Dropbear SSH, a lightweight alternative to OpenSSH

I use an ad-free, open-source Android app called SimpleSSHD that implements a Dropbear SSH server. Being able to SSH into your phone and wirelessly perform an incremental rsync backup of all your photos and data is life-changing compared to the hell that is cables and the MTP protocol.

Thank you to all these projects for delivering me from the clutches of MTP, I am indebted.

A word of caution: Many (most) IRC spambot detectors check if your connecting IP is also running a Dropbear SSHd service. This can cause you to be k-lined in some instances, and it's not immediately obvious to basically everyone why the anti-spambot bots are flagging your connection. Of course, this isn't Dropbear SSHd's fault. Just something you might want to keep in mind if you use both of these things.

If anyone is interested in other lightweight tools to complement a minimal embedded linux distro, check out Troglobit's GitHub repo: https://github.com/troglobit. He has a collection of tiny apps perfect for embedded systems, such as...

  - mdnsd (not in Busybox), 
  - merecat httpd (much more full-featured than busybox  httpd) 
  - inadyn dynamic DNS updater
  - finit (IMO much nicer than busybox's runsv)
  - watchdogd
  - uftpd
  - ntpd (with ipv6 support!)

He has been super responsive to requests as well.

Very common in embedded devices. This link isn't working at the moment, so here's a link to the actual project: https://matt.ucc.asn.au/dropbear/dropbear.html

Dropbear works well for preboot LUKS unlocking with remote servers.

I believe Dropbear still has limited to no SFTP support but otherwise I've been very happy with it.

Dropbear is the default SSH server for DietPi[0], a lightweight image for Raspberry Pi and other (mainly single board) computers.

[0] https://dietpi.com/

In a recent vulnerability assessment that I performed, I was surprised to find out that Cisco is using Dropbear on products such as UCS Managed C240M servers.

Check out the security track record before using this. There have been occasional RCE's.

Often used with ARM, why is it never used by default on X86/X64 distros? I would think that the "lightweight" alternative would be lean and mean, kind of like Nginx vs Apache.

I needed a ssh server with some tweaks a few years ago. I must say that the dropbear code was very neatly written, easy to read and easy to understand. It made me to choose dropbear instead of openssh for my tweaks.

I would have used dropbear on my main machine as well, but it doesn't seem to support ~/.ssh/config