You need to have the developer switch ON. The switch is virtualized above October/November 2012 Samsung models at least. Instructions here.
Instructions to get Bash, Vim, Ssh-agent etc tools after having the Developer switch ON
You need to open the Crosh and then type-and-press-enter like
"shell ENTER"
or see also"help ENTER"
. So this way get a full-blown bash with ssh-agent and Vim:CTRL+ALT T
crosh> shell
chrosos@localhost / $ echo $SHELL
/bin/bash
chrosos@localhost / $ vim
Perhaps related
Some discussion about getting Chromebook in use https://plus.google.com/109993695638569781190/posts/BHo38NLkMz4
the Secure Shell app has some problems with certain Chromebooks such as Samsung October 2012, hanging up to NaCL
P.s. And if you want to switch to your favorite keyboard layout such as Dvorak, you can find it in chrome://settings/languages.