Cross-Compiled Linux From Scratch - Embedded - Version GIT-0.0.1-20110514-x86

Chapter 14. Networking Software

14.4. Dropbear-0.52

Dropbear is a relatively small SSH 2 server and client. Dropbear has a small memory footprint suitable for memory-constrained environments, while still having the same features as OpenSSH. It does not depend on OpenSSL and it has a MIT style license. Optionally it can even be made smaller.

14.4.1. Installation of Dropbear

Dropbear incorrectly calls ld instead of gcc for linking, so fix it: 

cp Makefile.in{,.orig}
sed -e s/@LD@/@CC@/ Makefile.in.orig > Makefile.in

Configure dropbear: 

CC="${CC} -Os" ./configure --prefix=/usr --host=${CLFS_TARGET}

Now we will utilize /dev/urandom instead of /dev/random. To allow this to be utilized we use the following sed: 

cp -v options.h options.h.backup
sed -e "s@/dev/random@/dev/urandom@" options.h.backup > options.h
[Note]

Note

We are just telling dropbear to use the default configuration. For those for more adventureous, edit options.h to further configure dropbear.

Compile the package: 

make MULTI=1 PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp"

Install the package: 

make MULTI=1 PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp" \
    install DESTDIR=${CLFS}
ln -svf /usr/bin/dropbearmulti ${CLFS}/usr/sbin/dropbear
ln -svf /usr/bin/dropbearmulti ${CLFS}/usr/bin/dbclient
ln -svf /usr/bin/dropbearmulti ${CLFS}/usr/bin/dropbearkey
ln -svf /usr/bin/dropbearmulti ${CLFS}/usr/bin/dropbearconvert
ln -svf /usr/bin/dropbearmulti ${CLFS}/usr/bin/scp

Create the directory for the dropbear key files: 

install -dv ${CLFS}/etc/dropbear

Install the bootscripts from the clfs-bootscripts package: 

make install-sshd DESTDIR=${CLFS}

14.4.2. Contents of Dropbear

Installed programs: To be Written