local($_) = @_;
  local(%T) = (
    0010000, 'p',
    0020000, 'c',
    0040000, 'd',
    0060000, 'b',
    0100000, '-',
    0120000, 'l',
    0140000, 's',
  );
 
  return ($T{($_ & 0170000)} || '-')
     . (($_ & 00400) ? 'r' : '-')
     . (($_ & 00200) ? 'w' : '-')
     . (($_ & 04000) ? 's' :
       (($_ & 00100) ? 'x' : '-'))
     . (($_ & 00040) ? 'r' : '-')
     . (($_ & 00020) ? 'w' : '-')
     . (($_ & 02000) ? 's' :
       (($_ & 00010) ? 'x' : '-'))
     . (($_ & 00004) ? 'r' : '-')
     . (($_ & 00002) ? 'w' : '-')
     . (($_ & 01000) ? 't' :
       (($_ & 00001) ? 'x' : '-'));
}

`/usr/lib/perl/5.8.4/linux/stat.ph`

        eval 'sub S_IFMT () {00170000;}' unless defined(&S_IFMT);
        eval 'sub S_IFSOCK () {0140000;}' unless defined(&S_IFSOCK);
        eval 'sub S_IFLNK () {0120000;}' unless defined(&S_IFLNK);
        eval 'sub S_IFREG () {0100000;}' unless defined(&S_IFREG);
        eval 'sub S_IFBLK () {0060000;}' unless defined(&S_IFBLK);
        eval 'sub S_IFDIR () {0040000;}' unless defined(&S_IFDIR);
        eval 'sub S_IFCHR () {0020000;}' unless defined(&S_IFCHR);
        eval 'sub S_IFIFO () {0010000;}' unless defined(&S_IFIFO);
        eval 'sub S_ISUID () {0004000;}' unless defined(&S_ISUID);
        eval 'sub S_ISGID () {0002000;}' unless defined(&S_ISGID);
        eval 'sub S_ISVTX () {0001000;}' unless defined(&S_ISVTX);
        eval 'sub S_ISLNK {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFLNK));
        }' unless defined(&S_ISLNK);
        eval 'sub S_ISREG {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFREG));
        }' unless defined(&S_ISREG);
        eval 'sub S_ISDIR {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFDIR));
        }' unless defined(&S_ISDIR);
        eval 'sub S_ISCHR {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFCHR));
        }' unless defined(&S_ISCHR);
        eval 'sub S_ISBLK {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFBLK));
        }' unless defined(&S_ISBLK);
        eval 'sub S_ISFIFO {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFIFO));
        }' unless defined(&S_ISFIFO);
        eval 'sub S_ISSOCK {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFSOCK));
        }' unless defined(&S_ISSOCK);
        eval 'sub S_IRWXU () {00700;}' unless defined(&S_IRWXU);
        eval 'sub S_IRUSR () {00400;}' unless defined(&S_IRUSR);
        eval 'sub S_IWUSR () {00200;}' unless defined(&S_IWUSR);
        eval 'sub S_IXUSR () {00100;}' unless defined(&S_IXUSR);
        eval 'sub S_IRWXG () {00070;}' unless defined(&S_IRWXG);
        eval 'sub S_IRGRP () {00040;}' unless defined(&S_IRGRP);
        eval 'sub S_IWGRP () {00020;}' unless defined(&S_IWGRP);
        eval 'sub S_IXGRP () {00010;}' unless defined(&S_IXGRP);
        eval 'sub S_IRWXO () {00007;}' unless defined(&S_IRWXO);
        eval 'sub S_IROTH () {00004;}' unless defined(&S_IROTH);
        eval 'sub S_IWOTH () {00002;}' unless defined(&S_IWOTH);
        eval 'sub S_IXOTH () {00001;}' unless defined(&S_IXOTH);
    }
    if(defined(&__KERNEL__)) {
        eval 'sub S_IRWXUGO () {( &S_IRWXU| &S_IRWXG| &S_IRWXO);}' unless defined(&S_IRWXUGO);
        eval 'sub S_IALLUGO () {( &S_ISUID| &S_ISGID| &S_ISVTX| &S_IRWXUGO);}' unless defined(&S_IALLUGO);
        eval 'sub S_IRUGO () {( &S_IRUSR| &S_IRGRP| &S_IROTH);}' unless defined(&S_IRUGO);
        eval 'sub S_IWUGO () {( &S_IWUSR| &S_IWGRP| &S_IWOTH);}' unless defined(&S_IWUGO);
        eval 'sub S_IXUGO () {( &S_IXUSR| &S_IXGRP| &S_IXOTH);}' unless defined(&S_IXUGO);
        require 'linux/types.ph';
        require 'linux/time.ph';
    }

