Mercurial > prosody-modules
view mod_xhtmlim/mod_xhtmlim.lua @ 4764:a754f7e380b2
mod_dnsupdate: Rewrite port config vs DNS comparison code
I'm not sure if it was correct, which means it was hard to understand
and thus needed to be simplified. Hope this accomplishes that.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Mon, 08 Nov 2021 23:03:14 +0100 |
parents | 1f68287138e3 |
children |
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-- XEP-0071: XHTML-IM sanitizing local assert = assert; local st = require "util.stanza"; local url = require "socket.url"; local no_styles = module:get_option_boolean("strip_xhtml_style", true); -- Tables from XEP-0071 local xeptables = [[ <body/> class, id, title; style <head/> profile <html/> version <title/> <abbr/> class, id, title; style <acronym/> class, id, title; style <address/> class, id, title; style <blockquote/> class, id, title; style; cite <br/> class, id, title; style <cite/> class, id, title; style <code/> class, id, title; style <dfn/> class, id, title; style <div/> class, id, title; style <em/> class, id, title; style <h1/> class, id, title; style <h2/> class, id, title; style <h3/> class, id, title; style <h4/> class, id, title; style <h5/> class, id, title; style <h6/> class, id, title; style <kbd/> class, id, title; style <p/> class, id, title; style <pre/> class, id, title; style <q/> class, id, title; style; cite <samp/> class, id, title; style <span/> class, id, title; style <strong/> class, id, title; style <var/> class, id, title; style <a/> class, id, title; style; accesskey, charset, href, hreflang, rel, rev, tabindex, type <dl/> class, id, title; style <dt/> class, id, title; style <dd/> class, id, title; style <ol/> class, id, title; style <ul/> class, id, title; style <li/> class, id, title; style <img/> class, id, title; style; alt, height, longdesc, src, width ]]; -- map of whitelisted tag names to set of allowed attributes local tags = {}; -- { string : { string : boolean } } for tag, attrs in xeptables:gmatch("<(%w+)/>([^\n]*)") do tags[tag] = { xmlns = true, ["xml:lang"] = true }; for attr in attrs:gmatch("%w+") do tags[tag][attr] = true; end if no_styles then tags[tag]["style"] = nil; end end -- module:log("debug", "tags = %s;", require "util.serialization".serialize(tags)); -- TODO Decide if disallowed tags should be bounced or silently discarded. -- XEP says "ignore" and replace tag with text content, but that would -- need a different transform which can't use `maptags`. if not module:get_option_boolean("bounce_invalid_xhtml", false) then assert = function (x) return x end end local function sanitize_xhtml(tag) -- module:log("debug", "sanitize_xhtml(<{%s}%s>)", tag.attr.xmlns, tag.name); if tag.attr.xmlns == "http://www.w3.org/1999/xhtml" then local allowed = assert(tags[tag.name], tag.name); if allowed then for attr, value in pairs(tag.attr) do if not allowed[attr] then -- module:log("debug", "Removing disallowed attribute %q from <%s>", attr, tag.name); tag.attr[attr] = nil; elseif attr == "src" or attr == "href" then local urlattr = url.parse(value); local scheme = urlattr and urlattr.scheme; if scheme ~= "http" and scheme ~= "https" and scheme ~= "mailto" and scheme ~= "xmpp" and scheme ~= "cid" then tag.attr[attr] = "https://url.was.invalid/"; end end end else tag.name = "span" tag.attr = { xmlns = "http://www.w3.org/1999/xhtml" } end -- Check child tags tag:maptags(sanitize_xhtml); -- This tag is clean! return tag; end -- Not xhtml, probably best to discard it return nil; end -- Check for xhtml-im, sanitize if exists local function message_handler(event) local stanza = event.stanza; if stanza:get_child("html", "http://jabber.org/protocol/xhtml-im") then stanza = st.clone(stanza); if pcall(function() -- try stanza:get_child("html", "http://jabber.org/protocol/xhtml-im"):maptags(sanitize_xhtml); end) then event.stanza = stanza; else -- catch if stanza.attr.type ~= "error" then event.origin.send(st.error_reply(stanza, "modify", "not-acceptable", "Stanza contained illegal XHTML-IM tag")); end return true; end end end -- Stanzas received from clients module:hook("pre-message/bare", message_handler, 71); module:hook("pre-message/full", message_handler, 71); module:hook("pre-message/host", message_handler, 71); -- Stanzas about to be delivered to clients module:hook("message/bare", message_handler, 71); module:hook("message/full", message_handler, 71);