XMPP Notification Testing

Prosody

Server Setup

docker run --rm -d \
  --name prosody-test \
  -p 5222:5222 \
  -e PROSODY_VIRTUAL_HOSTS=localhost \
  -e PROSODY_LOGLEVEL=debug \
  prosodyim/prosody:13.0

Create Test Users

docker exec -it prosody-test prosodyctl register apprise localhost password123
docker exec -it prosody-test prosodyctl register receiver localhost password123

Install the Client

Download and install Gajim

sudo dnf install gajim

Log in as receiver@localhost and password password123

Test Apprise

Send a notification

# starttls setup below:
tox -e apprise -- -vv -b 'test message' \
   'xmpps://apprise:password123@localhost/receiver?verify=no'

SCRAM-PLUS and the Python TLS Ecosystem

The “Invalid channel binding” error

When connecting to certain XMPP servers you may see authentication fail with:

Authentication failed: not-authorized
Invalid channel binding

This is caused by SASL SCRAM-PLUS mechanisms (SCRAM-SHA-256-PLUS, SCRAM-SHA-1-PLUS). These are the highest-scored SASL mechanisms and slixmpp selects them automatically when the server advertises them. They embed TLS channel-binding data into the authentication exchange for extra protection against man-in-the-middle attacks.

The problem arises from a mismatch between what the client can supply and what the server expects:

• tls-unique — the traditional channel-binding type — is forbidden on TLS 1.3 connections (RFC 9266).
• tls-exporter — the TLS 1.3 replacement — requires Python 3.13+ and is not yet accepted by all server implementations.

When neither type is available or accepted, authentication fails with “Invalid channel binding.”

Quick fix: disable SCRAM-PLUS

Add ?scramplus=no to your Apprise URL to fall back to plain SCRAM mechanisms. The connection remains fully TLS-encrypted; only the extra channel-binding step is skipped.

apprise -vv -b "Test" \
  "xmpps://user:password@chat.example.com/recipient?scramplus=no"

Apprise automatically logs a targeted warning when it detects this error and suggests adding ?scramplus=no.

Background: a widespread Python ecosystem issue

This is not an Apprise-specific problem. The SASL SCRAM-PLUS breakage affects a large number of Python libraries and projects. The community member who first reported this issue to Apprise has been tracking every affected library at:

https://github.com/scram-sasl/info/issues/1

That page documents the full scope of the problem across the Python ecosystem and has been used to file upstream issues in Python and in many libraries. If this problem is affecting you, consider adding a comment or a thumbs-up there to help raise visibility and accelerate an upstream fix.