Mozilla-Source 1.8a2

/* notice that these valuse are octal. */
const PERM_IRWXU = 00700;  /* read, write, execute/search by owner */
const PERM_IRUSR = 00400;  /* read permission, owner */
const PERM_IWUSR = 00200;  /* write permission, owner */
const PERM_IXUSR = 00100;  /* execute/search permission, owner */
const PERM_IRWXG = 00070;  /* read, write, execute/search by group */
const PERM_IRGRP = 00040;  /* read permission, group */
const PERM_IWGRP = 00020;  /* write permission, group */
const PERM_IXGRP = 00010;  /* execute/search permission, group */
const PERM_IRWXO = 00007;  /* read, write, execute/search by others */
const PERM_IROTH = 00004;  /* read permission, others */
const PERM_IWOTH = 00002;  /* write permission, others */
const PERM_IXOTH = 00001;  /* execute/search permission, others */
 
const MODE_RDONLY   = 0x01;
const MODE_WRONLY   = 0x02;
const MODE_RDWR     = 0x04;
const MODE_CREATE   = 0x08;
const MODE_APPEND   = 0x10;
const MODE_TRUNCATE = 0x20;
const MODE_SYNC     = 0x40;
const MODE_EXCL     = 0x80;

`/usr/include/libpng12/png.h`

/* Transform masks for the high-level interface */
#define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
#define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
#define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
#define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
#define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
#define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
#define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
#define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
#define PNG_TRANSFORM_BGR            0x0080    /* read and write */
#define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
#define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
#define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
#define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* WRITE only */

`/usr/lib/python2.4/stat.py`

# Extract bits from the mode
 
def S_IMODE(mode):
    return mode & 07777
 
def S_IFMT(mode):
    return mode & 0170000
 
# Constants used as S_IFMT() for various file types
# (not all are implemented on all systems)
 
S_IFDIR  = 0040000
S_IFCHR  = 0020000
S_IFBLK  = 0060000
S_IFREG  = 0100000
S_IFIFO  = 0010000
S_IFLNK  = 0120000
S_IFSOCK = 0140000
 
# Functions to test for each file type
 
def S_ISDIR(mode):
    return S_IFMT(mode) == S_IFDIR
 
def S_ISCHR(mode):
    return S_IFMT(mode) == S_IFCHR
 
def S_ISBLK(mode):
    return S_IFMT(mode) == S_IFBLK
 
def S_ISREG(mode):
    return S_IFMT(mode) == S_IFREG
 
def S_ISFIFO(mode):
    return S_IFMT(mode) == S_IFIFO
 
def S_ISLNK(mode):
    return S_IFMT(mode) == S_IFLNK
 
def S_ISSOCK(mode):
    return S_IFMT(mode) == S_IFSOCK
 
# Names for permission bits
 
S_ISUID = 04000
S_ISGID = 02000
S_ENFMT = S_ISGID
S_ISVTX = 01000
S_IREAD = 00400
S_IWRITE = 00200
S_IEXEC = 00100
S_IRWXU = 00700
S_IRUSR = 00400
S_IWUSR = 00200
S_IXUSR = 00100
S_IRWXG = 00070
S_IRGRP = 00040
S_IWGRP = 00020
S_IXGRP = 00010
S_IRWXO = 00007
S_IROTH = 00004
S_IWOTH = 00002
S_IXOTH = 00001

`/usr/include/bits/stat.h`

/* Encoding of the file mode.  */
 
#define __S_IFMT        0170000 /* These bits determine file type.  */
 
/* File types.  */
#define __S_IFDIR       0040000 /* Directory.  */
#define __S_IFCHR       0020000 /* Character device.  */
#define __S_IFBLK       0060000 /* Block device.  */
#define __S_IFREG       0100000 /* Regular file.  */
#define __S_IFIFO       0010000 /* FIFO.  */
#define __S_IFLNK       0120000 /* Symbolic link.  */
#define __S_IFSOCK      0140000 /* Socket.  */
 
/* POSIX.1b objects.  Note that these macros always evaluate to zero.  But
   they do it by enforcing the correct use of the macros.  */
#define __S_TYPEISMQ(buf)  ((buf)->st_mode - (buf)->st_mode)
#define __S_TYPEISSEM(buf) ((buf)->st_mode - (buf)->st_mode)
#define __S_TYPEISSHM(buf) ((buf)->st_mode - (buf)->st_mode)
 
/* Protection bits.  */
 
#define __S_ISUID       04000   /* Set user ID on execution.  */
#define __S_ISGID       02000   /* Set group ID on execution.  */
#define __S_ISVTX       01000   /* Save swapped text after use (sticky).  */
#define __S_IREAD       0400    /* Read by owner.  */
#define __S_IWRITE      0200    /* Write by owner.  */
#define __S_IEXEC       0100    /* Execute by owner.  */

