FIX: Allow secure uploads if global s3 setting active and enable_s3_uploads validations (#8373)

The secure media functionality relied on `SiteSetting.enable_s3_uploads?` which, as we found in dev, did not take into account global S3 settings via `GlobalSetting.use_s3?`. We now use `SiteSetting.Upload.enable_s3_uploads` instead to be more consistent.

Also, we now validate `enable_s3_uploads` changes, because if `GlobalSetting.use_s3?` is true users should NOT be enabling S3 uploads manually.

app/jobs/regular/update_private_uploads_acl.rb

@@ -4,7 +4,7 @@ module Jobs
   class UpdatePrivateUploadsAcl < ::Jobs::Base
     # only runs when SiteSetting.prevent_anons_from_downloading_files is updated
     def execute(args)
-      return if !SiteSetting.enable_s3_uploads
+      return if !SiteSetting.Upload.enable_s3_uploads
 
       Upload.find_each do |upload|
         if !FileHelper.is_supported_media?(upload.original_filename)

config/locales/server.en.yml

@@ -208,6 +208,7 @@ en:
       secure_media_requirements: "S3 uploads must be enabled before enabling secure media."
       second_factor_cannot_be_enforced_with_disabled_local_login: "You cannot enforce 2FA if local logins are disabled."
       local_login_cannot_be_disabled_if_second_factor_enforced: "You cannot disable local login if 2FA is enforced. Disable enforced 2FA before disabling local logins."
+      cannot_enable_s3_uploads_when_s3_enabled_globally: "You cannot enable S3 uploads because S3 uploads are already globally enabled, and enabling this site-level could cause critical issues with uploads"
     conflicting_google_user_id: 'The Google Account ID for this account has changed; staff intervention is required for security reasons. Please contact staff and point them to <br><a href="https://meta.discourse.org/t/76575">https://meta.discourse.org/t/76575</a>'
 
   activemodel:

lib/site_settings/validations.rb

@@ -118,11 +118,13 @@ module SiteSettings::Validations
   end
 
   def validate_enable_s3_uploads(new_val)
-    validate_error :s3_upload_bucket_is_required if new_val == "t" && SiteSetting.s3_upload_bucket.blank?
+    return if new_val == "f"
+    validate_error :cannot_enable_s3_uploads_when_s3_enabled_globally if GlobalSetting.use_s3?
+    validate_error :s3_upload_bucket_is_required if SiteSetting.s3_upload_bucket.blank?
   end
 
   def validate_secure_media(new_val)
-    validate_error :secure_media_requirements if new_val == "t" && !SiteSetting.enable_s3_uploads?
+    validate_error :secure_media_requirements if new_val == "t" && !SiteSetting.Upload.enable_s3_uploads
   end
 
   def validate_enable_s3_inventory(new_val)

spec/jobs/regular/update_private_uploads_acl_spec.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe Jobs::UpdatePrivateUploadsAcl do
+  let(:args) { [] }
+
+  before do
+    SiteSetting.authorized_extensions = "pdf"
+  end
+
+  describe '#execute' do
+    context "if not SiteSetting.Upload.enable_s3_uploads" do
+      before do
+        SiteSetting.Upload.stubs(:enable_s3_uploads).returns(false)
+      end
+      it "returns early and changes no uploads" do
+        Upload.expects(:find_each).never
+        subject.execute(args)
+      end
+    end
+    context "if SiteSetting.Upload.enable_s3_uploads" do
+      let!(:upload) { Fabricate(:upload_s3, extension: 'pdf', original_filename: "watchmen.pdf", secure: false) }
+      before do
+        SiteSetting.login_required = true
+        SiteSetting.prevent_anons_from_downloading_files = true
+        SiteSetting::Upload.stubs(:enable_s3_uploads).returns(true)
+        Discourse.stubs(:store).returns(stub(external?: false))
+      end
+
+      it "changes the upload to secure" do
+        subject.execute(args)
+        expect(upload.reload.secure).to eq(true)
+      end
+    end
+  end
+end

spec/lib/site_settings/validations_spec.rb

@@ -125,7 +125,7 @@ describe SiteSettings::Validations do
         end
 
         it "should be ok" do
-          expect { subject.validate_enforce_second_factor("t") }.not_to raise_error(Discourse::InvalidParameters, error_message)
+          expect { subject.validate_enforce_second_factor("t") }.not_to raise_error
         end
       end
     end
@@ -150,14 +150,98 @@ describe SiteSettings::Validations do
           end
 
           it "should be ok" do
-            expect { subject.validate_enable_local_logins("f") }.not_to raise_error(Discourse::InvalidParameters, error_message)
+            expect { subject.validate_enable_local_logins("f") }.not_to raise_error
           end
         end
       end
 
       context "when the new value is true" do
         it "should be ok" do
-          expect { subject.validate_enable_local_logins("t") }.not_to raise_error(Discourse::InvalidParameters, error_message)
+          expect { subject.validate_enable_local_logins("t") }.not_to raise_error
+        end
+      end
+    end
+
+    describe "#validate_secure_media" do
+      let(:error_message) { I18n.t("errors.site_settings.secure_media_requirements") }
+
+      context "when the new value is true" do
+        context 'if site setting for enable_s3_uploads is enabled' do
+          before do
+            SiteSetting.enable_s3_uploads = true
+          end
+
+          it "should be ok" do
+            expect { subject.validate_secure_media("t") }.not_to raise_error
+          end
+        end
+
+        context 'if site setting for enable_s3_uploads is not enabled' do
+          before do
+            SiteSetting.enable_s3_uploads = false
+          end
+
+          it "is not ok" do
+            expect { subject.validate_secure_media("t") }.to raise_error(Discourse::InvalidParameters, error_message)
+          end
+
+          context "if global s3 setting is enabled" do
+            before do
+              GlobalSetting.stubs(:use_s3?).returns(true)
+            end
+
+            it "should be ok" do
+              expect { subject.validate_secure_media("t") }.not_to raise_error
+            end
+          end
+        end
+      end
+    end
+
+    describe "#validate_enable_s3_uploads" do
+      let(:error_message) { I18n.t("errors.site_settings.cannot_enable_s3_uploads_when_s3_enabled_globally") }
+
+      context "when the new value is true" do
+        context "when s3 uploads are already globally enabled" do
+          before do
+            GlobalSetting.stubs(:use_s3?).returns(true)
+          end
+
+          it "is not ok" do
+            expect { subject.validate_enable_s3_uploads("t") }.to raise_error(Discourse::InvalidParameters, error_message)
+          end
+        end
+
+        context "when s3 uploads are not already globally enabled" do
+          before do
+            GlobalSetting.stubs(:use_s3?).returns(false)
+          end
+
+          it "should be ok" do
+            expect { subject.validate_enable_s3_uploads("t") }.not_to raise_error
+          end
+        end
+
+        context "when the s3_upload_bucket is blank" do
+          let(:error_message) { I18n.t("errors.site_settings.s3_upload_bucket_is_required") }
+
+          before do
+            SiteSetting.s3_upload_bucket = nil
+          end
+
+          it "is not ok" do
+            expect { subject.validate_enable_s3_uploads("t") }.to raise_error(Discourse::InvalidParameters, error_message)
+          end
+        end
+
+        context "when the s3_upload_bucket is not blank" do
+          before do
+            SiteSetting.s3_upload_bucket = "some-bucket"
+          end
+
+          it "should be ok" do
+            expect { subject.validate_enable_s3_uploads("t") }.not_to raise_error
+          end
         end
       end
     end