Callback on pamauth() not invoked

[soletan]

I'm using your unixlib for pam authentication in a service communicating with clients over TCP. The important part of code is this:

// disable timeout so connection isn't dropped prior to authentication result is available
this.setTimeout( 0 );

console.log( "authenticating user %s using provided password", username );

var conn = this;

unix.pamauth( "system-auth", username, password, function( isAuthenticated )
{
    console.log( "authentication result is" );
    console.log( isAuthenticated );

    conn.end( isAuthenticated ? "OK\n" : "FAIL\n" );
} );

The conn is TCP stream clients are connected through. If I'm testing this service using valid credentials, it's echoing "OK". If I'm using wrong password, service is instantly returning either, but not echoing anything. In first case, the logs of my service include lines "authenticated result is" and "true", while there aren't any lines written on using wrong credentials.

Relying on this observation I consider callback not being invoked in case of wrong credentials at all. I've installed unixlib using

npm --global install unixlib

and it's loaded in code using

var unix = require( "/usr/lib/node_modules/unixlib" );

What's missing? Your C++-code seems to be invoking callback every time, though. OS is Ubuntu 12.04 LTS x64, node is 0.8.8 ...

[soletan]

Though I've disabled timeout, initially enabled timeout is bound to callback echoing "timeout" then and there is no such echo in case of using invalid creds.