HELO host check

[NickOvt]

Is there a way in Haraka to check HELO host and close the connection if the HELO host is not a valid ASCII string?
Only valid ASCII strings should be allowed as HELO host and currently it seems Haraka allows invalid hosts to connect too. But is there a way to enable the check or should that be raised to a PR Feature Request status?

[analogic]

I'm not sure if that's a good idea, but you could create a simple plugin for it. Just adjust the following code, which we use to reject unwanted connections from botnets:

'use strict';

exports.register = function () {
    plugin.register_hook('helo', 'check_ymlf');
    plugin.register_hook('ehlo', 'check_ymlf');
};

exports.check_ymlf = function (next, connection, helo) {
    if (helo.trim().toLowerCase() === 'ylmf-pc') {
        next(DENYDISCONNECT, 'I don\'t want talk to you ylmf');
    } else {
        next();
    }
};

[NickOvt]

Indeed a simple plugin that just check for valid ascii string would suffice. I am more wondering whether that is built-in somewhere in Haraka or if it would be a good idea to build that in Haraka. As any normal email client/server would never send/accept a non-ascii HELO host (punycode is fine as it is ASCII)

[analogic]

I live in a country where the ASCII character set is insufficient for writing names properly (e.g. Ján). I've seen owner names transferred via PC names through mail clients to SMTP communication, so I am very careful with wide restrictions. My configuration works in two modes: remote servers with all checks (I don't thing there is problem with non-ascii at all), and secondly, trusted clients with a "who cares" policy.

I'm not trying to argue whether it's a good or bad idea, but I'm not the one who will use it :)

[NickOvt]

There is a plugin already available. I'll close the discussion
https://github.com/haraka/haraka-plugin-helo.checks