Access control (WIP)

Work in progress of the access control feature:
* You can lock forums and limit posting / access to certain users:
(Members can be specified in a 'members.txt' file)
- 'threads':	Only moderators / members can start threads, but anybody can reply
- 'posts':	Only moderators / members can start threads or reply
- 'private':	Only moderators / members can access and participate in the forum (hidden to the public)
* Moderators can sign-in to do moderator actions
* Moderators can now reply to and append/delete in locked threads
* Moderators can now fully remove previously deleted (blanked-out) comments

.gitignore

@@ -1,5 +1,7 @@
 *.rss
 *.xml
 sticky.txt
+locked.txt
 mods.txt
+members.txt
 config.php

HISTORY.txt

@@ -1,3 +1,14 @@
+v8
+*	Access control: Major new feature! You can lock forums and limit posting / access to certain users:
+	(Members can be specified in a 'members.txt' file)
+	- 'threads':	Only moderators / members can start threads, but anybody can reply
+	- 'posts':	Only moderators / members can start threads or reply
+	- 'private':	Only moderators / members can access and participate in the forum (hidden to the public)
+*	Moderators can sign-in to do moderator actions
+*	Moderators can now reply to and append/delete in locked threads
+*	Moderators can now fully remove previously deleted (blanked-out) comments
+*	Config option to disable new user registrations site-wide (`FORUM_NEWBIES`)
+
 v7	05.NOV.11
 *	NNF can now be run from a folder, with thanks to Richard van Velzen
 	(this requires theme changes: URLs must be prepended with `FORUM_PATH`)

action.php

@@ -32,15 +32,22 @@
 
 	/* has the un/pw been submitted to authenticate the append?
 	   -------------------------------------------------------------------------------------------------------------- */
-	if (
-		NAME && PASS && AUTH
-		//only a moderator, or the post originator can append to a post
-		&& (isMod (NAME) || NAME == (string) $post->author)
-		//cannot append to a deleted post
-		&& !(bool) $post->xpath ("category[text()='deleted']")
-		//cannot append to a locked thread
-		&& !$xml->channel->xpath ("category[text()='locked']")
-	) {	
+	if (AUTH && TEXT && FORUM_ENABLED && (
+		//- if the thread is unlocked and the forum is either unlocked or thread-locked (anybody can reply)
+		(!(bool) $xml->channel->xpath ("category[text()='locked']") && (!FORUM_LOCK || FORUM_LOCK == 'threads')) ||
+		//- if the thread is locked, but you are a moderator (signed in)
+		((bool) $xml->channel->xpath ("category[text()='locked']") && CAN_MOD) ||
+		//- if the forum is post-locked, but you are a moderator (signed in) or member
+		(FORUM_LOCK == 'posts' && (CAN_MOD || isMember (NAME)))
+	) && (
+		//a moderator can always append
+		isMod (NAME) ||
+		//the owner of a post can append
+		(strtolower (NAME) == strtolower ($post->author) && (
+			//if the forum is post-locked, they must be a member to append to their own posts
+			(!FORUM_LOCK || FORUM_LOCK == 'threads') || isMember (NAME)
+		))
+	)) {
 		$now = time ();
 		$post->description .= "\n".template_tags (TEMPLATE_APPEND, array (
 			'AUTHOR'	=> safeHTML (NAME),
@@ -129,17 +136,29 @@
 
