Add bin and edit workflow

bin/gems/em-websocket-0.5.3/lib/em-websocket/handshake76.rb

@@ -0,0 +1,72 @@
+require 'digest/md5'
+
+module EventMachine::WebSocket
+  module Handshake76
+    class << self
+      def handshake(headers, path, secure)
+        challenge_response = solve_challenge(
+          headers['sec-websocket-key1'],
+          headers['sec-websocket-key2'],
+          headers['third-key']
+        )
+
+        scheme = (secure ? "wss" : "ws")
+        location = "#{scheme}://#{headers['host']}#{path}"
+
+        upgrade =  "HTTP/1.1 101 WebSocket Protocol Handshake\r\n"
+        upgrade << "Upgrade: WebSocket\r\n"
+        upgrade << "Connection: Upgrade\r\n"
+        upgrade << "Sec-WebSocket-Location: #{location}\r\n"
+        upgrade << "Sec-WebSocket-Origin: #{headers['origin']}\r\n"
+        if protocol = headers['sec-websocket-protocol']
+          validate_protocol!(protocol)
+          upgrade << "Sec-WebSocket-Protocol: #{protocol}\r\n"
+        end
+        upgrade << "\r\n"
+        upgrade << challenge_response
+
+        return upgrade
+      end
+
+      private
+
+      def solve_challenge(first, second, third)
+        # Refer to 5.2 4-9 of the draft 76
+        sum = [numbers_over_spaces(first)].pack("N*") +
+          [numbers_over_spaces(second)].pack("N*") +
+          third
+        Digest::MD5.digest(sum)
+      end
+
+      def numbers_over_spaces(string)
+        unless string
+          raise HandshakeError, "WebSocket key1 or key2 is missing"
+        end
+
+        numbers = string.scan(/[0-9]/).join.to_i
+
+        spaces = string.scan(/ /).size
+        # As per 5.2.5, abort the connection if spaces are zero.
+        raise HandshakeError, "Websocket Key1 or Key2 does not contain spaces - this is a symptom of a cross-protocol attack" if spaces == 0
+
+        # As per 5.2.6, abort if numbers is not an integral multiple of spaces
+        if numbers % spaces != 0
+          raise HandshakeError, "Invalid Key #{string.inspect}"
+        end
+
+        quotient = numbers / spaces
+
+        if quotient > 2**32-1
+          raise HandshakeError, "Challenge computation out of range for key #{string.inspect}"
+        end
+
+        return quotient
+      end
+
+      def validate_protocol!(protocol)
+        raise HandshakeError, "Invalid WebSocket-Protocol: empty" if protocol.empty?
+        # TODO: Validate characters
+      end
+    end
+  end
+end