code: def from_text(textring):
      
  
      keyring = {}
      for keytext in textring:
          keyname = dns.name.from_text(keytext)
          secret = base64.decodestring(textring[keytext])
          keyring[keyname] = secret
      return keyring
docs: Convert a dictionary containing (textual DNS name, base64 secret) pairs
      into a binary keyring which has (dns.name.Name, binary secret) pairs.
      @rtype: dict