# # README.SASL - Readme about SASL support in nmh # # $Id$ # SASL is short for the Simple Authentication and Security Layer. Is is a framework for adding authentication and encryption to network protocols. It is described in IETF RFC 2222. This release of nmh supports SASL for POP and SMTP. The SASL support is implemented using the Cyrus-SASL library. This library can be found at ftp://ftp.andrew.cmu.edu/pub/cyrus-mail. Obviously, SASL support only works if you use --enable-pop and the SMTP mail transport. This release of NMH only supports "Version 2" of the Cyrus SASL library. It should work with any newer Cyrus SASL release, but it was tested with Cyrus SASL 2.1.12. In particular, the CRAM-MD5 and GSSAPI (Kerberos 5) mechanisms were tested. Currently, security layers ("encryption" in SASL-speak) are only supported for POP. This means that if your POP server _and_ the selected GSSAPI mechanism supports it, POP communications will be encrypted. Currently SMTP does NOT support security layers; this may be added in a future release. If you are curious as to whether or not your communications are actually encrypted or not, you can use the -snoop flag to the POP utilities. Communication that is encrypted is preceeded by an (*). If you would like to use the GSSAPI SASL mechanism (Kerberos V), you should read very carefully the documentation that comes with Cyrus-SASL, specifically the GSSAPI documentation. Getting the GSSAPI plugin to work correctly with SASL can be "interesting" to say the least.