`/usr/include/linux/nfs.h`

#define NFS_FIFO_DEV    (-1)
#define NFSMODE_FMT     0170000
#define NFSMODE_DIR     0040000
#define NFSMODE_CHR     0020000
#define NFSMODE_BLK     0060000
#define NFSMODE_REG     0100000
#define NFSMODE_LNK     0120000
#define NFSMODE_SOCK    0140000
#define NFSMODE_FIFO    0010000

`/usr/include/linux/nfs3.h`

#define NFS3_FIFO_DEV           (-1)
#define NFS3MODE_FMT            0170000
#define NFS3MODE_DIR            0040000
#define NFS3MODE_CHR            0020000
#define NFS3MODE_BLK            0060000
#define NFS3MODE_REG            0100000
#define NFS3MODE_LNK            0120000
#define NFS3MODE_SOCK           0140000
#define NFS3MODE_FIFO           0010000
 
/* Flags for access() call */
#define NFS3_ACCESS_READ        0x0001
#define NFS3_ACCESS_LOOKUP      0x0002
#define NFS3_ACCESS_MODIFY      0x0004
#define NFS3_ACCESS_EXTEND      0x0008
#define NFS3_ACCESS_DELETE      0x0010
#define NFS3_ACCESS_EXECUTE     0x0020
#define NFS3_ACCESS_FULL        0x003f

`/usr/include/linux/stat.h`

#define S_IFMT  00170000
#define S_IFSOCK 0140000
#define S_IFLNK  0120000
#define S_IFREG  0100000
#define S_IFBLK  0060000
#define S_IFDIR  0040000
#define S_IFCHR  0020000
#define S_IFIFO  0010000
#define S_ISUID  0004000
#define S_ISGID  0002000
#define S_ISVTX  0001000
 
#define S_ISLNK(m)      (((m) & S_IFMT) == S_IFLNK)
#define S_ISREG(m)      (((m) & S_IFMT) == S_IFREG)
#define S_ISDIR(m)      (((m) & S_IFMT) == S_IFDIR)
#define S_ISCHR(m)      (((m) & S_IFMT) == S_IFCHR)
#define S_ISBLK(m)      (((m) & S_IFMT) == S_IFBLK)
#define S_ISFIFO(m)     (((m) & S_IFMT) == S_IFIFO)
#define S_ISSOCK(m)     (((m) & S_IFMT) == S_IFSOCK)
 
#define S_IRWXU 00700
#define S_IRUSR 00400
#define S_IWUSR 00200
#define S_IXUSR 00100
 
#define S_IRWXG 00070
#define S_IRGRP 00040
#define S_IWGRP 00020
#define S_IXGRP 00010
 
#define S_IRWXO 00007
#define S_IROTH 00004
#define S_IWOTH 00002
#define S_IXOTH 00001

Further File Permissions Reading

Related PHP Functions

Special file types

link invocation: Make a hard link via the link syscall
ln invocation: Make links between files
mkdir invocation: Make directories
mkfifo invocation: Make FIFOs (named pipes)
mknod invocation: Make block or character special files
readlink invocation: Print the referent of a symbolic link
rmdir invocation: Remove empty directories
unlink invocation: Remove files via unlink syscall

Changing file attributes

chown invocation: Change file owner and group
chgrp invocation: Change group ownership
chmod invocation: Change access permissions
touch invocation: Change file timestamps

Chmod, Umask, Stat, Fileperms, and File Permissions originally appeared on AskApache.

Optimize a Website for Speed, Security, and Easy Management

AskApache — Sun, 19 Oct 2008 00:45:26 +0000

Over the past 10 or so years I’ve been directly or indirectly involved in configuring/administrating/hacking thousands of websites, and I realized today that I’ve actually learned quite a bit about how to really make them work hard for me, instead of the other way around. It came as a mild shock to think of where I was back then vs. now because the improvements and optimizations are hundreds of smaller improvements, but taken together, the optimization hacks I’ve found through trial and error and much reading are as Donald would say, YOOUUGE compared to a basic website setup.

I use this awesome skeleton setup for all my high-paying clients sorry poor people! and also of course on this blog, which I use as a bleeding-edge dev server for my crazy testing. So realize that I’m already past this setup and using it to do cooler stuff. In order for you to use these more advanced ideas, you first need to get up to speed on what I’m doing so you know what I’m talking about. This article tries to help you accomplish that… remains to be seen.

