### Background
Several call sites use `FileStore#download` (through `Discourse.store.download`). In some cases the author seems aware that the method can raise an error if the download fails, and in some cases not. Because of this we're seeing some of these exceptions bubble all the way up and getting logged in production. Although they are not really actionable at that point. Rather each call site needs to be considered to figure out how to handle them.
### What is this change?
This change accomplishes primarily two things.
Firstly it separates the method into a safe version which will handle errors by returning `nil`, and an unsafe version which will re-package upstream errors in a new `FileStore::DownloadError` class.
Secondly it updates the call sites which have been doing error handling downstream to use the new safe version.
For backwards compatibility, there's an interim situation and a desired end state.
**Interim:**
```
FileStore#download → Old unsafe version. Will raise any error and show a deprecation warning.
FileStore#download! → New unsafe version. Will raise FileStore::DownloadError.
FileStore#download_safe → New safe version. Will return nil.
```
**Desired end-state:**
```
FileStore#download → New safe version. Will return nil.
FileStore#download! → New unsafe version. Will raise FileStore::DownloadError.
```
### What's next?
We need to do a quick audit of the call sites that are using the old unsafe version without any error handling, as well as check for call sites in plugins other repos. Follow-up PRs incoming.
The previous fix in e83d35d6 was incorrect, and the stub in the test was never actually hit. This commit moves the error handling to the right place and updates the specs to ensure the stub is always used.
These errors tend to indicate that the upload is missing on the remote store. This is bad, but we don't want it to block the dominant-color calculation process. This commit catches errors when there is an HTTP error, and fixes the `base_store.rb` implementation when `FileHelper.download` returns nil.
This commit renames all secure_media related settings to secure_uploads_* along with the associated functionality.
This is being done because "media" does not really cover it, we aren't just doing this for images and videos etc. but for all uploads in the site.
Additionally, in future we want to secure more types of uploads, and enable a kind of "mixed mode" where some uploads are secure and some are not, so keeping media in the name is just confusing.
This also keeps compatibility with the `secure-media-uploads` path, and changes new
secure URLs to be `secure-uploads`.
Deprecated settings:
* secure_media -> secure_uploads
* secure_media_allow_embed_images_in_emails -> secure_uploads_allow_embed_images_in_emails
* secure_media_max_email_embed_image_size_kb -> secure_uploads_max_email_embed_image_size_kb
The `add_column` `limit` parameter has no effect on a postgres `text` column. Instead we can perform the check in ActiveRecord.
We never expect this condition to be hit - users cannot control this value. It's just a safety net.
We previously had a system which would generate a 10x10px preview of images and add their URLs in a data-small-upload attribute. The client would then use that as the background-image of the `<img>` element. This works reasonably well on fast connections, but on slower connections it can take a few seconds for the placeholders to appear. The act of loading the placeholders can also break or delay the loading of the 'real' images.
This commit replaces the placeholder logic with a new approach. Instead of a 10x10px preview, we use imagemagick to calculate the average color of an image and store it in the database. The hex color value then added as a `data-dominant-color` attribute on the `<img>` element, and the client can use this as a `background-color` on the element while the real image is loading. That means no extra HTTP request is required, and so the placeholder color can appear instantly.
Dominant color will be calculated:
1. When a new upload is created
2. During a post rebake, if the dominant color is missing from an upload, it will be calculated and stored
3. Every 15 minutes, 25 old upload records are fetched and their dominant color calculated and stored. (part of the existing PeriodicalUpdates job)
Existing posts will continue to use the old 10x10px placeholder system until they are next rebaked
We do not zero-pad our base62 short URLs, so there is no guarantee that the length is 27. Instead, let's greedily match all consecutive base62 characters and look for a matching upload.
This reverts bd32656157 and 36f5d5eada.
This table holds associations between uploads and other models. This can be used to prevent removing uploads that are still in use.
