Mercurial > prosody-modules
view mod_register_dnsbl/mod_register_dnsbl.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 | 82482e7e92cb |
children |
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local adns = require "net.adns"; local async = require "util.async"; local inet_pton = require "util.net".pton; local to_hex = require "util.hex".to; local rbl = module:get_option_string("registration_rbl"); local function reverse(ip, suffix) local n, err = inet_pton(ip); if not n then return n, err end if #n == 4 then local a,b,c,d = n:byte(1,4); return ("%d.%d.%d.%d.%s"):format(d,c,b,a, suffix); elseif #n == 16 then return to_hex(n):reverse():gsub("%x", "%1.") .. suffix; end end module:hook("user-registering", function (event) local session, ip = event.session, event.ip; local log = (session and session.log) or module._log; if not ip then log("debug", "Unable to check DNSBL when IP is unknown"); return; end local rbl_ip, err = reverse(ip, rbl); if not rbl_ip then log("debug", "Unable to check DNSBL for ip %s: %s", ip, err); return; end local wait, done = async.waiter(); adns.lookup(function (reply) if reply and reply[1] and reply[1].a then log("debug", "DNSBL response: %s IN A %s", rbl_ip, reply[1].a); log("info", "Blocking %s from registering %s (dnsbl hit)", ip, event.username); event.allowed = false; event.reason = "Blocked by DNSBL"; end done(); end, rbl_ip); wait(); end);