Plugins that talk to Nextcloud, Paperless or an AI provider used to need
the password or key in their own settings, readable by the plugin and
stored in the browser. A plugin can now declare credentials in its
manifest and send requests "with credential X" through the server:
- `credentials` in the manifest: admin scope (secret and server from the
admin config) or user scope (the user connects an account; the server
address is fixed or chosen by the user)
- `/api/plugin-secrets`: the user's connected accounts, encrypted per
mail account under `PLUGIN_SECRETS_DIR`; listing never returns secrets
- `/api/plugin-proxy`: adds the secret and forwards only to the
credential's own origin, through the SSRF guard unless the admin set
the server up or listed it in `PLUGIN_PROXY_PRIVATE_ORIGINS`; no
redirects or WebDAV moves to other servers, streamed bodies capped at
512 MB up and 2 GB down, 300 requests a minute per plugin, 8 at once
per user, and one audit line per request without paths or bodies
- a capture mode that stores a secret from a sign-in response (Nextcloud
Login Flow v2) and removes it from what the plugin gets back
Linus Rath