* DEV: Create upload_references
* DEV: Use UploadReference instead of PostUpload
* DEV: Use UploadReference for SiteSetting
* DEV: Use UploadReference for Badge
* DEV: Use UploadReference for Category
* DEV: Use UploadReference for CustomEmoji
* DEV: Use UploadReference for Group
* DEV: Use UploadReference for ThemeField
* DEV: Use UploadReference for ThemeSetting
* DEV: Use UploadReference for User
* DEV: Use UploadReference for UserAvatar
* DEV: Use UploadReference for UserExport
* DEV: Use UploadReference for UserProfile
* DEV: Add method to extract uploads from raw text
* DEV: Use UploadReference for Draft
* DEV: Use UploadReference for ReviewableQueuedPost
* DEV: Use UploadReference for UserProfile's bio_raw
* DEV: Do not copy user uploads to upload references
* DEV: Copy post uploads again after deploy
* DEV: Use created_at and updated_at from uploads table
* FIX: Check if upload site setting is empty
* DEV: Copy user uploads to upload references
* DEV: Make upload extraction less strict
This will make future changes to the 'pull hotlinked images' system easier. This commit should not introduce any functional change.
For now, the old post_custom_field data is kept in the database. This will be dropped in a future commit.
Due to default CSP web workers instantiated from CDN based assets are still
treated as "same-origin" meaning that we had no way of safely instansiating
a web worker from a theme.
This limits the theme system and adds the arbitrary restriction that WASM
based components can not be safely used.
To resolve this limitation all js assets in about.json are also cached on
local domain.
{
"name": "Header Icons",
"assets" : {
"worker" : "assets/worker.js"
}
}
This can then be referenced in JS via:
settings.theme_uploads_local.worker
local_js_assets are unconditionally served from the site directly and
bypass the entire CDN, using the pre-existing JavascriptCache
Previous to this change this code was completely dormant on sites which
used s3 based uploads, this reuses the very well tested and cached asset
system on s3 based sites.
Note, when creating local_js_assets it is highly recommended to keep the
assets lean and keep all the heavy working in CDN based assets. For example
wasm files can still live on the CDN but the lean worker that loads it can
live on local.
This change unlocks wasm in theme components, so wasm is now also allowed
in `theme_authorized_extensions`
* more usages of upload.content
* add a specific test for upload.content
* Adjust logic to ensure that after upgrades we still get a cached local js
on save
This commit introduces two new APIs for handling unused uploads, one
can be used to exclude uploads in bulk when the data model allow and
the other one excludes uploads one by one.
This is necessary to allow for large file uploads via
the direct S3 upload mechanism, as we convert the external
file to an Upload record via ExternalUploadManager once
it is complete.
This will allow for files larger than 2,147,483,647 bytes (2.14GB)
to be referenced in the uploads table.
This is a table locking migration, but since it is not as highly
trafficked as posts, topics, or users, the disruption should be minimal.
When secure media is enabled or when upload secure status
is updated, we also try and update the upload ACL. However
if the object storage provider does not implement this we
get an Aws::S3::Errors::NotImplemented error. This PR handles
this error so the update_secure_status method does not error
out and still returns whether the secure status changed.
Previously certain images may lead to convert / identify to run for unreasonable
amounts of time
This adds a maximum amount of time these commands can run prior to forcing
them to stop
SVG files can have dimensions expressed in inches, centimeters, etc., which may lead to the dimensions being misinterpreted (e.g. “8in” ends up as 8 pixels).
If the file type is `svg`, ask ImageMagick to work out what size the SVG file should be rendered on screen.
NOTE: The `pencil.svg` file was obtained from https://freesvg.org/1534028868, which has placed the file in to the public domain.
This PR adds security_last_changed_at and security_last_changed_reason to uploads. This has been done to make it easier to track down why an upload's secure column has changed and when. This necessitated a refactor of the UploadSecurity class to provide reasons why the upload security would have changed.
As well as this, a source is now provided from the location which called for the upload's security status to be updated as they are several (e.g. post creator, topic security updater, rake tasks, manual change).
* FEATURE - Add SiteSettings to control JPEG image quality
`recompress_original_jpg_quality` - the maximum quality of a newly
uploaded file.