 	/* has the un/pw been submitted to authenticate the delete?
 	   -------------------------------------------------------------------------------------------------------------- */
-	if (
-		NAME && PASS && AUTH
-		//only a moderator, or the post originator can delete a post/thread
-		&& (isMod (NAME) || NAME == (string) $post->author)
-		//cannot delete a locked thread
-		&& !$xml->channel->xpath ("category[text()='locked']")
-
+	if (AUTH && FORUM_ENABLED && (
+		//- if the thread is unlocked and the forum is either unlocked or thread-locked (anybody can reply)
+		(!(bool) $xml->channel->xpath ("category[text()='locked']") && (!FORUM_LOCK || FORUM_LOCK == 'threads')) ||
+		//- if the thread is locked, but you are a moderator (signed in)
+		((bool) $xml->channel->xpath ("category[text()='locked']") && CAN_MOD) ||
+		//- if the forum is post-locked, but you are a moderator (signed in) or member
+		(FORUM_LOCK == 'posts' && (CAN_MOD || isMember (NAME)))
+	) && (
+		//a moderator can always delete
+		isMod (NAME) ||
+		//the owner of a post can delete
+		(strtolower (NAME) == strtolower ($post->author) && (
+			//if the forum is post-locked, they must be a member to delete their own posts
+			(!FORUM_LOCK || FORUM_LOCK == 'threads') || isMember (NAME)
+		))
 	//deleting a post?
-	) if ($ID) {
+	)) if ($ID) {
 		//full delete? (option ticked, is moderator, and post is on the last page)
-		if (isset ($_POST['remove']) && isMod (NAME) && $i <= (count ($xml->channel->item)-2) % FORUM_POSTS) {
+		if (
+			(isMod (NAME) && $i <= (count ($xml->channel->item)-2) % FORUM_POSTS) &&
+			//if the post has already been blanked, delete it fully
+			(isset ($_POST['remove']) || $post->xpath ("category[text()='deleted']"))
+		) {
 			//remove the post from the thread entirely
 			unset ($xml->channel->item[$i]);
 
@@ -225,15 +244,15 @@
 	$FILE = (preg_match ('/^[^.\/]+$/', @$_GET['file']) ? $_GET['file'] : '') or die ('Malformed request');
 
 	//get a write lock on the file so that between now and saving, no other posts could slip in
-	$f = fopen ("$FILE.rss", 'c'); flock ($f, LOCK_EX);
+	$f   = fopen ("$FILE.rss", 'c'); flock ($f, LOCK_EX);
 	$xml = simplexml_load_file ("$FILE.rss") or die ('Invalid file');
 
 	//what’s the current status?
 	$LOCKED = (bool) $xml->channel->xpath ("category[text()='locked']");
 
 	/* has the un/pw been submitted to authenticate the un/lock? (only a moderator can un/lock a thread)
 	   -------------------------------------------------------------------------------------------------------------- */
-	if (NAME && PASS && AUTH && isMod (NAME)) {
+	if (CAN_MOD && AUTH) {
 		if ($LOCKED) {
 			//if there’s a "locked" category, remove it
 			//note: for simplicity this removes *all* channel categories as NNF only uses one atm,

config.example.php

@@ -8,6 +8,9 @@
 
 /* --- copy this file as 'config.php' and customise to your liking --- */
 
+//uncomment this if you want to show PHP errors in the browser
+#error_reporting (-1);
+
 //forum’s title. used in theme, and in RSS feeds
 //WARNING: changing this won’t update the index RSS feed containing this name; delete 'index.xml' and then post/delete
 //         a thread to regenerate the 'index.xml' file so as to see the change

index.php

@@ -18,7 +18,7 @@
 /* ====================================================================================================================== */
 
 //has the user submitted a new thread? (and is the info valid?)
-if (FORUM_ENABLED && NAME && PASS && AUTH && TITLE && TEXT && @$_POST['email'] == 'example@abc.com') {
+if (CAN_POST && AUTH && TITLE && TEXT && @$_POST['email'] == 'example@abc.com') {
 	//the file on disk is a simplified version of the title:
 	$translit = preg_replace (
 		//replace non alphanumerics with underscores and don’t use more than 2 in a row
@@ -79,7 +79,7 @@
 /* ====================================================================================================================== */
 /* sub-forums
    ---------------------------------------------------------------------------------------------------------------------- */
-//don’t all sub-sub-forums
+//don’t allow sub-sub-forums (yet)
 if (!PATH) foreach (array_filter (
 	//get a list of folders:
 	//include only directories, but ignore directories starting with ‘.’ and the users / themes folders
@@ -161,7 +161,7 @@
 /* new thread form
    ---------------------------------------------------------------------------------------------------------------------- */
 //(exclude if posting has been disabled)
-if (FORUM_ENABLED) $FORM = array (
+if (CAN_POST) $FORM = array (
 	'NAME'	=> safeString (NAME),
 	'PASS'	=> safeString (PASS),
 	'TITLE'	=> safeString (TITLE),

shared.php

@@ -5,22 +5,22 @@
    you may do whatever you want to this code as long as you give credit to Kroc Camen, <camendesign.com>
 */
 
