Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- `app/controllers/activitypub/collections_controller.rb`:
  Conflict due to glitch-soc having to take care of local-only
  pinned toots in that controller.
  Took upstream's changes and restored the local-only special
  handling.
- `app/controllers/auth/sessions_controller.rb`:
  Minor conflicts due to the theming system, applied upstream
  changes, adapted the following two files for glitch-soc's
  theming system:
  - `app/controllers/concerns/sign_in_token_authentication_concern.rb`
  - `app/controllers/concerns/two_factor_authentication_concern.rb`
- `app/services/backup_service.rb`:
  Minor conflict due to glitch-soc having to handle local-only
  toots specially. Applied upstream changes and restored
  the local-only special handling.
- `app/views/admin/custom_emojis/index.html.haml`:
  Minor conflict due to the theming system.
- `package.json`:
  Upstream dependency updated, too close to a glitch-soc-only
  dependency in the file.
- `yarn.lock`:
  Upstream dependency updated, too close to a glitch-soc-only
  dependency in the file.

app/validators/ed25519_key_validator.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class Ed25519KeyValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    return if value.blank?
+
+    key = Base64.decode64(value)
+
+    record.errors[attribute] << I18n.t('crypto.errors.invalid_key') unless verified?(key)
+  end
+
+  private
+
+  def verified?(key)
+    Ed25519.validate_key_bytes(key)
+  rescue ArgumentError
+    false
+  end
+end

app/validators/ed25519_signature_validator.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class Ed25519SignatureValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    return if value.blank?
+
+    verify_key = Ed25519::VerifyKey.new(Base64.decode64(option_to_value(record, :verify_key)))
+    signature  = Base64.decode64(value)
+    message    = option_to_value(record, :message)
+
+    record.errors[attribute] << I18n.t('crypto.errors.invalid_signature') unless verified?(verify_key, signature, message)
+  end
+
+  private
+
+  def verified?(verify_key, signature, message)
+    verify_key.verify(signature, message)
+  rescue Ed25519::VerifyError, ArgumentError
+    false
+  end
+
+  def option_to_value(record, key)
+    if options[key].is_a?(Proc)
+      options[key].call(record)
+    else
+      record.public_send(options[key])
+    end
+  end
+end