Fix S3 keys/paths for user avatars

Also fixes the avatars controller to work with all back-ends

app/controllers/settings_controller.rb

@@ -34,10 +34,12 @@ class SettingsController < ApplicationController
       end
 
       if @user.avatar_new.present?
-        @user.avatar.attach(@user.avatar_new)
-        @user.avatar.blob.update(filename: @user.avatar_filename)
-        @user.save!
-        LdapManager::UpdateAvatar.call(user: @user)
+        if store_user_avatar
+          LdapManager::UpdateAvatar.call(user: @user)
+        else
+          @validation_errors = @user.errors
+          render :show, status: :unprocessable_entity and return
+        end
       end
 
       if @user.pgp_pubkey && (@user.pgp_pubkey != @user.ldap_entry[:pgp_key])
@@ -187,4 +189,21 @@ class SettingsController < ApplicationController
       salt = BCrypt::Engine.generate_salt
       BCrypt::Engine.hash_secret(password, salt)
     end
+
+    def store_user_avatar
+      data = @user.avatar_new.tempfile.read
+      @user.avatar_new.tempfile.rewind
+      hash = Digest::SHA256.hexdigest(data)
+      ext = @user.avatar_new.content_type == "image/png" ? "png" : "jpg"
+      filename = "#{hash}.#{ext}"
+
+      if filename == @user.avatar.filename.to_s
+        @user.errors.add(:avatar, "must be a new file/picture")
+        false
+      else
+        key = "users/#{@user.cn}/avatars/#{filename}"
+        @user.avatar.attach io: @user.avatar_new.tempfile, key: key, filename: filename
+        @user.save
+      end
+    end
 end