-Authenticate as \fIUSER\fR.
-.IP
-When a connection is made the server sends a \fB221\fR response before any
-command is received. This contains an algorithm name and a challenge encoded
-in hex. Currently the algorithm name is omitted if it is "sha1".
-.IP
-The \fIRESPONSE\fR consists of the selected hash of the user's password
-concatenated with the challenge, encoded in hex.