An Optimized Website, The Real Deal

This first article is to give you some ideas and get you thinking and reading before the first article in this series comes out. This series details how to setup, configure, secure, optimize, and manage a website the best possible way I can come up with. It pieces together all the AskApache hacks and tricks and uses methods and ideas discussed all over this blog and all over the net and glues them all together to show you how to have the most optimized, fastest, best website setup I can think of.

Knowing the why and how behind the operation of a Web Server allows us to optimize that operation. For this example we will be creating the website www.askapache.com, which will be running WordPress and php. We will also set up static.askapache.com to serve all of our sites uploads, images, css and javascript files, flash files, etc. with advanced caching and security using Apache Server .htaccess files. So lets get started and take a look at this site structure for a moment.

/home/askapache.com
|-- /home/askapache.com/backups/
|-- /home/askapache.com/htdocs/
|-- /home/askapache.com/inc/
|-- /home/askapache.com/logs/
|-- /home/askapache.com/static/
|-- /home/askapache.com/tmp/
|-- /home/askapache.com/.htpasswd-basic
`-- /home/askapache.com/.htpasswd-digest

/backups/ – For encrypted backups of WordPress database and site files. And any other backups.
/htdocs/ – The document root for www.askapache.com
/inc/ – Folder to keep your php include files for extra security and easy management.
/logs/ – Save your php, apache, and other logs here or create symlinks to them.
/static/ – The document root for static.askapache.com
/tmp/ – Only need this if your host doesn’t already have a /tmp folder

Strong Security, Top to Bottom

Simply by implementing correct access permissions, file permissions, password protection and segmenting various folders and services we are already ahead of the game. I’ve always taken security extremely seriously, so you can benefit from alot of the simple solutions I’m recommending for a really locked down site.

Indeed, security is a major part of every step of this setup process, as security concerns are what drives a lot of the motivations I have for coming up with this setup in the first place. We will be doing very simple but very effective site security like the following items, which is a short list compared to everything we will be doing.

Fixing file permissions automatically
Searching for modified files on the server
Encrypting your backups
Get alerted to breakin attempts
Block tons of bad clients
Disallowing cgi scripts or any other handlers, just serve files.
Configuring PHP
Password Protection for certain areas

Ready for Warfare?

My past work for an Internet Service Provider, followed by 4 years of auditing the security of organizations external/internal networks has given me a fresh perspective on website security, and I think it allows me to see what would really be effective at preventing and killing attacks. In fact just last night I was once again doing some research into some off-the-wall security topics, and I discovered a new defense method that I will be writing about very soon. I believe that this new method, could be quickly adopted and implemented by hosting providers and software developers, which would result in us finally taking the Internet back from all those zombies and robots. This method will be discussed in great detail soon, and will be a core part of this site setups security and optimization.

Built to Bleed Speed

Serve’s files as fast and efficiently as possible using advanced caching, HTTP Protocols, php/server configurations.

Many of the articles and research on this blog is about improving the speed and efficiency of your website. In fact that is why I am helping develop open-source software to block spammers from WordPress blogs… not because I’m bothered by the spam, but because they make the net slow! So lets look at some of the ideas we’ll be implementing.

Many techniques I’ve been using and tweaking for several years, and recently many of them were included in the high-performance websites list. Of course we will be taking a look at this list in practical terms, meaning almost all of it, the caching, compression, etc., will be automated in keeping with our “comfort” goal, which is to say we want to make the Web Developer and Server Admin’s lives as easy and comfy as possible. After all, we do the work right?

Reduce HTTP requests – Reducing 304 requests with Cache-Control Headers
Use a customized php.ini – Creating and using a custom PHP.ini
Add an Expires header – Caching with mod_expires on Apache
Gzip components
Make CSS and unobtrusive Javascript as external files not inline
Reduce DNS lookups – Use Static IP address, use a subdomain with static IP address for static content.
Minimize Javascript – Refactor the code, compress with dojo
Avoid external redirects – Use internal redirection with mod_rewrite, The correct way to redirect with 301
Turn off ETags – Prevent Caching with htaccess
Make AJAX cacheable and small

AskApache.com, Fastest Site Ever!

Ok it might not be the #1, but surely the top 10.. ;)

I’m very proud of the performance I am able to achieve on this site. Very proud. I started looking for ways to improve the wp-cache and wp-super-cache WordPress plugins, and came up with hacks for both of them.. but they still didn’t do what I wanted so I started from scratch and wrote my own caching plugin.

With much more advanced caching options and unquestionably higher performance and lower time usage on the machine. I’m hesitant to release it to the public until I get faded on it.. I just really love it.. it has been running my site for several months now and I keep finding ways to improve it.. Stay tuned.

One feature it has is the ability to allow negotiation of a resource between apache and the client. Think almost transparent mutli-lingual blogs, mutliple formats per document (look at the rdf for this page for an example*). But that plugin is the future and this is the present.. so back to it we go.

