This is from current github master. Making self-signed cert with -nodes option as suggested in http://docs.mongodb.org/manual/tutorial/configure-ssl/ creates a key file with no password. Trying to start mongod using the resulting pem file produces a diagnostic saying the --sslPEMKeyPassword option is required, and then the server dosn't start. Supplying --sslPEMKeyPassword "" (i.e. an empty string as password) suppresses the error.

"Doc change" option below is checked because the doc file should be updated to say how to deal with the password.