lemmy/crates/apub/src/objects/post.rs
Nutomic 3471f3533c
Sanitize html (#3708)
* HTML sanitization in apub code

* Sanitize API inputs

* fmt

* Dont allow html a, img tags

---------

Co-authored-by: Dessalines <dessalines@users.noreply.github.com>
2023-07-26 14:01:15 -04:00

339 lines
11 KiB
Rust

use crate::{
activities::{verify_is_public, verify_person_in_community},
check_apub_id_valid_with_strictness,
local_site_data_cached,
objects::{read_from_string_or_source_opt, verify_is_remote_object},
protocol::{
objects::{
page::{Attachment, AttributedTo, Page, PageType},
LanguageTag,
},
ImageObject,
InCommunity,
Source,
},
};
use activitypub_federation::{
config::Data,
kinds::public,
protocol::{values::MediaTypeMarkdownOrHtml, verification::verify_domains_match},
traits::Object,
};
use anyhow::anyhow;
use chrono::NaiveDateTime;
use html2md::parse_html;
use lemmy_api_common::{
context::LemmyContext,
request::fetch_site_data,
utils::{
is_mod_or_admin,
local_site_opt_to_sensitive,
local_site_opt_to_slur_regex,
sanitize_html,
sanitize_html_opt,
},
};
use lemmy_db_schema::{
self,
source::{
community::Community,
local_site::LocalSite,
moderator::{ModLockPost, ModLockPostForm},
person::Person,
post::{Post, PostInsertForm, PostUpdateForm},
},
traits::Crud,
};
use lemmy_utils::{
error::LemmyError,
utils::{
markdown::markdown_to_html,
slurs::{check_slurs_opt, remove_slurs},
time::convert_datetime,
validation::check_url_scheme,
},
};
use std::ops::Deref;
use url::Url;
const MAX_TITLE_LENGTH: usize = 200;
#[derive(Clone, Debug)]
pub struct ApubPost(pub(crate) Post);
impl Deref for ApubPost {
type Target = Post;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl From<Post> for ApubPost {
fn from(p: Post) -> Self {
ApubPost(p)
}
}
#[async_trait::async_trait]
impl Object for ApubPost {
type DataType = LemmyContext;
type Kind = Page;
type Error = LemmyError;
fn last_refreshed_at(&self) -> Option<NaiveDateTime> {
None
}
#[tracing::instrument(skip_all)]
async fn read_from_id(
object_id: Url,
context: &Data<Self::DataType>,
) -> Result<Option<Self>, LemmyError> {
Ok(
Post::read_from_apub_id(&mut context.pool(), object_id)
.await?
.map(Into::into),
)
}
#[tracing::instrument(skip_all)]
async fn delete(self, context: &Data<Self::DataType>) -> Result<(), LemmyError> {
if !self.deleted {
let form = PostUpdateForm::builder().deleted(Some(true)).build();
Post::update(&mut context.pool(), self.id, &form).await?;
}
Ok(())
}
// Turn a Lemmy post into an ActivityPub page that can be sent out over the network.
#[tracing::instrument(skip_all)]
async fn into_json(self, context: &Data<Self::DataType>) -> Result<Page, LemmyError> {
let creator_id = self.creator_id;
let creator = Person::read(&mut context.pool(), creator_id).await?;
let community_id = self.community_id;
let community = Community::read(&mut context.pool(), community_id).await?;
let language = LanguageTag::new_single(self.language_id, &mut context.pool()).await?;
let page = Page {
kind: PageType::Page,
id: self.ap_id.clone().into(),
attributed_to: AttributedTo::Lemmy(creator.actor_id.into()),
to: vec![community.actor_id.clone().into(), public()],
cc: vec![],
name: Some(self.name.clone()),
content: self.body.as_ref().map(|b| markdown_to_html(b)),
media_type: Some(MediaTypeMarkdownOrHtml::Html),
source: self.body.clone().map(Source::new),
attachment: self.url.clone().map(Attachment::new).into_iter().collect(),
image: self.thumbnail_url.clone().map(ImageObject::new),
comments_enabled: Some(!self.locked),
sensitive: Some(self.nsfw),
language,
published: Some(convert_datetime(self.published)),
updated: self.updated.map(convert_datetime),
audience: Some(community.actor_id.into()),
in_reply_to: None,
};
Ok(page)
}
#[tracing::instrument(skip_all)]
async fn verify(
page: &Page,
expected_domain: &Url,
context: &Data<Self::DataType>,
) -> Result<(), LemmyError> {
// We can't verify the domain in case of mod action, because the mod may be on a different
// instance from the post author.
if !page.is_mod_action(context).await? {
verify_domains_match(page.id.inner(), expected_domain)?;
verify_is_remote_object(page.id.inner(), context.settings())?;
};
let community = page.community(context).await?;
check_apub_id_valid_with_strictness(page.id.inner(), community.local, context).await?;
verify_person_in_community(&page.creator()?, &community, context).await?;
let local_site_data = local_site_data_cached(&mut context.pool()).await?;
let slur_regex = &local_site_opt_to_slur_regex(&local_site_data.local_site);
check_slurs_opt(&page.name, slur_regex)?;
verify_domains_match(page.creator()?.inner(), page.id.inner())?;
verify_is_public(&page.to, &page.cc)?;
Ok(())
}
#[tracing::instrument(skip_all)]
async fn from_json(page: Page, context: &Data<Self::DataType>) -> Result<ApubPost, LemmyError> {
let creator = page.creator()?.dereference(context).await?;
let community = page.community(context).await?;