Pamper the Webmaster with Extreme Comfort

This section alone would make this setup appealing. I have developed all types of techniques and methods to make my life as easy as possible. I could literally DIE right now and this blog would continue to run and operate for years on its own. The general philosophy that I have used to get to where I can goto the beach with my laptop and do all this crazy stuff is the idea of perfection. That may sound a little put-offish, but it basically means I will focus in on one very specific area for improvement or research and just get sick with it. Most of this blogs articles are enlightening examples of this in action. I will take a relatively unknown or unused piece of code or software and experiment with it until I feel I have it down, then I move on to the next item of never-ending research. Mostly I think this is just plain habit from when I was studying security. I’m much better at this then that :)

Apache ErrorDocuments

The 57 HTTP Status Codes and Apache ErrorDocuments article is a prime example. I was simply searching for an authoritative list of HTTP status codes, an issue not many web people find worth their time, and that search led to some of the most useful stuff I’ve found about the Web

This “Comfort” article will include multi-language, intelligent, and optimized error documents for handling any type of HTTP error with class and allow us to stop spammers, save bandwidth, redirect correctly, etc.. You will probably be surprised at all the uses an Apache ErrorDocument can have.. It IS one of the foundations of the HTTP-based Net after all.

Emphasis on Easy Upgrades

The whole setup is geared to make hassle-free WordPress/PHP/application upgrades possible by keeping different types of files in separate places, keeping backups, other misc tricks and since all of these files are in /home/askapache.com, your FTP connection can still access every file easily. Sometimes security and optimizing your server can lead to it being more of a pain to do updates, backups, and general maintenance. This article tries to overwhelm the balance with a trifecta of goals.

Move to a new host? Ok!

Comfort to me also means being able to pack up the whole website and database and move to another web host in under an hour. I can move the whole AskApache site to one of several other hosting providers accounts I have in about 30minutes. If this was a clients site or I was getting paid more, I’d also be focused on round-robin DNS technology, balance-load setups, and just go crazy making it fast.

Staying Online, Improving Uptime

Ever since I started sharing information and software to stop all these resource hogging zombies attacking everything I’ve been attacked several times. Normally I get over 10K exploit attempts or requests per day, which I pretty much block 100%. But a few times they’ve actually tried to DDOS me off the net in a distributed attack. I have implemented several “poor mans” techniques to put up your best effort at surviving, which I did. Basically you want to configure your server to KILL connections just as fast as possible and prevent your server resources from skyrocketing and surpassing your quotas. A skilled attacker could easily shut you down even without the use of a widespread botnet if they are clever, which could be devastating to your small blog or site if it goes down at a crucial instant.

Organization with Templates and Systems

I used to work with a guy who did alot of the coldfusion programming for us, and I used to cringe every time I was called in to upgrade a site or do a re-design. Files and folders EVERYWHERE! Literally images in every folder, multiple index.html, index1.html, index-old.html, and on and on it went.. It would take me hours just to reverse-engineer the site enough so I could modify files on it without having some unkown consequence happen.

Do You Have a Cluttered Desktop?

Everyone has this problem, what I do all the time is just grab everything on my desktop and put it in a folder named with the date. Then the process repeats itself and invariably a few months later I’m looking at a cluttered screen again.

This absolutely is the worst thing that can happen to a website, worst for security, comfort for webmaster, and speed. So this setup addresses that issue completely heads on. With all the different pages, tools, and resources available on this blog, I can almost promise you that my site has less files than yours. No small feat to be sure, but worth every second I spent researching how to do it now that its on and popping.

What’s a Website really?

All hosts are different, but any host worth their salt is running some kind of BSD/Linux operating system, and that is good news because those operating systems all use very similarly excellent file/folder structures with huge organization systems. If your web hosting provider is running on a Windows based operating system or other locked/proprietary software than this article is not for you and I would recommend switching hosts to a BSD/Linux open-source operating system.

Listening for Requests with Web Hosting and DNS

First you set your website up so it can start serving.

You buy your domain name, which just gives you the right to use it.
You pay your webhost for an account on their machine running a Server connected to the Net via a fast connection link.
You pay a DNS provider to redirect requests for your domain name to be sent to your webhosts machine running the server.

Sub-Domain for Serving Assets

This is a very cool method I’ve been using more and more frequently because it makes updates, upgrades, and changes so much easier to manage. And segmenting various parts of the site is smart security, and even smarter in the way of speeding up a website and keeping your servers running mean and lean.

