Getting Twitter API PIN-based OAuth working using PHP?

[Thunderstruck-]

Anyone knows anything about Twitter PHP API that supports PIN-based authorization? I need an infinite access token (one which will not expire) and i'm actually looking at two libraries:

• adamwynne / twitter-api seems pretty old, no PIN auth. documentation
• jmathai / twitter-async a more recent one but no documentation about PIN auth.

I cannot get them work: i can call \[code\]getAuthorizeUrl()\[/code\] and get the PIN and the right callback to my \[code\]step1.php\[/code\] page; but then i'm stuck, and i don't know how to use the PIN submitted by the user. It seems that i need to set \[code\]oauth_verifier\[/code\] parameter of \[code\]getAccessToken\[/code\], but all this stuff is undocumented.Any help would be much appreciated.