lemmy/crates/apub/src/lib.rs
Nutomic a2a594b763
Extract Activitypub logic into separate library (#2288)
* Create example for apub lib

* some rewriting of apub lib

* Add LocalInstance struct for apub lib to avoid using Lemmy Settings

* Move ActorType trait to lemmy_apub, because its not needed in library

* Use reqwest_retry instead of custom impl, dont specify timeout on every send()

* Some improvements to example

* Moved inbox handling to library

* bug fixes

* Move context and serde helpers into library

* wip: example changes

* Add lemmy_utils feature to build only LemmyError

* Rename to activitypub_federation

* Remove lemmy_utils dep from activitypub_federation using generic error type

* Finish activitypub example

* Cleanup and fix tests

* Reorganize library files

* Remove ApubObject.to_tombstone()

* Extract activitypub library into separate git repository
2022-06-02 16:33:41 +02:00

224 lines
6.7 KiB
Rust

use crate::fetcher::post_or_comment::PostOrComment;
use activitypub_federation::{
core::{inbox::ActorPublicKey, signatures::PublicKey},
InstanceSettingsBuilder,
LocalInstance,
};
use anyhow::Context;
use lemmy_api_common::utils::blocking;
use lemmy_db_schema::{newtypes::DbUrl, source::activity::Activity, utils::DbPool};
use lemmy_utils::{error::LemmyError, location_info, settings::structs::Settings};
use lemmy_websocket::LemmyContext;
use once_cell::sync::{Lazy, OnceCell};
use std::env;
use url::{ParseError, Url};
pub mod activities;
pub(crate) mod activity_lists;
pub(crate) mod collections;
pub mod fetcher;
pub mod http;
pub(crate) mod mentions;
pub mod objects;
pub mod protocol;
static CONTEXT: Lazy<Vec<serde_json::Value>> = Lazy::new(|| {
serde_json::from_str(include_str!("../assets/lemmy/context.json")).expect("parse context")
});
// TODO: store this in context? but its only used in this crate, no need to expose it elsewhere
fn local_instance(context: &LemmyContext) -> &'static LocalInstance {
static LOCAL_INSTANCE: OnceCell<LocalInstance> = OnceCell::new();
LOCAL_INSTANCE.get_or_init(|| {
let settings = InstanceSettingsBuilder::default()
.http_fetch_retry_limit(context.settings().http_fetch_retry_limit)
.worker_count(context.settings().federation.worker_count)
.testing_send_sync(env::var("APUB_TESTING_SEND_SYNC").is_ok())
.verify_url_function(|url| check_apub_id_valid(url, &Settings::get()))
.build()
.expect("configure federation");
LocalInstance::new(
context.settings().hostname,
context.client().clone(),
settings,
)
})
}
/// Checks if the ID is allowed for sending or receiving.
///
/// In particular, it checks for:
/// - federation being enabled (if its disabled, only local URLs are allowed)
/// - the correct scheme (either http or https)
/// - URL being in the allowlist (if it is active)
/// - URL not being in the blocklist (if it is active)
///
/// `use_strict_allowlist` should be true only when parsing a remote community, or when parsing a
/// post/comment in a local community.
#[tracing::instrument(skip(settings))]
fn check_apub_id_valid(apub_id: &Url, settings: &Settings) -> Result<(), &'static str> {
let domain = apub_id.domain().expect("apud id has domain").to_string();
let local_instance = settings
.get_hostname_without_port()
.expect("local hostname is valid");
if domain == local_instance {
return Ok(());
}
if !settings.federation.enabled {
return Err("Federation disabled");
}
if apub_id.scheme() != settings.get_protocol_string() {
return Err("Invalid protocol scheme");
}
if let Some(blocked) = settings.to_owned().federation.blocked_instances {
if blocked.contains(&domain) {
return Err("Domain is blocked");
}
}
if let Some(allowed) = settings.to_owned().federation.allowed_instances {
