matrix-docker-ansible-deploy/docs/configuring-captcha.md

(Adapted from the upstream project)

Overview

Captcha can be enabled for this home server. This file explains how to do that.

The captcha mechanism used is Google's ReCaptcha. This requires API keys from Google. If your homeserver is Dendrite then hCapcha can be used instead.

ReCaptcha

Getting keys

Requires a site/secret key pair from:

http://www.google.com/recaptcha/admin

Must be a reCAPTCHA v2 key using the "I'm not a robot" Checkbox option

Setting ReCaptcha keys

Once registered as above, add the following configuration to your inventory/host_vars/matrix.example.com/vars.yml file:

# for Synapse
matrix_synapse_enable_registration_captcha: true
matrix_synapse_recaptcha_public_key: 'YOUR_SITE_KEY'
matrix_synapse_recaptcha_private_key: 'YOUR_SECRET_KEY'

# for Dendrite
matrix_dendrite_client_api_enable_registration_captcha: true
matrix_dendrite_client_api_recaptcha_public_key: 'YOUR_SITE_KEY'
matrix_dendrite_client_api_recaptcha_private_key: 'YOUR_SECRET_KEY'

hCaptcha

Getting keys

Requires a site/secret key pair from:

https://dashboard.hcaptcha.com/sites/new

Setting hCaptcha keys

matrix_dendrite_client_api_enable_registration_captcha: true
matrix_dendrite_client_api_recaptcha_public_key: 'YOUR_SITE_KEY'
matrix_dendrite_client_api_recaptcha_private_key: 'YOUR_SECRET_KEY'

matrix_dendrite_client_api_recaptcha_siteverify_api: 'https://hcaptcha.com/siteverify'
matrix_dendrite_client_api_recaptcha_api_js_url: 'https://js.hcaptcha.com/1/api.js'
matrix_dendrite_client_api_recaptcha_form_field: 'h-captcha-response'
matrix_dendrite_client_api_recaptcha_sitekey_class: 'h-captcha'