[Dovecot] problems with auth protocol

Hello there,

I have a client connecting to dovecot and comunicating like this:

• OK Dovecot ready.

• AUTHENTICATE MYAUTH

• base64 challange base64_response {NNN}

• NO Invalid base64 data in continued response

The problem is that dovecot seems to reject the response because of the {NNN} in the end of the string. If I remove the {NNN} it authenticates just fine.

Any idea of whether it's standard or not?

Thanks you.