Console
(config)# line con 0
(config-line)# password conpasswd
(config-line)# login

Vty
(config)# line vty 0 15
(config-line)# password vtypasswd
(config-line)# login

ssh
(config)# username mario password mak
(config)# username joe password sixpak
(config)# ip domain-name test.com !-- required for rsa key generation
(config)# crypto key generate rsa !-- This will prompt for a modulus: 512, 1024, 2048
(config)# line vty 0 15
(config-line)# login local
(config-line)# transport input ssh telnet

(config)# show crypto key mypubkey rsa