Sasl is the simple authentication and security layer (as defined by rfc 2222). it provides a system for adding plugable authenticating support to connection-based protocols. the sasl extension for php makes the cyrus sasl library functions available to php. it aims to provide a 1-to-1 wrapper around the sasl library to provide the greatest amount of implementation flexibility. to that end, it is possible to build both a client-side and server-side sasl implementation entirely in php.