SASLbased

SASLbased is a term used to describe authentication implementations that use the Simple Authentication and Security Layer (SASL) framework to perform client authentication to a server. SASL provides a generic, pluggable approach that allows protocols to support multiple authentication methods without baking them into the protocol itself. It defines a challenge-response exchange and a mechanism for negotiating a preferred authentication method between client and server. In addition, SASL can negotiate optional security layers for integrity and privacy.

SASL-based authentication relies on a set of mechanisms, such as PLAIN, SCRAM-SHA-1, SCRAM-SHA-256, DIGEST-MMD5, CRAM-MD5, and GSSAPI (which often uses Kerberos). Mechanisms may or may not expose the user password to the server; their design aims to minimize password exposure and support secure password verification. The server advertises supported mechanisms, the client selects one, and the exchange proceeds to authenticate the user and, if requested, establish a protection layer.

SASL is employed by many protocols, including SMTP, IMAP, POP3, LDAP, XMPP, and various message queues. It is not a stand-alone authentication protocol; rather, it provides a framework that these protocols can adopt to accommodate diverse authentication methods.

Security considerations: SASL-based authentication should be used only over an encrypted channel or with mechanisms that provide confidentiality or integrity, as plain credentials can be exposed. Administrators should select robust mechanisms and monitor configuration for compatibility and security.