Do not use artifacts metadata to access single artifact

app/controllers/projects/artifacts_controller.rb

@@ -7,7 +7,7 @@ class Projects::ArtifactsController < Projects::ApplicationController
   before_action :authorize_update_build!, only: [:keep]
   before_action :extract_ref_name_and_path
   before_action :validate_artifacts!
-  before_action :set_path_and_entry, only: [:file, :raw]
+  before_action :entry, only: [:file]
 
   def download
     if artifacts_file.file_storage?
@@ -41,7 +41,10 @@ class Projects::ArtifactsController < Projects::ApplicationController
   end
 
   def raw
-    send_artifacts_entry(build, @entry)
+    path = Gitlab::Ci::Build::Artifacts::Path
+      .new(params[:path])
+
+    send_artifacts_entry(build, path)
   end
 
   def keep
@@ -93,9 +96,8 @@ class Projects::ArtifactsController < Projects::ApplicationController
     @artifacts_file ||= build.artifacts_file
   end
 
-  def set_path_and_entry
-    @path = params[:path]
-    @entry = build.artifacts_metadata_entry(@path)
+  def entry
+    @entry = build.artifacts_metadata_entry(params[:path])
 
     render_404 unless @entry.exists?
   end

lib/api/jobs.rb

@@ -98,10 +98,11 @@ module API
         build = get_build!(params[:job_id])
         not_found! unless build.artifacts?
 
-        entry = build.artifacts_metadata_entry(params[:artifact_path])
-        not_found! unless entry.exists?
+        path = Gitlab::Ci::Build::Artifacts::Path
+          .new(params[:artifact_path])
+        not_found! unless path.valid?
 
-        send_artifacts_entry(build, entry)
+        send_artifacts_entry(build, path)
       end
 
       desc 'Download the artifacts file from a job' do

spec/requests/api/jobs_spec.rb

@@ -220,14 +220,6 @@ describe API::Jobs do
                         'Gitlab-Workhorse-Send-Data' => /artifacts-entry/)
         end
       end
-
-      context 'when request path is invalid' do
-        it 'does not find artifact file' do
-          get_artifact_file('invalid/path')
-
-          expect(response).to have_http_status(404)
-        end
-      end
     end
 
     context 'when job does not have artifacts' do