# File lib/openssl/x509.rb, line 108
        def scan(dn)
          str = dn
          ary = []
          while true
            if md = TypeAndValue.match(str)
              matched = md.to_s
              remain = md.post_match
              type = md[1]
              value, tag = expand_value(md[2], md[3], md[4]) rescue nil
              if value
                type_and_value = [type, value]
                type_and_value.push(tag) if tag
                ary.unshift(type_and_value)
                if remain.length > 2 && remain[0] == ?,
                  str = remain[1..-1]
                  next
                elsif remain.length > 2 && remain[0] == ?+
                  raise OpenSSL::X509::NameError,
                    "multi-valued RDN is not supported: #{dn}"
                elsif remain.empty?
                  break
                end
              end
            end
            msg_dn = dn[0, dn.length - str.length] + " =>" + str
            raise OpenSSL::X509::NameError, "malformed RDN: #{msg_dn}"
          end
          return ary
        end