Add /usr/sbin and /sbin to default root PATH When dropbear is used in a very restricted environment (such as in a initrd), the default user shell is often also very restricted and doesn't take care of setting the PATH so the user ends up with the PATH set by dropbear. Unfortunately, dropbear always sets "/usr/bin:/bin" as default PATH even for the root user which should have /usr/sbin and /sbin too. For a concrete instance of this problem, see the "Remote Unlocking" section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/ It speaks of a bug in the initramfs script because it's written "blkid" instead of "/sbin/blkid"... this is just because the scripts from the initramfs do not expect to have a PATH without the sbin directories and because dropbear is not setting the PATH appropriately for the root user. I'm thus suggesting to use the attached patch to fix this misbehaviour (I did not test it, but it's easy enough). It might seem anecdotic but multiple Kali users have been bitten by this. From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403

Multi-binary compilation
========================

To compile for systems without much space (floppy distributions etc), you
can create a single binary. This will save disk space by avoiding repeated
code between the various parts.
If you are familiar with "busybox", it's the same principle.

To compile the multi-binary, first "make clean" (if you've compiled
previously), then

make PROGRAMS="programs you want here" MULTI=1

To use the binary, symlink it from the desired executable:

ln -s dropbearmulti dropbear
ln -s dropbearmulti dbclient
etc

then execute as normal:

./dropbear <options here>