We had an issue where onebox thumbnail was too large and thus was optimized, and we are using the image URLs in post to redact and re-embed, based on the sha1 in the URL. Optimized image URLs have extra stuff on the end like _99x99 so we were not parsing out the sha1 correctly. Another issue I found was for posts that have giant images, the original was being used to embed in the email and thus would basically never get included because it is huge.
For example the URL 787b17ea61_2_690x335.jpeg was not parsed correctly; we would end up with 787b17ea6140f4f022eb7f1509a692f2873cfe35_2_690x335.jpeg as the sha1 which would not find the image to re-embed that was already attached to the email.
This fix will use the first optimized image of the detected upload when we are redacting and then re-embedding to make sure we are not sending giant things in email. Also, I detect if it is a onebox thumbnail or the site icon and force appropriate sizes and styles.
`max-width: 50%; max-height: 400px;` is a good fallback, however, if width and height are given and are smaller than fallback - we should persist that smaller size.
This was made adjustable to allow rolling back quickly if problems came
up. The new behaviour was made default in 93137066 and no problems with
this have been reported.
This PR introduces a few important changes to secure media redaction in emails. First of all, two new site settings have been introduced:
* `secure_media_allow_embed_images_in_emails`: If enabled we will embed secure images in emails instead of redacting them.
* `secure_media_max_email_embed_image_size_kb`: The cap to the size of the secure image we will embed, defaulting to 1mb, so the email does not become too big. Max is 10mb. Works in tandem with `email_total_attachment_size_limit_kb`.
`Email::Sender` will now attach images to the email based on these settings. The sender will also call `inline_secure_images` in `Email::Styles` after secure media is redacted and attachments are added to replace redaction messages with attached images. I went with attachment and `cid` URLs because base64 image support is _still_ flaky in email clients.
All redaction of secure media is now handled in `Email::Styles` and calls out to `PrettyText.strip_secure_media` to do the actual stripping and replacing with placeholders. `app/mailers/group_smtp_mailer.rb` and `app/mailers/user_notifications.rb` no longer do any stripping because they are earlier in the pipeline than `Email::Styles`.
Finally the redaction notice has been restyled and includes a link to the media that the user can click, which will show it to them if they have the necessary permissions.
`Nokogiri::HTML.fragment` is a huge hack (a comment in the source code
admits this). The current behavior of `Email::Styles` is to try to
emulate `fragment` using nokogumbo, but it misses some edge cases. In
particular, meta tags in a email template don't make it through to the
final email.
Instead of treating the provided HTML as an indeterminate fragment, this
commit makes `Email::Styles` treat the HTML as a complete document. This
means that the generated HTML for an email will now always contain top
level structure (a doctype, html, head and body tags).
This new behavior is behind a hidden site setting for now and defaults
off.
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
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.
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.
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
In some very rare cases CssParser could be loaded but CssParser::Parser not
this ensures we check for the actual constant we plan to call for concurrent
digest generations
This feature adds the ability to customize the HTML part of all emails using a custom HTML template and optionally some CSS to style it. The CSS will be parsed and converted into inline styles because CSS is poorly supported by email clients. When writing the custom HTML and CSS, be aware of what email clients support. Keep customizations very simple.
Customizations can be added and edited in Admin > Customize > Email Style.
Since the summary email is already heavily styled, there is a setting to disable custom styles for summary emails called "apply custom styles to digest" found in Admin > Settings > Email.
As part of this work, RTL locales are now rendered correctly for all emails.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