if community.posting_restricted_to_mods {
is_mod_or_admin(&mut context.pool(), creator.id, community.id).await?;
}
let mut name = page
.name
.clone()
.or_else(|| {
page
.content
.clone()
.as_ref()
.and_then(|c| parse_html(c).lines().next().map(ToString::to_string))
})
.ok_or_else(|| anyhow!("Object must have name or content"))?;
if name.chars().count() > MAX_TITLE_LENGTH {
name = name.chars().take(MAX_TITLE_LENGTH).collect();
}
// read existing, local post if any (for generating mod log)
let old_post = page.id.dereference_local(context).await;
let form = if !page.is_mod_action(context).await? {
let first_attachment = page.attachment.into_iter().map(Attachment::url).next();
let url = if first_attachment.is_some() {
first_attachment
} else if page.kind == PageType::Video {
// we cant display videos directly, so insert a link to external video page
Some(page.id.inner().clone())
} else {
None
};
check_url_scheme(&url)?;
let local_site = LocalSite::read(&mut context.pool()).await.ok();
let allow_sensitive = local_site_opt_to_sensitive(&local_site);
let page_is_sensitive = page.sensitive.unwrap_or(false);
let include_image = allow_sensitive || !page_is_sensitive;
// Only fetch metadata if the post has a url and was not seen previously. We dont want to
// waste resources by fetching metadata for the same post multiple times.
// Additionally, only fetch image if content is not sensitive or is allowed on local site.
let (metadata_res, thumbnail) = match &url {
Some(url) if old_post.is_err() => {
fetch_site_data(
context.client(),
context.settings(),
Some(url),
include_image,
)
.await
}
_ => (None, None),
};
// If no image was included with metadata, use post image instead when available.
let thumbnail_url = thumbnail.or_else(|| page.image.map(|i| i.url.into()));
let (embed_title, embed_description, embed_video_url) = metadata_res
.map(|u| (u.title, u.description, u.embed_video_url))
.unwrap_or_default();
let slur_regex = &local_site_opt_to_slur_regex(&local_site);
let body_slurs_removed =
read_from_string_or_source_opt(&page.content, &page.media_type, &page.source)
.map(|s| remove_slurs(&s, slur_regex));
let language_id =
LanguageTag::to_language_id_single(page.language, &mut context.pool()).await?;
let name = sanitize_html(&name);
let embed_title = sanitize_html_opt(&embed_title);
let embed_description = sanitize_html_opt(&embed_description);
PostInsertForm {
name,
url: url.map(Into::into),
body: body_slurs_removed,
creator_id: creator.id,
community_id: community.id,
removed: None,
locked: page.comments_enabled.map(|e| !e),
published: page.published.map(|u| u.naive_local()),
updated: page.updated.map(|u| u.naive_local()),
deleted: Some(false),
nsfw: page.sensitive,
embed_title,
embed_description,
embed_video_url,
thumbnail_url,
ap_id: Some(page.id.clone().into()),
local: Some(false),
language_id,
featured_community: None,
featured_local: None,
}
} else {
// if is mod action, only update locked/stickied fields, nothing else
PostInsertForm::builder()
.name(name)
.creator_id(creator.id)
.community_id(community.id)
.ap_id(Some(page.id.clone().into()))
.locked(page.comments_enabled.map(|e| !e))
.updated(page.updated.map(|u| u.naive_local()))
.build()
};
let post = Post::create(&mut context.pool(), &form).await?;
// write mod log entry for lock
if Page::is_locked_changed(&old_post, &page.comments_enabled) {
let form = ModLockPostForm {
mod_person_id: creator.id,
post_id: post.id,
locked: Some(post.locked),
};
ModLockPost::create(&mut context.pool(), &form).await?;
}
Ok(post.into())
}
}
#[cfg(test)]
mod tests {
#![allow(clippy::unwrap_used)]
#![allow(clippy::indexing_slicing)]
use super::*;
use crate::{
objects::{
community::tests::parse_lemmy_community,
person::tests::parse_lemmy_person,
post::ApubPost,
tests::init_context,
},
protocol::tests::file_to_json_object,
};
use lemmy_db_schema::source::site::Site;
use serial_test::serial;
#[tokio::test]
#[serial]
async fn test_parse_lemmy_post() {
let context = init_context().await;
let (person, site) = parse_lemmy_person(&context).await;
let community = parse_lemmy_community(&context).await;
let json = file_to_json_object("assets/lemmy/objects/page.json").unwrap();
let url = Url::parse("https://enterprise.lemmy.ml/post/55143").unwrap();
ApubPost::verify(&json, &url, &context).await.unwrap();
let post = ApubPost::from_json(json, &context).await.unwrap();
assert_eq!(post.ap_id, url.into());
assert_eq!(post.name, "Post title");
assert!(post.body.is_some());
assert_eq!(post.body.as_ref().unwrap().len(), 45);
assert!(!post.locked);
assert!(!post.featured_community);
assert_eq!(context.request_count(), 0);
Post::delete(&mut context.pool(), post.id).await.unwrap();
Person::delete(&mut context.pool(), person.id)
.await
.unwrap();
Community::delete(&mut context.pool(), community.id)
.await
.unwrap();
Site::delete(&mut context.pool(), site.id).await.unwrap();
}
}