Module: Protocol::HTTP2::Padded

Included in:
DataFrame, HeadersFrame, PushPromiseFrame
Defined in:
lib/protocol/http2/padded.rb

Overview

Certain frames can have padding: http2.github.io/http2-spec/#padding

--------------- |Pad Length? (8)| ---------------———————————————–+ | Data (*) … --------------------------------------------------------------- | Padding (*) … ---------------------------------------------------------------

Provides padding functionality for HTTP/2 frames. Padding can be used to obscure the actual size of frame payloads.

Instance Method Summary collapse

Instance Method Details

#pack(data, padding_size: nil, maximum_size: nil) ⇒ Object

Pack data with optional padding into the frame.



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# File 'lib/protocol/http2/padded.rb', line 34

def pack(data, padding_size: nil, maximum_size: nil)
	if padding_size
		set_flags(PADDED)
		
		buffer = String.new.b
		
		buffer << padding_size
		buffer << data
		
		if padding_size
			buffer << ("\0" * padding_size)
		end
		
		super buffer
	else
		clear_flags(PADDED)
		
		super data
	end
end

#padded? ⇒ Boolean

Check if the frame has padding enabled.

Returns:

  • (Boolean) 


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# File 'lib/protocol/http2/padded.rb', line 26

def padded?
	flag_set?(PADDED)
end

#unpack ⇒ Object

Unpack frame data, removing padding if present.



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# File 'lib/protocol/http2/padded.rb', line 58

def unpack
	if padded?
		padding_size = @payload[0].ord
		
		# 1 byte for the padding octet, and padding_size bytes for the padding itself:
		data_size = @payload.bytesize - (1 + padding_size)
		
		if data_size < 0
			raise ProtocolError, "Invalid padding length: #{padding_size}"
		end
		
		return @payload.byteslice(1, data_size)
	else
		return @payload
	end
end