if !allowed.contains(&domain) {
return Err("Domain is not in allowlist");
}
}
Ok(())
}
#[tracing::instrument(skip(settings))]
pub(crate) fn check_apub_id_valid_with_strictness(
apub_id: &Url,
is_strict: bool,
settings: &Settings,
) -> Result<(), LemmyError> {
check_apub_id_valid(apub_id, settings).map_err(LemmyError::from_message)?;
let domain = apub_id.domain().expect("apud id has domain").to_string();
let local_instance = settings
.get_hostname_without_port()
.expect("local hostname is valid");
if domain == local_instance {
return Ok(());
}
if let Some(mut allowed) = settings.to_owned().federation.allowed_instances {
// Only check allowlist if this is a community, or strict allowlist is enabled.
let strict_allowlist = settings.to_owned().federation.strict_allowlist;
if is_strict || strict_allowlist {
// need to allow this explicitly because apub receive might contain objects from our local
// instance.
allowed.push(local_instance);
if !allowed.contains(&domain) {
return Err(LemmyError::from_message(
"Federation forbidden by strict allowlist",
));
}
}
}
Ok(())
}
pub enum EndpointType {
Community,
Person,
Post,
Comment,
PrivateMessage,
}
/// Generates an apub endpoint for a given domain, IE xyz.tld
pub fn generate_local_apub_endpoint(
endpoint_type: EndpointType,
name: &str,
domain: &str,
) -> Result<DbUrl, ParseError> {
let point = match endpoint_type {
EndpointType::Community => "c",
EndpointType::Person => "u",
EndpointType::Post => "post",
EndpointType::Comment => "comment",
EndpointType::PrivateMessage => "private_message",
};
Ok(Url::parse(&format!("{}/{}/{}", domain, point, name))?.into())
}
pub fn generate_followers_url(actor_id: &DbUrl) -> Result<DbUrl, ParseError> {
Ok(Url::parse(&format!("{}/followers", actor_id))?.into())
}
pub fn generate_inbox_url(actor_id: &DbUrl) -> Result<DbUrl, ParseError> {
Ok(Url::parse(&format!("{}/inbox", actor_id))?.into())
}
pub fn generate_site_inbox_url(actor_id: &DbUrl) -> Result<DbUrl, ParseError> {
let mut actor_id: Url = actor_id.clone().into();
actor_id.set_path("site_inbox");
Ok(actor_id.into())
}
pub fn generate_shared_inbox_url(actor_id: &DbUrl) -> Result<DbUrl, LemmyError> {
let actor_id: Url = actor_id.clone().into();
let url = format!(
"{}://{}{}/inbox",
&actor_id.scheme(),
&actor_id.host_str().context(location_info!())?,
if let Some(port) = actor_id.port() {
format!(":{}", port)
} else {
"".to_string()
},
);
Ok(Url::parse(&url)?.into())
}
pub fn generate_outbox_url(actor_id: &DbUrl) -> Result<DbUrl, ParseError> {
Ok(Url::parse(&format!("{}/outbox", actor_id))?.into())
}
fn generate_moderators_url(community_id: &DbUrl) -> Result<DbUrl, LemmyError> {
Ok(Url::parse(&format!("{}/moderators", community_id))?.into())
}
/// Store a sent or received activity in the database, for logging purposes. These records are not
/// persistent.
#[tracing::instrument(skip(pool))]
async fn insert_activity(
ap_id: &Url,
activity: serde_json::Value,
local: bool,
sensitive: bool,
pool: &DbPool,
) -> Result<bool, LemmyError> {
let ap_id = ap_id.to_owned().into();
Ok(
blocking(pool, move |conn| {
Activity::insert(conn, ap_id, activity, local, sensitive)
})
.await??,
)
}
/// Common methods provided by ActivityPub actors (community and person). Not all methods are
/// implemented by all actors.
pub trait ActorType: ActorPublicKey {
fn actor_id(&self) -> Url;
fn private_key(&self) -> Option<String>;
fn inbox_url(&self) -> Url;
fn shared_inbox_url(&self) -> Option<Url>;
fn shared_inbox_or_inbox_url(&self) -> Url {
self.shared_inbox_url().unwrap_or_else(|| self.inbox_url())
}
fn get_public_key(&self) -> PublicKey {
PublicKey::new_main_key(self.actor_id(), self.public_key().to_string())
}
}