Implement SASL_MECHANISM_SCRAM_SHA_256 and SASL_MECHANISM_SCRAM_SHA_512

State machine for sasl scram
Add Tcl_TraceVar() for sasl-mechanism
Modularized sasl stuff into sasl.c / Refactor
Updated doc
Set sasl-username to username, if not set
Enhance logging
Leave got900() in servmsg.c instead of sasl.c
Constant time memory comparison
Update valid cap sasl mechanism list on server 908
Handle SASL AUTHENTICATE server error
pre sasl mechanism ECDH-X25519-CHALLENGE

eggdrop.conf

@@ -1113,12 +1113,18 @@ server add ssl.example.net +7000
 #   1 = ECDSA-NIST256P-CHALLENGE    (Uses a certificate; usually requires a
 #                                    public key to be registered with NickServ
 #                                    or other similar service. Set certificate
-#                                    to use in sasl-ecdsa-key setting below)
+#                                    to use in sasl-ecdsa-key setting below.
+#                                    Beware: NIST curve could be backdoored,
+#                                    so please use EXTERNAL or SCRAM instead.)
 #
 #   2 = EXTERNAL                    (Some other method you set up. Certificates
 #                                    used are defined in ssl-certificate and
 #                                    ssl-privatekey settings in SSL section)
 #
+#   3 = SCRAM-SHA-256
+#
+#   4 = SCRAM-SHA-512
+#
 #set sasl-mechanism 0
 
 # Set username to authenticate to IRC NickServ with

src/mod/server.mod/Makefile

@@ -40,5 +40,5 @@ distclean: clean
  .././server.mod/server.h .././server.mod/isupport.c \
  .././server.mod/tclisupport.c .././server.mod/servmsg.c \
  .././server.mod/../irc.mod/irc.h \
- .././server.mod/../channels.mod/channels.h .././server.mod/cmdsserv.c \
- .././server.mod/tclserv.c
+ .././server.mod/../channels.mod/channels.h .././server.mod/sasl.c \
+ .././server.mod/cmdsserv.c .././server.mod/tclserv.c