94 lines
2.6 KiB
Ruby
94 lines
2.6 KiB
Ruby
# frozen_string_literal: true
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module Compression
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class Strategy
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ExtractFailed = Class.new(StandardError)
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DestinationFileExistsError = Class.new(StandardError)
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def can_handle?(file_name)
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file_name.include?(extension)
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end
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def decompress(dest_path, compressed_file_path, max_size)
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sanitized_compressed_file_path = sanitize_path(compressed_file_path)
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sanitized_dest_path = sanitize_path(dest_path)
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get_compressed_file_stream(sanitized_compressed_file_path) do |compressed_file|
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available_size = calculate_available_size(max_size)
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entries_of(compressed_file).each do |entry|
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entry_path = build_entry_path(sanitized_dest_path, entry, sanitized_compressed_file_path)
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if !is_safe_path_for_extraction?(entry_path, sanitized_dest_path)
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next
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end
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FileUtils.mkdir_p(File.dirname(entry_path))
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if is_file?(entry)
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remaining_size = extract_file(entry, entry_path, available_size)
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available_size = remaining_size
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else
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extract_folder(entry, entry_path)
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end
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end
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decompression_results_path(sanitized_dest_path, sanitized_compressed_file_path)
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end
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end
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private
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def sanitize_path(filename)
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Pathname.new(filename).realpath.to_s
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end
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# https://guides.rubyonrails.org/security.html#file-uploads
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def sanitize_filename(filename)
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filename.strip.tap do |name|
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# NOTE: File.basename doesn't work right with Windows paths on Unix
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# get only the filename, not the whole path
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name.sub! /\A.*(\\|\/)/, ''
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# Finally, replace all non alphanumeric, underscore
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# or periods with underscore
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name.gsub! /[^\w\.\-]/, '_'
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end
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end
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def calculate_available_size(max_size)
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1024**2 * (max_size / 1.049) # Mb to Mib
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end
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def entries_of(compressed_file)
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compressed_file
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end
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def is_file?(entry)
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entry.file?
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end
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def chunk_size
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@chunk_size ||= 1024**2 * 2 # 2MiB
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end
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def extract_file(entry, entry_path, available_size)
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remaining_size = available_size
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if ::File.exist?(entry_path)
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raise DestinationFileExistsError, "Destination '#{entry_path}' already exists"
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end
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::File.open(entry_path, 'wb') do |os|
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while (buf = entry.read(chunk_size))
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remaining_size -= buf.size
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raise ExtractFailed if remaining_size.negative?
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os << buf
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end
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end
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remaining_size
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end
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def is_safe_path_for_extraction?(path, dest_directory)
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File.expand_path(path).start_with?(dest_directory)
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end
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end
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end
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