Full Site Structure Expanded

/home/askapache.com
|-- /home/askapache.com/backups/
|-- /home/askapache.com/htdocs/
|   |-- /home/askapache.com/htdocs/about/
|   |-- /home/askapache.com/htdocs/admin/
|   |-- /home/askapache.com/htdocs/cgi-bin/
|   |-- /home/askapache.com/htdocs/.htaccess
|   |-- /home/askapache.com/htdocs/index.php
|   `-- /home/askapache.com/htdocs/robots.txt
|-- /home/askapache.com/inc/
|   |-- /home/askapache.com/inc/config.inc.php
|   `-- /home/askapache.com/inc/settings.inc.php
|-- /home/askapache.com/logs/
|   |-- /home/askapache.com/logs/access.log
|   |-- /home/askapache.com/logs/error.log
|   |-- /home/askapache.com/logs/logins.log
|   |-- /home/askapache.com/logs/modsec_audit.log
|   |-- /home/askapache.com/logs/modsec_debug.log
|   `-- /home/askapache.com/logs/php_error.log
|-- /home/askapache.com/static/
|   |-- /home/askapache.com/static/css/
|   |-- /home/askapache.com/static/flv/
|   |-- /home/askapache.com/static/img/
|   |-- /home/askapache.com/static/js/
|   |-- /home/askapache.com/static/mp3/
|   |-- /home/askapache.com/static/pdf/
|   |-- /home/askapache.com/static/swf/
|   |-- /home/askapache.com/static/.htaccess
|   |-- /home/askapache.com/static/index.html
|   `-- /home/askapache.com/static/robots.txt
|-- /home/askapache.com/tmp/
|-- /home/askapache.com/.htpasswd-basic
`-- /home/askapache.com/.htpasswd-digest

Full Expanded Structure

/home/askapache.com
|-- /home/askapache.com/backups/
|-- /home/askapache.com/htdocs/
|   |-- /home/askapache.com/htdocs/about/
|   |   `-- /home/askapache.com/htdocs/about/index.html
|   |-- /home/askapache.com/htdocs/admin/
|   |   |-- /home/askapache.com/htdocs/admin/.htaccess
|   |   `-- /home/askapache.com/htdocs/admin/index.html
|   |-- /home/askapache.com/htdocs/cgi-bin/
|   |   |-- /home/askapache.com/htdocs/cgi-bin/bin/
|   |   |   |-- /home/askapache.com/htdocs/cgi-bin/bin/.htaccess
|   |   |   |-- /home/askapache.com/htdocs/cgi-bin/bin/php.cgi*
|   |   |   |-- /home/askapache.com/htdocs/cgi-bin/bin/php.ini
|   |   |   |-- /home/askapache.com/htdocs/cgi-bin/bin/php4.cgi*
|   |   |   `-- /home/askapache.com/htdocs/cgi-bin/bin/php5.cgi*
|   |   |-- /home/askapache.com/htdocs/cgi-bin/private/
|   |   |   |-- /home/askapache.com/htdocs/cgi-bin/private/.htaccess
|   |   |   |-- /home/askapache.com/htdocs/cgi-bin/private/debug.php
|   |   |   `-- /home/askapache.com/htdocs/cgi-bin/private/stats.php
|   |   |-- /home/askapache.com/htdocs/cgi-bin/.htaccess
|   |   |-- /home/askapache.com/htdocs/cgi-bin/login.php
|   |   |-- /home/askapache.com/htdocs/cgi-bin/printenv.cgi*
 
|   |   `-- /home/askapache.com/htdocs/cgi-bin/redir.cgi*
|   |-- /home/askapache.com/htdocs/.htaccess
|   |-- /home/askapache.com/htdocs/index.php
|   `-- /home/askapache.com/htdocs/robots.txt
|-- /home/askapache.com/inc/
|   |-- /home/askapache.com/inc/config.php
|   `-- /home/askapache.com/inc/functions.php
|-- /home/askapache.com/logs/
|   |-- /home/askapache.com/logs/access.log
|   |-- /home/askapache.com/logs/error.log
|   |-- /home/askapache.com/logs/logins.log
|   |-- /home/askapache.com/logs/modsec_audit.log
|   |-- /home/askapache.com/logs/modsec_debug.log
|   `-- /home/askapache.com/logs/php_error.log
|-- /home/askapache.com/static/
|   |-- /home/askapache.com/static/css/
|   |   `-- /home/askapache.com/static/css/apache.css
|   |-- /home/askapache.com/static/flv/
|   |   `-- /home/askapache.com/static/flv/apache.flv
|   |-- /home/askapache.com/static/img/
|   |   |-- /home/askapache.com/static/img/apache.gif
|   |   |-- /home/askapache.com/static/img/apache.jpg
|   |   `-- /home/askapache.com/static/img/apache.png
|   |-- /home/askapache.com/static/js/
|   |   `-- /home/askapache.com/static/js/apache.js
|   |-- /home/askapache.com/static/mp3/
|   |   `-- /home/askapache.com/static/mp3/apache.mp3
|   |-- /home/askapache.com/static/pdf/
|   |   `-- /home/askapache.com/static/pdf/apache.pdf
|   |-- /home/askapache.com/static/swf/
|   |   `-- /home/askapache.com/static/swf/apache.swf
|   |-- /home/askapache.com/static/.htaccess
|   |-- /home/askapache.com/static/index.html
|   `-- /home/askapache.com/static/robots.txt
|-- /home/askapache.com/tmp/
|-- /home/askapache.com/.htpasswd-basic
`-- /home/askapache.com/.htpasswd-digest

