X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=include%2Fsecurity.php;h=6ea515bffe41ff907b5bffb7ee1d237b0bc397f5;hb=ab89aa90caced4f60fc0ae944c7190e156a872e2;hp=6b8128bdd8516cf406c13492a711cedda999b505;hpb=c37ffd2999453de17bd6b0c98b708a0f55bacdc7;p=friendica.git

diff --git a/include/security.php b/include/security.php
index 6b8128bdd8..6ea515bffe 100755
--- a/include/security.php
+++ b/include/security.php
@@ -202,7 +202,7 @@ function permissions_sql($owner_id,$remote_verified = false,$groups = null) {
 				" AND ( allow_cid = '' OR allow_cid REGEXP '<%d>' ) 
 				  AND ( deny_cid  = '' OR  NOT deny_cid REGEXP '<%d>' ) 
 				  AND ( allow_gid = '' OR allow_gid REGEXP '%s' )
-				  AND ( deny_gid  = '' OR NOT deny_gid REGEXP '%s') 
+				  AND ( deny_gid  = '' OR NOT deny_gid REGEXP '%s')
 				",
 				intval($remote_user),
 				intval($remote_user),
@@ -212,4 +212,125 @@ function permissions_sql($owner_id,$remote_verified = false,$groups = null) {
 		}
 	}
 	return $sql;
-}
\ No newline at end of file
+}
+
+
+function item_permissions_sql($owner_id,$remote_verified = false,$groups = null) {
+
+	$local_user = local_user();
+	$remote_user = remote_user();
+
+	/**
+	 * Construct permissions
+	 *
+	 * default permissions - anonymous user
+	 */
+
+	$sql = " AND allow_cid = '' 
+			 AND allow_gid = '' 
+			 AND deny_cid  = '' 
+			 AND deny_gid  = '' 
+			 AND private = 0
+	";
+
+	/**
+	 * Profile owner - everything is visible
+	 */
+
+	if(($local_user) && ($local_user == $owner_id)) {
+		$sql = ''; 
+	}
+
+	/**
+	 * Authenticated visitor. Unless pre-verified, 
+	 * check that the contact belongs to this $owner_id
+	 * and load the groups the visitor belongs to.
+	 * If pre-verified, the caller is expected to have already
+	 * done this and passed the groups into this function.
+	 */
+
+	elseif($remote_user) {
+
+		if(! $remote_verified) {
+			$r = q("SELECT id FROM contact WHERE id = %d AND uid = %d AND blocked = 0 LIMIT 1",
+				intval($remote_user),
+				intval($owner_id)
+			);
+			if(count($r)) {
+				$remote_verified = true;
+				$groups = init_groups_visitor($remote_user);
+			}
+		}
+		if($remote_verified) {
+		
+			$gs = '<<>>'; // should be impossible to match
+
+			if(is_array($groups) && count($groups)) {
+				foreach($groups as $g)
+					$gs .= '|<' . intval($g) . '>';
+			} 
+
+			$sql = sprintf(
+				" AND ( private = 0 OR ( private = 1 AND wall = 1 AND ( allow_cid = '' OR allow_cid REGEXP '<%d>' ) 
+				  AND ( deny_cid  = '' OR  NOT deny_cid REGEXP '<%d>' ) 
+				  AND ( allow_gid = '' OR allow_gid REGEXP '%s' )
+				  AND ( deny_gid  = '' OR NOT deny_gid REGEXP '%s'))) 
+				",
+				intval($remote_user),
+				intval($remote_user),
+				dbesc($gs),
+				dbesc($gs)
+			);
+		}
+	}
+
+	return $sql;
+}
+
+
+/*
+ * Functions used to protect against Cross-Site Request Forgery
+ * The security token has to base on at least one value that an attacker can't know - here it's the session ID and the private key.
+ * In this implementation, a security token is reusable (if the user submits a form, goes back and resubmits the form, maybe with small changes;
+ * or if the security token is used for ajax-calls that happen several times), but only valid for a certain amout of time (3hours).
+ * The "typename" seperates the security tokens of different types of forms. This could be relevant in the following case:
+ *    A security token is used to protekt a link from CSRF (e.g. the "delete this profile"-link).
+ *    If the new page contains by any chance external elements, then the used security token is exposed by the referrer.
+ *    Actually, important actions should not be triggered by Links / GET-Requests at all, but somethimes they still are,
+ *    so this mechanism brings in some damage control (the attacker would be able to forge a request to a form of this type, but not to forms of other types).
+ */ 
+function get_form_security_token($typename = "") {
+	$a = get_app();
+	
+	$timestamp = time();
+	$sec_hash = hash('whirlpool', $a->user["guid"] . $a->user["prvkey"] . session_id() . $timestamp . $typename);
+	
+	return $timestamp . "." . $sec_hash;
+}
+
+function check_form_security_token($typename = "", $formname = 'form_security_token') {
+	if (!x($_REQUEST, $formname)) return false;
+	$hash = $_REQUEST[$formname];
+	
+	$max_livetime = 10800; // 3 hours
+	
+	$a = get_app();
+	
+	$x = explode(".", $hash);
+	if (time() > (IntVal($x[0]) + $max_livetime)) return false;
+	
+	$sec_hash = hash('whirlpool', $a->user["guid"] . $a->user["prvkey"] . session_id() . $x[0] . $typename);
+	
+	return ($sec_hash == $x[1]);
+}
+
+function check_form_security_std_err_msg() {
+	return t('The form security token was not correct. This probably happened because the form has been opened for too long (>3 hours) before subitting it.') . EOL;
+}
+function check_form_security_token_redirectOnErr($err_redirect, $typename = "", $formname = 'form_security_token') {
+	if (!check_form_security_token($typename, $formname)) {
+		$a = get_app();
+		notice( check_form_security_std_err_msg() );
+		goaway($a->get_baseurl() . $err_redirect );
+	}
+}