You can not connect with PuTTY as bitcoind only listens to RPC-JSON commands.
Anything that can send over the HTTP(S) protocol is fine. See the JSON-RPC class for PHP.
Assuming that you want bitcoind to accept remote RPC-JSON calls, you would need to setup your bitcoin.conf file like so:
rpcuser = randomUsername
rpcpassword = strongRandomPassword
rpcallowip = ipOfAllowedHost
rpcssl = 1
Then, navigate to your data directory .bitcoin and generate a self-signed certificate. Do not enter a password when it prompts you for one.
openssl genrsa -out server.pem 2048
openssl req -new -x509 -nodes -sha1 -days 3650 -key server.pem > server.cert
Restart bitcoind and test the SSL functionality. You should see the certificate details, pressing enter twice will return a HTTP/1.0 401 Authorization Required.
openssl s_client -connect localhost:8332
That's it, bitcoind will now accept RPC-JSON commands through through HTTPS.