-//let me know when I’m being stupid
-error_reporting (-1);
-
 //default UTF-8 throughout
 mb_internal_encoding ('UTF-8');
 mb_regex_encoding    ('UTF-8');
 
 /* constants: some stuff we don’t expect to change
    ---------------------------------------------------------------------------------------------------------------------- */
-define ('START', 		microtime (true));			//record how long the page takes to generate
 define ('FORUM_ROOT',		dirname (__FILE__));			//full server-path for absolute references
 define ('FORUM_PATH',							//relative from webroot--if running in a folder
 	str_replace ('//', '/', dirname ($_SERVER['SCRIPT_NAME']).'/')	//(always starts with a slash and ends in one)
 );
 define ('FORUM_URL',		'http://'.$_SERVER['HTTP_HOST']);	//todo: https support
 
+//for HTTP authentication (private forums)
+define ('HTTP_AUTH_UN',		@$_SERVER['PHP_AUTH_USER']);		//username if using HTTP authentication
+define ('HTTP_AUTH_PW',		@$_SERVER['PHP_AUTH_PW']);		//password if using HTTP authentication
+
 //these are just some enums for templates to react to
 define ('ERROR_NONE',		0);
 define ('ERROR_NAME',		1);					//name entered is invalid / blank
@@ -59,77 +59,115 @@
 date_default_timezone_set (FORUM_TIMEZONE);
 
 
-/* get input
+/* common input
    ====================================================================================================================== */
-//all pages can accept a name / password when committing actions (new thread / post &c.)
-define ('NAME', safeGet (@$_POST['username'], SIZE_NAME));
-define ('PASS', safeGet (@$_POST['password'], SIZE_PASS, false));
+//all our pages use path (often optional) so this is done here
+define ('PATH', preg_match ('/[^.\/&]+/', @$_GET['path']) ? $_GET['path'] : '');
+//these two get used an awful lot
+define ('PATH_URL', !PATH ? FORUM_PATH : safeURL (FORUM_PATH.PATH.'/', false));	//when outputting as part of a URL
+define ('PATH_DIR', !PATH ? '/' : '/'.PATH.'/');				//serverside, like `chdir` / `unlink`
+
+//we have to change directory for `is_dir` to work, see <uk3.php.net/manual/en/function.is-dir.php#70005>
+//being in the right directory is also assumed for reading 'mods.txt' and when generating the RSS (`indexRSS`)
+//(oddly with `chdir` the path must end in a slash)
+@chdir (FORUM_ROOT.PATH_DIR) or die ("Invalid path");
+
 
