Diff

mod_pubsub_post/README.markdown @ 3503:882180b459a0

mod_pubsub_post: Restructure authentication and authorization (BC) This deprecates the default "superuser" actor model and makes the default equivalent to the previous "request.id". A single actor and secret per node is supported because HTTP and WebHooks don't normally include any authorization identity. Allowing authentication bypass when no secret is given should be relatively safe when the actor is unprivileged, as will be unless explicitly configured otherwise.
author Kim Alvefur <zash@zash.se>
date Sat, 30 Mar 2019 21:16:13 +0100
parent 3502:42e9e3c5eb02
child 3505:106b4ae4469b
line wrap: on
line diff
--- a/mod_pubsub_post/README.markdown	Sat Mar 30 19:24:18 2019 +0100
+++ b/mod_pubsub_post/README.markdown	Sat Mar 30 21:16:13 2019 +0100
@@ -17,56 +17,60 @@
 
 # Configuration
 
-## Authentication
-
-Authentication can be handled in two different ways.
-
-### None
-
-``` {.lua}
-pubsub_post_actor = "superuser"
-```
-
-The module uses an internal actor that has all privileges and can always
-do everything. It is strongly suggested that you do not expose this to
-the Internet. *Maybe* it shouldn't be the default...
+All settings are optional.
 
-### IP
-
-``` {.lua}
-pubsub_post_actor = "request.ip"
-```
+## Actor identification
 
-Uses the IP address from the HTTP request as actor, which means this
-pseudo-JID must be given a 'publisher' affiliation. This should work
-nicely with the `autocreate_on_publish` setting, where the first actor
-to attempt to publish to a nonexistent node becomes owner of it, which
-includes publishing rights.
-
-## WebSub
+First we have to figure out who is making the request.
+This is configured on a per-node basis like this:
 
 ``` {.lua}
 -- Per node secrets
-pubsub_post_secrets = {
-    my_node = "shared secret"
+pubsub_post_actors = {
+    princely_musings = "hamlet@denmark.lit"
 }
-
--- Same secret for all nodes
-pubsub_post_secret = "shared secret"
+pubsub_post_default_actor = "nobody@nowhere.invalid"
 ```
 
-This enables the
+`pubsub_post_default_actor` is used when trying to publish to a node
+that is not listed in `pubsub_post_actors`. Otherwise the IP address
+of the connection is used.
+
+## Authentication
+
 [WebSub](https://www.w3.org/TR/2018/REC-websub-20180123/) [Authenticated
 Content
 Distribution](https://www.w3.org/TR/2018/REC-websub-20180123/#authenticated-content-distribution)
-authentication method, where payloads are signed using a shared secret.
+authentication is used.
+
+``` {.lua}
+pubsub_post_secrets = {
+    princely_musings = "shared secret"
+}
+pubsub_post_default_secret = "default secret"
+```
 
-## Setting up affiliations
+`pubsub_post_default_secret` is used when trying to publish to a node
+that is not listed in `pubsub_post_secrets`. Otherwise the request
+proceeds with the previously identified actor.
+
+::: {.alert .alert-danger}
+If configured without a secret and a default actor that has permission
+to create nodes the service becomes wide open.
+:::
+
+## Authorization
+
+Authorization is handled via pubsub affiliations. Publishing requires an
+affiliation with the _publish_ capability, usually `"publisher"`.
+
+### Setting up affiliations
 
 Prosodys PubSub module supports [setting affiliations via
 XMPP](https://xmpp.org/extensions/xep-0060.html#owner-affiliations), in
 trunk since [revision
-384ef9732b81](https://hg.prosody.im/trunk/rev/384ef9732b81).
+384ef9732b81](https://hg.prosody.im/trunk/rev/384ef9732b81), so
+affiliations can be configured with a capable client.
 
 It can however be done from another plugin: