Mercurial > prosody-modules
view mod_auth_token/token_auth_utils.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 | 0fb12a4b6106 |
children |
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local base64 = require "util.encodings".base64; local hmac = require "openssl.hmac"; local luatz = require "luatz"; local otp = require "otp"; local DIGEST_TYPE = "SHA256"; local OTP_DEVIATION = 1; local OTP_DIGITS = 8; local OTP_INTERVAL = 30; local nonce_cache = {}; local function check_nonce(jid, otp_value, nonce) -- We cache all nonces used per OTP, to ensure that a token cannot be used -- more than once. -- -- We assume that the OTP is valid in the current time window. This is the -- case because we only call check_nonce *after* the OTP has been verified. -- -- We only store one OTP per JID, so if a new OTP comes in, we wipe the -- previous OTP and its cached nonces. if nonce_cache[jid] == nil or nonce_cache[jid][otp_value] == nil then nonce_cache[jid] = {} nonce_cache[jid][otp_value] = {} nonce_cache[jid][otp_value][nonce] = true return true; end if nonce_cache[jid][otp_value][nonce] == true then return false; else nonce_cache[jid][otp_value][nonce] = true; return true; end end local function verify_token(username, password, otp_seed, token_secret, log) local totp = otp.new_totp_from_key(otp_seed, OTP_DIGITS, OTP_INTERVAL) local token = string.match(password, "(%d+) ") local otp_value = token:sub(1,8) local nonce = token:sub(9) local signature = base64.decode(string.match(password, " (.+)")) local jid = username.."@"..module.host if totp:verify(otp_value, OTP_DEVIATION, luatz.time()) then log("debug", "The TOTP was verified"); local hmac_ctx = hmac.new(token_secret, DIGEST_TYPE) if signature == hmac_ctx:final(otp_value..nonce..jid) then log("debug", "The key was verified"); if check_nonce(jid, otp_value, nonce) then log("debug", "The nonce was verified"); return true; end end end log("debug", "Verification failed"); return false; end return { OTP_DEVIATION = OTP_DIGITS, OTP_DIGITS = OTP_DIGITS, OTP_INTERVAL = OTP_INTERVAL, DIGEST_TYPE = DIGEST_TYPE, verify_token = verify_token; }