81 lines
2.0 KiB
Ruby
81 lines
2.0 KiB
Ruby
class SafeFetch::Fetcher
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def initialize(options)
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@options = options
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end
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def fetch
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with_tempfile do |tempfile|
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response = stream_response(tempfile)
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raise SafeFetch::HttpError, "#{response.code} #{response.message}" unless response.is_a?(Net::HTTPSuccess)
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yield SafeFetch::Result.new(
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tempfile: duplicate_tempfile(tempfile),
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filename: options.filename,
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content_type: normalize_content_type(response['content-type'])
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)
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end
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end
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private
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attr_reader :options
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def with_tempfile
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tempfile = Tempfile.new('chatwoot-safe-fetch', binmode: true)
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yield tempfile
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ensure
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tempfile&.close!
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end
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def stream_response(tempfile)
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response = nil
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bytes_written = 0
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SsrfFilter.public_send(options.method, options.url, **options.request_options) do |res|
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response = res
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next unless res.is_a?(Net::HTTPSuccess)
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validate_content_type!(res['content-type'])
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bytes_written = write_response_body(res, tempfile, bytes_written)
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end
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response
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end
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def validate_content_type!(content_type)
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return unless options.validate_content_type?
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return if allowed_content_type?(content_type)
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raise SafeFetch::UnsupportedContentTypeError, "content-type not allowed: #{content_type}"
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end
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def write_response_body(response, tempfile, bytes_written)
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response.read_body do |chunk|
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bytes_written += chunk.bytesize
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raise SafeFetch::FileTooLargeError, "exceeded #{options.effective_max_bytes} bytes" if bytes_written > options.effective_max_bytes
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tempfile.write(chunk)
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end
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bytes_written
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end
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def allowed_content_type?(value)
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mime = normalize_content_type(value)
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return false if mime.blank?
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options.allowed_content_type_prefixes.any? { |prefix| mime.start_with?(prefix) } ||
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options.allowed_content_types.include?(mime)
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end
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def duplicate_tempfile(tempfile)
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duplicated = tempfile.dup
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duplicated.rewind
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duplicated
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end
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def normalize_content_type(value)
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value.to_s.split(';').first&.strip&.downcase
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end
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end
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