def signs
      signs = {}
      self.each_file do |path, data|
        # find META-INF/xxx.{RSA|DSA}
        next unless path =~ /^META-INF\// && data.unpack("CC") == [0x30, 0x82]
        signs[path] = OpenSSL::PKCS7.new(data)
      end
      signs
    end
def signs
      signs = {}
      self.each_file do |path, data|
        # find META-INF/xxx.{RSA|DSA}
        next unless path =~ /^META-INF\// && data.unpack("CC") == [0x30, 0x82]
        signs[path] = OpenSSL::PKCS7.new(data)
      end
      signs
    end
apk's signature information
 @return [Hash{ String => OpenSSL::PKCS7 } ] key: sign file path, value: signature
 @since 0.7.0