transferred Code Ocean from original repository to GitHub

lib/nonce_store.rb

@@ -0,0 +1,17 @@
+class NonceStore
+  def self.build_cache_key(nonce)
+    "lti_nonce_#{nonce}"
+  end
+
+  def self.add(nonce)
+    Rails.cache.write(build_cache_key(nonce), Time.now, expires_in: Lti::MAXIMUM_SESSION_AGE)
+  end
+
+  def self.delete(nonce)
+    Rails.cache.delete(build_cache_key(nonce))
+  end
+
+  def self.has?(nonce)
+    Rails.cache.exist?(build_cache_key(nonce))
+  end
+end