98 lines
2.4 KiB
Ruby
98 lines
2.4 KiB
Ruby
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# frozen_string_literal: true
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module SafeZip
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class Entry
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attr_reader :zip_archive, :zip_entry
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attr_reader :path, :params
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def initialize(zip_archive, zip_entry, params)
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@zip_archive = zip_archive
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@zip_entry = zip_entry
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@params = params
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@path = ::File.expand_path(zip_entry.name, params.extract_path)
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end
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def path_dir
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::File.dirname(path)
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end
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def real_path_dir
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::File.realpath(path_dir)
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end
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def exist?
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::File.exist?(path)
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end
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def extract
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# do not extract if file is not part of target directory
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return false unless matching_target_directory
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# do not overwrite existing file
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raise SafeZip::Extract::AlreadyExistsError, "File already exists #{zip_entry.name}" if exist?
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create_path_dir
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if zip_entry.file?
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extract_file
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elsif zip_entry.directory?
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extract_dir
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elsif zip_entry.symlink?
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extract_symlink
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else
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raise SafeZip::Extract::UnsupportedEntryError, "File #{zip_entry.name} cannot be extracted"
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end
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rescue SafeZip::Extract::Error
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raise
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rescue => e
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raise SafeZip::Extract::ExtractError, e.message
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end
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private
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def extract_file
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zip_archive.extract(zip_entry, path)
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end
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def extract_dir
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FileUtils.mkdir(path)
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end
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def extract_symlink
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source_path = read_symlink
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real_source_path = expand_symlink(source_path)
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# ensure that source path of symlink is within target directories
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unless real_source_path.start_with?(matching_target_directory)
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raise SafeZip::Extract::PermissionDeniedError, "Symlink cannot be created targeting: #{source_path}"
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end
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::File.symlink(source_path, path)
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end
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def create_path_dir
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# Create all directories, but ignore permissions
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FileUtils.mkdir_p(path_dir)
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# disallow to make path dirs to point to another directories
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unless path_dir == real_path_dir
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raise SafeZip::Extract::PermissionDeniedError, "Directory of #{zip_entry.name} points to another directory"
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end
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end
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def matching_target_directory
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params.matching_target_directory(path)
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end
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def read_symlink
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zip_archive.read(zip_entry)
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end
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def expand_symlink(source_path)
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::File.realpath(source_path, path_dir)
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rescue
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raise SafeZip::Extract::SymlinkSourceDoesNotExistError, "Symlink source #{source_path} does not exist"
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end
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end
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end
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