Class: GoogleSafeBrowsing::ResponseHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/google_safe_browsing/response_helper.rb

Class Method Summary collapse

Class Method Details

.escape_and_join(values) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 205

def self.escape_and_join(values)
  values.map do |v|
    ActiveRecord::Base::sanitize(v)
  end.join(', ')
end

.parse_data_line(line) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 194

def self.parse_data_line(line)
  split_line = line.split(':')

  ret = {}
  ret[:action]        = split_line[0]
  ret[:chunk_number]  = split_line[1].to_i
  ret[:hash_length]   = split_line[2].to_i
  ret[:chunk_length]  = split_line[3].to_i
  ret
end

.parse_data_response(response) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 20

def self.parse_data_response(response)
  ret = {}

  ret[:lists] = []
  ret[:data_urls] = {}

  current_list = ''
  response.split("\n").each do |line|
    vals = line.split(':')
    case vals[0]
    when 'n'
      ret[:delay_seconds] = vals[1].to_i
      @delay_seconds = ret[:delay_seconds].to_i
    when 'i'
      ret[:lists] << vals[1]
      current_list = vals[1]
      ret[:data_urls][current_list] = []
    when 'u'
      ret[:data_urls][current_list] << vals[1]
    when 'r'
      # reset (delete all data and try again)
    when 'ad'
      # vals[1] is a CHUNKLIST representing add chunks to delete
      # we can also delete the associated Shavar Hashes
      # we no longer have to report that we received these chunks
      AddShavar.delete_chunks_from_list(current_list,
                                        ChunkList.new(vals[1]))
    when 'sd'
      # vals[1] is a CHUNKLIST representing sub chunks to delete
      # we no longer have to report that we received these chunks
      SubShavar.delete_chunks_from_list(current_list,
                                        ChunkList.new(vals[1]))
    else
      GoogleSafeBrowsing.logger.warn \
        "Unknown data response directive: #{vals[0]}"
    end
  end

  ret
end

.parse_full_hash_response(response) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 3

def self.parse_full_hash_response(response)
  f = StringIO.new(response)

  full_hashes = []
  while(! f.eof? )
    hash = {}

    meta = f.gets.chomp.split(':')
    hash[:list] = meta[0]
    hash[:add_chunk_num] = meta[1]

    hash[:full_hash] = f.read(meta[2].to_i).unpack('H*')[0]
    full_hashes << hash
  end
  full_hashes
end

.pop_and_join(records) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 211

def self.pop_and_join(records)
  records.pop(10_000).join(', ')
end

.receive_data(url, list) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 61

def self.receive_data(url, list)
  urls = url.split(',')
  url = urls[0]
  mac = urls[1]

  open(url) do |f|
    body = f.read

    unless mac.blank? || HttpHelper.valid_mac?(body, mac)
      raise InvalidMACVerification
    end

    f.rewind

    while(line = f.gets)
      line_actions = parse_data_line(line)

      chunk  = f.read(line_actions[:chunk_length])
      # f iterator is now set for next chunk

      add_attrs = { chunk_number: line_actions[:chunk_number],
                    list: list,
                    prefix: nil,
                    host_key: nil
                  }

      case line_actions[:action]
      when 'a'
        if line_actions[:chunk_length] == 0
          record_add_shavar_to_insert(add_attrs)
        else
          chunk_iterator = chunk.bytes.to_enum
          counter = 0
          begin
            while true
              add_attrs[:host_key] = BinaryHelper.read_bytes_as_hex(chunk_iterator, 4)
              count = chunk_iterator.next
              if count > 0
                count.times do |i|
                  add_attrs[:prefix] = BinaryHelper.read_bytes_as_hex(chunk_iterator, line_actions[:hash_length])
                  record_add_shavar_to_insert(add_attrs)
                end
              else
                add_attrs[:prefix] = add_attrs[:host_key]
                record_add_shavar_to_insert(add_attrs)
              end
              counter += 1
            end
          rescue StopIteration
            GoogleSafeBrowsing.logger.info <<-LOG.gsub(/\n\s*/, '')
              Added #{counter} host_keys for add chunk number
              #{line_actions[:chunk_number]}
              LOG
          end
        end
      when 's'
        sub_attrs = add_attrs.merge({ add_chunk_number: nil })
        if line_actions[:chunk_length] == 0
          record_sub_shavar_to_insert(sub_attrs)
        else
          chunk_iterator = chunk.bytes.to_enum
          counter = 0
          begin
            while true
              sub_attrs[:host_key] = BinaryHelper.read_bytes_as_hex(chunk_iterator, 4)
              count = chunk_iterator.next
              if count > 0
                count.times do |i|
                  sub_attrs[:add_chunk_number] = BinaryHelper.unpack_add_chunk_num(BinaryHelper.read_bytes_from(chunk_iterator, 4))
                  sub_attrs[:prefix] = BinaryHelper.read_bytes_as_hex(chunk_iterator, line_actions[:hash_length])
                  record_sub_shavar_to_insert(sub_attrs)
                end
              else
                sub_attrs[:add_chunk_number] = BinaryHelper.unpack_add_chunk_num(BinaryHelper.read_bytes_from(chunk_iterator, 4))
                sub_attrs[:prefix] = sub_attrs[:host_key]
                record_sub_shavar_to_insert(sub_attrs)
              end
              counter += 1
            end
          rescue StopIteration
            GoogleSafeBrowsing.logger.info <<-LOG.gsub(/\n\s*/, '')
              Added #{counter} host_keys for sub chunk number
              #{line_actions[:chunk_number]}
            LOG
          end
        end
      else
        GoogleSafeBrowsing.logger.info <<-LOG.gsub(/\n\s*/, '')
          neither a nor s =================================================
        LOG
      end

    end
  end

  while @add_shavar_values && @add_shavar_values.any?
    AddShavar.connection.execute <<-SQL
      INSERT INTO gsb_add_shavars (prefix, host_key, chunk_number, list)
      VALUES #{pop_and_join @add_shavar_values}
      SQL
  end
  while @sub_shavar_values && @sub_shavar_values.any?
  SubShavar.connection.execute <<-SQL
    INSERT INTO gsb_sub_shavars (prefix,
                                 host_key,
                                 add_chunk_number,
                                 chunk_number,
                                 list)
    VALUES #{pop_and_join @sub_shavar_values}
    SQL
  end

  FullHash.delete_subbed

  @add_shavar_values = []
  @sub_shavar_values = []
end

.record_add_shavar_to_insert(h) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 179

def self.record_add_shavar_to_insert(h)
  @add_shavar_values ||= []
  values = [h[:prefix], h[:host_key], h[:chunk_number], h[:list]]
  @add_shavar_values << "(#{escape_and_join values})"
end

.record_sub_shavar_to_insert(h) ⇒ Object 



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# File 'lib/google_safe_browsing/response_helper.rb', line 184

def self.record_sub_shavar_to_insert(h)
  @sub_shavar_values ||= []
  values = [h[:prefix],
            h[:host_key],
            h[:add_chunk_number],
            h[:chunk_number],
            h[:list]]
  @sub_shavar_values << "(#{escape_and_join values})"
end