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# encoding: binary
# frozen_string_literal: true
module WebSocket
module Frame
module Handler
class Handler75 < Base
# @see WebSocket::Frame::Base#supported_frames
def supported_frames
%i[text close]
end
# @see WebSocket::Frame::Handler::Base#encode_frame
def encode_frame
case @frame.type
when :close then "\xff\x00"
when :text then
ary = ["\x00", @frame.data, "\xff"]
ary.map { |s| s.encode('UTF-8', 'UTF-8', invalid: :replace) }
ary.join
else raise WebSocket::Error::Frame::UnknownFrameType
end
end
# @see WebSocket::Frame::Handler::Base#decode_frame
def decode_frame
return if @frame.data.size.zero?
pointer = 0
frame_type = @frame.data.getbyte(pointer)
pointer += 1
if (frame_type & 0x80) == 0x80
# If the high-order bit of the /frame type/ byte is set
length = 0
loop do
return unless @frame.data.getbyte(pointer)
b = @frame.data.getbyte(pointer)
pointer += 1
b_v = b & 0x7F
length = length * 128 + b_v
break unless (b & 0x80) == 0x80
end
raise WebSocket::Error::Frame::TooLong if length > ::WebSocket.max_frame_size
unless @frame.data.getbyte(pointer + length - 1).nil?
# Straight from spec - I'm sure this isn't crazy...
# 6. Read /length/ bytes.
# 7. Discard the read bytes.
@frame.instance_variable_set '@data', @frame.data[(pointer + length)..-1]
# If the /frame type/ is 0xFF and the /length/ was 0, then close
if length.zero?
@frame.class.new(version: @frame.version, type: :close, decoded: true)
end
end
else
# If the high-order bit of the /frame type/ byte is _not_ set
raise WebSocket::Error::Frame::Invalid if @frame.data.getbyte(0) != 0x00
# Addition to the spec to protect against malicious requests
raise WebSocket::Error::Frame::TooLong if @frame.data.size > ::WebSocket.max_frame_size
msg = @frame.data.slice!(/\A\x00[^\xff]*\xff/)
if msg
msg.gsub!(/\A\x00|\xff\z/, '')
msg.force_encoding('UTF-8')
@frame.class.new(version: @frame.version, type: :text, data: msg, decoded: true)
end
end
end
end
end
end
end
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