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util/paths.lua @ 12180:53e0ae770917
util.xml: Do not allow doctypes, comments or processing instructions
Yes. This is as bad as it sounds. CVE pending.
In Prosody itself, this only affects mod_websocket, which uses util.xml
to parse the <open/> frame, thus allowing unauthenticated remote DoS
using Billion Laughs. However, third-party modules using util.xml may
also be affected by this.
This commit installs handlers which disallow the use of doctype
declarations and processing instructions without any escape hatch. It,
by default, also introduces such a handler for comments, however, there
is a way to enable comments nontheless.
This is because util.xml is used to parse human-facing data, where
comments are generally a desirable feature, and also because comments
are generally harmless.
author | Jonas Schäfer <jonas@wielicki.name> |
---|---|
date | Mon, 10 Jan 2022 18:23:54 +0100 |
parent | 11183:2ac63715ef6f |
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local t_concat = table.concat; local path_sep = package.config:sub(1,1); local path_util = {} -- Helper function to resolve relative paths (needed by config) function path_util.resolve_relative_path(parent_path, path) if path then -- Some normalization parent_path = parent_path:gsub("%"..path_sep.."+$", ""); path = path:gsub("^%.%"..path_sep.."+", ""); local is_relative; if path_sep == "/" and path:sub(1,1) ~= "/" then is_relative = true; elseif path_sep == "\\" and (path:sub(1,1) ~= "/" and (path:sub(2,3) ~= ":\\" and path:sub(2,3) ~= ":/")) then is_relative = true; end if is_relative then return parent_path..path_sep..path; end end return path; end -- Helper function to convert a glob to a Lua pattern function path_util.glob_to_pattern(glob) return "^"..glob:gsub("[%p*?]", function (c) if c == "*" then return ".*"; elseif c == "?" then return "."; else return "%"..c; end end).."$"; end function path_util.join(a, b, c, ...) -- (... : string) --> string -- Optimization: Avoid creating table for most uses if b then if c then if ... then return t_concat({a,b,c,...}, path_sep); end return a..path_sep..b..path_sep..c; end return a..path_sep..b; end return a; end function path_util.complement_lua_path(installer_plugin_path) -- Checking for duplicates -- The commands using luarocks need the path to the directory that has the /share and /lib folders. local lua_version = _VERSION:match(" (.+)$"); local lua_path_sep = package.config:sub(3,3); local dir_sep = package.config:sub(1,1); local sub_path = dir_sep.."lua"..dir_sep..lua_version..dir_sep; if not string.find(package.path, installer_plugin_path, 1, true) then package.path = package.path..lua_path_sep..installer_plugin_path..dir_sep.."share"..sub_path.."?.lua"; package.path = package.path..lua_path_sep..installer_plugin_path..dir_sep.."share"..sub_path.."?"..dir_sep.."init.lua"; end if not string.find(package.path, installer_plugin_path, 1, true) then package.cpath = package.cpath..lua_path_sep..installer_plugin_path..dir_sep.."lib"..sub_path.."?.so"; end end return path_util;