The buzz about apache and open-source is very real, apache is becoming more of a discussed topic as people realize the power and importance of Doing it and Doing it and Doing it well. – Movable Type Apache Installs made easy, Checking out Apache Web logs, Securing Wordpress with .htaccess, WordPress Permalinks and .htaccess, New search and replace module for apache!, creating an .htaccess template, .htaccess allow directive

Check back in a week for the first article, or better yet subscribe to my rss feed or use the comment form below to get notified.

Optimize a Website for Speed, Security, and Easy Management originally appeared on AskApache.

SEO Secrets of AskApache Part 2

AskApache — Fri, 17 Oct 2008 21:44:22 +0000

In part I: SEO Secrets of AskApache.com we talked about content and building a website to be your “SEO Base”. This article discusses some advanced SEO concepts to get a site indexed, move your best pages higher in search results, and controlling the pagerank/seo-juice of your site. but relatively easy ways to control and tweak WHAT urls on your site are indexed, and HOW. I’ve heard some people refer to this as “controlling pagerank flow” and “controlling pagerank juice”, basically we want our best pages to rank higher in the search engine results.

Big Picture: Going from no website to AskApache.com in less than a year can be accomplished by anyone with unique content and a resolve to avoid any shortcuts and take it one step at a time.

We want what Google wants, to provide the most relevant content for someone who is doing a search. Basically, you want every url on your site that has unique content to be included in the index. In other words, you have to think like a search engine!

The Goal of Google

Here’s what I mean, Google approaches search with the overwhelming goal of bringing the content to a searcher that is the most-likely to be what that searcher is searching for. Another way of looking at it is something I read on Google…

Google’s goal is to get you off of their site as fast as possible by providing you with exactly what you are looking for.

Think about SEO like this

If you search for htaccess tutorial for seo on Google, would you be more likely to visit a tutorial about using .htaccess for seo or a category page for htaccess articles? AskApache.com has both of those urls included in the index, but the article ranks higher than the category page, as it very well should.

Get Your URLS Indexed

Before I explain how I am able to help Google and other search engines rank my article pages higher than my category pages, we need to get the urls in the index or nothing will show up. There are many well-discussed methods for getting included in the index, so I’ll just list a few that I use.

Provide High-Quality original content, people will link to it
Get a sitemap and use Google Webmaster Tools
Publish an RSS/Atom Feed and ping the net when you publish a post
Use robots.txt and robots meta tags

Your URLs in the index

Here’s how to find out which of your pages are indexed.

Indexed pages in your site: site:
Pages that link to your site’s front page: link:
The current cache of your site: cache:
Information about your site: info:
Pages that are similar to your site: related:

Break It Down

Yo homeslice! I didn’t mean break dance.. I mean lets simplify AskApache in the context of getting our urls indexed high/low. Here’s the stats: 1 Homepage, 206 Articles, 19 Pages, 31 Categories

1 Homepage

This page is generally the highest ranking page in the index, it should contain links to your best urls, and provide easy navigation

206 Specific Topic Articles

These are the article’s (like this one) of AskApache.com and are the main source of search engine traffic. You want each url (if its a good article) to be ranked as high as possible. Some keys are to really make each article specific to a topic by using best-practice (X)HTML.

19 Static Pages

Most of these are pages like the online-tools hosted on this site, or other basic pages like about, contact us, site-map, etc.. Some of these you may want to rank very high ( like the /about/ page ) and some you may not want to even be included in the index.

31 Specific Topic Category Pages

These are tricky because they are generally just lists of articles from each category, which isn’t specific enough to get much seach-engine-traffic, but is very useful to site visitors. I beefed up my category pages by adding additional information about the category topic in addition to excerpts of the articles.