`image_preview_jpg_quality` - the maximum quality of OptimizedImages
Dependency on gifsicle, allow_animated_avatars and allow_animated_thumbnails
site settings were all removed. Animated GIF images are still allowed, but
the generated optimized images are no longer animated for those (which were
used for avatars and thumbnails).
The added 'animated' is populated by extracting information using FastImage.
This field was used to selectively reoptimize old animations. This process
happens in the background.
Upload.secure_media_url? raised an exceptions when the URL was invalid,
which was a issue in some situations where secure media URLs must be
removed.
For example, sending digests used PrettyText.strip_secure_media,
which used Upload.secure_media_url? to replace secure media with
placeholders. If the URL was invalid, then an exception would be raised
and left unhandled.
Now instead in UrlHelper.rails_route_from_url we return nil if there is something wrong with the URL.
Co-authored-by: Bianca Nenciu <nenciu.bianca@gmail.com>
There is an fk to user_profile that can make destroying uploads fail
if they happen to be set as user profile.
This ensures we clear this information when destroying uploads.
There are more relationships, but this makes some more progress.
The previous fix (f43c0a5d85) wasn't working for images that were already uploaded.
The "metadata" (eg. 'for_*' and 'secure' attributes) were not added to existing uploads.
Also used 'Upload.get_from_url' is the admin/site_setting controller to properly retrieve
an upload from its URL.
Fixed the Upload::URL_REGEX to use the \h (hexadecimal) for the SHA
Follow-up-to: f43c0a5d85
This reverts commit 20780a1eee.
* SECURITY: re-adds accidentally reverted commit:
03d26cd6: ensure embed_url contains valid http(s) uri
* when the merge commit e62a85cf was reverted, git chose the 2660c2e2 parent to land on
instead of the 03d26cd6 parent (which contains security fixes)
This introduces new APIs for obtaining optimized thumbnails for topics. There are a few building blocks required for this:
- Introduces new `image_upload_id` columns on the `posts` and `topics` table. This replaces the old `image_url` column, which means that thumbnails are now restricted to uploads. Hotlinked thumbnails are no longer possible. In normal use (with pull_hotlinked_images enabled), this has no noticeable impact
- A migration attempts to match existing urls to upload records. If a match cannot be found then the posts will be queued for rebake
- Optimized thumbnails are generated during post_process_cooked. If thumbnails are missing when serializing a topic list, then a sidekiq job is queued
- Topic lists and topics now include a `thumbnails` key, which includes all the available images:
```
"thumbnails": [
{
"max_width": null,
"max_height": null,
"url": "//example.com/original-image.png",
"width": 1380,
"height": 1840
},
{
"max_width": 1024,
"max_height": 1024,
"url": "//example.com/optimized-image.png",
"width": 768,
"height": 1024
}
]
```
- Themes can request additional thumbnail sizes by using a modifier in their `about.json` file:
```
"modifiers": {
"topic_thumbnail_sizes": [
[200, 200],
[800, 800]
],
...
```
Remember that these are generated asynchronously, so your theme should include logic to fallback to other available thumbnails if your requested size has not yet been generated
- Two new raw plugin outlets are introduced, to improve the customisability of the topic list. `topic-list-before-columns` and `topic-list-before-link`
We have the `# frozen_string_literal: true` comment on all our
files. This means all string literals are frozen. There is no need
to call #freeze on any literals.
For files with `# frozen_string_literal: true`
```
puts %w{a b}[0].frozen?
=> true
puts "hi".frozen?
=> true
puts "a #{1} b".frozen?
=> true
puts ("a " + "b").frozen?
=> false
puts (-("a " + "b")).frozen?
=> true
```
For more details see: https://samsaffron.com/archive/2018/02/16/reducing-string-duplication-in-ruby
* When copying the markdown for an image between posts, we were not adding the srcset and data-small-image attributes which are done by calling optimize_image! in cooked post processor
* Refactored the code which was confusing in its current state (the consider_for_reuse method was super confusing) and fixed the issue
* Add uploads:sync_s3_acls rake task to ensure the ACLs in S3 are the correct (public-read or private) setting based on upload security
* Improved uploads:disable_secure_media to be more efficient and provide better messages to the user.
