Updated Sunday, January, 24 2013, trying to address all issues raised in the comments below.
I have used Android QuickSSHd in the past to connect my Android devices with my Linux desktop. Since I installed CyanogenMod 10.1 nighty builds on them, none of the known SSH apps seem to work anymore. The Cyanogen wiki has a page about how to setup the Dopbear SSH daemon, but also states that since CynogenMod 9.x it is no longer included.
Apparently the original OpenSSH_6.0p1 is included with Android 4.2.1 (JellyBean) although it is not configured
and support for sftp is missing. Here is what I did to have it up and running.