--- /dev/null
+**********************************************
+IMAP AND SMTP AUTHENTICATION WITH SQUIRRELMAIL
+Preliminary documentation - 20 Nov 2002
+Chris Hilts chilts@birdbrained.org
+**********************************************
+
+Prior to SquirrelMail 1.3.3, only plaintext logins for IMAP and SMTP were
+supported. With the release of SquirrelMail 1.3.3, support for the
+CRAM-MD5 and DIGEST-MD5 auth mechanisms has been added. TLS support has
+also been added. It is possible to use different methods for both IMAP and
+SMTP. TLS is able to be enabled on a per-service basis as well.
+Unless the administrator changes the authentication methods, SquirrelMail
+will default to the "classic" plaintext methods, without TLS.
+
+REQUIREMENTS
+------------
+
+CRAM/DIGEST-MD5
+* SquirrelMail 1.3.3 or higher
+* The mhash extension for PHP. (Debian users: You're lucky. Type 'apt-get
+ install php4-mhash' and you're done.)
+
+TLS
+* SquirrelMail 1.3.3 or higher
+* PHP 4.3.0 or higher
+* The "STARTTLS" command is NOT supported. The server you wish to use TLS
+ on must have a dedicated port listening for TLS connections. (ie. port
+ 993 for IMAP, 465 for SMTP)
+
+CONFIGURATION
+-------------
+
+All configuration is done using conf.pl, under main menu option #2.
+
+KNOWN ISSUES
+------------
+
+DIGEST-MD5 has three different methods of operation. (qop options "auth",
+"auth-int" and "auth-conf"). This implementation currently supports "auth"
+only. Work is being done to add the other two modes.
+
+DIGEST-MD5 _may_ fail when authenticating with servers that supply more
+than one "realm". I have no servers of this type to test on, so if you do
+and it fails, let me know! (A big help would be for you to telnet to your
+server, start a DIGEST-MD5 auth session, and include the challenge from the
+server in your bug report.)
+
+To get the challenge with IMAP:
+ telnet <your server> imap
+ [server says hello]
+ A01 AUTHENTICATE DIGEST-MD5
+ <copy the gobbledygook that the server sends - this is what I need>
+ *
+ [server says auth aborted]
+ A02 LOGOUT
+ [server says goodbye, closes connection]
+
+To get the challenge with SMTP:
+ telnet <your server> smtp
+ [server sends some sort of "hello" banner]
+ EHLO myhostname
+ [server will probably list a bunch of capabilities]
+ AUTH DIGEST-MD5
+ <copy the gobbledygook that the server sends - this is what I need>
+ *
+ [server says auth aborted]
+ QUIT
+ [server says bye, closes connection]
+
+[End]