Add bin and edit workflow

bin/gems/em-websocket-0.5.3/lib/em-websocket/handshake04.rb

@@ -0,0 +1,37 @@
+require 'digest/sha1'
+require 'base64'
+
+module EventMachine
+  module WebSocket
+    module Handshake04
+      def self.handshake(headers, _, __)
+        # Required
+        unless key = headers['sec-websocket-key']
+          raise HandshakeError, "sec-websocket-key header is required"
+        end
+
+        string_to_sign = "#{key}258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+        signature = Base64.encode64(Digest::SHA1.digest(string_to_sign)).chomp
+
+        upgrade = ["HTTP/1.1 101 Switching Protocols"]
+        upgrade << "Upgrade: websocket"
+        upgrade << "Connection: Upgrade"
+        upgrade << "Sec-WebSocket-Accept: #{signature}"
+        if protocol = headers['sec-websocket-protocol']
+          validate_protocol!(protocol)
+          upgrade << "Sec-WebSocket-Protocol: #{protocol}"
+        end
+
+        # TODO: Support sec-websocket-protocol selection
+        # TODO: sec-websocket-extensions
+
+        return upgrade.join("\r\n") + "\r\n\r\n"
+      end
+
+      def self.validate_protocol!(protocol)
+        raise HandshakeError, "Invalid WebSocket-Protocol: empty" if protocol.empty?
+        # TODO: Validate characters
+      end
+    end
+  end
+end