class digest_auth_handler :Digest authentication. Authentication information is obtained by the passed key_handler.
?enable_auth_in_advance:bool -> #key_handler ->
This handler is compatible with RFC 2069 and RFC 2617. In particular, the following protocol options are available:
Authentication-Infoheader is completely ignored
enable_auth_in_advance: If set to
true, authentication can be done in advance, i.e. before the server requests authentication. This reduces the number of messages exchanged with the server, but may be an additional security risk.