Modifications to the SWAT setup are as follows:

Install OpenSSL.

Generate certificate and private key.

root# /usr/bin/openssl req -new -x509 -days 365 -nodes -config \
/usr/share/doc/packages/stunnel/stunnel.cnf \
-out /etc/stunnel/stunnel.pem -keyout /etc/stunnel/stunnel.pem

Remove SWAT entry from [x]inetd.

Start stunnel.

root# stunnel -p /etc/stunnel/stunnel.pem -d 901 \
-l /usr/local/samba/bin/swat swat

Afterward, simply connect to SWAT by using the URL https://myhost:901, accept the certificate, and the SSL connection is up.