* Rename uploads:ensure_correct_acl task to uploads:secure_upload_analyse_and_update as it does more than check the ACL
* Many improvements to uploads:secure_upload_analyse_and_update
* Make sure that upload.access_control_post is unscoped so deleted posts are still fetched, because they still affect the security of the upload.
* Add escape hatch for capture_stdout in the form of RAILS_ENABLE_TEST_STDOUT. If provided the capture_stdout code will be ignored, so you can see the output if you need.
* Because custom emoji count as post "uploads" we were
marking them as secure when updating the secure status for post uploads.
* We were also giving them an access control post id, which meant
broken image previews from 403 errors in the admin custom emoji list.
* We now check if an upload is used as a custom emoji and do not
assign the access control post + never mark as secure.
For example /t/ URLs were being replaced if they contained secure-media-uploads so if you made a topic called "Secure Media Uploads Are Cool" the View Topic link in the user notifications would be stripped out.
Refactored code so this secure URL detection happens in one place.
Basically, say you had already downloaded a certain image from a certain URL
using pull_hotlinked_images and the onebox. The upload would be stored
by its sha as an upload record. Whenever you linked to the same URL again
in a post (e.g. in our case an og:image on review.discourse) we would
would reuse the original upload record because of the sha1.
However when you turned on secure media this could cause problems as
the first post that uses that upload after secure media is enabled
will set the access control post for the upload to the new post.
Then if the post is deleted every single onebox/link to that same image
URL will fail forever with 403 as the secure-media-uploads URL fails
if the access control post has been deleted.
To fix this when cooking posts and pulling hotlinked images, we only
allow using an original upload by URL if its access control post
matches the current post, and if the original_sha1 is filled in,
meaning it was uploaded AFTER secure media was enabled. otherwise
we just redownload the media again to be safe, as the URL will always
be new then.
When pull_hotlinked_images tried to run on posts with secure media (which had already been downloaded from external sources) we were getting a 404 when trying to download the image because the secure endpoint doesn't allow anon downloads.
Also, we were getting into an infinite loop of pull_hotlinked_images because the job didn't consider the secure media URLs as "downloaded" already so it kept trying to download them over and over.
In this PR I have also refactored secure-media-upload URL checks and mutations into single source of truth in Upload, adding a SECURE_MEDIA_ROUTE constant to check URLs against too.
Add TopicUploadSecurityManager to handle post moves. When a post moves around or a topic changes between categories and public/private message status the uploads connected to posts in the topic need to have their secure status updated, depending on the security context the topic now lives in.
### General Changes and Duplication
* We now consider a post `with_secure_media?` if it is in a read-restricted category.
* When uploading we now set an upload's secure status straight away.
* When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file.
* Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is).
* When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload.
### Viewing Secure Media
* The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions
* If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor`
### Removed
We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled.
* We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context.
* We no longer have to set `secure: false` for uploads when uploading for a theme component.
When uploading a file to a theme component, and that file is existing and has already been marked as secure, we now automatically mark the file as secure: false, change the ACL, and log the action as the user (also rebake the posts for the upload)
This PR introduces a new secure media setting. When enabled, it prevent unathorized access to media uploads (files of type image, video and audio). When the `login_required` setting is enabled, then all media uploads will be protected from unauthorized (anonymous) access. When `login_required`is disabled, only media in private messages will be protected from unauthorized access.
A few notes:
- the `prevent_anons_from_downloading_files` setting no longer applies to audio and video uploads
- the `secure_media` setting can only be enabled if S3 uploads are already enabled and configured
- upload records have a new column, `secure`, which is a boolean `true/false` of the upload's secure status
- when creating a public post with an upload that has already been uploaded and is marked as secure, the post creator will raise an error
- when enabling or disabling the setting on a site with existing uploads, the rake task `uploads:ensure_correct_acl` should be used to update all uploads' secure status and their ACL on S3
