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.

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labels:
- 'Type-S2SAuth'
---

Introduction
============

[PKIX over Secure HTTP (POSH)][rfc7711] describes a method of
securely delegating a domain to a hosting provider, without that hosting
provider needing keys and certificates covering the hosted domain.

# Validating

This module performs POSH validation of other servers. It is *not*
needed to delegate your own domain.

# Delegation

You can generate the JSON delegation file from a certificate by running
`prosodyctl mod_s2s_auth_posh /path/to/example.crt`. This file needs to
be served at `https://example.com/.well-known/posh/xmpp-server.json`.