1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 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
|