-//if name & password are provided, validate them
-if (
+/* access control
+   ====================================================================================================================== */
+/* name / password authorisation:
+   ---------------------------------------------------------------------------------------------------------------------- */
+//all pages can accept a name / password when committing actions (new thread / post &c.)
+//in the case of HTTP authentication (sign in / private forums), these are provided in the request header
+define ('NAME', HTTP_AUTH_UN ? HTTP_AUTH_UN : safeGet (@$_POST['username'], SIZE_NAME));
+define ('PASS', HTTP_AUTH_PW ? HTTP_AUTH_PW : safeGet (@$_POST['password'], SIZE_PASS, false));
+
+if ((
+	//if any HTTP authentication is given, we don’t need to validate form fields
+	HTTP_AUTH_UN && HTTP_AUTH_PW
+) || (
+	//if an input form was submitted:
 	NAME && PASS &&
 	//the email check is a fake hidden field in the form to try and fool spam bots
 	isset ($_POST['email']) && @$_POST['email'] == 'example@abc.com' &&
 	//I wonder what this does...?
 	((isset ($_POST['x']) && isset ($_POST['y'])) || (isset ($_POST['submit_x']) && isset ($_POST['submit_y'])))
-) {
+)) {
 	//users are stored as text files based on the hash of the given name
 	$name = hash ('sha512', strtolower (NAME));
 	$user = FORUM_ROOT."/users/$name.txt";
-	//create the user, if new (if registrations are allowed)
-	if (FORUM_NEWBIES && !file_exists ($user)) file_put_contents ($user, hash ('sha512', $name.PASS));
+
+	//create the user, if new:
+	//- if registrations are allowed (`FORUM_NEWBIES`)
+	//- you can’t create new users with the HTTP_AUTH sign in
+	if (FORUM_NEWBIES && !HTTP_AUTH_UN && !file_exists ($user)) file_put_contents ($user, hash ('sha512', $name.PASS));
+
 	//does password match?
 	define ('AUTH', @file_get_contents ($user) == hash ('sha512', $name.PASS));
+
+	//if signed in with HTTP_AUTH, confirm that it’s okay to use
+	//(e.g. the user could still have given the wrong password with HTTP_AUTH)
+	define ('HTTP_AUTH', HTTP_AUTH_UN ? AUTH : false);
 } else {
-	define ('AUTH', false);
+	define ('AUTH',      false);
+	define ('HTTP_AUTH', false);
 }
 
-//all our pages use path (often optional) so this is done here
-define ('PATH', preg_match ('/[^.\/&]+/', @$_GET['path']) ? $_GET['path'] : '');
-//these two get used an awful lot
-define ('PATH_URL', !PATH ? FORUM_PATH : safeURL (FORUM_PATH.PATH.'/', false));	//when outputting as part of a URL
-define ('PATH_DIR', !PATH ? '/' : '/'.PATH.'/');				//serverside, like `chdir` / `unlink`
+//get the lock status of the current forum we’re in:
+//"threads"	- only users in "mods.txt" / "members.txt" can start threads, but anybody can reply
+//"posts"	- only users in "mods.txt" / "members.txt" can start threads or reply
+//"private"	- only users in "mods.txt" / "members.txt" can enter and use the forum, it is hidden from everybody else
+define ('FORUM_LOCK', trim (@file_get_contents ('locked.txt')));
 
-//we have to change directory for `is_dir` to work, see <uk3.php.net/manual/en/function.is-dir.php#70005>
-//being in the right directory is also assumed for reading 'mods.txt' and when generating the RSS (`indexRSS`)
-//(oddly with `chdir` the path must end in a slash)
-@chdir (FORUM_ROOT.PATH_DIR) or die ("Invalid path");
+//if the sign-in link was clicked, invoke a HTTP_AUTH request in the browser
+if (!HTTP_AUTH && isset ($_GET['login'])) {
+	header ('WWW-Authenticate: Basic');
+	header ('HTTP/1.0 401 Unauthorized');
+}
 
+/* access rights
+   ---------------------------------------------------------------------------------------------------------------------- */
 //get the list of moderators:
 $MODS = array (
-	//mods.txt on root for mods on all sub-forums
+	//'mods.txt' on root for mods on all sub-forums
 	'GLOBAL'=> file_exists (FORUM_ROOT.'/mods.txt')
 		? file (FORUM_ROOT.'/mods.txt', FILE_IGNORE_NEW_LINES + FILE_SKIP_EMPTY_LINES)
 		: array (),
-	//if in a sub-forum, the local mods.txt
+	//if in a sub-forum, the local 'mods.txt'
 	'LOCAL'	=> PATH && file_exists ('mods.txt')
 		? file ('mods.txt', FILE_IGNORE_NEW_LINES + FILE_SKIP_EMPTY_LINES)
 		: array ()
 );
 