Higher Pagerank = Higher Up in Search Results

So Googlebot and other search engine robots have these crazy complicated algorithms (many patented) that SEO Industry types may get caught up in and try to technically analyze them. I’m sure you’ve seen/read/heard the complicated advice that will always be pushed by many… advice like:

analyze the number of words in the description/title/1st paragraph/etc.
Make sure your “keyword” is sprinkled throughout the text every 10-30th word..
Other equally unexciting technical analysis

Now if you’ve had success with that then props to you, success is success, but I personally choose to completely ignore all that. The number 1 thing that the top search engines advise is to design your page for a Human Visitor, not a computer. The golden rule for me is how I would rank the page, not how some algorithm would.

Designing for a Human Visitor

This is a major factor in your site being at the top vs. nowhere. You design your HTML to be as minimal as possible (see source code for my homepage) and contain ONLY the neccessary elements. Above all, use semantically sound XHTML markup. (view source of W3C)

External CSS/Javascript

Get your javascript and CSS out of your HTML and use external files (like this site) ALWAYS! You should start with just the HTML, no css, no colors, no javascript, and THEN you add the .css and then you add the javascript.

Site Accessibility

Say your browser didn’t have a mouse, didn’t support images, css, javascript, or even colors! Your HTML should be structured such that your page is still easily readable and easy to navigate. You can use lynx, links, and many other terminal-based browsers to test for this… please see the Web Accessibility Initiative (WAI) for detailed info.

Web accessibility refers to the practice of making websites usable by people of all abilities and disabilities. When sites are correctly designed, developed and edited, all users can have equal access to information and functionality. For example, when a site is coded with semantically meaningful HTML, with textual equivalents provided for images and with links named meaningfully, this helps blind users using text-to-speech software and/or text-to-Braille hardware.

Controlling a URL’s Pagerank

A few tools and techniques are available for controlling the “juice” or “pagerank” of your urls.

Robots.txt
Robots Meta Tags
Links

Robots.txt

I’ve done quite a bit of research and experimentation with robots.txt files, which is a file located in the root of your website at http://www.askapache.com/robots.txt that is downloaded by all legitimate search engine spiders/bots and used as a Blacklist to prevent certain urls from being indexed. Here are a few of the articles on this site, which you may skip if you like as they don’t illustrate the big-picture that I am going to discuss now.

How To Use Robots.txt

Even though robots.txt files are for whitelisting and blacklisting urls, I have found that they should only be used as an extreme form of blacklisting. When you Disallow a url in your robots.txt file, that means most search engine bots won’t even LOOK at the url. As you can see in the below example, I only disallow urls that shouldn’t ever be LOOKED at. The real powertool is the robots meta tag.

User-agent: *
Disallow: /cgi-bin
Disallow: /wp-admin
Disallow: /wp-includes
Disallow: /wp-content
 
Sitemap: http://www.askapache.com/sitemap.xml

Robots Meta Tag

Ok I’m really trying to simplify, because what you should understand is the big-picture. Every page can have a robots meta tag in the header, and this robots meta tag can tell the search-engine to index/not-index AND follow/not-follow. Here are some examples:

content=”index” / noindex

index means the search engine is free to index, archive, cache, and follow the page whereas noindex means DO NOT include this page in the search engine results.

content=”follow” / nofollow

follow means the search engine is free to LOOK at the page and follow the links on the page whereas nofollow means DO NOT follow the links on the page.

WordPress Auto-Robots meta tag code

Just add this to any plugin file and it will add the right robots meta tag to your site.. tweak to taste.

function askapache_robots_header(){
 global $wpdb;
 
 $robot = '';

 if ( is_paged() || is_search() || is_404() || is_author() || is_tag() )
   $robot = '';
 elseif ( is_home() || is_front_page() || is_single() )
   $robot = '';
 elseif ( is_category() || is_page() )
   $robot = '';
 
 echo $robot . "\n";
}
add_action( 'wp_head', 'askapache_robots_header' );

Links

External and Internal Links are the crux of SEO. It’s important to start FIRST on your Internal Links and linking structure… Once you are satisfied that the correct pages are indexed and ranked appropriately, then you can begin to look at external links.

The fewer links on a page, generally the better.
If every page of your site points to the same url on your site, pagerank goes up from the number of internal links.
Use of the rel, title, alt attribute semantically is very helpful. (next, prev, index)
Put your best links higher up in the XHTML, and put helpful/solid links at the end.
You can add rel="nofollow" to links that you dont want followed.

The web has gotten to be so full of malicious/non-helpful SEO activity that I recommend developing your content NOT external links. If you want to do this right and provide great content that makes search engine users happy and makes the web better, then explore this blog and develop content until the next article in this series, where I’ll show you how to make your site explode.

Stay tuned for Part III, which will dive deeper into the pipeworks of AskApache.com

SEO Secrets of AskApache Part 2 originally appeared on AskApache.