[Dovecot] auth unix sockets

[Uldis Pakuls]

Hi,

I'm working on "avelsieve" SqurrelMail plug-in to implement SIEVE "file" back end for dovecot.

1. My be someone my explain me, how to use client auth socket to authenticate against dovecot-auth unix socket.
As fas as I understood login must be sent in form "user\0\user\0password" as base64 encoded string.

pp code (I'm using socket used by postfix auth):
--------------------
<?php
$authstr = base64_encode('test at virtual.net\0test at virtual.net\0test');
$fp = fsockopen("unix:///var/spool/postfix/private/auth",0, $errno, $errstr, 30);
if (!$fp) {
    echo "$errstr ($errno)<br />\n"; }
else {
    $out = "$authstr\r\n";
    fwrite($fp, $out);
    while (!feof($fp)) { echo fgets($fp, 128); }
    fclose($fp);
}
?> 
-----------------------

Dovecot auth complains about syntax
It seems 'auth mech' also is required. thus; how to correctly use dovecot client auth socket to authenticate?
(some FAQ?, php sample code?) 

2. [most important] dovecot LDA uses auth maser sockets to read userdb and get home directory path to deliver mail and locate sieve scripts.
I need some home path to locate users sieve script. Wow to obtain it using dovecot auth sockets?

Tnx

Uldis