util/termcolours.lua
author Jonas Schäfer <jonas@wielicki.name>
Mon, 10 Jan 2022 18:23:54 +0100
branch0.11
changeset 12185 783056b4e448
parent 8558 4f0f5b49bb03
child 10427 317bcc4f25f5
permissions -rw-r--r--
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.

-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
--
-- luacheck: ignore 213/i


local t_concat, t_insert = table.concat, table.insert;
local char, format = string.char, string.format;
local tonumber = tonumber;
local ipairs = ipairs;
local io_write = io.write;
local m_floor = math.floor;
local type = type;
local setmetatable = setmetatable;
local pairs = pairs;

local windows;
if os.getenv("WINDIR") then
	windows = require "util.windows";
end
local orig_color = windows and windows.get_consolecolor and windows.get_consolecolor();

local _ENV = nil;
-- luacheck: std none

local stylemap = {
			reset = 0; bright = 1, dim = 2, underscore = 4, blink = 5, reverse = 7, hidden = 8;
			black = 30; red = 31; green = 32; yellow = 33; blue = 34; magenta = 35; cyan = 36; white = 37;
			["black background"] = 40; ["red background"] = 41; ["green background"] = 42; ["yellow background"] = 43;
			["blue background"] = 44; ["magenta background"] = 45; ["cyan background"] = 46; ["white background"] = 47;
			bold = 1, dark = 2, underline = 4, underlined = 4, normal = 0;
		}

local winstylemap = {
	["0"] = orig_color, -- reset
	["1"] = 7+8, -- bold
	["1;33"] = 2+4+8, -- bold yellow
	["1;31"] = 4+8 -- bold red
}

local cssmap = {
	[1] = "font-weight: bold", [2] = "opacity: 0.5", [4] = "text-decoration: underline", [8] = "visibility: hidden",
	[30] = "color:black", [31] = "color:red", [32]="color:green", [33]="color:#FFD700",
	[34] = "color:blue", [35] = "color: magenta", [36] = "color:cyan", [37] = "color: white",
	[40] = "background-color:black", [41] = "background-color:red", [42]="background-color:green",
	[43]="background-color:yellow",	[44] = "background-color:blue", [45] = "background-color: magenta",
	[46] = "background-color:cyan", [47] = "background-color: white";
};

local fmt_string = char(0x1B).."[%sm%s"..char(0x1B).."[0m";
local function getstring(style, text)
	if style then
		return format(fmt_string, style, text);
	else
		return text;
	end
end

local function gray(n)
	return m_floor(n*3/32)+0xe8;
end
local function color(r,g,b)
	if r == g and g == b then
		return gray(r);
	end
	r = m_floor(r*3/128);
	g = m_floor(g*3/128);
	b = m_floor(b*3/128);
	return 0x10 + ( r * 36 ) + ( g * 6 ) + ( b );
end
local function hex2rgb(hex)
	local r = tonumber(hex:sub(1,2),16);
	local g = tonumber(hex:sub(3,4),16);
	local b = tonumber(hex:sub(5,6),16);
	return r,g,b;
end

setmetatable(stylemap, { __index = function(_, style)
	if type(style) == "string" and style:find("%x%x%x%x%x%x") == 1 then
		local g = style:sub(7) == " background" and "48;5;" or "38;5;";
		return g .. color(hex2rgb(style));
	end
end } );

local csscolors = {
	red = "ff0000"; fuchsia = "ff00ff"; green = "008000"; white = "ffffff";
	lime = "00ff00"; yellow = "ffff00"; purple = "800080"; blue = "0000ff";
	aqua = "00ffff"; olive  = "808000"; black  = "000000"; navy = "000080";
	teal = "008080"; silver = "c0c0c0"; maroon = "800000"; gray = "808080";
}
for colorname, rgb in pairs(csscolors) do
	stylemap[colorname] = stylemap[colorname] or stylemap[rgb];
	colorname, rgb = colorname .. " background", rgb .. " background"
	stylemap[colorname] = stylemap[colorname] or stylemap[rgb];
end

local function getstyle(...)
	local styles, result = { ... }, {};
	for i, style in ipairs(styles) do
		style = stylemap[style];
		if style then
			t_insert(result, style);
		end
	end
	return t_concat(result, ";");
end

local last = "0";
local function setstyle(style)
	style = style or "0";
	if style ~= last then
		io_write("\27["..style.."m");
		last = style;
	end
end

if windows then
	function setstyle(style)
		style = style or "0";
		if style ~= last then
			windows.set_consolecolor(winstylemap[style] or orig_color);
			last = style;
		end
	end
	if not orig_color then
		function setstyle() end
	end
end

local function ansi2css(ansi_codes)
	if ansi_codes == "0" then return "</span>"; end
	local css = {};
	for code in ansi_codes:gmatch("[^;]+") do
		t_insert(css, cssmap[tonumber(code)]);
	end
	return "</span><span style='"..t_concat(css, ";").."'>";
end

local function tohtml(input)
	return input:gsub("\027%[(.-)m", ansi2css);
end

return {
	getstring = getstring;
	getstyle = getstyle;
	setstyle = setstyle;
	tohtml = tohtml;
};