Mercurial > prosody-modules
view mod_mam/rsm.lib.lua @ 4651:8231774f5bfd
mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8
The `body:sub()` call risks splitting the string in the middle of a
multi-byte UTF-8 sequence. This should have been caught by util.stanza
validation, but that would have caused some havoc, at the very least causing
the notification to not be sent.
There have been no reports of this happening. Likely because this module
isn't widely deployed among users with languages that use many longer UTF-8
sequences.
The util.encodings.utf8.valid() function is O(n) where only the last
sequence really needs to be checked, but it's in C and expected to be fast.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 22 Aug 2021 13:22:59 +0200 |
parents | 57ee26681561 |
children |
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local stanza = require"util.stanza".stanza; local tostring, tonumber = tostring, tonumber; local type = type; local pairs = pairs; local xmlns_rsm = 'http://jabber.org/protocol/rsm'; local element_parsers = {}; do local parsers = element_parsers; local function xs_int(st) return tonumber((st:get_text())); end local function xs_string(st) return st:get_text(); end parsers.after = xs_string; parsers.before = function(st) local text = st:get_text(); return text == "" or text; end; parsers.max = xs_int; parsers.index = xs_int; parsers.first = function(st) return { index = tonumber(st.attr.index); st:get_text() }; end; parsers.last = xs_string; parsers.count = xs_int; end local element_generators = setmetatable({ first = function(st, data) if type(data) == "table" then st:tag("first", { index = data.index }):text(data[1]):up(); else st:tag("first"):text(tostring(data)):up(); end end; before = function(st, data) if data == true then st:tag("before"):up(); else st:tag("before"):text(tostring(data)):up(); end end }, { __index = function(_, name) return function(st, data) st:tag(name):text(tostring(data)):up(); end end; }); local function parse(set) local rs = {}; for tag in set:childtags() do local name = tag.name; local parser = name and element_parsers[name]; if parser then rs[name] = parser(tag); end end return rs; end local function generate(t) local st = stanza("set", { xmlns = xmlns_rsm }); for k,v in pairs(t) do if element_parsers[k] then element_generators[k](st, v); end end return st; end local function get(st) local set = st:get_child("set", xmlns_rsm); if set and #set.tags > 0 then return parse(set); end end return { parse = parse, generate = generate, get = get };