SCRAM-SHA-256(-PLUS) support

[- Neustradamus -]

Hello the ML,

I contact you today to know what is the progession for SCRAM-SHA-256(-PLUS) 
support in GNU SASL.
It is possible to see for other too.

Note: Exim uses GNU SASL.
https://www.exim.org/
https://www.exim.org/exim-html-current/doc/html/spec_html/ch-the_gsasl_authenticator.html
https://lists.exim.org/lurker/message/20120214.025212.404e5fa7.en.html

GNU SASL supports:
- SCRAM-SHA-1
- SCRAM-SHA-1-PLUS
-> http://www.gnu.org/software/gsasl/

---------------------------------------------------------------

CRAM-MD5 to Historic:
- https://tools.ietf.org/html/draft-ietf-sasl-crammd5-to-historic-00 // 20 
November 2008

RFC6331: Moving DIGEST-MD5 to Historic
- https://tools.ietf.org/html/rfc6331 since July 2011

RFCs:
- RFC5802: Salted Challenge Response Authentication Mechanism (SCRAM) SASL and 
GSS-API Mechanisms: https://tools.ietf.org/html/rfc5802
- RFC7677: SCRAM-SHA-256 and SCRAM-SHA-256-PLUS Simple Authentication and 
Security Layer (SASL) Mechanisms: https://tools.ietf.org/html/rfc7677 - since 
2015-11-02
- RFC5056: On the Use of Channel Bindings to Secure Channels: 
https://tools.ietf.org/html/rfc5056
- RFC5929: Channel Bindings for TLS: https://tools.ietf.org/html/rfc5929
- RFC5803: Lightweight Directory Access Protocol (LDAP) Schema for Storing 
Salted: Challenge Response Authentication Mechanism (SCRAM) Secrets: 
https://tools.ietf.org/html/rfc5803
- RFC7804: Salted Challenge Response HTTP Authentication Mechanism: 
https://tools.ietf.org/html/rfc7804

IANA:
- Simple Authentication and Security Layer (SASL) Mechanisms: 
https://www.iana.org/assignments/sasl-mechanisms/sasl-mechanisms.xhtml
- Channel-Binding Types: 
https://www.iana.org/assignments/channel-binding-types/channel-binding-types.xhtml

Cyrus SASL supports:
- SCRAM-SHA-1
- SCRAM-SHA-1-PLUS
- SCRAM-SHA-224
- SCRAM-SHA-224-PLUS
- SCRAM-SHA-256
- SCRAM-SHA-256-PLUS
- SCRAM-SHA-384
- SCRAM-SHA-384-PLUS
- SCRAM-SHA-512
- SCRAM-SHA-512-PLUS
-> https://cyrusimap.org/sasl/sasl/authentication_mechanisms.html
-> https://github.com/cyrusimap/cyrus-sasl/commits/master

Dovecot SASL supports:
- SCRAM-SHA-1
-> https://doc.dovecot.org/configuration_manual/authentication/password_schemes/

More informations:
- https://github.com/scram-xmpp/info/issues/1

Thanks in advance.

Regards,

Neustradamus