use activitypub_federation::{ config::Data, fetch::webfinger::{extract_webfinger_name, Webfinger, WebfingerLink, WEBFINGER_CONTENT_TYPE}, }; use actix_web::{web, web::Query, HttpResponse}; use lemmy_api_common::context::LemmyContext; use lemmy_db_schema::{ source::{community::Community, person::Person}, traits::ApubActor, CommunityVisibility, }; use lemmy_utils::{cache_header::cache_3days, error::LemmyResult}; use serde::Deserialize; use std::collections::HashMap; use url::Url; #[derive(Deserialize)] struct Params { resource: String, } pub fn config(cfg: &mut web::ServiceConfig) { cfg.route( ".well-known/webfinger", web::get().to(get_webfinger_response).wrap(cache_3days()), ); } /// Responds to webfinger requests of the following format. There isn't any real documentation for /// this, but it described in this blog post: /// https://mastodon.social/.well-known/webfinger?resource=acct:gargron@mastodon.social /// /// You can also view the webfinger response that Mastodon sends: /// https://radical.town/.well-known/webfinger?resource=acct:felix@radical.town async fn get_webfinger_response( info: Query, context: Data, ) -> LemmyResult { let name = extract_webfinger_name(&info.resource, &context)?; let links = if name == context.settings().hostname { // webfinger response for instance actor (required for mastodon authorized fetch) let url = Url::parse(&context.settings().get_protocol_and_hostname())?; vec![webfinger_link_for_actor(Some(url), "none", &context)] } else { // webfinger response for user/community let user_id: Option = Person::read_from_name(&mut context.pool(), name, false) .await .ok() .flatten() .map(|c| c.actor_id.into()); let community_id: Option = Community::read_from_name(&mut context.pool(), name, false) .await .ok() .flatten() .and_then(|c| { if c.visibility == CommunityVisibility::Public { let id: Url = c.actor_id.into(); Some(id) } else { None } }); // Mastodon seems to prioritize the last webfinger item in case of duplicates. Put // community last so that it gets prioritized. For Lemmy the order doesnt matter. vec![ webfinger_link_for_actor(user_id, "Person", &context), webfinger_link_for_actor(community_id, "Group", &context), ] } .into_iter() .flatten() .collect::>(); if links.is_empty() { Ok(HttpResponse::NotFound().finish()) } else { let json = Webfinger { subject: info.resource.clone(), links, ..Default::default() }; Ok( HttpResponse::Ok() .content_type(&WEBFINGER_CONTENT_TYPE) .json(json), ) } } fn webfinger_link_for_actor( url: Option, kind: &str, context: &LemmyContext, ) -> Vec { if let Some(url) = url { let type_key = "https://www.w3.org/ns/activitystreams#type" .parse() .expect("parse url"); let mut vec = vec![ WebfingerLink { rel: Some("http://webfinger.net/rel/profile-page".into()), kind: Some("text/html".into()), href: Some(url.clone()), ..Default::default() }, WebfingerLink { rel: Some("self".into()), kind: Some("application/activity+json".into()), href: Some(url), properties: HashMap::from([(type_key, kind.into())]), ..Default::default() }, ]; // insert remote follow link if kind == "Person" { let template = format!( "{}/activitypub/externalInteraction?uri={{uri}}", context.settings().get_protocol_and_hostname() ); vec.push(WebfingerLink { rel: Some("http://ostatus.org/schema/1.0/subscribe".into()), template: Some(template), ..Default::default() }); } vec } else { vec![] } }