Hash the salt, user-id, and now avatar version into the filename.
This allows the URL contents to be immutable, and thus to be marked as
immutable and cacheable. Since avatars are served unauthenticated,
hashing with a server-side salt makes the current and past avatars not
enumerable.
This requires plumbing the current (or future) avatar version through
various parts of the upload process.
Since this already requires a full migration of current avatars, also
take the opportunity to fix the missing `.png` on S3 uploads (#12852).
We switch from SHA-1 to SHA-256, but truncate it such that avatar URL
data does not substantially increase in size.
Fixes: #12852.
Due to recent refactoring in 9fb03cb2c7, a user could not
upload avatar if the server uses local upload backend and there
was already an avatar file for that user.
This commit fixes it to just check if there exists a file only
when importing and not when the user is actually trying to
change the avatar.
Fixes#30676.
In #23380, we are changing all occurrences of uri with url in order to
follow the latest URL standard. Previous PRs #25038 and #25045 has
replaced the occurences of uri that has no direct relation with realm.
This commit changes just the model property, which has no API
compatibility concerns.
Actions like deleting realms may leave unreferenced uploads in the
attachment storage backend.
Fix these by walking the complete contents of the attachment storage
backend, and removing files which are no longer present in the
database. This may take quite some time, as it is necessarily O(n) in
the number of files uploaded to the system.
Enforcing a consistent `type` helps us double-check that we're not
playing fast-and-loose with any file paths for local files. As noted
in the comment, this is purely for defense-in-depth.
Passing `write_local_file` a consistent `type` requires removing the
"avatars" out of `realm_avatar_and_logo_path` -- which makes it
consistent across upload backends.
This, in turn, requires a compensatory change to zerver.lib.export, to
be explicit that the realm icons are exported from the avatars
directory. This clarity is likely an improvement.
Anders Kaseorg
Alex Vandiver
Sahil Batra
Vector73