1 files changed, 71 insertions, 0 deletions
diff --git a/app/uploaders/object_storage/cdn/google_cdn.rb b/app/uploaders/object_storage/cdn/google_cdn.rb
new file mode 100644
index 00000000000..ea7683f131c
--- /dev/null
+++ b/app/uploaders/object_storage/cdn/google_cdn.rb
@@ -0,0 +1,71 @@
+# rubocop:disable Naming/FileName
+# frozen_string_literal: true
+
+module ObjectStorage
+  module CDN
+    class GoogleCDN
+      include Gitlab::Utils::StrongMemoize
+
+      attr_reader :options
+
+      def initialize(options)
+        @options = HashWithIndifferentAccess.new(options.to_h)
+
+        GoogleIpCache.async_refresh unless GoogleIpCache.ready?
+      end
+
+      def use_cdn?(request_ip)
+        return false unless config_valid?
+
+        ip = IPAddr.new(request_ip)
+
+        return false if ip.private?
+
+        !GoogleIpCache.google_ip?(request_ip)
+      end
+
+      def signed_url(path, expiry: 10.minutes)
+        expiration = (Time.current + expiry).utc.to_i
+
+        uri = Addressable::URI.parse(cdn_url)
+        uri.path = path
+        uri.query = "Expires=#{expiration}&KeyName=#{key_name}"
+
+        signature = OpenSSL::HMAC.digest('SHA1', decoded_key, uri.to_s)
+        encoded_signature = Base64.urlsafe_encode64(signature)
+
+        uri.query += "&Signature=#{encoded_signature}"
+        uri.to_s
+      end
+
+      private
+
+      def config_valid?
+        [key_name, decoded_key, cdn_url].all?(&:present?)
+      end
+
+      def key_name
+        strong_memoize(:key_name) do
+          options['key_name']
+        end
+      end
+
+      def decoded_key
+        strong_memoize(:decoded_key) do
+          Base64.urlsafe_decode64(options['key']) if options['key']
+        rescue ArgumentError
+          Gitlab::ErrorTracking.log_exception(ArgumentError.new("Google CDN key is not base64-encoded"))
+          nil
+        end
+      end
+
+      def cdn_url
+        strong_memoize(:cdn_url) do
+          options['url']
+        end
+      end
+    end
+  end
+end
+
+# rubocop:enable Naming/FileName