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plugins/mod_auth_internal_plain.lua @ 12181:783056b4e448 0.11 0.11.12
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 | 11544:c98aebe601f9 |
child | 12646:3f38f4735c7a |
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-- 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. -- local usermanager = require "core.usermanager"; local new_sasl = require "util.sasl".new; local saslprep = require "util.encodings".stringprep.saslprep; local secure_equals = require "util.hashes".equals; local log = module._log; local host = module.host; local accounts = module:open_store("accounts"); -- define auth provider local provider = {}; function provider.test_password(username, password) log("debug", "test password for user '%s'", username); local credentials = accounts:get(username) or {}; password = saslprep(password); if not password then return nil, "Password fails SASLprep."; end if secure_equals(password, saslprep(credentials.password)) then return true; else return nil, "Auth failed. Invalid username or password."; end end function provider.get_password(username) log("debug", "get_password for username '%s'", username); return (accounts:get(username) or {}).password; end function provider.set_password(username, password) log("debug", "set_password for username '%s'", username); password = saslprep(password); if not password then return nil, "Password fails SASLprep."; end local account = accounts:get(username); if account then account.password = password; return accounts:set(username, account); end return nil, "Account not available."; end function provider.user_exists(username) local account = accounts:get(username); if not account then log("debug", "account not found for username '%s'", username); return nil, "Auth failed. Invalid username"; end return true; end function provider.users() return accounts:users(); end function provider.create_user(username, password) password = saslprep(password); if not password then return nil, "Password fails SASLprep."; end return accounts:set(username, {password = password}); end function provider.delete_user(username) return accounts:set(username, nil); end function provider.get_sasl_handler() local getpass_authentication_profile = { plain = function(_, username, realm) local password = usermanager.get_password(username, realm); if not password then return "", nil; end return password, true; end }; return new_sasl(host, getpass_authentication_profile); end module:provides("auth", provider);