+//get the list (if any) of users allowed to access this current forum
+$MEMBERS = file_exists ('members.txt') ? file ('members.txt', FILE_IGNORE_NEW_LINES + FILE_SKIP_EMPTY_LINES) : array ();
+
+//can the current user moderate in this forum?
+define ('CAN_MOD', HTTP_AUTH ? isMod (NAME) : false);
+
+//can the current user post new threads in the current forum?
+//(posting replies is dependent on the the thread -- if locked -- so tested in 'thread.php')
+define ('CAN_POST', FORUM_ENABLED && (
+	//- if the user is a moderator or member of the current forum, they can post
+	CAN_MOD || isMember (NAME) ||
+	//- if the forum is unlocked (mods will have to log in to see the form)
+	!FORUM_LOCK
+));
+
+//if the forum is private, check the current user and issue an auth request if not signed in or allowed
+if (FORUM_LOCK == 'private' && !(CAN_MOD || isMember (NAME))) {
+	header ('WWW-Authenticate: Basic');
+	header ('HTTP/1.0 401 Unauthorized');
+	//todo: a proper error page, if I make a splash/login screen for a private root-forum
+	die ("Authorisation required.");
+}
 
 /* ---------------------------------------------------------------------------------------------------------------------- */
 
 //stop browsers caching, so you don’t have to refresh every time to see changes
 header ('Cache-Control: no-cache', true);
 header ('Expires: 0', true);
 
-
-/* ====================================================================================================================== */
-
-//<stackoverflow.com/questions/2092012/simplexml-how-to-prepend-a-child-in-a-node/2093059#2093059>
-//we could of course do all the XML manipulation in DOM proper to save doing this…
-class allow_prepend extends SimpleXMLElement {
-	public function prependChild ($name, $value=null) {
-		$dom = dom_import_simplexml ($this);
-		$new = $dom->insertBefore (
-			$dom->ownerDocument->createElement ($name, $value),
-			$dom->firstChild
-		);
-		return simplexml_import_dom ($new, get_class ($this));
-	}
-}
-
 /* ====================================================================================================================== */
 
 //sanitise input:
@@ -165,7 +203,7 @@ function template_tags ($template, $values) {
 	return $template;
 }
 
-//produces a truncated list of pages around the current page
+//produces a truncated list of page numbers around the current page
 function pageList ($current, $total) {
 	//always include the first page
 	$PAGES[] = 1;
@@ -273,12 +311,17 @@ function formatText ($text) {
 
 /* ====================================================================================================================== */
 
-//check to see if a name is a known moderator in mods.txt
+//check to see if a name is a known moderator in 'mods.txt'
 function isMod ($name) {
 	global $MODS;
 	return in_array (strtolower ($name), array_map ('strtolower', $MODS['GLOBAL'] + $MODS['LOCAL']));
 }
 
+function isMember ($name) {
+	global $MEMBERS;
+	return in_array (strtolower ($name), array_map ('strtolower', $MEMBERS));
+}
+
 /* ====================================================================================================================== */
 
 //regenerate a folder's RSS file (all changes happening in a folder)
@@ -330,11 +373,11 @@ function indexRSS () {
 
 	/* sitemap
 	   -------------------------------------------------------------------------------------------------------------- */
+	//we’re going to use the RSS files as sitemaps
 	chdir (FORUM_ROOT);
 
-	//we’re going to use the RSS files as sitemaps
-	$folders = array ('');
 	//get list of sub-forums
+	$folders = array ('');
 	foreach (array_filter (
 		//include only directories, but ignore directories starting with ‘.’ and the users / themes folders
 		preg_grep ('/^(\.|users$|themes$)/', scandir (FORUM_ROOT.'/'), PREG_GREP_INVERT), 'is_dir'
@@ -370,4 +413,19 @@ function indexRSS () {
 	clearstatcache ();
 }
 
-?>
+/* ====================================================================================================================== */
+
+//<stackoverflow.com/questions/2092012/simplexml-how-to-prepend-a-child-in-a-node/2093059#2093059>
+//we could of course do all the XML manipulation in DOM proper to save doing this…
+class allow_prepend extends SimpleXMLElement {
+	public function prependChild ($name, $value=null) {
+		$dom = dom_import_simplexml ($this);
+		$new = $dom->insertBefore (
+			$dom->ownerDocument->createElement ($name, $value),
+			$dom->firstChild
+		);
+		return simplexml_import_dom ($new, get_class ($this));
+	}
+}
+
+?>