1RFC info from the gsasl README (with newer RFCs added).
2
3Implemented:
4  ANONYMOUS (RFC 2245, RFC 4505)
5  CRAM-MD5 (RFC 2195)
6  DIGEST-MD5 (RFC 2831)
7  EXTERNAL (RFC 2222, RFC 4422)
8  GSSAPI (RFC 2222, RFC 4752, requires GSS, Heimdal or MIT Kerberos)
9  LOGIN (non-standard)
10  PLAIN (RFC 2595, RFC 4616)
11
12Not implemented:
13  GS2-KRB5 (RFC 5801, no CB, requires GSS, Heimdal, or MIT Kerberos)
14  KERBEROS_V5 (experimental, requires Shishi)
15  NTLM (non-standard, client only, requires Libntlm)
16  SCRAM-SHA-1 and SCRAM-SHA-1-PLUS (RFC 5802)
17  SECURID (RFC 2808)
18