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.

---
labels:
- Statistics
summary: Collect statistics on message encryption
---

Description
===========

This module measures the rate at which text messages are exchanged, and their
encryption status.

::: {.alert .alert-warning}
This module can leak information about your users’ behaviour to anyone who can
access these statistics, so avoid enabling it on a server with few users.
:::